POSTER SESSION 2

P442
Ventricular rate is not related to survival in patients with heart failure and atrial fibrillation

Abstract

Introduction: Atrial fibrillation (AF) is common in patients with chronic heart failure (CHF), and is associated with significant morbidity and mortality. Although there is robust evidence that heart rate is a risk factor in CHF and that reducing elevated heart rates improves survival in patients who are in sinus rhythm, the importance of strict heart rate control in AF is still not clear. This study sought to investigate the influence of resting ventricular rate on survival in CHF, comparing those who are in sinus rhythm to those in AF.

Methods: A total of 1415 CHF patients (mean age 76+-11 years, 36% females, 65% IHD, 41% NYHA II, 44% NYHA III, 14% NYHA IV), of whom 62% (n=875) were in sinus rhythm and 38% (n=540) in permanent AF were evaluated from the BIOSTAT-CHF Scotland study. Patients from both in-patient and out-patient settings were included. We analysed the heart rate and rhythm data recorded on a 12 lead ECG at the baseline review. Multivariate Cox proportional hazards models & Kaplan-Meier curves were used to assess the influence of heart rate on survival in CHF patients with AF or sinus rhythm.

Results: During a median per-person follow-up of 1.5 yrs (QIR 0.7-2.2), there were 330 (23%) all-cause deaths. Although Kaplan-Meier survival curves displayed significant differences between the AF and sinus rhythm groups (log-rank test p=0.014), multivariate Cox survival models showed no significant difference between the 2 groups (hazard ratio [HR]: 0.98, 95% CI: 0.75-1.29; p=0.9). When assessing the influence of heart rate, multivariate Cox models showed that higher heart rates (per 10 beats/min increments) were associated with worse survival in patients in sinus rhythm (HR: 1.14, 95% CI: 1.03-1.25; p=0.008), but not for those in AF (HR: 0.98, 95% CI: 0.91-1.07, p= 0.7), for both preserved and reduced ejection fraction heart failure. When separated into two categories (heart rate <80bpm vs. ≥80bpm), those in sinus rhythm with a heart rate ≥80bpm had a significantly worse survival than those with a heart rate <80bpm (HR: 1.57, 95% CI: 1.10-2.23, p=0.012).

Conclusion: Although higher heart rate was associated with worse survival for CHF patients in sinus rhythm, it does not appear to be associated with survival in those who are in AF. These findings question the value of strict heart rate control in CHF patients with atrial fibrillation, thus necessitating further research in this area.

P443
The occurence of cardiovascular disease in apparently idiopathic AF patients and the role of early cardiac CT angiography (a 5yr follow-up study)

Abstract

Purpose: Idiopathic atrial fibrillation (iAF) may be a first expression of underlying subclinical vascular disease. The purpose of this study was to determine the incidence of cardiovascular disease (CVD) in patients originally diagnosed with idiopathic paroxysmal AF during 5 years of follow-up, and whether there is an association of the incidence of CVD with the presence of coronary artery disease (CAD) on baseline coronary CT angiography (CTA).

Methods: Between January 2008 and March 2011 we included all consecutive idiopathic paroxysmal AF patients who underwent CTA before electrophysiological study and catheter ablation. All patients were at baseline free of hypertension, diabetes, congestive heart failure, previous known coronary artery and peripheral vascular disease, previous stroke, thyroid, pulmonary, and renal disease, and had no structural abnormalities on echocardiography.

Results: A total of 115 patients with iAF (age 54.7 ± 10.1 years; 28.7% female) were included. During a mean follow-up of 64 ± 8.3 months, CVD occurred in 26% of the patients and MACCE occurred in 6% of the patients. Unexpected subclinical CT angiographic coronary artery disease was present in 56 (49%) of the patients. Patients who developed CVD were significantly older and more often had CAD on CTA compared to those without CVD during follow-up (respectively 59.6 years and 52.8 years, p=0.001; 35.7% and 16.9%, p=0.02). The prevalence of soft plaques on CT was significantly higher in patients developing CVD than in those who do not (76.5% and 11.8%; p<0.001). Baseline characteristics were equal in those with CTA-CAD versus those without CTA-CAD. There was no significant difference in AF progression rate (20.3% and 28.6%; p=0.30).

Conclusions: Patients originally diagnosed with idiopathic AF often develop cardiovascular disease within 5 years of follow-up. Early cardiac CT angiography may help to identify those who are prone to develop CVD in such a way that preventative measures can be accurately deployed in these patients.

P444
Yield of electrophysiolocal study to unmask supraventricular tachycardia in patients < 45 years scheduled for pulmonary vein isolation due to symptomatic atrial fibrillation

Abstract

Purpose: The importance of supraventricular tachycardia (SVT) in relation to pulmonary veins (PV) triggers in the aetiology of atrial fibrillion (AF) in young patients is unclear. Therefore, the benefit of electrophysiological study (EPS) prior to PV isolation (PVI) and treatment of an induced SVT by RF ablation instead of performing PVI remains to be determined. The purpose of this study was to (1) characterise the group of patients < 45 years scheduled to undergo pulmonary vein isolation (PVI) for documented symptomatic AF and (2) to evaluate the yield of EPS prior to PVI.

Methods: We analysed patients < 45 years old scheduled for PVI from January 2011 until December 2014. PVI was performed with the PVAC catheter (medtronic, USA). Follow up was performed at 3 and 12 months with ECG and/or Holter recording. Patients were encouraged to present for ECG recording when symptomatic.

Results: 124 consecutive pts were included. Mean age was 39 years (19-45), 82% were male, and 82% had paroxysmal AF. Mean LVEF was 59% while mean LA dimension was 38mm (25-54mm). 75% had no history of any other tachycardia, while 12% were known with atrial flutter and 8% with paroxysmal AT or supraventricular extra systole. Three pts had previously been treated with RF ablation for atrioventricular (AV)-nodal re-entry tachycardia (AVNRT) and 1 for atrioventricular re-entry tachycardia (AVRT). 65 pts (52%) underwent EPS prior to PVI. 12 pts had dual AV-nodal physiology without inducible AVNRT. In 7 pts AVNRT was inducible and subsequently treated with RF ablation without PVI and in 1 pt AVRT was induced employing a left lateral concealed accessory pathway which was ablated without performing PVI. After ≥ 12 months follow up, 6 of the 8 pts (75%) in which SVT ablation was performed instead of PVI were free of AF.

Conclusion: AVNRT is common in AF pts<45 yrs, and slow pathway ablation leads to freedom of AF in most of these pts. EP study is a recommended first step to determine the proper ablation target in this population.

P445
Left ventricular fibrosis is associated with kidney dysfunction in patients with atrial fibrillation

Abstract

Aims: To evaluate relationship between left (LV) ventricular myocardial fibrosis and kidney function in patients with atrial fibrillation (AF).

Methods: All AF patients had preserved LV systolic function defined as ejection fraction of ≥50%. Patients with low risk of stroke, severe valvular heart disease, recent (less than 6 months) thromboembolic or haemorrhagic event, known severe chronic kidney or hepatic dysfunction, malignancy or active inflammatory disorders were excluded.

LV myocardial fibrosis was assessed non-invasively by echocardiography-based acoustic densitometry. Calibrated integrated backscatter (cIB) was established as difference between pericardial and myocardial reflectivity. Estimated glomerular filtration rate (eGFR) was calculated with CKD-EPI (Chronic Kidney Disease Epidemiology Collaboration) formula. Data are presented as median and interquartile range. Linear regression analysis was used to test associations between LV cIB and eGFR.

Results: We studied 93 patients with AF (median age 71, 66% males, 40% permanent AF). Median cIB in the studied cohort was 23.4 (21.2-27.0) dB. Median eGFR was 73.5 (65.0-82.6) ml/min/1.73 m². When stratified according to eGFR as follows: <60, 60 to 69, 70 to 79, 80 to 89, and ≥90 ml/min/1.73 m²; cIB was significantly different across the groups (Figure). The main difference was driven by lower cIB in AF patients with eGFR <60 ml/min/1.73 m² versus all other strata. On multivariable analysis, eGFR remained a significant predictor of cIB (β=0.21, p<0.05) even after adjustment for presence of hypertension, coronary heart disease, heart failure, diabetes mellitus, and AF type.

Conclusion: More advanced LV myocardial fibrosis is independently associated with kidney dysfunction in AF patients with preserved LV ejection fraction.

cIB in AF patients with different eGFR

P446
Clinical outcomes of atrial fibrillation ablation according to technological step-up of CARTO mapping systems: a single center experience

Abstract

Background: Currently, CARTO® system is useful for electro-anatomical atrial mapping and used widely. However it is not known whether technological step-up of mapping system can improve clinical outcome of radiofrequency catheter ablation (RFCA) of atrial fibrillation (AF).

Methods and Results: Two hundred ninety eight patients who underwent RFCA procedure for the first time were investigated. Patients with follow-up period of <6 months were excluded. All patients were assessed from the medical record of the primary outcome as maintenance of sinus rhythm after the first session. RFCA procedures were performed by CARTO XP in 80 patients and by CARTO3 in 218 patients. In 83 of 218 cases with CARTO3, RFCA procedure was supported by intra-cardiac echocardiography (ICE), and 21 of 83 cases were performed RFCA supported with contact force sensing catheter. During a mean follow-up of 346±45 days, atrial tachyarrythmia recurred in 92 of 298 (31%) patients. While 38 of 80 (48%) cases using CARTO XP maintained sinus rhythm, 168 of 218 (77%) cases using CARTO3 were in sinus rhythm (p=0.001). Among CARTO3 group, there were 74 of 83 (89%) cases using ICE and 20 of 21 (95%) cases using contact force that maintained sinus rhythm.

Conclusion: With the technological step-up of CARTO mapping systems, the acquisition of ICE and contact force could improve clinical outcome of RFCA of AF.

P447
Left atrial remodeling in patients with atrial fibrillation is related to left ventricular myocardial fibrosis

Abstract

Aims: To evaluate whether left ventricular (LV) myocardial fibrosis is associated with left atrial (LA) remodeling in patients with atrial fibrillation (AF).

Methods: All study patients had preserved LV systolic function defined as ejection fraction of ≥50%. Patients with low risk of stroke (CHA2DS2-VASc score=0 (males) or 1 in females), severe valvular heart disease, recent (<6 months) thromboembolic or haemorrhagic event, severe chronic kidney or hepatic dysfunction, respiratory failure, advanced malignancy or active inflammatory disorders were excluded.

LV myocardial fibrosis was assessed non-invasively by echocardiography-based acoustic densitometry. Calibrated integrated backscatter (cIB) was established as difference between pericardial (reference tissue with high connective tissue content) and myocardial reflectivity on 2D echocardiography. LV cIB was calculated as an average of cIB obtained from interventricular septum and LV posterior wall. Echocardiography was also used to measure LA volume index. Data are presented as median and interquartile range. Linear regression analysis was used to test association between LV cIB and LA volume index.

Results: We studied 93 patients with AF (median age 71 (65-77) years, 66% male; 40% permanent AF). The median CHA2DS2-VASc score was 3.5 (2-5).

Median LV cIB in the studied cohort was 23.8 (21.2-27) dB. The median LA volume index was 35.1 (30.0-47.3) ml/m². There was no significant difference in cIB among patients with different types of AF (i.e., permanent vs. paroxysmal vs. persistent, p>0.05). There was no significant association between cIB and AF duration (p>0.05).

On univariate regression analysis, cIB was significantly associated with LA volume index (β=0.26, p=0.003). On multivariable analysis, cIB was significantly associated with LA volume index (β=0.18, p=0.014) after adjustment for gender, presence of hypertension, coronary heart disease and NYHA heart failure class. Significant predictors of LA remodeling on multivariable analysis apart from LV cIB were duration of AF history (β=0.18, p=0.03), progression from paroxysmal to persistent or permanent AF (β=0.40, p<0.001), and age (β=0.31, p<0.001).

Conclusion: Atrial and ventricular remodeling are closely related in patients with AF and preserved LV ejection fraction, and predicted by associated comorbidities.

P448
Inhibition of rotors by vernakalant but does not lead to termination of atrial fibrillation

Abstract

Purpose: With prolonged AF duration, antiarrhythmic drugs, like vernakalant, lose their efficacy to cardiovert AF. Changes in conduction patterns in the presence of antiarrhythmic drugs and mechanisms of AF termination have not been studied extensively.

Methods: AF was maintained in goats by burst pacing for 3 (3wk AF, n=6) or 22 (22wk AF, n=5) weeks. High-density mapping of AF was performed simultaneously in right and left atria during open chest experiments. Mapping was performed at baseline and at two different dosages of vernakalant. Fibrillation waves and rotors, detected as phase singularities (PS), were analyzed in 60s electrograms.

Results: In both groups, vernakalant increased refractory period and AF cycle length and decreased conduction velocity. In 22wkAF goats more waves, breakthroughs (BT) and PS per cycle were observed than in 3wkAF goats. The majority of PS detected were short lived, lasting less than one cycle. Vernakalant reduced waves, BTs and PS dose-dependently in both groups. Vernakalant strongly reduced the number of rotors with >2 rotations. Despite elimination of these rotors, none of the 22wAF goats terminated AF at low dose, where all 3wkAF goats did cardiovert. At high dose, the number of waves was further reduced and in 60% of 22wkAF goats AF terminated.

Conclusions: Vernakalant reduces the complexity of AF conduction patterns. The low cardioversion rate of long-term AF after rotor elimination, within mapped fields, shows that AF can be maintained without the contribution of rotors. Instead, the reduced number of non-rotating fibrillation waves may underlie cardioversion by vernakalant.

Quantification of conduction patterns.

P449
Quality of life improvement following PVI for paroxysmal AF is sustained during long term follow-up

Abstract

Introduction: The AFEQT (AF Effect on Quality of Life) survey is a validated tool used to assess quality of life (QoL) specifically for AF subjects across three domains: symptoms, daily activities and treatment concerns. Previous studies have shown positive QoL improvement after PVI, but long term studies are rare.

Methods: Data from 280 subjects in the randomized TOCCASTAR study were assessed for QoL changes from baseline to 12 months, and at each successive 6 month interval. PAF subjects were treated with a contact force (CF) sensing catheter (TactiCath™ St. Jude Medical) or non CF sensing control. Surveys were administered by qualified investigators during clinic visits. Results were tabulated for overall QoL and for each domain.

Results: Significant QoL improvements were observed in both arms from baseline to 12 months (median change from baseline to 12 months: 31.4, p < 0.001) with a non-significant difference between CF and Control (32.7 vs. 29.4, p = 0.253). Overall, patients with clinically relevant treatment success showed a significantly higher improvement than those with a failure (33.3 vs. 24.8, p=0.002). QoL score changes from baseline were slightly correlated with follow-up visits from 12 through 30 months (Spearman's rank correlation coefficient: 0.085, p = 0.016) indicating no decrease in the improvements resulting from initial treatment with PVI.

Conclusion: Subjects with PAF experienced significant improvement in QoL after treatment with PVI. Sustained reduction in symptoms and improvement in activity level resulted in higher overall AFEQT scores after 30 months FU. Subjects treated with TactiCath are more likely to see additional improvement in daily activities score than control. In patients with PAF, QoL is significantly improved after PVI and remains so after 30 months.

P450
A combination of epicardial and endocardial catheter ablation approaches to atrial arrhythmias after multiple failed atrial fibrillation ablations

Abstract

Background: To explore whether a combination of endocardial and epicardial (endo/epi) RFCA could change outcome in patients (pts), who suffered from recurrence of atrial arrhythmias (AA) after multiple endo RFCA of AF.

Methods: 21 pts (11 men, age 63±9 years), who had a recurrence of AA und undergone multiple RFCA (median 2, range 2-6) due to AF, were recruited consecutively in current study. Biatrial voltage maps (endo/epi) were carried out. Low voltage zone (LVZ) was defined as bipolar amplitude <0.05mV and considered as untreated substrate to AF. Re-PVI was performed if necessary. Substrate modification (SM) was performed if LVZ existed. Endpoint of SM was defined as bidirectional block of linear ablation lines and lack of local capture (10V/2ms). Afterwards an induction protocol was performed from RAA/LAA/CS. In case of spontaneous or induced regular AT, activation/entrainment mapping was performed to locate the origin of the focus or reentrant circuit in order to eliminate AT.

Results: Re-PVI was performed in 11 pts (52%). SM was performed in 19 pts (90%), including: endo/epi - 17 septal lines (SL), 15 roof lines, 9 anterior lines, 9 mitral isthmus lines; only endo - 12 endo posterior line (n=12) and 3 right atrial septal lines between SVC and FO; only epi - 17 in epi interatrial groove (IAG). Except 1 true focal AT, 17 macroreentrant tachycardias (MRTs) were eliminated, including 9 CTI-dependent MRTs and 7 MRTs from LA. In addition, 3 localized RT from IAG and 1 from epi roof of LA. Epi local capture in the vicinity of IAG was observed in a total of 17 patients, who received endo SL in LA and after endo confirmation of bidirectional block of SL. In 3 out of these 17 patients after receiving an epi SL, durations of pacing (beneath SL) to LAA were prolonged over 100 ms. Noninducibility was reached in all 21 patients. By the median 6 months of follow-up, 71% of patients remain at sinus rhythm without a significant increased major complication rate.

Conclusions: The combination of endo/epi RFCA aiming to recurrence of AA after multiple failed AF ablations may change the current concept of catheter ablation, especially for those who needs a true bidirectional block of SL or AA originated from IAG or epi LA roof. This combined approach was effective for pts with severe atrial myopathy.

P451
Second-generation cryoballoon ablation for persistent atrial fibrillation: single centre experience

Abstract

Introduction: Sparse data is available about 1-year clinical outcome of second-generation Cryoballoon (CB-Adv) ablation as index procedure for persistent atrial fibrillation (PersAF).

Methods: Seventy-five consecutive patients (53 male, 70.7%; mean age 66.4±9.5 years) with PersAF undergoing PVI using the CB-Adv were enrolled. Recurrence of atrial tachyarrhythmias (ATas) was defined as any symptomatic or documented episode >30 seconds.

Results: All PVs identified were successfully isolated with 1.6±0.3 mean freezes. Mean procedure and fluoroscopy times were 92.3±35.4 and 13.2±5.7 minutes. Among 31/75 patients (41.3%) presenting AF at begin of the procedure, 9/31 (29%) converted to sinus rhythm during ablation. Persistent phrenic nerve palsy (PNP) occurred in 5/75 (6.7%) patients. At 1-year follow-up, after a 3-months blanking period, 48/75 (64%) patients were in sinus rhythm. Among patients experiencing arrhythmic recurrences, 10/27 (37%) underwent a second procedure with radiofrequency catheter, showing reconnection in 5 right-sided and in 4 left-sided PVs (5/11, 45.5%; 4/11, 36.4%). In multivariate analysis PersAF duration (p<0.01) and relapses during BP (p=0.03) were independent predictors of recurrences.

Conclusions: At 1-year follow-up, CB-Adv ablation for PersAF results in 64% success rate. PNP is the most common complication. Persistent AF duration and relapses during the BP are significant predictors of recurrences.

P452
Cryoballoon temperature monitoring during pulmonary vein isolation as a surrogate marker for acute procedural success

Abstract

Purpose: Studies on second-generation 28mm cryoballoon (CB) for the treatment of paroxysmal atrial fibrillation (PAF) reported encouraging success rates. Customarily, contrast angiography is used to assess proper pulmonary vein (PV) occlusion. The purpose of the present study was to assess whether the intraballoon temperature decline (IBTD) during energy delivery can predict proper PV occlusion and serve as a surrogate for acute procedural success.

Methods: A total of 46 patients with PAF or persistent AF underwent PV isolation (PVI) using the second-generation 28mm CB. A freeze cycle was applied to all PV demonstrating grade III or IV contrast occlusion. The trend of IBTD over the first 60 seconds as well as the absolute value of temperature after 1 minute of energy delivery were assessed. PVI was verified using a spiral mapping catheter at the end of the cryo-application.

Results: A total of 46 patients (age 60±11 years, mean LA-diameter 42.4±8.6mm, 39/46 [85%] PAF) underwent CB-based PVI. During 181 initial freeze cycles targeting 181 PVs with grade III or IV occlusion, 142/181 (78.4%) PVs were successfully isolated. Temperature measurements after 10, 20, 30, 40, 50 and 60 seconds for each successful and failed initial freeze cycle were analyzed. A CB temperature after 1 min of -40°C,-40°C,-40°C and -39°C for the RSPV,RIPV,LSPV and LIPV respectively was associated with successful acute PVI.(Table 1)

An absolute temperature drop between 10 and 60 seconds of 64°C, 42°C, 41°C, and 43°C for the RSPV, RIPV, LSPV and LIPV demonstrated a positive predictive value of 88%, 77%, 76% and 95% for acute PVI respectively with a sensitivity 100%,58%,60% and 100%, specificity 16%,65%,80% and 44% and Negative Predictive Value 19%,33%,58% and 9% respectively.

Conclusion: The intraballoon temperature at 1 minute and the absolute temperature drop between the initial 10 and 60 seconds of energy delivery may predict successful PVI.

Table 1: Cryoballoon temperature after 1 minute of energy delivery associated with successful acute isolation.

P453
Efficacy of intracardiac ultrasound-guided catheter ablation for durable pulmonary vein isolation in patients with paroxysmal atrial fibrillation

Abstract

Background: A high incidence of pulmonary vein (PV) reconnection has been reported in patients with atrial fibrillation (AF) recurrence after PV isolation; however, only a few studies have examined the incidence of PV reconnection in patients without AF recurrence following an index ablation procedure. Furthermore, the effects of different mapping methods on three-dimensional map integration remain unknown.

Objective: The aims of the present study were to examine the incidence of PV reconnection in patients without AF recurrence, and to assess whether there is a difference in the incidence of PV reconnection between two strategies of mapping/ablation.

Methods: Between November 2011 and August 2014, 144 patients with paroxysmal AF (111 men; mean age 63 ± 13 years) underwent an electrophysiological study 6 months after an index ablation procedure to assess for chronic PV isolation irrespective of AF recurrence. Computed tomography image integration with intracardiac echocardiography (ICE) has been used to perform PV isolation since March 2013 in our hospital; therefore, the patients were divided into 2 groups depending on the use of ICE (non-Carto-Sound group and Carto-Sound group).

Results: The percentage of patients with durable isolation of all PVs was 24% (25/105) and 41% (16/39) (p = 0.036) in the non-Carto-Sound and Carto-Sound groups, respectively. The number of reconnected PVs was decreased in the Carto-Sound compared with that in the non-Carto-Sound group (1.5 ± 1.2 vs. 1.0 ± 1.0, p = 0.013). Patients with AF recurrence had more recovery of PV conduction than those without recurrence in the non-Carto-Sound group (2.0 ± 1.1 PVs vs. 1.3 ± 1.2 PVs, p = 0.004); however, there was no significant difference in the incidence of PV reconnection in patients with and without AF recurrence in the Carto-Sound group (1.2 ± 1.1 PVs vs. 0.9 ± 1.0 PVs, p = 0.422). In the Carto-Sound group, more patients with AF recurrence required additional ablation for non-PV firing during a repeat procedure than patients without recurrence (3/9 [33%] vs. 3/30 [10%], p=0.123).

Conclusion: Image integration using Carto-Sound in patients undergoing catheter ablation for paroxysmal AF significantly improved the durability of PV isolation.

P454
Radiofrequency catheter ablation versus balloon cryoablation of atrial fibrillation: markers of myocardial damage, inflammation and thrombogenesis

Abstract

Purpose: Several studies suggest that cryoablation is associated with lesser inflammatory response and activation of coagulation compared to radiofrequency (RF) ablation. In our study we aimed to compare cryoballoon (CB) and RF catheter ablation of paroxysmal atrial fibrillation (AF) and their effects on markers of myocardial damage, inflammation and activation of coagulation.

Methods: Fourty-one patients received either CB (CB group, n=23) or fluoroscopy-only guided RF (RF group, n=18) ablation of AF. We measured troponin I (TnI), high sensitivity CRP (hsCRP) and interleukin 6 (IL-6) levels at baseline from cubital vein, from right and left atrium before and after ablation, and from cubital vein the following day. In addition, prothrombin fragment 1+2 (F1+2), soluble P-selectin (sP-sel) and d-dimer were measured before and after ablation from both atria.

Results: We observed higher TnI release in CB than in RF group (7,01 mcg/l (IQR 5,30-9,09) vs 2,32 mcg/l (IQR 1,45-2,98), p<0,001). However, the levels of inflammatory markers and markers of activation of coagulation did not differ between the two groups.

Conclusions: Compared to fluoroscopy-only guided RF ablation of AF, CB causes a more significant myocardial damage. However, the two ablation techniques do not seem to differ in the inflammatory response and activation of coagulation.

P455
Initial experience with a novel laser catheter balloon for paroxismal and short lasting persistent atrial fibrillation ablation

Abstract

Purpose: Recently, a laser balloon catheter has been introduced for pulmonary vein isolation that allows the direct visualization of target tissue for ablation. We analyzed the initial experience with this catheter and the medium term results in relation to atrial fibrillation (AF) subtype.

Methods: The study shows the results of the pulmonary vein isolation in 55 consecutive patients with paroxysmal (PAF: 80%) and short-lasting persistent (PerAF: 20%) atrial fibrillation. Total procedural times were measured and follow-up included regular visits every 3 months with 48H holter monitoring.

Results: Pulmonary vein isolation was achieved in 216/218 (99%) pulmonary veins. Mean procedural time (from catheter introduction to removal) and mean fluoroscopy time were 156 ± 30min and 38 ± 15min, respectively. Fluoroscopy time decreased between the first 20 procedures and the following cases (from 47 to 33 min, p=0.002). The most frequent complication was the transient phrenic nerve palsy (7.7%) that appeared only in the first 18 cases. Fifty patients were followed during an average of 11 months and recurrence rate for first procedure was 15% and 33% for PAF and PerAF (fig. 1, p=0.2).

Conclusions: The laser catheter balloon is a safe and effective system to obtain the electrical isolation of the pulmonary veins. It should be emphasized the ability to adapt to the pulmonary venous anatomy with a single catheter and the effectiveness to achieve the pulmonary vein electrical isolation with a favourable clinical outcome at medium term follow-up including PerAF patients.

AT/AF Free Survival

P456
Clinical use of lesion size index during pulmonary vein isolation with contact force sensing catheters

Abstract

Background: In experimental studies contact force (CF) is an important determinant of radiofrequency (RF) ablation. An index of lesion size (LSI) has been developed in animal models to adjust RF power and duration in relation to CF to produce a desired lesion size, potentially minimizing excessive ablation, but clinical data are lacking. PURPOSE: To analyze parameters influencing clinical outcome in patients undergoing pulmonary vein isolation (PVI) with a predefined LSI.

Methods: 73 consecutive patients (age 57±12, 77% male, 42% hypertensive, 60% paroxysmal, left atrial (LA) area 28±8 cm2) underwent RF antral PVI aiming to obtain CF >10 and <40 g. RF applications were stopped when an LSI of 5 in the posterior LA wall and 5.5 at other LA sites was obtained in <60 sec. A deflectable sheath was used in all cases.

Results: 97% of PV were isolated (bidirectional) with 41±17 RF applications per patient (RF time 26±12 min). In 3% elevation of esophageal temperature precluded complete isolation. The objective LSI was obtained in 79% of applications with a duration of 38±13 sec and a CF of 21±9 g. In 28% of applications the LSI objective was reached in <30 sec. Recurrence of any atrial tachyarrhythmia during 10±3 months of follow-up occurred in 19 patients (26%). CF, FTI, proportion with objective LSI reached and RF duration did not predict outcome. CF trended higher in recurrent patients and, when divided into quartiles, patients with highest CF (> 21.2 gr) had 50% recurrence rate. The table shows uni and multivariable predictors: LA area and CF quartile were the only independent predictors of recurrence.

Conclusions: PVI can be obtained adjusting RF application duration to a predefined LSI of 5 to 5.5. The apparent paradoxical relation between high CF and high recurrence rate suggests that at sites with high CF LSI calculation (RF duration) may need readjustment.

P457
Sequential unipolar and bipolar radiofrequency versus repeated unipolar radiofrequency ablation of paroxysmal atrial fibrillation by nMARQ catheter

Abstract

Pulmonary vein isolation (PVI) is the most accepted approach for paroxysmal atrial fibrillation (PAF) ablation. nMARQTM catheter (Biosense Webster, Diamond Bar, CA, USA) is a new device which allows to deliver radiofrequency in unipolar or bipolar modality.

Aims: We compared two techniques for PVI with a novel, open-irrigated multielectrode mapping and radiofrequency (RF) ablation catheter.

Methods and Results: Sixty-two consecutives patients (mean age 64.3±9.2 years, 23 male) with symptomatic drug-refractory AF underwent PVI using by nMARQTM catheter. During ablation radiofrequency (RF) energy was systematically delivered at least twice for each electrode; additional RF pulses were allowed until PVI was achieved. 27 patients were assigned to unipolar (Group UU) and 35 patients to sequential unipolar and bipolar (Group UB) radiofrequency ablation with the same catheter. Unipolar RF was delivered for 45 seconds with maximum power of 20 W, bipolar RF was delivered for 60 seconds with a maximum power of 15.

Esophageal temperature was monitored by a probe in all patients and ablation was immediately stopped if temperature was ≥ 39,5°C. Post discharge from the hospital, pts underwent 24 hours Holter ECG recordings at 3, 6 and 9 months follow-up after the first ablation procedure. AF and sustained left atrial tachycardia (AT) documented after 2 months blanking period were considered as arrhythmia recurrence.

Procedure duration was 149.6±64.9 min in the Group UU and 142.4±40.9 min in the Group UB (p=0.6). Fluoroscopy time was 23.7±6.7 min in the Group UU and 25.9±10.7 min in the Group UB (p=0.2). Spontaneous PV reconnection or provoked by adenosine was observed in 12 pts (9 pts (33.3%) in Group UU and 3 pts (8.6%) in Group UB, p=0.02). After a mean follow up of 12.0±3.3 months 15 pts (55.6%) in the Group UU and 28 pt (80%) in the Group UB were free from arrhythmia recurrences (p=0.038). No major complications occurred during the study.

Conclusion: Irrigated multi-electrode RF ablation is fast and effective, providing a high rate of isolated PVs without the need of touch-up lesions. Sequential unipolar and bipolar radiofrequency ablation with nMARQ catheter is superior to sequential unipolar ablation.

P458
Atrial fibrillation ablation with Amigo robotic arm: a comparison with manual navigation

Abstract

Aim: Robotic control of the ablation catheter allows to reduce radiation exposure and to increase comfort for the operator. Our aim is to evaluate immediate and long term efficacy of atrial fibrillation ablation with the AMIGO™ robotic arm comparing to manual navigation.

Methods and Results: We evaluated 14 consecutive patients submitted to atrial fibrillation ablation with robotic arm (group A) and compared to 17 consecutive patients submitted to ablation with manual navigation during the same time interval (control group B). The same catheter and mapping system were used in both groups- Smarttouch® and CARTO®. Baseline characteristics (sex, age, paroxysmal vs persistent atrial fibrillation, presence of structural heart disease and left atrium volume) did not differ significantly (p=ns) between groups. The four pulmonary veins were isolated in all patients of both groups. Cavo-tricuspide isthmus ablation was performed in 4 patients in group A and 6 patients in group B. Additional left atrium lines were performed in one patient of group A. The procedure lasted longer in the robotic arm group (202 ± 62 vs 138 ± 39 min; p=0.002) but not requiring more fluoroscopy time (23 ± 12 vs 17 ± 8 min; p=ns) or more radiofrequency delivery (48 ± 9 vs 51 ± 46 min; p=ns).

During an average follow up of 662±150 days, recurrence free from any documented supraventricular arrhythmia was 85.7%in group A vs 82.4% in group B (p=NS). There were no complications reported in both groups (including major complications and death of any cause).

Conclusions: In this group of consecutive patients submitted to atrial fibrillation, AMIGO™ robotic arm and manual conventional navigation achieved similar efficacy and safety in the immediate and long term. Although the procedure lasted longer, the patient was not exposed to higher fluoroscopy time or to a higher extent of radiofrequency delivery.

P459
Characteristics and efficacy of radiofrequency catheter ablation for symptomatic atrial premature contractions

Abstract

Background: Frequent atrial premature contractions (APCs) sometimes develop severe symptoms and they are often refractory to antiarrhythmic drugs. However, there are few reports about radiofrequency catheter ablation (RFCA) for frequent APCs, so the aim of this study is to evaluate characteristics and efficacy in APC ablation cases.

Methods: We investigated 14 patients (mean age, 56±19 years; 7 males) who underwent RFCA for symptomatic drug-refractory APCs, and evaluated patients characteristics, Holter electrocardiogram (ECG) findings, and results of RFCA. Atrial fibrillation (AF) had never been recorded in 12-lead electrocardiogram or Holter ECG before RFCA in all patients.

Results: Median APC burden was 11.7±11.9% in Holter ECG. On echocardiography, mean left ventricular ejection fraction was 65.4±7.4% and mean left atrium diameter was 33.9±4.4 mm. The origin of APCs were following; pulmonary vein (PV):7, superior vena cava: 2, coronary sinus: 1, right atrium: 3, and left atrium: 1.

We also divided these patients into PV origin group and Non-PV origin group. Holter ECG analysis revealed that the APC burden was greater (20.7±11.9 % vs 5.8±7.0 %; p=0.030), and the rate of APC short run was slower (118±20 beats /min. vs 166±24 beats /min.; p=0.013) in the Non-PV origin group than in the PV origin group.

Five patients (36%) had recurrence with 1 frequent APC, 2 paroxysmal AF, and 2 atrial tachycardias, which were all eliminated in the second session. After the multiple procedure (mean 1.4±0.5 procedures), no recurrence was seen during the median 14±3 months follow-up.

Conclusion: PV was the major origin of symptomatic APCs. Although some cases required multiple procedures, successful RFCA for APCs was performed.

P460
Three-minute single shot versus three-minute double shot cryoballoon ablation for the treatment of atrial fibrillation

Abstract

Background: Safety and efficacy of cryoballoon (CB) ablation for the treatment of paroxysmal and short-lasting persistent atrial fibrillation (AF) are currently comparable to those reported with radiofrequency ablation. Second-generation balloons allow for shorter applications and have further ameliorated ablation results.

Aim: We hypothesized performing single shot applications for each pulmonary vein (PV) and adapting ablation time to the achievement of PV isolation would optimize second-generation CB ablation results.

Methods: Double shot (DS) versus single shot (SS) CB ablation were retrospectively compared. In the SS group, ablation was interrupted 60 seconds after PV isolation (as determined by a 8-pole circular catheter during ablation) or after 3 minutes (if PV isolation documentation was not feasible). Recurrence/complication rates and procedural/fluoroscopic times were compared.

Results: Fifty consecutive patients (age 55 ± 12 years, 74% male, 72% paroxysmal AF) were included. Procedural, fluoroscopy and application times in the DS (n = 26) vs. SS (n = 24) groups were 148.5 (16.9), 20.4 (4.5) minutes and 1434.8 (215.4) seconds vs. 107.5 (17.9), 17.5 (5.5) minutes and 718.7 (124.4) seconds, respectively (p < 0.001). Complication rate was similar (4 DS vs. 3 SS patients). After a 6.56 (2.1) month follow-up period, recurrence rate was also comparable (5 DS vs. 4 SS patients). Left atrial size and time in AF prior to ablation were the only independent predictors of AF recurrence in the multivariate analysis.

Conclusions: The SS strategy appears to be as effective and safe as the DS strategy and it reduces procedural and fluoroscopic times.

P462
FIRM only ablation in patients with persistent atrial fibrillation: acute and medium term results

Abstract

Introduction: Modulation of focal impulses and rotors (FIRM) has been described to be highly effective in preventing AF recurrences if added to pulmonary vein Isolation (PVI). The aim of the present study is to evaluate safety and efficacy of such an ablation without PVI in persistent AF cases. We present acute and medium term results of the patients (pt)included already.

Methods: Patients (pt) with persistent AF undergo FIRM ablation supported by EnSite™ NavX™ (St. Jude).Endocardial Mapping of focal and rotational activity is performed using RhythmviewTM (Topera Inc). Routine cerebral MRI and esophageal endoscopy are performed to notice silent cerebral lesions (SCL) and silent endoscopically detected esophageal lesions (EDEL). Follow up is performed every 3 months including 48h Holter and event recorder in case of palpitations without documentation in the Holter ECG.

Results: Twenty one patients were included already (mean age 62±10 years, 72% men, mean LA diameter 42 ±4 mm). Median rate of sources was 1 [0-3] in RA and 3 [1-4] in LA. In none of the patients AF termination in sinus rhythm could be observed. CL prolongation occurred in 10/21 pt (47%) with conversion in a regular AT in 2/21 pt (11%). Mean procedure duration, fluoroscopy time, LAtime and RF time were 227 ±47 min, 26 ±8, 137 ±31 and 36 ±14 min. Minor or major complications occurred in one patient (1 late pericardial tamponade), EDEL have been observed in 1/21 pt (4.8%) and SCL in 4/17 pt (25%), whereas pre-existing SCL could be detected in 10/17 pt (59%). Rate of early recurrences was 10/15 (67%). Regular AT was observed in 7/10 recurrences (70%). Two of these patients showed both, AF and AT. In June 2015 we will present complete 6 months follow up of all the presented cases.

Conclusions: FIRM only ablation seems to be safe regarding silent and overt complications. Rate of SCL is comparable to published rates of RF ablation. The rate of EDEL is very low due to avoidance of posterior ablations. Procedural parameters seem to be comparable to that of conventional ablation concepts for persistent AF cases. Early recurrences occur often as regular AT. Inclusion of linear ablations might be a useful concept in case of extensive regional ablation which might have created critical isthmus sites.

P463
Does the size of isolation area after pulmonary vein isolation with balloon-based techniques really matter for the long term outcome?

Abstract

Purpose: Aim of this retrospective study was to determine if the isolation area (IA) after pulmonary vein isolation (PVI) is related to different energy sources used and to long term outcome.

Methods: Thirty-nine patients with AF (mean age, 59±11 years; paroxysmal AF 90%, early persistent AF 10%) were enrolled. The source of ablation energy was cryo in 27 patients (69%) and laser in 12 patients (30%). An high-density voltage map, was realized after and before ablation in every patient. After PVI, the border between “scar” ablated area and the healthy atrial tissue was defined using the offset 0.5–0.1 mV (where 0.1 mV was defined as scar or completely silent tissue). The boundaries between the two tissues was designed by a circle which included both ipsilateral PV. Using an algorithm implemented in the Navx Velocity 3.0, the area (expressed in cm2) of lesion was automatically calculated by the system, from the border line to the first main branch bifurcation. Patients were divided into 2 groups according to the ablation energy source (group 1: cryo, group 2: laser).

Results: Subgroup analysis showed that IA was significantly greater in patients treated with cryo than laser in both PV (respectively 72±7 cm2 for left PV and 76±5 cm2 for right PV vs 54±6 cm2 for left PV and 48±7 cm2 for right PV, P=0.005). After a 36 months follow-up, 8% of patients in group 1 and 5 of patients in group 2 had a AF recurrence, without any difference between groups (P=0.6).

Conclusions: Cryo was associated to larger IA, compared to laser; this difference, however, did not correlate with a significantly higher success at long term follow up.

PV isolation area before and after PVI

P464
Feasibility of left atrial ablation for the treatment of atrial tachyarrhythmias in patients with left atrial appendage closure devices

Abstract

Purpose: Recently left atrial appendage (LAA)-closure devices were introduced as an alternative for oral anticoagulation (OAC) in patients with atrial fibrillation (AF). Due to potential overlap of the ablation target area and a previously implanted LAA-closure device left atrial (LA) ablation for treatment of AF remains a subject of debate. We report on the feasibility of AF ablation after implantation of a LAA-closure device.

Methods: Eight patients (69±8 years) with symptomatic paroxysmal (n=5) or persistent AF (CHA2DS2-VASc score = 3.6, HAS-BLED score = 3.6) and previously implanted WATCHMAN (7/8) or AMPLATZER (1/8) LAA-closure devices, received a radiofrequency based LA ablation (4/8 circumferential pulmonary vein isolation (CPVI), 1/8 CPVI+anterior line ablation, 1/8 re-isolation of LAA via mitral isthmus line, 1/8 ablation of anterior line, ostial potentials and mitral isthmus line, 1/8 CPVI+ablation of mitral and anterior lines) 149±99 days after LAA-closure.

Results: Successful LA ablation could be performed without device interference in all patients. After 387±355 days a transesophageal echocardiography was performed in all patients to evaluate device related complications. No device dislocation or leakage was observed. In 1/8 patients (13%) a device related thrombus (Picture 1) was found despite anticoagulation with Dabigatran (110mg twice daily). 5/8 patients (63%) remained in stable sinus rhythm; no bleeding events or stroke occurred during a FU of 395±238 days.

Conclusion: LA ablation after LAA-closure appears to be feasible and can be performed without device interference, dislocation or leakage. Device related thrombus formation in one patient suggests the need for further TEE examinations after LA ablation in patients with previously implanted LAA-closure devices.

Picture 1: Device related thrombus

P465
Activation mapping during pulmonary vein pacing allows precise localization of conduction gaps in the wide circumferential ablation lines to complete pulmonary vein isolation

Abstract

Introduction: Inability to achieve pulmonary vein isolation (PVI) upon completion of the wide circumferential ablation (WCA) is frequently encountered during radiofrequency ablation (RFA) for treatment of atrial fibrillation (AF). Different methods are used in an attempt to localize the conduction gaps (CG) for targeted additional RFA to achieve PVI. However, a systematic approach to precisely define the location of CGs to avoid unnecessary ablation has not been studied.

Methods: A group of 30 consecutive patients with AF who had initial intra-procedure inability to achieve PVI with completion of WCA of each ipsilateral PV pairs were studied. Maps were acquired using CARTO® system during pacing (Pace Map) from the Lasso® positioned in a stable ostial location in each of the PVs. The WCA line was divided into 8 circumferential segments and used as a reference for comparison. Mapping was performed along the outer border of the WCA line to define the segment with the earliest exit site. RFA was delivered around the site of earliest activation on the WCA line to assess if PVI was achieved or Lasso activation sequence changed, which then triggered repeat mapping.

Results: There were 35 PV pairs [19 left PVs (LPV) and 16 Right PV (RPV)] with 46 CGs in the 30 patients studied. A total of 71 maps were acquired and localized one CG in 26 PV pairs , 2 CGs in 7 PV pairs as well as 3 CGs in 2 PV Pairs. Average mapping time was 5 with a median of 4 minutes/gap. A total of 142 RF applications were delivered for the 46 gaps (average 3.1, median 3 applications/gap) achieving entrance and exit block in all the PVs. Each RF application was delivered for 30-45 seconds. The first pace map from each of the ipsilateral superior and inferior PVs successfully indicated 94% (CI 94+4%) of all the CGs (67/71 maps). Additional maps were performed to localize the gaps not identified by the initial maps to achieve 100 % PVI in all the veins without any ablation delivered in the Carina or inside any of the PVs.

Conclusion: Precise localization of the conduction gaps in the WCA lines can be easily achieved with the above-described simple and quick pace-map technique. Ablation guided by mapping to localize conductions gaps avoided any ablation in the carina or ostial location in the veins to achieve PVI.

P466
Relationship between reduced left atrial function and electro-anatomical remodeling in patients undergoing atrial fibrillation ablation

Abstract

Purpose: Areas with reduced atrial electrogram amplitude ("low voltage areas", LVAs) are considered to represent fibrotic remodeling. We assessed the incidence of LVAs in patients undergoing catheter ablation of atrial fibrillation (AF) and analyzed their relationship with left atrial function determined by echocardiography.

Methods: In 36 patients with paroxysmal AF, myocardial function of the left atrium was assessed on the day prior to ablation by using 2-dimensional speckle-tracking echocardiography in sinus rhythm. LA voltage maps were created during sinus rhythm before ablation. LVAs were defined as areas presenting with a bipolar electrogram amplitude of <0.5 mV. Percentage of LVAs in relation to the whole LA surface was compared between patients with reduced LA function (LA strain < 18%) and patients with normal LA function (LA strain ≥ 18%).

Results: In the whole group, mean percentage of LVAs was 4% ± 8 (min/max: 0/34%) and mean LA strain was 24% ± 6 (min/max: 12/38%). Reduced LA function (LA strain <18%) was found in 5 patients (14.0%) with a mean LA strain of 15% ± 3. Percentage of LVAs in these patients was significantly higher than in patients without LA dysfunction (15% ± 7 vs. 2% ± 5, p = 0.001, respectively).

Conclusion: This is the first study showing the relationship between left atrial dysfunction determined by echocardiography and the extent of areas with reduced atrial electrogram amplitude. Our data further support the hypothesis, that reduced LA function determined by speckle tracking echocardiography represents left atrial structural remodeling.

P468
Galectin-3 in patients with atrial fibrillation undergoing radiofrequency catheter ablation

Abstract

Background: Galectin-3 (Gal-3) is an emerging biomarker in heart failure that is involved in fibrosis and inflammation. However, its potential value as a prognostic marker in atrial fibrillation (AF) is unknown. The aim of this study was to assess the impact of AF catheter ablation on Gal-3 and evaluate its prognostic impact for predicting rhythm outcome after catheter ablation.

Methods: Gal-3 was measured at baseline and after 6 months using specific ELISA. AF recurrences were defined as any atrial arrhythmia lasting longer than 30 sec within 6 months after ablation.

Results: In 105 AF patients (65% males, age 62±9 years, 52% paroxysmal AF) undergoing catheter ablation, Gal-3 was measured at baseline and after 6 months and compared with an AF-free control cohort (n=14, 50 % males, age 58±11 years). Gal-3 was higher in AF patients compared with AF-free controls (7.8±2.9 vs. 5.8±1.8, ng/mL, p=0.013). However, on multivariable analysis, BMI (p=0.007) but not AF (p=0.068) was associated with Gal-3. In the AF cohort, on univariable analysis higher Gal-3 levels were associated with female gender (p=0.028), higher BMI (p=0.005) and both CHADS2 (p=0.008) and CHA2DS2-VASC (p=0.016) scores, however, on multivariable analysis only BMI remained significantly associated with baseline Gal-3 (p=0.016). Gal-3 was similar 6 months after AF catheter ablation and was not associated with sinus rhythm maintenance.

Conclusions: Although galectin-3 levels are higher in AF patients, this is driven by cardiometabolic co-morbidities and not heart rhythm. Gal-3 is not useful for predicting rhythm outcome of catheter ablation.

P469
Optimal settings of VisiTag module for contact force-guided circumferential pulmonary vein isolation of atrial fibrillation

Abstract

Background: The VisiTag Module installed on the CARTO system allows the evaluation of multiple parameters of radiofrequency lesion formation and displays this as automatic tags. The purpose of this study was to evaluate the optimal VisiTag settings of minimum contact force (Min-CF) and duration of stable catheter positioning (Min-duration) for CF-guided circumferential pulmonary vein isolation (CPVI) of atrial fibrillation.

Methods: A total of 51 patients underwent an initial CPVI by a point-by-point ablation technique guided by an integrated three-dimensional computed tomographic reconstruction. Each application of radiofrequency (RF) energy was delivered for 40 to 60 seconds (s) with a target CF of 20g. The RF duration near the esophagus was limited to 30s under esophageal temperature monitoring (<41 degrees Celsius). The ratio of the total number of radiofrequency applications to that of tags displayed on the CARTO system was calculated for each setting, and compared among eight settings according to the combination of Min-CF (5g or 10g) and Min-duration (5, 10, 20, or 30s).

Results: The total radiofrequency application was approximately equal to that of tags with 5g/20s and 10g/10s settings, and the ratio was 0.92±0.07 and 0.92±0.14, respectively (P=0.85). There were significantly differences between the ratios with 5g/20s and 10g/10s between the others (P<0.01). The variation coefficient was smaller with 5g/20s than with 10g/10s (0.072 vs. 0.149).

Conclusion: The VisiTag setting of 5g/20s can be suitable for CF-guided CPVI.

P470
Characterization of endocardial voltage attenuation and pulmonary vein isolation following convergent epicardial ablation for persistent atrial fibrillation

Abstract

Purpose: The Convergent procedure (nContact, Morrisville NC, USA) has shown promise in ablation of persistent (Pe) and longstanding persistent (LSPe) AF. We sought to characterize endocardial LA voltage attenuation and PV isolation following the epicardial (EPI) portion of the procedure.

Methods: Seventeen of 41 pts undergoing Convergent ablation of Pe or LSPe AF from Dec 2013 to Jan 2015 had no previous AF ablation procedure and are reported here. Posterior LA lesions were created from right to left PV's in 2 layers from inferior to superior, along the ridge (left PV's), septum (right PV's) and carina between right PV's. In the same procedure pts underwent endocardial voltage mapping and ablation with EnSite 3-D mapping system. A circular mapping catheter recorded voltage on the posterior LA and whether PV isolation was present. Scar during AF was set <0.1 mV.

Results: There were 11 M/6F, age 65+/-8 yrs, EF 48+/-16, LA 5.5+/-0.8 undergoing first-time ablation for Pe (n=6) or LSPe (n=11) AF. A mean of 23+/-7 EPI RF lesions (35+/-10 min) were placed on the posterior LA and surrounding PV's. There was consistent dense voltage attenuation of the posterior LA in all pts (Figure). Fifteen of 68 PV's (22%) were isolated with EPI ablation alone (LSPV-0, LIPV-6, RSPV-3, RIPV-6). Sites requiring endocardial ablation were uniformly at the superior portion of the upper PV's, within the carinae and septal aspect of the right PV's. Typically focal PV connection was noted in the LIPV and RIPV, while more extensive ablation was required over the roof.

Conclusion: EPI ablation using the nContact system results in reproducible dense posterior LA voltage attenuation. Minimal focal RF ablation from the endocardium can achieve complete PV isolation.

Voltage map following EPI ablation

P471
Excellent outcomes at long term follow-up following minimally invasive surgical ablation for stand-alone atrial fibrillation

Abstract

Purpose: Minimally invasive surgical treatment of atrial fibrillation (AF) has gained popularity during the past decade, however there is paucity of data about the long-term outcomes of this novel approach.

Methods: Study population included 125 consecutive patients undergoing stand-alone surgical treatment of atrial fibrillation via a closed-chest, right-sided monolateral thoracoscopic approach (box lesion set) by means of a versapolar (combining uni/bipolar) radiofrequency ablation device. Mean age was 62,5 ± 10,4 yrs, and the prevalence of paroxysmal, persistent and long-standing(LS-persistent) AF was 37,6%, 11,2% and 51,2% respectively with a median AF duration of 60 months. Mean left atrial antero-posterior diameter was 48,6 ± 8,6 mm.

Results: The procedure was successfully accomplished via an endoscopic approach in all patients except one requiring conversion to mini-sternotomy. Hospital mortality was 0% and no major complications occurred during the post-operative hospital stay except for a thrombo-embolic event occurring in 2 patients (1,6%). Multivariate Cox regression analysis identified long-standing persistent AF (OR:9.5;CI=2.5-35.4;p=0.001) and female gender (OR:3.03; CI=1.06-8.7;p=0.039) as independent risk factors for AF recurrence; instead, paroxysmal AF was associated with improved rhythm outcomes (OR:0.12;CI=0.04-0.36;p<0.001). At a median follow-up of 60 months, overall stable sinus rhythm was achieved in 79.2%(99/125 pts.) (paroxysmal: 91,5%, 43/47 pts.; persistent: 78,6%, 11/14 pts.; LS-persistent: 70,3%, 45/64 pts.); Finally, there was a trend towards the stabilization of rhythm over the follow-up time, as depicted by Spearman analysis showing a positive correlation among sinus rhythm restoration and follow-up duration (rho=0.82).

Conclusions: Totally endoscopic AF surgical ablation (box lesion) is a safe and effective procedure providing excellent and stable results over time at long-term follow-up. Rhythm outcomes in patients with LS-persistent AF may be further improved with an integrated hybrid approach.

P472
An automated algorithm for the segmentation of the left atrial blood pool as a key step in the assessment and display of left atrial wall thickness

Abstract

Introduction: Left atrial wall thickness (LAWT) may influence atrial electrical properties and AF treatment outcome. Comprehensive structural assessment of the LA wall must be made in three dimensions and depends on the accurate identification of the LA endocardial border. We test a novel method for the automatic segmentation of the LA blood pool based on a leak-sensing region growing algorithm.

Methods: We analyzed 9 CT Coronary Angiograms using our automated algorithm designed to minimise error associated with manual removal of neighbouring contrast enhanced structures (right atrium, aorta, left ventricle). We calculated LA volume and surface area. Multi OTSU thresholding identifies regions of similar Hounsfield Unit intensity. The relationship between neighbouring regions of similar intensity is established by a leak-sensing region growing algorithm, which prevents leaks in the dynamic region grown from the atrial chamber. Leaks are avoided by detecting narrow passages at the image pixel level. We compared with results from manual segmentation.

Results: Type A intra-class correlation coefficient (ICC) between measurements of the LA volume assessed using the fully automated and the standard approach, using an absolute agreement definition for average measures, was 0.978 (95%CI 90.1–99.5, p<0.001) and for the LA surface area 0.918 (95%CI 63.8–98.2, p=0.001).

Conclusion: There is excellent agreement between this automated method for LA blood pool segmentation and a method requiring manual removal of connected neighbouring structures. This represents progress towards a fully automated observer independent assessment of left atrial wall thickness in three dimensions.

P473
Stereotactic radiosurgery in threatment of ventricular tachycardias

Abstract

Introduction: We present case report of 72-old lady with recurrent ventricular tachycardia and recurrent arrhythmic storm. She was long time treated for dilated cardiomyopathy (EF LK 25%), mitral regurgitation III/IV, she was implanted ICD-CRT (1/2013). She was treated with BB in maximal well tolerated dose, coronary arteries had only mild coronary stenosis. ECG monitoring reports very frequent PVCs of the same morphology. During repeated EP studies VT of the same morphology was induced like spontaneous PVCs. Catheter RF ablations were ineffective. Because of repetitive arrhythmic storms she was indicated for stereotactic radiotherapy with Cyberknife.

Goal: The use of stereotactic radiotherapy (Cyberknife) after the therapeutic failure of catheter RF ablation of ventricular tachycardia.

Methodology: Arythmogenic substrate was localized with CARTO mapping during first two EP studies. First EP study was endocardial, second EP study was combined endo and epicardial mapping (subxiphoidal access was added). The source of arrhythmia was localized at the base of lateral wall of left ventricle each time. Electroanatomic maps of CARTO was merged with CT scans. Combined catheter RF ablation endocardial /epicardial was ineffective.

To focus Cyberknife, a spiral CT was used to define arythmogenic substrate in accordance with former mentioned imaginings. To influence whole goal tissue during the heart revolution, beam was set to affect the movement of whole wall of ventricle from end-diastole to end-systole. LV electrode in lateral branch of coronary sinus of current stimulating system was used as fiducial marker for respiratory movement compensation

Cyberknife therapy was performed of 25 Gy dose in one time session, with following hospitalization at cardiology ward.

Results: follow up after radiotherapy was one year. VTs were detected only once day during hard diarrhoea 4th month after procedure (terminated by antitachycardia pacing), mineral dysbalance is supposed. 10 days after intervention the number of PVCs decreased from 9-10% to 1-3% and non sustained ventricle tachycardias diminished as documented in ECG monitoring during hospital stay with follow-up repetitive ambulatory ECG holter monitoring. After 6 weeks systolic function of LV was improved (EF LK 35-40%). We have found no complication.

Resume: stereotactic radiotherapy CyberKnife is first time used in ablation of ventricular tachycardia after previous failure of endo/epicardial catheter RF ablation. The intervention was not followed by any complication, in one year follow up there were once day recurrence of VTs (during diarrhoea).

P474
Experience with non-invasive mapping system (ECVUE) to guide ablation

Abstract

Introduction: The EcVue system has been proved as a successful tool to identify and map the mechanism of atrial and ventricular tachycardia in a non-invasive way, nonetheless further data on its usefulness for intra-procedural mapping guiding the ablation are still sparse.

Methods: Between November 2012 and September 2014, we proceeded to non-invasive electro-anatomic mapping before and during the procedure using EcVue in 50 patients. This is a single centre descriptive study where we describe our experience using the non-invasive mapping system EcVue.

Results: Fifty patients (26 men, mean age 43 ± 17 years), 20 with ACHD and 6 with SHD. Among them, 41 had inducible arrhythmia not being AF (two patients with both atrial and ventricular arrhythmias; one patient with two procedures). A total of 71 arrhythmias were targeted: 28 atrial (AT), 44 ventricular (VE) and 1 accessory pathway (AP). Only 3 AT were macroreentrant (2 CTI dependent and 1 left atrial flutter). We achieved a successful pre-procedural mapping in 75% of AT, 93,2 % of VE and in the case of AP. Failed procedures: In 4 AT, the system mapping failed due to a poor visualisation of p-wave (low amplitude and/or masked in QRS or T wave). The site of arrhythmia determined by conventional mapping, pace-map (as described above) and/or where the success ablation was carried out was different from the site predicted by the system in 3VE and 3 AT.

Successful ablation: Two ablations were abandoned because the site predicted was too close to the compact AV node. Of the remain attempted ablations the ablation guided by the system success in 93 % of AT (26/28), in 93 % of VE (39/42), and in the AP as well.

Conclusions: EcVue system predicts properly the location and mechanism of different kind of arrhythmias, moreover and despite the complexity of cases, in the majority of cases the system guide successfully the ablation.

P476
Use of electrical coupling index in typical atrial flutter ablation

Abstract

Purpose: A new generation ablation system with an irrigated ablation catheter in conjunction with an advanced electro-anatomic mapping and navigation system allows the evaluation of the Electrical Coupling Index (ECI), an indication of tip-to-tissue contact. Aim of our study was to evaluate if this index could also give an indication about ablation lesion efficacy.

Methods: In patients undergoing typical right atrial flutter ablation, we compared the values of the ECI before, during (at the plateau) and after isthmus ablation. Permanent tissue damage or ablation lesion efficacy was defined as the reduction in the local potential > 90% or as potential split in 2 separate signals. In absence of these endpoints, lesions were deemed ineffective. Results. 15 consecutive patients (11 males, age 69.3±11.4 years) with history of typical atrial flutter underwent an ablation with Contact™ Therapy™ Cool Path™ Cardiac Ablation System in conjunction with EnSite™ Velocity Contact™ technology between Sep 2012 and Aug 2013. Target site for ablation was the isthmus between the inferior vena cava and the tricuspid valve. All the procedures were successful, without complications. The number of radiofrequency (RF) applications was 10.8±6.7 (range 6-28) and RF time was 330.3±177.5s. ECI values are reported in the table.

RF effective applications needed less time and the ECI post-ablation was inferior compared to ineffective RF applications. The absolute and percentage ECI variations (pre-post ablation) were significantly greater when applications were effective (p<0.001). From our data, it is possible to determine a 13% cut-off value in the ECI variation that could be considered as the target for an effective ablation.

Conclusion: The Electrical Coupling Index can be used as a marker of ablation lesion efficacy in the the ablation of typical right atrial flutter.

P477
The non-fluoroscopic navigation reduces significantly not only the x-ray exposure but the cumulative radiofrequency time as well during radiofrequency catheter ablation of the cavo-tricuspid isthmus

Abstract

Purpose: To study the impact of non-fluoroscopic navigation (NFN) on several procedural and clinical parameters during radiofrequency (RF) catheter ablation (CA) of the cavo-tricuspid isthmus (CTI) in patients with CTI-dependent atrial flutter.

Methods: Data about 124 consecutive patients with CTI CA performed were retrospectively collected. Patients who have undergone CA of another arrhythmogenic substrate within the same session were not included in the analysis. The patients were divided in 2 groups: 1) conventional CA with 2 diagnostic catheters deployed in the coronary sinus and around the tricuspid annulus (NFN-, 67 ablations); 2) CA with the same 2 catheters plus NFN system using cutaneous patches (NFN+, 69 ablations). The CA in both groups was done using 8-mm tipped non-irrigated catheter. The following parameters were analyzed: procedural success, procedural duration in minutes, fluoroscopic time in minutes, dose-area product (DAP) in μGy*m2, total number of RF applications, total RF time in seconds, recurrences. Independent samples T-test was used for statistical analysis. P-value <0.05 was considered significant.

Results: The mean age in group NFN+ was 56.3±11.6 years (21-78 y.), males were 49 (79%), females–13; in group NFN- the mean age was 55.8±11.7 y. (19-77 y.), males were 45 (72.6%), females–17; P=NS. The follow-up was 20.7±12.4 months (4-46 mo). Immediate procedural success was achieved in 122 patients (98.4%), recurrences of atrial flutter were observed in 11 patients (8.9%). A total of 136 CA were performed–single procedure in 113 patients, 2 procedures in 10 patients, 3 procedures in 1 patient. Long-term success after 1 or more CA was achieved in all patients. In the NFN+ group there was 1 complication (0.8%)–complete AV block with implantation of permanent pacemaker. There were not significant differences between the groups in the procedural duration (169.6±48 versus 157.6±50.3 min.), the total number of RF applications (28.4±18.3 vs. 29.5±18.8), and the recurrences (6.5 vs. 11.3%). In the group NFN+ the fluoroscopic time was shorter (9.4±7 vs. 16.7±8.7 min.), P <0.001; DAP was lower (2128.3±1800.7 vs. 4129.9±2726 μGy*m2), P<0.001; the total RF time was shorter (1870.5±1265.9 vs. 2335.5±1264.2 sec.), P =0.034.

Conclusions: The immediate and long-term success during RFCA of CTI is high, the rate of recurrence is low, and the rate of serious complications is very low, irrespective of the use of NFN. NFN reduces not only the x-ray exposure but the total RF time as well. It does not influence the procedural duration, the total number of RF applications and the recurrence rate.

P478
Are patients with Wolff-Parkinson-White pattern with syncope as the single symptom different from those completely symptom-free?

Abstract

Purpose: Syncope is a common symptom particularly in young individuals and in this age group vasovagal origin is by far the leading cause. In patients with Wolff Parkinson White (WPW) pattern the significance of syncope remains controversial. The aim of the present study was to evaluate the potential dangerousness of syncope as the single symptom in patients with WPW pattern.

Methods: This prospective open label, single center, parallel groups study is designed to assess and compare clinical (age, sex, accessory pathway localization), electrophysiological (effective refractory period (ERP) of accessory pathway (AP), presence of retrograde conduction over AP, inducibility of atrioventricular reciprocating tachycardia or atrial fibrillation and presence of multiple AP during invasive electrophysiological testing) and RF ablation procedure outcomes in patients with isolated syncope and in totally asymptomatic WPW undergoing RF ablation.

Results: From January 2010 to February 2012, 199 consecutive patients with WPW pattern were admitted in our department. All patients underwent invasive electrophysiological studies followed by RF ablation. 97 patients (49%) with palpitations and 1 resuscitated from sudden death were excluded from the study. The remaining 101 patients were divided in 2 groups. Group 1 (asymptomatic group) included 33 totally asymptomatic patients (33%), mostly athletes and patients with high-risk occupations. Group 2 (study group) included 68 patients (67%) with syncope as the single symptom.

Significant differences were observed between asymptomatic and syncope group: mean value of ERPAP 263 vs 232 msec (p<.0001), mean age 28 vs 36 y/o (p=.0023), left-sided localization of AP 7 vs 31 patients (p=.04) and inducibility of AVRT 10 vs 36 patients (p=.001) mostly in males.

Others assessed parameters: sex, inducibility of AF, presence of retrograde conduction over the AP, more than one AP, were not statistically different between the 2 groups. First procedural success rate of RF ablation was 95% in both groups without complications.

Conclusion: Patients with syncope as the single symptom have a much shorter ERPAP, a well-known risk factor of sudden death, than totally asymptomatic patients. Their other characteristics are older age (over 30), left-sided localization of the AP and inducibility of tachycardia mostly in males. Isolated syncope in patients with WPW pattern could therefore be considered as a symptom of gravity leading to propose RF ablation performed safely with a high immediate success rate.

P480
Efficacy of the renal denervation in patients with resistant hypertension and atrial fibrillation

Abstract

Background: Patients with resistant hypertension (RH) have high risk of paroxysmal and permanent atrial fibrillation (AF). Effective treatment of arterial hypertension (AH) usually decrease the number of paroxysms.

Objective: The purpose of our study was to estimate the efficacy of renal denervation (RDN) in patients with RH and AF.

Methods: The study included 13 patients with a history of AF - 4 males (31%) N 9 females (69%), the average age was–54 ±6,2. Two (8%) patients had permanent AF, 3 (23%)–persistent AF, 8 patients (62%)–paroxysmal AF. All patients underwent RDN. Procedure was performed by an experienced electrophysiologist in both renal arteries (RA) using specialized electrode Symplicity: power = 8-10 W and temperature 55°C, 4 - 10 points for each RA, for 2 minutes per point.

Results: The mean office systolic blood pressure (SBP) initially was - 174,08 ± 23,9 mm Hg, diastolic BD (DBP) -100,25 ± 15,6 mm Hg. At 12 months we observed sustained reduction in BP: SBP–148,2±20,0 mm Hg, DBP - 90,8 ± 11,9 mm Hg. The number of highly symptomatic paroxysms AF requiring cardioversion (pharmacological and/or electrical) decreased from 9,25 (2; 24) per year before operation to 1, 45 (1; 2) per year during the period of 12 month after RDN (p<0,01). Five patients had (38%) significant improvement in tolerance of AF paroxysms. After RDN 8 patients withdrawn antiarrhythmics (amiodaron or 1C class), and only 3 of 11 patients with paroxysmal/ persistent AF need to continue antiarrhythmics use. Two patients with permanent AF during a year after RDN had normosystolic AF decreasing their beta-blocker dose.

Conclusion: RDN has led to a significant and sustained blood pressure reduction in patients with RH and AF. RDN has decreased the amount of highly symptomatic AF paroxysms and the necessity for antiarrhythmic drugs admission and cardioversion.

P481
Distance to the origin, not the earliness activation or pacemap, determines a cure of ventricular tachyarrhythmias: a distinct subgroup of outflow tachyarrhythmias

Abstract

Background: Despite sufficiently earlier activation during ventricular tachyarrhythmias (VA) and/or an excellent pacemap in the right ventricular outflow tract (RVOT), some VAs (OT-VAs) may require a left-sided ablation for a cure. The purpose of this study was to present data on 5 patients with OT-VAs whose common ECG features and intracardiac electrograms during ablation defined them as having a distinct subgroup different from the well-known idiopathic OT-VAs.

Methods: The study group consisted of 5 patients (50±14 years; all men), with idiopathic OT-VAs. The characteristics of the baseline 12-lead ECG, transformation of the 12-lead ECG, and intracardiac electrocardiograms during radiofrequency (RF) catheter ablation were assessed in all patients.

Results: In all patients, the earliest activation during the OT-VAs (local electrogram-QRS interval= -34±6.8 ms) and excellent pacemaps were obtained at the anterior portion of the RVOT. However, the RF catheter ablation at this site with an irrigated tip catheter failed. In these 5 patients, the clinical OT-VAs had a LBBB QRS morphology and inferior axis with a precordial R/S transition in leads V3-V4 (V3/V3-V4= 1/4), and negative components (qs/rs= 4/1) in lead I. Relatively earlier activation (local electrogram-QRS interval= -23±16.5 ms) and a good pacemap were also recorded at the distal portion of the great cardiac vein (d-GCV). After RF catheter ablation at the RVOT, the QRS morphology of the OT-VAs slightly changed: the R wave was decreased in the inferior leads and increased in the precordial leads, and the S waves became shallower in leads V1-2. Successful ablation was finally obtained at the left ventricular (LV) OT beneath the junction of the left and right coronary cusps in 3 patients and left coronary cusp in the remaining 2. At the successful ablation sites, the local electrogram-QRS interval was -1.6±11.8 ms, and the pacemap scores were very low. However, those sites were just contralateral to the initially ablated RVOT site, and the distance was 15.8±3.0 mm. Furthermore, the successful sites also were near the d-GCV at a distance of 15.3±8.1 mm.

Conclusions: In this subgroup, the OT-VA origin was confined to a narrow area among the RVOT, LVOT, and d-GCV. Therefore, irrespective of the earliness local activation or pacemap score, RF catheter ablation at sites close to the OT-VA origins was crucial for the cure.

P482
The transseptal or transaortic approach for pediatric left sided accessory pathway ablation in era of NavX/Ensite? Comparison of four apporaches

Abstract

The ablation of left sided accessory pathways (LSAP) can be performed via transaortic (AO) or transseptal (TS) approach. Both technique can be achieved with non-fluoroscopic approach, however this significantly increases the procedure duration.

The aim was to assess the safety and feasibility of 4 strategies for LSAP: standard RTG approach with AO (RTG+AO) or TS (RTG+TS) access and low fluoroscopic NavX/Ensite approach with AO (NX+AO) or TS (NX+TS) access.

Ablation was performed using 2-electrodes (fixed 4 and deflectable 10 poles). In the NavX group procedure was started from RA, CS and location His bundle. Aorta was reconstructed before passage to the left ventricle. Short fluoro was used during TS. We analyzed the procedural (duration of GA and procedure), X-ray (fluoroscopy (FT), air-kerma dose (D)) and ablation parameters (time to 1st and the last application (1stAP, L_AP), the number of applications (N_AP), total RF duration (RF_T) and success rate.

We included 176 pts with LSAP (age 13,3±4 years, 73F) with SVT (76), WPW (96) or palpitations. In 118 pts the NavX was used. In 102 of them short fluoro was needed. Ablation was completed with AO in 109 and TS in 77 pts. There were 38 patients in RTG+AO group, 16 in RTG+TS, 58 in NX+AO and 56 in NX+TS.

TS vs AO ablation. There were no difference in procedure duration (70±30 vs 73±32min) between groups. There were lower FT and D in TS group (9±11 vs 13±11 min. and 32±45 vs 66±168mGy) as well as the time to 1stAP and L_AP and lower N_AP and RF_T (24±13 vs 31±13 min,. 44±29 vs 53±28 min., 7,8±9,2 vs 10,1±9,4, 243±189 vs 274±232 sec.). The NavX significantly reduced the RTG parameters without change to ablation parameters.

The shortest procedure duration was for NX+TS (66±23 min.), with shortest FT (5,4±5,3 minutes) lowest D (22±41 mGy). The RTG+TS approach was technique with shortest 1stAP and L_AP, with lowest N_AP and total RF_T (22±11 min., 36±21 min., 4,9±4,3 and 192 ± 132 sec.).

The success rate for RTG+AO was 86%, RTG+TS 86%, NX+AO=100% and NX+TS=94%.

We conclude that transseptal approach can be recommended approach in pediatric population with left sided WPW. The implementation of NavX into routine RF ablation of left sided pathways reduces x-ray burden, improving success rate without sacrificing the procedure duration.

P483
long term follow up of victims of out of hospital cardiac arrest with first rhythm ventricular fibrillation treated with an ICD in secondary prevention

Abstract

Purpose: Victims of out of hospital cardiac arrest (OHCA) of presumed cardiac origin with a shockable first rhythm (ventricular tachycardia/fibrillation: VT/VF) have the greatest chance to survive at discharge with a good neurological outcome. Although implantation of an ICD is indicated in survivors of OHCA, little is known about the long-term arrhythmic recurrence rate, mortality, and cardiovascular events in this population. The aim of the study was to assess event-free survival in patients with OHCA due to VF only, who received an ICD in secondary prevention.

Methods: All OHCAs with first rhythm VF that occurred in Ticino, Switzerland, from 2002 to 2013, and subsequently treated with an ICD in secondary prevention were included in the current analysis. All-cause mortality, appropriate or inappropriate ICD interventions, and cardiovascular events (myocardial infarction, coronary revascularization, stroke, hospitalization for heart failure) were analyzed, according to ischemic or non-ischemic aetiology of cardiac disease, by means of logrank test.

Results: From 2002 to 2013 390 OHCAs occurred with VF as first rhythm; 57 (15%) survivors received an ICD in secondary prevention. Underlying disease was ischemic in 33 (60%) (group A) and non-ischemic in 24 (40 %) (group B). Median age was 63 years (84% male). Median ejection fraction was 40%. During follow up (median 48 months) 6 patients (10%) died, corresponding to a mortality of 1.8 per 100 person year (95%CI 0.8-4.0). IHD patients had a lower, though not significant, 5 year cumulative survival (85% vs 94%, p=0.20), a lower cumulative event free survival (76% vs. 89%, p=0.20) and lower cumulative non appropriate shocks-free survival (64% vs 91%, p=0.07). Conversely the cumulative probability of appropriate shock was higher in IHD patients (29% vs. 5%, logrank test p=0.038, hazard ratio=6.7, 95%CI 0.8-53).

Conclusions: Patients with OHCA due to VF who received an ICD presented a good long term survival with a relatively small number of events during follow up. In the subgroup of patients with ischemic aetiology a higher rate of ICD appropriate interventions was observed.

P484
Prognostic value of the epinephrine test following thoracoscopic left cardiac sympathetic denervation in patients with inherited arrhythmia syndrome

Abstract

Background: Inherited arrhythmia syndromes, such as congenital long-QT syndrome (LQTS) and catecholaminergic polymorphic ventricular tachycardia (CPVT), are associated with syncope, lethal ventricular arrhythmia, and sudden cardiac death. Left cardiac sympathetic denervation (LCSD) is an effective treatment option for these patients along with β-blocker and implantable cardioverter defibrillator, and. However, there is no standard test to evaluate the efficacy of LCSD. The purpose of this study was to investigate the epinephrine test for evaluating the efficacy of LCSD and for prognosis after LCSD in patients with inherited arrhythmia syndrome.

Methods: Patients who underwent video-assisted LCSD for inherited arrhythmia syndromes between November 2010 and May 2014 were retrospectively enrolled. Parameters of epinephrine tests in the periprocedural period and development of cardiac events during follow-up were analyzed.

Results: Nine patients with LQTS and one patient with CPVT (24.8±9.9 years old, 2 males) who underwent thoracoscopic LCSD were enrolled. All patients were taking high dose of β-blockers at the time of LSCD. Six patients experienced epinephrine-induced tachyarrhythmia before LCSD, whereas only one patient experienced epinephrine-induced tachyarrhythmia after LCSD (60.0% vs. 10.0%, p=0.063). Changes of QTc (ΔQTc) during the epinephrine tests were 49.33 ± 55.5 msec and 34.44 msec in pre and post-LCSD epinephrine tests, respectively (p=0.348). In post-LCSD epinephrine tests, one patient presented with polymorphic ventricular tachycardia and two patients presented with T-wave alternans (TWA). Of the three patients who presented with tachycardia or TWA in post-LCSD epinephrine test, one remained symptomatic and another underwent aborted cardiac arrest after LCSD. The seven patients who were stable in the post-LCSD epinephrine test remained asymptomatic after LCSD.

Conclusion: Epinephrine-induced tachyarrhythmia was reduced by LCSD in patients with inherited tachyarrhythmia syndrome. Instability in post-LCSD epinephrine tests might be associated with poor prognosis after LCSD in those patients.

P485
Re-evaluation of the left ventricular ejection fraction before ICD generator replacement: time for a systematic approach?

Abstract

Introduction: In patients with a primary prevention ICD, the risk of arrhythmic events seems markedly lower in case the left ventricular ejection fraction (LVEF) improves to above 35% during follow-up. This observation calls for corroborative analyses, which are difficult to perform as current ICD-guidelines do not recommend systematic re-evaluation of the LVEF. In that context, we examined the rate of LVEF assessment before battery replacement in our tertiary centre, and determined how often the LVEF had improved to above 35%. In addition, we explored factors that are associated with a recovery in left ventricular function.

Methods: Retrospective cohort of generator replacements in ICD-patients from the Radboud University Medical Centre, Nijmegen, The Netherlands. Patients studied had an ICD/CRT-D in the setting of primary prevention (LVEF ≤ 35%). Whenever available, the LVEF at the time of replacement was recorded. Baseline characteristics of patients with and without LVEF improvement were compared.

Results: Of the 95 patients studied, LVEF reassessment was available in 45 (47%). Out of these patients, 16 (36%) had an LVEF > 35%, of which 11 patients with an LVEF > 45%. Patients with an LVEF > 35% at the time of replacement more often had nonischemic heart disease (75% vs. 24%, p=0.001) and more often had a history of hypertension (75% vs 21%, p<0.001) as compared to the subset with an LVEF ≤ 35%. The LVEF at the time of initial implant (≈28%) and the proportion of CRT-Ds (≈80%) did not differ between the two groups.

Conclusions: Similar to previous reports, LVEF re-assessment was performed in about half of patients in case of generator replacement. Notably, when performed, recovery of the LVEF was seen in more than a third of patients, predominantly in case of nonischemic heart disease. These data underscore the need for systematic evaluation and subsequent follow-up of arrhythmic events to provide further insight for clinical decision making.

P486
Outcomes of patients with valvular cardiomyopathy after prophylactic defibrillator implantation

Abstract

Introduction and Aim: At the present time there is still lack of evidence regarding the evolution of patients with valvular cardiomyopathy referred for desfibrillator implantation for primary prevention of sudden cardiac death. We aimed to describe the follow up of this particular population using as reference those patients ischemic and non ischemic nor valvular myocardiopathy.

Methods: Retrospective multicenter study performed in fifteen Spanish hospitals. Consecutives patients referred for desfibrillator implantation (at least those performed in 2010 and 2011) were included.

Results: Over all 1173 patients, 73 (6,13%) had the diagnosed of valvular cardiomyopathy. When compared with those patients with ischemic cardiomyopathy (n=659; 56,1%) or non ischemic nor valvular cardiomyopathy (n= 442; 37,6%), this subgroup presented more advanced NYHA class, broader QRS and history of atrial fibrillation. During a mean follow up of 38,04 ± 21,35 months, 185 patients died (15,7%) without significant differences between groups (16,6%, 15,1% y 16,5% respectively; p=0,4). Of them, 116 were from cardiovascular cause (9,8%), again without significant differences between groups (12,5%; 8,9% y 10,9%; p=0,1). Finally there was neither difference regarding the rate of appropriate (15,7%) or inappropriate (9,1%) desfibrillator intervention.

Conclusions: Patients with valvular cardiomyopathy who undergo desfibrillator implantation for sudden cardiac death prevention have similar appropriate desfibrillator discharge rates and mortality as do those with ischemic and non ischemic nor valvular cardiomyopathy.

P487
Manufacturer change at the time of ICD replacement: italian survey and preliminary data from the DECODE study

Abstract

Introduction: Development of uniform standard among ICD manufacturers is mandatory in the era of rapidly changing technology and hardware availability. Although the interchangeability of the ICD systems is ensured by established and codified specifications, some barriers seem to be present in changing ICD manufacturer at the time of device replacement.

Methods: We evaluated the clinical practice of ICD/CRT-D system change during a 1,5-year time frame in 36 Italian centers. A nation-wide survey was administered to implanting physicians in order to assess what are the drivers for a Manufacturer Change. These results were compared with data of 929 consecutive device replacements performed in the same centers between March 2013 and November 2014, included in the Decode Study. The factors associated to a change of ICD manufacturer were analyzed.

Results: The reasons to change ICD manufacturer were: administrative in 36,3% of answers (cost of the new device 11,7%, device assigned by tender 24,6%); clinical needs in 57,3% (higher expected longevity of the new device 25,2%, remote monitoring 5,2%, physical characteristics–volume or shape–14,7%, specific algorithms/features 12,2%); recall/advisory 5,9%; other reasons 0,7%. In the real practice of the centers, 801 patients underwent device replacement and 126 patients received a device upgrade. Devices in analysis were 27% single-chamber (SC), 27% dual-chamber (DC) ICDs and 46% CRT-D. A system failure had occurred in 6,4%. A manufacturer change occurred in 261 cases (28%): 89 were SC ICDs (36%), 73 were DC ICDs (29%) and 99 were CRT-D (23%). Median longevity was 1792 (95% CI 1748-1841) days for CRT-D, 2095 (95% CI 2018-2161) days for DC ICDs and 2300 (95% CI 2193-2446) days for SC ICDs. System Failure, device type, longevity of replaced device, system upgrade, high left ventricular lead output (≥ 4,5V@0,5ms) and patient in remote monitoring were considered as potential influencing factors for changing ICD manufacturer. CRT-D (OR 0.69, 95% CI 0.5-0.96; p=0.028) was a negative predictor, whereas longevity below median values (OR 1.53, 95% CI 1.1-2.12; p=0.001) was an independent predictor of manufacturer change at the time of ICD replacement, at multivariate analysis.

Conclusions: At the time of ICD replacement, manufacturer change occurs in 28% of patients, mainly with devices exhibiting a lower-than expected longevity. Conversely, it is less likely to occur with CRT-D devices that are equipped with more specific technology and less frequently require addition of features. These findings agree with the physician's opinion captured by the Survey.

P488
Prevalence of subcutaneous implantable defibrillator (S-ICD) related complications in patients with congenital heart disease: results from a pooled analysis from the IDE study and EFFORTLESS registry

Abstract

Introduction: The Subcutaneous Implantable Cardioverter Defibrillator (S-ICD) has potential advantages for pts with congenital heart disease (CHD). However, the prevalence of S-ICD related complications is unknown.

Methods: A pooled analysis of 865 pts in the EFFORTLESS Registry (an international observational database) and the US IDE study was used.

Results: 19 CHD vs. 846 non-CHD pts with a median follow up of 567 & 639 days, respectively, were included. A total of 71 events (in 66 pts, 7.6 %) were identified. There were similar overall complication rates for both groups (10.5 vs 9.6% [p=0.89], Table) with inappropriate shocks for T-wave oversensing as the only complication in the CHD group (n=2). The rate of inappropriate shocks was similar for both groups (10.5 vs 10.9% [p=0.96]).

Conclusion: The cohort of CHD patient with an S-ICD shows complication rates to be comparable to non-CHD patients.

P489
Early impacts of right ventricular pacing on left ventricular strain and dyssynchrony

Abstract

Objectives: We aimed at demonstrating early impacts of right ventricular apical pacing (RVA) on left ventricular dyssynchrony (LVD) and left ventricular strain in patients with preserved EF and to assess that brain natriuretic peptide (BNP) after 2 months of implantation is correlated for LVD.

Methods: 40 patients with implanted (VVI) and (DDD) pacemakers were examined before implantation and after 2 and 6 months of implantation for BNP, left ventricular (LV) EF, S wave by tissue Doppler (S) , Myocardial performance index (MPI) and LVD. Speckle tracking was used to assess global longitudinal (GLS), radial (GRS) and circumferential (GCS) strains and to assess LVD by time to peak (TP) radial strain.

Results: There was no change in LV EF and S wave in the first 6 months of implantation in both groups. MPI increased after 6 months with P value of 0.001 for both group. Aortic preejection delay (APED), interventricular conduction delay and TP increased significantly in both groups. However only APED and TP were significant when comparing both groups together. GLS was significant in both groups but GRS was statistically significant after 6 month in DDD group (P = 0.005) and after 2 months in VVI group (P = 0.03). Mean BNP level in VVI pacing was higher than DDD pacing after two months with P value = 0.001 and P value = 0.023 after 6 months. BNP was correlated to APED (r = 0.651, P value = 0.001), TP (r = 0.404 , P value = 0.015) , GLS (r = 0.521, P value = 0.01) and pacing percentage (r = 0.687 , P value = 0.00)

Conclusion: RVA affects LV GLS early in the first 6 months when EF and S wave still normal. GRS was affected in VVI group earlier than DDD group after 2 months mostly due to loss of atrioventricular synchrony in VVI mode . BNP is correlated to LV dyssynchrony and pacing percentage.

relationship between BNP and pacing

P490
Intra-individual comparison of two algorithms for the reduction of ventricular pacing percentage in sick sinus syndrome: twelve-month results from the VIPERS study

Abstract

Purpose: Reducing unnecessary ventricular pacing prevents progression to permanent AF and improves long-term patient outcome. Modern pacemakers are provided with algorithms suitable for this purpose that are mainly based on two working principles: class 1 algorithms periodically search for intrinsic atrioventricular (AV) conduction prolonging the AV delay up to 400 ms; class 2 algorithms are based on a DDD-AAI mode switch, adopting AAI mode whenever spontaneous ventricular rhythm is detected and reactivating the DDD mode in case of ventricular conduction block. IRSplus and VpS algorithms belong to class 1) and 2), respectively.

Methods: The study is a prospective, multicenter, single-blinded, randomized clinical trial comparing IRSplus and VpS. Patients implanted with a dual chamber PM for sick sinus syndrome (SSS) have been enrolled. Permanent AF, second or third degree AV blocks were exclusion criteria. Patients were randomized in a 1:1 ratio to a DDD mode either with IRSplus or VP Suppression (VpS) algorithms. After 6 months patients crossed-over and the alternative algorithm was kept for the next 12 months.

Ventricular Pacing percentage (VP%), mean AV interval, atrial burden percentage and echocardiographic status were evaluated at 6-, 12- and 18- month follow-ups. Twelve-month follow-up data are currently available. Non-normal distributions are indicated as median (interquartile range). Wilcoxon signed-rank test has been used for the intrapatient comparison.

Results: A total of 230 patients (62% males, mean age 75 (69-79) years) have been enrolled. Mean ejection fraction was 57 (50-60)%, mean stroke risk index CHA2DS2VASc was 2(1-2). At the enrollment, most patients were in NYHA class I (57%) or II (40%). Main indications to PM therapy were brady-tachy SSS (75%) or SSS with syncope (15%). IRSplus and VpS algorithms provided a VP% of 1 (0-11)% and 3.5 (0-27)%, respectively (p = 0.001). AV intervals were 227 (202-254) ms with IRSplus and 216 (188-240) ms with VpS, (p =0.01). No significant differences were observed in atrial pacing percentage, AF burden, ejection fraction.

Conclusions: Twelve-month follow-up data show that both IRSplus and VpS algorithms are highly effective in reducing unnecessary ventricular pacing in the selected population. IRSplus achieved the lowest median VP% while ensuring a 1:1 AV synchrony.

P491
Long-term single-center experience with subaxillary approach in cardiac defibrillators implantation in young patients population

Abstract

Purpose: We describe our long-term experience with performing subaxillary approach for cardiac defibrillators (ICD) implantation in young patients. Aim of our technique was to minimize the esthetic impact of devices and reduce risk of lead lesions.

Methods: From 2003 to 2012, 22 patients underwent ICD implantation by subaxillary approach. All interventions were performed under general anesthesia. After skin incision along midaxillary line, a thoracic surgeon prepared the device pocket under the pectoralis major muscle. Axillary vein was punctured under radiological guidance by contrast medium injection. Cardiac leads were positioned according to standard methods. Finally, the device was located between inferior portion of pectoralis major muscle and sternum, in the sagittal plane, and between external intercostal muscles and pectoralis minor muscle, in the frontal plane.

Results: 22 single and dual-chamber ICD were implanted (mean age 30±11 years). All procedures were successful without acute complications; overall hospitalization was comparable to standard approach. During mean follow-up period of 58±24 months no deaths, infections or device migrations occurred. Two ventricular lead dislodgements requiring repositioning occurred within one month and one defibrillation lead fracture occurred five years after implantation. All patients were extremely satisfied with the esthetic result. As regard defibrillation lead performance, a mild rise in pacing threshold and a statistically significant decrease in pacing lead impedance were observed without any consequences (Table 1). Ten patients underwent elective device replacements (mean duration 61±13 months) without periprocedural complications.

Conclusion: Subaxillary approach is a safe and feasible technique which requires a simple surgical procedure, it improves esthetic impact and patients acceptance of devices and therefore their perception of illness.

P492
Follow up cost of patients subjected to cardiac rhythm management device implantation

Abstract

Purpose: The objective of the study is to estimate the follow up cost and its components (direct health-care, direct non-health-care and indirect costs) in patients subjected to pacemaker (PM) and implantable cardioverter-defibrillator (ICD) implantation.

Methods: A single-center, prospective, study which was conducted for one year's reriod. In total, 464 consecutive patients were recruited (370 were subjected to PM implantation, from which 240 initials, 130 replacements and 94 to ICD implantation, from which 80 initials, 14 replacements). Resource data were assessed at patients' enrolment in the study and at 6th and 12th months of patients' follow-up. Then, the annual patients' follow up costs were calculated using the bottom-up approach.

Results: The annual follow up cost for the patients who were subjected to PM implantation (initial or replacement) was found to be: The mean direct health-care cost (outpatient visits, hospitalizations, medication use and the cost of laboratory and imagining diagnostic examinations) was €1.386 (€1.069-€1.962). The mean direct non-health care cost was €359 (€207-€551). Finally the mean indirect cost was €71 (€70-€72). The mean (95% confidence interval) total annual follow-up cost for the patients who were subjected to PM implantation was € 1.816 (€ 1.433- € 2.421). The annual follow up cost for the patients were subjected to ICD implantation (initial or replacement) was found to be: The mean direct health-care cost (outpatient visits, hospitalizations, medication use and the cost of laboratory and imagining diagnostic examinations) was 2.279 (1743-3.081). The mean direct non-health care costs was €173 (€11-€386). Finally the mean indirect cost was €367 (€72-€802). The mean (95% confidence interval) total annual follow-up cost for the patients who were subjected to ICD implantation was € 2.819 (€ 2.115-€ 3.703).

Conclusions: The study provides unique data regarding the follow up cost and its separate components of patients with CRMDs in Greece. Moreover the findings indicate a low annual follow-up cost.

P493
Long-term performance of a MRI-conditional ventricular lead: Beflex MRI RF46D (Ventricular) and RF45D (atrial)

Abstract

Objective: The aim of this study was to assess the long-term electrophysiological properties and complication rate in a recently approved MRI-conditional leads: Beflex MRI RF45D and RF46D (Sorin Group).

Method and Results: We conducted a retrospective cohort study of 173 patients underwent implant of Sorin generator model Esprit (S, D/R ). The atrial lead (RF45D) was implanted in 91 patients and the ventricular lead (RF46D) in 132 patients (97 women and 126 men; mean age of 77, 3± 7, 9 years (range 50-90), and followed for up to 4 years (RF45D: Mean 855 ± 398; Median 788 days. RF46D: Mean 841 ± 434; Median 745 days). At all follow-up controls (1 and 14 days, and 3, 6, 12, 24, 36 and 48 months after implantation), pacing threshold at 0,35ms, R-wave amplitudes and pacing impedance were measured in bipolar lead configuration. At 3 years after implantation, the measured values were 0, 88 ± 0, 30 V (threshold); 3, 6 ± 1, 7 mV (P-wave), and 510 ± 95 Ohm (impedance) for RF45D leads, and. were 0, 84 ± 0, 27 V; 12, 3 ± 3, 6 mV (R-wave), and 631 ± 136 Ohm for RF46D leads During the entire follow-up period only three out 132 ventricular leads (2, 3 %) required invasive intervention, which was necessitated by dislocation. No insulation defects or conductor fractures were observed. Twenty three patients died during the 3-year observation period. None of the deaths was thought to be related to the pacemaker therapy. One patient upgraded to ICD-CRT stimulation. Four patients were lost to follow-up.

Conclusion: The studied Beflex MRI RF45D and RF46D leads offer stable and reliable clinical performance in the long-term and excellent electrophysiological values.

P494
Low dislodgement and phrenic nerve stimulation (PNS) incidences observed in new straight quadripolar LV leads

Abstract

Purpose: The Attain Ability Straight Model 4396 lead, released in 2009, was the first straight left ventricular (LV) lead manufactured by Medtronic. The shape was designed specifically for implanting in patients with small and tortuous veins. Since then, Medtronic developed a new generation of quadripolar LV leads which includes a straight shape (Attain Performa Model 4398) in the portfolio. We sought to compare the performance of the new Model 4398 leads to its predicate straight lead Model 4396.

Methods: Model 4398 leads were evaluated as part of the world-wide Attain Performa Quadripolar LV lead clinical trial. Implant procedure related data were collected. Adverse device effects were reported upon occurrence and were reviewed by an independent physician panel. Model 4396 leads were studied in a clinical trial prior to market release in the US. The Log-rank test was used to compare event rates.

Results: Among 317 subjects implanted with a Model 4398 lead, one lead dislodgement and 2 PNS complications were reported in a median follow-up time 6.6 months. There were 5 dislodgements and 3 PNS complications in 152 subjects implanted with the Model 4396 lead (Table, p=0.0073). Implant sites and vein sizes were comparable for the two cohorts (Table). Conclusion A significant improvement was observed comparing the Attain Performa Model 4398 quadripolar straight lead to its predicate Attain Ability Model 4396 dual electrode straight lead. Both dislodgement rate (0.3%) and PNS complication rate (0.6%) were extremely low. The Model 4398 straight lead is a valuable addition to the quadripolar lead family.

P495
Permanent cardiac pacing in infants and neonates. Long-term experience of a single center

Abstract

Introduction: In children with significant bradyarrhythmia permanent cardiac pacing (PCP) is necessary. In the youngest children epicardial leads are preferred. In our hospital out of 758 children with implanted pacemaker (PM) systems, 148 were infants and neonates. Our experience in PCP in the smallest patients is presented.

Material and Methods: In 148 children at ≤ 12 months of age, including 61 neonates, PCP were used. The indications for pacemaker implantation was heart block in 137 children (congenital in 70, post cardiac surgery in 64, post cardiological interventions in 2 and post RF ablation in 1 pt.) and dysfunction of sinus node in 11 children (congenital in 8 and surgical in 3 pts.) In 99 children congenital heart disease (CHD) was diagnosed, in 3 cardiomyopathy, 46 pts had normal heart. The mean patient's body weight at the PM implantation was 4105 g (1600-8500g). In all but one epicardial pacing was used, with steroid eluting leads in 122 children. VVIR pacing mode was used in 126, VVI in 7 and DDD in 15 pts.

Results: During the follow-up period (from 1 month to 25 years, mean 8,8 years) 39 (26,3%) children died, 35 of them had CHD, 26 were after cardiac operation, 3 pts. had cardiomyopathy, 1 boy long QT syndrome. Nowadays 9 pts. are adults, 55 children still have their first implanted system with good parameters, in 41 pts. PM was changed because of battery depletion. In 13 children pacing system was reimplanted, in 2 of them we changed VVIR system into resynchronization pacing because of progressive heart failure and they improved significantly. The mean time from the first PM implantation to the first pacing system changing was 55,9 months (6 - 129 months).

Conclusions: The main indication for permanent cardiac pacing in infants and neonates is heart block. The epicardial pacing system with steroid eluting lead gives good results and should be preferred in small children. Coincidence of complex CHD and bradyarrhythmia which needs pacemaker implantation significantly deteriorates the prognosis.

P496
optimization of rate-adaptive pacing in patients with hear failure

Abstract

Objectives: Chronotropic incompetence is one of the causes of heart failure (HF) in pacemaker-dependent patients. Adaptive-rate mode providing increase in heart rate (HR) during physical activity partly allows overcoming this problem. There are no universally accepted recommendations for optimization of rate-adaptive mode. The aim of the study was to work out an algorithm for selection of optimal rete-adaptive regimen in pacemaker-dependent patients with HF.

Methods: 52 patients with permanent atrial fibrillation,cardiac pacing in mode VVIR (rate-adaptive sensor–accelerometer) and HF were enrolled. The patients were divided in the intervention group (n=30) and the control group (n=22). Optimal maximum sensor rate (MSR) was estimated during non-invasive pacemaker stress-echocardiography (PASE). Coronary angiography was performed in case of stress-induced myocardial wall motion abnormalities. Chronotropic response to physical activity was assessed during cardiopulmonary exercise testing (CPET) on a treadmill according to CAEP protocol.In the control group the settings of rate-adaptive mode were programmed by experienced specialists.

Results: New or worsened myocardial wall motion abnormalities were observed in 18 patients (60%) during PASE. Among them 15 patients had normal coronary arteries,3 patients-significant stenoses.In patients with normal coronary arteries wall motion abnormalities may be caused by reduced coronary flow due to right ventricular pacing dyssynchrony. MSR was programmed 5 bpm below the threshold of stress-induced myocardial wall motion abnormalities.Inadequate increase of HR during CPET was detected in 27 patients (90%).These patients underwent correction of activity threshold and response factor (slope/gain) to achieve an adequate increment of HR up to 3-7 beats per minute (bpm) for 1 ml/kg/min of oxygen consumption (VO2)(Weber,1988).Repeated CPET after 3 months showed an increase in VO2peak (from 12,5±2,87 to 14,3 ±2,82 ml/kg/min),anaerobic threshold (from 10,04±1,79 to 11,34 ±2,17 ml/kg/min) and time of exercise by 2,83 min (p<0,0001 for all).Repeated Echo-CG showed improvement of diastolic function:reduction in the E/E' ratio from 11,7 ±3,2 to 10,3±2,9 (p=0,019),systolic pulmonary artery pressure from 44 ±13,6 to 39,5 ± 12,4 mm Hg (p=0,006) and left atrial volume index from 68,14±44,6 to 64,6±42,5 ml/m2 (p=0,072).There were no any significant changes in the control group.

Conclusion: In patients with HF optimization of rate-adaptive pacing using PASE and CPET provides an increase in VO2peak, improvement of physical tolerance and diastolic function.

P497
Long lasting ventricular pacing in patients with SSS increases left ventricle diastolic dysfunction and myocardial fibrosis even after DDD pacing upgrade

Abstract

In patients with SSS, atrial or atrioventricular pacing is the therapy of choice. In some patients ventricular pacemakers were implanted in the past and these systems were upgraded to DDD pacing over time. VVI pacing can be deleterious in terms of symptoms in SSS patients but moreover it can be harmful to the heart muscle.

The aim of the study was to assess the hemodynamic and structural consequences of long term ventricular pacing in patients with SSS and primary VVI pacemaker implantation and afterwards pacing system upgrade to DDD.

The study group consisted of 61 patients (44 F, 17 M), aged now 77+/-8 years, implanted with VVI pacemaker for 101+/-54 month, and then upgraded to DDD pacing lasting 57+/-41 months. The control group included 57 patients (35 F, 22 M), aged now 79+/6 years, implanted primarily with DDD pacemaker, with mean pacing time 96+/-38 months. Standard echocardiographic measurements were performed in both groups. Transmitral diastolic flow parameters were assessed as indicators of left ventricle filling pattern. N-terminal procollagen-III-peptide and N-terminal procollagen-I-peptide measurements were used as markers of myocardial fibrosis.

Results are shown in Table:

There were no differences in basic echocardiographic parameters such as LVEDD, LVESD, EF, LA. There was a trend towards greater percentage of paroxysmal atrial fibrillation in study group (35/61 vs 23/57, p=0,06).

Conclusions: Long lasting ventricular pacing in patients with SSS increases left ventricle diastolic dysfunction and myocardial fibrosis parameters. This could negatively influence the atrial arytmogenesis.

P498
Incidence of pneumonia following pacemaker implantation in the elderly

Abstract

Purpose: Pacemaker implantation is a common intervention for bradyarrhythmia, which is a disease associated with ageing. The outcome of elderly patients with pacemakers was assessed by retrospective review of medical and pacing notes, with an assessment of readmissions following pacing. We find an association between age at time of pacemaker implantation and incidence of postoperative lower respiratory tract infection (LRTI).

Methods: Retrospective audit of all patients undergoing implantation of first pacemaker, or change of pacemaker device, at an English district general hospital. Review of 164 consecutive case notes, post-procedural chest Xray and pacing notes, and subsequent admissions to hospital in the six weeks following implantation.

Results: The incidence of LRTI in the six weeks following implantation of pacemaker is 14/164, with mean age 85.1±1.6 years (95% CI: 81.6–88.6). In comparing patients of all ages, those who develop LRTI are significantly older (no LRTI: 78.9±0.8 vs LRTI: 85.1±1.6 years; p = 0.025, unpaired t-test). When limiting the analysis to patients aged 80 or above only, there was still a significant correlation between age and subsequent LRTI (No LRTI: 85.5±0.4 vs LRTI: 88.1±1.4 years; p = 0.049, unpaired t-test). There is no correlation between in-patient status and subsequent development of LRTI.

Conclusions: Elderly patients undergoing pacemaker implantation more commonly develop post-operative LRTI in the first six weeks following implantation. As part of routine care the ipsilateral forearm to the device is immobilised to prevent lead displacement. This may be a significant risk factor in the development of LRTI, and may be justification for empirical antibiotics in patients being paced over the age of 81 years old, based on our data.

P499
Influence of types of heart rhythm disorders into sexuality and sexual behaviors among men after pacemaker implantation

Abstract

In our previous research we documented that cardiac pacemaker implantation influence the attitude towards sexuality and sexual behaviors. There is no research evaluating how those problems depends on different types of heart rhythm disorders such as sinus node dysfunction (SND) or atrio-ventricular block (AVB). Aim of this study was to assess the influence of AVB or SND into attitude towards sexuality and sexual behaviors among men with implanted cardiac pacemaker.

Methods: 52 men (aged 57 ± 11) with heart rhythm disorders: 27 with SND and 25 with AVB were included into the trial. Patients with coexistence both heart rhythm disorders were excluded. Average follow-up from cardiac pacemaker implantation was 6.9 ± 4.2y. In all patients a measurements of sexual need was made based on validated the Mell-Krat Scale (SFK-M) and International Index of Erectile Function (IIEF). Total score in SFK-M for men is 52 but optimal value for population of Poland is 39. The erectile dysfunction was recognized when score was above 25 points, dysfunction orgasmic function, sexual desire and overall satisfaction were recognized when scores were below 7 and intercourse dysfunction below 10 score.

Results: All included men had one sexual partners–women and all had active sexual life. The average results obtained in Mell-Krat Scale (sexual need) was 34.7 ± 6.59 for SND and 31.6 ± 7.6 for AVB, p=0.11; NS. 14 (26.9%) of subjects included had results below optimal. The exact results of IIEF are presented in the table below. In most of areas, men with AVB had statistically worsen results if compare to the patients with SND.

Conclusions: Men with implanted cardiac pacemakers due to atrio-ventricular blocks had statistically more problems with erectile function, if compare to the men with sinus node dysfunction. Most of dysfunctions can be described as mild or moderate. Problems with orgasmic functions seem to be especially important in patients with AV blocks.

P500
Cardiac resynchronization therapy: left ventricular lead placement guided by coronary venous electroanatomic mapping

Abstract

Introduction: The implant of cardiac resynchronization therapy (CRT) devices driven by non-fluroscopic navigation systems demonstrates how an electroanatomical mapping of the coronary sinus for the optimization of the left electrode placement, is feasible. Purpose. Aim of this study was to evaluated the latest activated region in coronary sinus (CS) in patients underwent CRT devices implant.

Methods and results: 46 consecutive CRT patients (38 males, age 72.9±7.3 years) underwent intra-procedural coronary venous EAM using EnSite NavX. A guidewire was used to map the coronary veins during intrinsic activation and right ventricular (RV) pacing. The latest activated region were reported in Table 1.

Conclusion: Coronary venous EAM can be used intra procedurally to guide LV lead placement to the latest activated region. This approach especially contributes to optimization of LV lead electrical delay in patients with multiple target veins. Conventional anatomical LV lead placement strategy does not target the vein with maximal electrical delay in many of these patients.

P501
LV lead revision of anteroseptal and apical postions - it can make a difference

Abstract

Purpose: The impact of LV lead position as if affects response to cardiac resynchronization therapy (CRT) remains controversial. The purpose of this study is to assess the incremental benefits, if any, of revising LV lead position in patients with a CRT pacemaker or defibrillator system where the LV lead is located antero-septally or apically.

Methods: Consecutive patients with a CRT pacemaker or defibrillator referred for a generator change or upgrade to ICD were included. All patients had to a standard original indication for CRT, including a history of dilated or ischemic LV dysfunction, QRS width ≥ 120 msec and were on optimized medical therapy. LV lead position was assessed by antero-posterior and lateral chest x-ray and biplane fluoroscopy. Patients with either an apical or anteroseptal location of their LV lead underwent lead revision with a targetted lateral basal or mid segment location (American Society of Echocardiography model) at the time of their procedure. Baseline clinical and quantitative echocardiagraphic assessment was perfomed and repeated after 6 months follow-up. Patient with a reduction in end sysltolic volume (ESV) ≥ 15% and/or increase in ejection fraction (EF) ≥ 5% were considered incremental responders.

Results: Thirteen patients, mean age 67.5±4.0 years, five with ischemic cardiomyopathy and 8 with a dilated cardiomyopathy underwent LV lead revision. Eleven patients had an antero-septal lead and two patients had an apical lead location. In 12 patients, the new LV lead position was successfully acheived at a lateral mid or basal cardiac segment. One patient developed rapid, persistent atrial fibrillation during follow-up and underwent cardioversion and AV node ablation. Nine (9) of the 13 patients, (69%), met the criteria for incremental response. These patients had a baseline EF of 22.9% ± 3.6 SEM and ESV of 146 ±33.2 mL SEM versus a six month EF of 35.7% ± 4.1 and ESV of 117.9 ±29 mL. Of the four patients who did not respond, the baseline EF and ESV was 25.4 % ± 3.3 and 134.3 ±34.1 mL versus 22.5% ±5.1 and 165.7±31.4 mL at six months. Eight of the nine echo responders experienced clinical improvement. One patient ultimately developed a pocket infection and underwent device extraction and re-implant on the contralateral side.

Conclusion: Patients with CRT systems and an antero-septal or apical LV lead may benefit from LV lead revision. Further assessment of this approach with a larger, randomized, controlled trial is warranted.

P502
Ventricular lead position and mechanical dyssynchrony in response to cardiac resynchronization therapy

Abstract

Purpose: To evaluate both the influence of baseline left ventricular (LV) mechanical dyssynchrony and ventricular leads location on long-term outcome in patients with cardiac resynchronization therapy (CRT).

Materials and Methods: A retrospective study including 40 patients in sinus rhythm with CRT implantation according to the current guidelines. Two groups were taken: group I, N=20, with high response to CRT, group II, N=20, with low response to CRT (non-responders). High response was defined as >15% decrease of end-systolic LV volume (LVESV), 10% relative increase of LV ejection fraction (LVEF), an improvement of at least 1 NYHA functional class (FC) of heart failure. Right atrial (RA) lead was implanted into the RA appendage, right ventricular (RV) lead - into the interventricular septum (IVS) or in the RV apex, LV lead - into coronary sinus veins. Ventricular leads position was assessed using ECG vector analysis during the isolated LV/RV pacing for the observation period. LV mechanical dyssynchrony was evaluated with tissue Doppler imaging before CRT implantation and in 12 month follow-up (FU). 12 LV segments were used to determine both LV lead location and the latest mechanical LV activation zone. Leads location to each other was assessed according to the 12 LV segments and 3 RV segments. The mean duration of FU was 12±1.7 months.

Results: Baseline patient group characteristics had no differences in gender, age, NYHA FC and echocardiography. Biventricular pacing was ≥95% during the observation period. Ischemic cardiomyopathy was obtained in 52.5% (N=21) of all patients, and significantly prevailed in Group II, p=0.014. Number of latest mechanical LV activation zones was bigger in Group I, p=0.051. Overlap of LV lead location and the latest mechanical LV activation zone was bigger in Group I, p=0.028. Comparison of three conventional interlead location (IL) schemes to the dynamics of the LV volumes and LVEF showed that the biggest IL was associated with the biggest LVESV reduction and LVEF increase, r=0.410 (LVESV/IL), r=0.493 (LVEF/IL), p<0.05. After 12 month FU there were significant improvement in LV diameters, volumes, LVEF and NYHA functional class in Group I, p<0.001. In 12 month FU the absence of mechanical dyssynchrony in Group I was 95% vs. 80% (Group II) without statistical differences. Conclusions: Placing the LV lead concordant with the site of the latest mechanical LV activation was associated with superior response to CRT during long-term FU. Baseline mechanical dyssynchrony and interlead location can be predictors of the better CRT response.

P503
Anatomical and electrical interlead distance predict outcome in cardiac resynchronization therapy patients

Abstract

Introduction: Approximately one third of CRT recipients do not respond to the therapy. Procedural strategy may play a pivotal role in obtaining CRT response.

Methods: From the CRT MORE, 216 patients with left bundle branch block and sinus rhythm who received CRT, were included in analysis. At implantation the electrical inter-lead distance (EID), defined as the time interval between spontaneous peak R-waves of the same QRS complex detected at the RV and LV pacing sites, was measured. The anatomical distance between the RV and LV lead was determined on chest X-rays in postero-anterior and lateral views. A positive clinical response was defined as “Improved” Clinical Composite Score at the 6-month follow-up. A positive echocardiographic response was defined as a decrease of at least 15% in left ventricular end-systolic volume (LVESV) at the 6-month follow-up visit in comparison with the baseline visit.

Results: The mean EID was 74±41ms and the mean horizontal corrected inter-lead distance (HCID) was 125±73mm. After 12 months, 138 (64%) patients were classified as responders according to the echocardiographic criteria and 87 (40%) patients were clinical responders. To investigate the ability of EID and HCID to predict clinical response, receiving operating characteristic curves analysis was performed. Optimal sensitivity and specificity were obtained at a cut off level of 84ms for EID (53% and 67%, respectively) and 90mm for HCID (80% and 48%, respectively). In a multivariable model, only baseline IED and HCID above best cut-off values were independently associated with the occurrence of cardiovascular hospitalization or death (HR [CI] 0.2628 [0.1106, 0.6244], p<0.05 for EID >84ms, HR [CI] 0.3289 [0.1731, 0.6252], p<0.05 for HCID>90mm). At 24 months, the rate of freedom from events was 94% in patients fulfilling both conditions, 88% in patients fulfilling one condition and 71% in patients with both variables below the stated cut off values.

Conclusions: Both anatomical and electrical RV-LV interlead distance are predictors of CRT response. Positioning the LV lead at a site that results in EID>84ms and HCID>90mm seems associated with a very good outcome.

P504
Does CRT benefit heart failure patients with long PR-interval but no ventricular dyssynchrony by reducing mitral regurgitation?

Abstract

Introduction: Cardiac resynchronization therapy (CRT) is recommended for patients with left bundle-branch block (LBBB) and heart failure (HF). The utility of CRT in patients not fulfilling these criteria remains unclear. Prolonged PR-interval is common in HF patients. A sub-study of the MADIT-CRT trial found that prolonged PR-interval and non-LBBB ECG morphology was associated with response to CRT. We use a computer model to explore whether CRT can be beneficial in absence of baseline ventricular dyssynchrony, when the baseline PR-interval is prolonged. We further investigate the role of altered filling and mitral regurgitation (MR).

Methods: We used the CircAdapt computational model of the heart and circulatory system to simulate acute response to CRT in HF with lengthened PR interval. We performed simulations representing HF with relatively synchronous activation and PR interval ranging from 80 ms to 320 ms. We then simulated CRT with a programmed AV delay of 120 ms. Simulations were performed both in the presence and absence of MR. Response was calculated as %-change in both stroke volume (SV) and maximum rate of LV pressure rise LV dp/dt(max).

Results: Positive response to CRT was observed when baseline PR interval was above 210 ms and 250 ms in the presence and absence of MR, respectively (Figure). Greater % response was seen in SV than LV dp/dt(max). Response in absence of MR still occurred due to the decrease in AV delay causing a longer passive filling phase.

Conclusion: These computer simulations demonstrate that CRT can provide acute haemodynamic benefit by normalizing the functional PR-interval, even in the absence of baseline ventricular dyssynchrony. Response arose from both reducing MR and improving passive filling. These results warrant further animal and patient studies.

P505
Usefulness of ventricular sense response in last-generation CRT devices

Abstract

Introduction: Last generation CRT devices incorporate a system to maintain biventricular pacing in patients with atrial arrhythmias exceeding the lower rate of stimulation. During these arrhythmias, the CRTdevice senses the right ventricular activity and triggers a biventricular spike without delay, with zero V-V interval. The objective of our study was to determine the electrical effect of this stimulation mode.

Material and Method: Fifteen patients with last-generation CRT devices implanted, St Jude, Medtronic, Boston Scientific, were studied.

All patients had own rhythm, complete left bundle branch block (LBBB) and preserved AV conduction. Baseline elecrocardiogram was performed in all patients, as well as noninvasive synchrony index and curves using the Synchromax II method The QRS duration of resting electrocardiogram was compared to the duration with VVI pacing with a rate above the basal one and with the VSR (ventricular sense response) turned on. In order to activate the VSR the devices were programmed to VVI mode at a rate significantly lower than the basal rate. The absence of P waves sensing activates the VSR mode.

Results: The mean baseline QRS duration was 174 ± 20 msec. Equal to that observed in VSR mode. With the optimization of the CRT mean QRS was 128 ± 20 msec. The morphology of the basal wave and the stimulation with VSR mode were the same. However, in all cases Synchromax`s Curve 5 (optimal synchronization) was obtained) with normalization of the Synchrony Index.

Conclusion: In the group of patients studied, the VSR mode doesn't produce effect on the electrical resynchronization , both QRS duration and the morphology of the curves of electrical dyssynchrony, resulting totally ineffective.

P506
Multiple BiV stimulation combinations by using two RV leads improve potential for response to CRT: Results of the TriV HF ICD study

Abstract

Introduction: Cardiac resynchronization therapy (CRT) non-responder rates continue to be approximately 30%. To demonstrate the potential benefit of multiple pacing site combination options, the effect of three CRT pacing configurations with differing right ventricular (RV) stimulation sites were evaluated.

Methods: This randomized, feasibility trial evaluated three CRT pacing configurations with two RV lead positions - RV-apex ("BiV Apex"), close to His Bundle ("BiV His") and RV-apex+His Bundle ("TriV") - with a left ventricular (LV) lead. Changes in intraoperative LV dP/dtmax were evaluated and acute response was defined as an increase of ≥10% versus intrinsic rhythm. Chronic measures were assessed after 12 months of follow up and included the Packer Heart Failure Composite Response score, 6 minute hall walk (6MHW), echocardiographic, electrocardiographic and exercise tolerance parameters, B-type natriuretic peptide (BNP) and Quality of Life.

Results: Acute hemodynamic testing was completed in 34/39 patients and resulted in significant increases in LV dP/dtmax in each CRT configuration. 29 of 34 (85%) patients exhibited ≥1 configuration with significant acute response (dP/dtmax rise≥10%). During follow up Packer scores improved for the majority (73%) of patients, which was consistent with improvements in QRS width, 6MHW, BNP, ejection fraction, mitral regurgitation, NYHA class, Quality of Life, CPX workload and peak VO2. The chronic improvement rate as indicated by Packer's score did not differ between the three configurations (71% for BiV Apex and TriV, and 79% for BiV His).

Conclusions: Concomitant multisite pacing at the RV apex and nearby His bundle is feasible and effective and may provide an additional option for CRT non-responders.

P507
Response to cardiac resynchronisation therapy correlates with less appropriate ICD interventions and lower mortality

Abstract

Background: Among other effects, cardiac resynchronisation therapy (CRT) has the potential to permanently improve or even normalise ejection fraction (EF). In such responders, defibrillator back-up might be obsolete in the long run. Aim of this study was to correlate EF evolution with the incidence of arrhythmias during long-term follow-up.

Methods: 265 CRT-D patients in whom a device was implanted between February 2000 and March 2014 were identified; 90 (34%) patients had to be excluded as their follow-up was < 2 years. All available reports from CRT interrogation and echocardiographies were collected. EF values were pooled to yearly groups of ± 6 months. Ventricular tachycardia (VT) was > 170bpm and ventricular fibrillation (VF) > 230bpm. EF response was defined as increase to >40% at the last available echocardiographic control.

Results: We studied 175 patients, age 65±10 years, 85% male, EF 25±6%, 81% primary prevention, 87% in sinus rhythm. 40 patients (22.9%) died after mean 4.2 ± 1.9 years. Persistent response was registered in 69 (39%) and ICD therapies in 55 patients (31%). Responders were less likely to need appropriate ICD-therapy (14% vs. 42%, p = 0.0001) or to die (7% vs 33%, p < 0.0001). Cumulative 5-year survival was 95% and 73% in responders vs. non-responders and cumulative 3-year incidence of ICD therapy 14% and 35%, respectively (p value < 0.05). Of the 10 responder patients (14%) who had ICD therapies, none had such for VF and none improved to > 45%. 3 of them had VT therapy only in the first years, 3 of them 4 to 5 years after implant and with an EF of 35 to 45%, 2 of them 3 to 5 years after implant with an EF of 45% and the last 2 were implanted for secondary prevention anyhow.

Conclusion: Even though patients who responded to CRT have a significant lower risk of mortality and appropriate ICD-therapies during long-term follow-up, 14% experienced ICD-therapy. These results are not in favour of downgrading responders to CRT pacemakers, at least not if EF has not completely normalised.

P508
Association between right ventricular lead position and clinical outcome in cardiac resynchronization therapy: validation by cardiac computed tomography

Abstract

Purpose: The conflicting data on the benefit of a septal versus apical right ventricular (RV) lead position in cardiac resynchronization therapy (CRT) might be due to the inaccuracy of fluoroscopy-guided RV lead positioning. We aimed to compare clinical and echocardiographic outcomes in CRT patients with a septal versus free wall and a mid-RV versus apical RV lead position, respectively, after determination of the true RV lead positions by cardiac computed tomography (CT).

Methods: We included 179 consecutive patients with left bundle branch block undergoing CRT (mean age 71 ± 9 years, 39 female, ischemic heart disease 49 %, QRS width 174 ± 21 ms, left ventricular (LV) ejection fraction (EF) 25 ± 6% and LV end-systolic volume (ESV) 194 ± 70 ml, NYHA class II/III/IV: 47/50/3 %. A septal RV lead position was intended in all patients as guided by procedural fluoroscopy. All patients underwent post-implant cardiac CT to assess accurate RV lead position in a simplistic RV segmentation dividing the RV long-axis into equal thirds (basal, mid-RV, and apical) and the short-axis into a septal and free wall region. Clinical and echocardiographic follow-up was performed after six months.

Results: The RV lead position was septal in 87 (49 %) and free wall in 92 (51 %) patients, and in the mid-RV and apical segments in 71 (40 %) and 108 (60 %) patients. No RV leads were anchored in the basal RV segments. Comparing patients with a septal versus free wall RV lead position, NYHA classification improved ≥ 1 class in 52 % versus 59 % of patients (P = 0.35). Mean increase in EF and reduction in ESV were comparable between the two groups (11 ± 9 vs. 12 ± 9 % [P=0.24] and 32 ± 25 vs. 36 ± 21 % [P = 0.22], respectively). In patients with a mid-RV and apical lead position NYHA class improved in 58 % and 54 % of patients, respectively (P = 0.60). Mean increase in EF and reduction in ESV were similar between these two groups (12 ± 9 vs. 12 ± 8 % [P = 0.67] and 34 ± 23 vs. 34 ± 23 % [P = 1.00], respectively).

Conclusion: Despite targeting RV lead placement to the septum during CRT implant, the true RV lead position is RV free wall in a large proportion of patients as verified by cardiac CT. Clinical outcome and reverse LV remodeling after CRT were not associated with RV lead position.

P509
Small-caliber lead failure after generator exchange

Abstract

Introduction and Objectives: Sprint Fidelis defibrillator lead (Medtronic) was recalled in 2007 due to an increased risk of failure. Generator exchange (GE) procedure has been associated with the development of Fidelis lead dysfunction. The aim of this study was to compare the rate of dysfunction during de first year after GE between Sprint Fidelis and not recalled leads of the same manufacturer.

Methods: Multicentre retrospective study involved patients from UMBRELLA database who underwent GE with previous normal lead function and minimum follow up of 1 year after the procedure. The incidence of lead dysfunction was determined via remote monitoring and defined as pacing impedance >1500 ohm, high-voltage impedance >100 ohm, R wave sensing under 2 mv or noise.

Results: A total of 531 patients were included. Results are shown in Table. The incidence of Fidelis dysfunction was 3,5%. No significant differences were found between Fidelis and the others in survival analysis (Log-Rank 0,002, p=0,962)

Conclusions: In our population, the incidence of Sprint Fidelis lead dysfunction after GE was lower than previously reported and no significant differences were found compared with the other leads. A study limitation is that our Fidelis cohort was highly selected with normal behaviour after a mean time of 5 years after the implant and therefore with a theoretical low probability of dysfunction. This may have influenced the results

P510
Lead extraction experience with high frequency 80 Hz laser sheaths

Abstract

Purpose: Laser lead extraction is a challenging procedure, especially in patients with old or multiple pacemaker (PM) or implantable cardioverter defibrillator (ICD) leads. The mechanical force is a leading cause of complications during the extraction procedure. Use of new laser sheaths, which deliver a rate of 80 pulses per second, can probably reduce intra-operative adverse events by reduction of extraction force.

Methods: Between January 2012 and October 2014, 157 PM and ICD leads were treated in 80 patients using high frequency 80 Hz laser sheaths. Indications for lead removals were pocket infection (45.0%), septicaemia or endocarditis (28.75%), lead dysfunction (22.5%) and upgrade from PM to ICD (3.75%). Data on procedural success rates, intra- and postoperative outcomes, as well as 30-day mortality were collected into a database and analysed retrospectively.

Results: The mean patient age was 62.1 ± 17.8 years (range 18-85), and 72.5% were male. The mean time from initial lead implantation was 99.5 ± 63.5 months (range 24-321). Eighty one (51.6%) PM and 76 (48.4%) ICD leads had to be extracted. The mean procedural time was 68.5 ± 26.2 min (range 30-109). One hundred and fifty three of 157 leads (97.45%) were completely removed. The overall complication rate was 2.5%, including one major (superior vena cava perforation) (1.25%) and one minor (pocket haematoma) (1.25%) complication. No death occurred during the 30-day follow-up.

Conclusions: The high frequency 80 Hz laser sheaths allow for safe and effective removal of chronically implanted PM and ICD leads, combining high procedural success with low complication rates.

P511
Device explantation due to infection - What are the causative microorganisms?

Abstract

Introduction: Device-related infections are a serious and life threatening complication after pacemaker and ICD implantation. With the increasing number of device implantations in patients with high comorbidity the number of these infections is continously growing. Both diagnosis and treatment of such infections pose a severe problem in tertiary heart centers. It is important to know the precise microbiological occurrence and resistance pattern of the patients, which was investigated in this study.

Methods: We examined retrospectively 557 consecutive patients (120 ♀, 417 ♂) who were referred to us with a device-related infection treated between March 2004 and June 2014. The diagnosis was based on either pocket erythema, erosion, abscess, persistent bacteremia and/ or positive blood culture or endocarditis with or without vegetation on the lead and/or cardiac valve.

Result: Of 557 (mean age 70 years ± 12) patients with proven device-related infection, 326 patients had a pacemaker (10 CRTP), 229 patients an ICD (105 CRTD), 2 Optimizer®.

In 496 (89%) patients a microbiological assessment was done either from the explanted lead fragment or by analysis of the blood culture. In 321 patients (65%) we found a causative microorganism, 175 (35%) were sterile.

The causing microorganisms in our patient cohort were: 139 (43%) Staphylococcus epidermidis, 85 (27%) with Staphylococcus aureus, 52 (16%) coagulase negative Streptococcus, 45 (14%) with others, e.g. MRSA, enterococci, Pseudomonas.

168 (34 %) of these 496 patients with positive microbial occurrence had a multi-drug resistant bacteria (at least 3 different antibiotics and Oxacillin resistance).

Summary: Staphylococci is the most common proven bacteria causing device related infections, in our patient cohort in about 70%. We found a high rate of multidrug resistant bacteria, which was higher than we previously expected. A complex therapy with device explantation and adequate antibiotic therapy depending on the resistance pattern is often necessary in these cases. Because microbial occurrence can only partially be found in lead fragments after device explantation due to persistent antibiotic therapy, blood cultures should be taken early prior to initiation of antibiotic therapy.

P512
Safety and effectiveness of transvenous extraction of pacemaker and implantable cardioverter-defibrillator leads in patients under or over 80 years of age

Abstract

Background: In contemporary practice, the proportion of elderly individuals in the population is growing and the need for percutaneous transvenous lead extraction in elderly patients has been increasingly required. The elderly have more risk factors than younger patients needing lead extraction. However, the safety of lead extraction for elderly patients remains unclear.

Methods: Between 2005 and 2014, we collected data of 250 consecutive patients who underwent percutaneous transvenous lead extraction and compared incidence of major adverse events (MAE; death, myocardial infarction, stroke, cardiac tamponade, Pulmonary Embolism, blood transfusion or pneumohemothorax ) between patients <80 years and patients ≥80 years old. The primary endpoint of this study was incidence of MAEs after procedure. The secondary endpoint was hospitalization period.

Results: There were 68 patients (27.2%) with age ≥80 years and 182 patients (72.8%) with age <80 years. The most common indication for lead extraction in elderly patients was infection (97.1%). All patients underwent successful transvenous removal of endocardial leads. Two of 68 patients (2.9%) had evidence of MAE in elderly patients. No significant difference of MAE was found in the elderly group (2.9vs.2.2%, P=0.921). There was no difference in hospitalization periods between those age ≥80 years and age <80 years (37.9±31.3days vs 31.4±27.4days, P =0.105).

Conclusions: In elderly patients, percutaneous transvenous lead extraction could be performed safely without prolonged hospital stay.

P513
Relations between syncope-induced brain injury and coagulation changes during positive head-up tilt test in patients with vasovagal syncope

Abstract

Syncope is an effect of temporal, global hypoperfusion of brain. It is known that even short episodes of circulatory arrest may lead to brain injury. Some release of brain injury markers - neuron-specific enolase (NSE) as well as clotting disturbances was described in relation to tilt-test (HUTT) induced syncope in patients with vasovagal syncope.

Aim of Study: Evaluation of injuring influence of vasovagal syncope (VVS) on the brain evaluated by release of NSE, in relation to clotting changes during HUTT in pts. with VVS.

Study population: 90 pts. (58 women) aged 17-76yrs (mean age 36,1), with VVS, referred to HUTT.

Methods: All pts. underwent standard HUTT. All pts. lies at supine position by 30 minutes after antecubiltal vein canniulation. Blood sample for NSE evaluation was collected before and 1 hour after HUTT. Before HUTT and at the onset of HUTT-provoked syncope blood sample was collected for analysis of clotting parameters: prothrombin time (INR), activated partial thromboplastin time APTT, serum concentrations of fibrinogen (FIB) and d-dimer (d-Dim).

Results: HUTT was positive in 77 pts. (85,6%). Significant increase of NSE level after HUTT in all pts. With HUTT-induced syncope, (3,2 vs. 4,5 ng/ml; p<0,01) was observed. There were no significant increase of NSE in pts. with negative HUTT. Substantial increase of serum levels of FIB (3,0 to 3,3 g/l p< 0,006), d-Dim (258,0 vs 398,0 ug/l; p<0,001), with decrease of APTT (31,2 to 26,6 s; p<0,0001) were observed in patient fainted during HUTT. Correlation between syncope induced rise of NSE and d-dimer level before HUTT (K=0,33; p<0,04) and after the test (K=-0,36; p<0,04) were found. It suggest that activation of fibrinolysis revealing by rise of d-dimer concentration may protect the brain injury related to the syncope induced by orthostatic stress.

Conclusions: Syncope induced by orthostatic stress during tilt test in pts. With vasovagal syncope is concerned both release of brain injury markers and induction of changes in clotting-fibrillation process.

Endogenous activation of fibrinolysis during HUTT-induced syncope, revealing by rise of d-dimer concentration, may protect against of brain injury related to clinical circumstances in patients with vasovagal syncope.

P514
Exercise-induced syncope: mechanism and clinical outcomes

Abstract

Purpose: Evaluation of syncope occurring during exercise pose a significant diagnostic challenge. This condition is considered a predictor of poor prognosis and it is of critical importance to exclude potential life-threatening disorders. However, few studies with a small number of patients have addressed this question. The aim of our study is analyze the diagnosis and long-term evolution of patients who suffered an exercise-induced syncope of unknown etiology.

Methods: All consecutive patients evaluated by our Syncope Unit in the setting of a Syncope Protocol in the Emergency Department were prospectively included in our database. We selected all patients who suffered syncope during exercise and analyzed diagnostic tests carried out, final diagnosis and clinical outcome during a long-term follow-up.

Results: 324 patients with syncope of unknown etiology after initial assessment were evaluated in a 5-years period (2005-2010). 22 of them (7%) referred syncope associated with exercise (mean age 43 SD 17 years, 16 male). None of them had previous history of heart disease. Baseline ECG was normal in 18 (82%). Echocardiogram was performed in all patients, being unremarkable in 20 (91%); in other 2 cases severe aortic stenosis and pulmonary embolism with right ventricular acute dysfunction were found. Treadmill test was performed in 18 patients, unremarkable in all cases but one, where severe ischemia was suggested. Coronary angiography confirmed significant lesion in LAD. 24-hour monitoring was performed in all patients without positive findings. Head-up tilt test was performed in 18 patients, 12 with positive response (66.6%). At five years, none of the patients experienced arrhythmic events or died.

Conclusion: The syncope of effort without apparent cause after an initial assessment turned out to be benign in a high percentage of cases. Despite a low diagnostic yield a protocoled cardiac study is mandatory to detect potentially malignant condition. Neurally-mediated syncope remains the most common causes of syncope even during exercise and should be taken into account in the differential diagnosis. Tilt table test may be very useful to establish the mechanism of syncope in these patients.

P515
Evidence of transmural activation recovery interval gradients in intact human cardiac restitution studies

Abstract

Purpose: The action potential restitution properties of the heart govern the potential risk of arrhythmia. Although restitution is known to vary with different protocols, little known about how this behaviour varies by pacing different regions of the the intact human heart.

Methods: Restitution was studied in 10 patients (60% female) with structurally normal hearts. Decapolar diagnostic EP catheters were placed in the anterior Right Ventricle (RV) and lateral the left ventricle (LV) in an apico-basal orientation, and epicardially via the LV branch of the coronary sinus (CS) for transmural measurement. Pacing was conducted from each site at basic cycle length (BCL) of 600ms, followed by S1-S2 restitution protocol. Activation recovery intervals (ARIs) were recorded as a surrogate of action potential duration, starting with S2 stimulus at 1000ms and decrementing to refractory period of the tissue.

Results: Mean age was 45 ± 15yrs. Loess regression, with 95% confidence intervals of restitution, showed shorter LV epicardial ARI's throughout restitution when compared with the LV endocardium (Mean Transmural ARI gradient 30ms, p<0.01 )(Fig 1.). Apico-basal ARI's in the RV and LV endocardium showed no significant gradient. Restitution slope gradients were >1 in 62% of tracings (median 1.6 ± 0.14).

Conclusion: Transmural ARI gradients within the LV are present in normal patients, without significant apico-basal ARI gradients. Restitution slopes appear to be steeper than> 1 in normal healthy ventricles. This data has important implications in modelling conduction-repolarsation kinetics in the intact human heart.

P516
Electrophysiological markers that can guide high rate pacing to avert occurrence of Torsade de Pointes in the chronic atrioventricular block dog model

Abstract

Purpose: High rate pacing (HRP) is recommended in the guidelines to suppress Torsade de Pointes (TdP) arrhythmias. In the chronic atrioventricular block (CAVB) dog model, remodeling causes a reproducible incidence of TdP: within 5 minutes after dofetilide repolarization lengthens, spatial and temporal dispersion increase and subsequent single and multiple ectopic beats (s and mEBs) are followed by repetitive TdP episodes. The aim of this study was to investigate by what mechanism HRP averts TdP and what repolarization marker could be used to guide HRP.

Methods: Seven CAVB-dogs, ventricular paced at 60bpm, became inducible (defined as = ≥3TdP). In the second serial experiment, HRP (100bpm) was initiated after the first sEB. Surface electrocardiogram, right and left ventricular (RV and LV) monophasic action potential (MAP) were recorded and in a subset a multipolar electrode was introduced in the LV.

Results: HRP averted recurrent inducibility in 86%, 6/7 (p<0.05). Repolarization markers increased before the first sEB, increase in short term variability of repolarization (STV) was most abrupt. Seconds after capture of HRP all ectopy was alienated, accompanied by a decrease in repolarization markers (Table 1). Remarkably MAPD did not decrease in 3/6 successfully treated subjects. LV intraventricular dispersion did decrease directly.

Conclusion: HRP is very effective in averting TdP by decreasing spatial and temporal markers of repolarization. The abrupt increase in STV can be useful to guide HRP.

P517
Effect of myocardial ischemia on inferolateral early repolarization

Abstract

Background: In isolation, inferolateral early repolarization (ER) is associated with a small increase in arrhythmic risk. The amplitude of the J wave correlates with arrhythmia susceptibility. In acute myocardial ischemia, ER is associated with ventricular fibrillation. However, the effect of ischemia on ER has not been studied.

Methods: We retrospectively analyzed procedural ECGs of patients with ER undergoing a controlled, 1-minute coronary occlusion for collateral function determination. The ECG lead with the highest baseline J-wave amplitude (ER lead) was analyzed before (PRE), at 60 seconds of coronary balloon occlusion (OCCL) and 60 seconds after balloon deflation (POST).

Results: Fifty patients with ER in the pre-procedural ECG (90% inferior, 10% lateral) underwent 53 coronary balloon occlusions. Heart rate (p=0.765) and R-wave amplitude (p=0.618) did not differ between measurements.

At OCCL, the ER lead showed ST elevation in 26 (49%) cases (+0.115 mV±0.103 mV). In this group, J-wave amplitude (JWA) increased from PRE to OCCL (0.112±0.090 mV vs 0.211±0.112 mV, p<0.001), and was not different from PRE at POST (0.127±0.098 mV; p=0.132).

In 27 (51%) cases, the ER lead showed ST depression at OCCL (-0.055±0.042 mV). In this group, JWA decreased from PRE to OCCL (0.080±0.053 mV to 0.044±0.081 mV, p=0.004), and was not different from PRE at POST (0.094±0.066 mV; p=0.09). The change of JWA was related to the extent of ST deviation (linear regression analysis; r2 = 0.672; p<0.001).

Conclusion: In acute ischemia, the behavior of the J-wave amplitude parallels the behavior of the respective ST segment. This is consistent with the J wave being a phenomenon of repolarization.

P518
A novel mutation in beta-myosin heavy chain gene in a family with hypertrophic cardiomyopathy

Abstract

Purpose: Hypertrophic cardiomyopathy (HCM) can lead to sudden cardiac death (SCD), mainly due to ventricular tachyarrhythmia or ventricular tachycardia. At least 27 genes with over 450 mutations have been implicated in HCM, and those with the highest mutation frequency encode core sarcomere proteins, including cardiac-beta myosin heavy chain (MYH7; 15-25%), cardiac myosin binding protein C (MYBPC3; 15-25%) and cardiac troponin T (TNNT2;<5%). Our aim was to determine a causing mutation in these sarcomeric genes in a Turkish family with HCM and high-risk for SCD.

Methods: MYH7, MYBPC3 and TNNT2 genes were screened using array-based re-sequencing in proband. 10 members of proband's family with a positive history for HCM and SCD were evaluated with a physical examination, 12-lead electrocardiography two-dimensional echocardiography. The exon 22 of MYH7 gene was confirmed with Sanger sequencing in proband. All family members were genotyped using RFLP-PCR method (Figure 1).

Results: Mutation analysis of the proband has revealed a novel missense mutation (c.2464A>C, p.Met822Leu) in exon 22 of the MYH7 gene. Six family members were found to have the novel mutation, of 3 had severe cardiac hypertrophy. Other 3 cases with mutation were asymptomatic who were under 12 years old. Family members without mutation had no cardiac disease. According to Human Gene Mutation Database, this mutation has not been reported previously.

Conclusions: The identification of this novel missense mutation has important implications for elucidating the pathogenesis of familial hypertrophic cardiomyopathy. In addition, this result need to be validated by further functional studies and analysis of other family members.

Figure 1

P519
LQT syndrome: a new tool for risk stratification

Abstract

Since early 00, risk stratification of Long QT syndrome is based on QTc, gender and the genotype. However several Authors suggested additional associations between genetic variables and outcome and also the availability of genetic databases and genetic tools. Here we aimed at including this novel information in an improved LQTS risk stratification scheme.

Methods: We analyzed a cohort of 662 genotyped LQTS individuals (50% women, median age at first visit 21 years, with a median QTc of 482ms). The most informative set of variables were selected among QTc, gender, genetic locus, gene region, pathogenic prediction of Polyphen2 and SIFT using LASSO regression.

Results: The study cohort included 356 patients carrying missense variants on KCNQ1, 216 patients on KCNH2, 81 patients on SCN5A and 9 patients on KCNE1 (MAF<0.5% in EVS).By analysing the most informative set of variables(QTc, gender, genetic locus and gene region), we developed a LQTS-specific cardiac events risk score, which allows stratifying patients into three risk groups.

Survival analyses showed a statistically significant difference in terms of cardiac events free survival among the three score groups (p =2.37 x 10-13), with a probability of events before age 40y and in absence of therapy corresponding to 82.5%, 71.9% and 43% for low, intermediate and high risk groups respectively.

Cox regression showed an HR of 1.70 (p = 0.022)for intermediate and 4.1 (p = 4.59 x 10-11) for high risk. In particular, the proposed model allows an improvement from the "standard" scheme with a better classification of high- and low-risk groups (Fig.1).

Conclusions: We created a new prediction tool that can help in the interpretation of mutations and may drive physicians in the managment of LQTS patients.

Figure 1

P520
Positive inotropic support in acute cardiac decompensation - haemodynamic and arrhythmogenic effects of levosimendan and catecholamines combined treatment in experimental heart failure

Abstract

Background: Ca2+-sensitiser levosimendan became first-line treatment in acute systolic dysfunction besides catecholamines (CAs). We aimed to evaluate haemodynamic and arrhythmogenic effects of levosimendan (LEV) administered together with catecholamines (dobutamine, DOB; dopamine, DA; norepinephrine, NE) in a canine heart failure (HF) model.

Methods: HF (n=12) was induced by chronic right ventricular tachy-pacing (240/min), continued until acute cardiac decompensation. Two experimental groups of anesthetized (ketamine-midazolam) animals were constituted: Group I. - continuous infusion of LEV (0.1 g/kg/min iv.) combined with 10-10 minutes infusion of different CA doses: DOB3-6-12, DA4-8-16 és NE0,04-0,08-0,16 (μg/kg/min, iv.); Group II.–CAs were given in same doses without LEV. Measured variables: blood pressure (BP), left ventricular end-diastolic pressure (LVEDP), contractility (dP/dtmin-max), duration of monophasic action potential at 50%, 90% of repolarisation (MAPD50, MAPD90). Number of ventricular premature beats (VES), ventricular tachycardias were also counted.

Results: In Group I. LEV alone did not alter mean BP (105±13 mmHg) and LVEDP (28±5 mmHg). However, dP/dtmax, dP/dtmin (1779±313 and -1967±322 mmHg/s) were increased by 56±15, 49±15 D% (p<0,001). There was further increase in dP/dtmax with combination of LEVO and CAs, maximal effect was observed with LEV+DA16 (+73±19 D%, p<0,001). LVEDP tended to decrease during LEV+DOB12 and to increase at LEV+NE0,16 (ns). In the CAs-only group (II.) basal haemodynamic parameters (BP, LVEDP, dP/dtmax, dP/dtmin) did not differ from Group I. Moreover, CAs without LEV exerted cardiovascular responses similar to those in LEV+CA group.

Malignant ventricular arrhythmias or increase in VES occurrence were not observed in both groups. During LEV infusion LV MAPD50 decreased significantly (214±8 vs 242±9 msec, p<0,01), which was further shortened by LEV+NA0,16 (204±20 msec, p<0,02).

Conclusion: Co-administration of levosimendan and catecholamines elicited similar improvement in cardiac contractility to catecholamines given separately. This beneficial effect was not accompanied by malignant arrhythmias, despite of MAPD50 shortening during LEV infusion.

P521
The lung impedance monitoring in treatment of chronic heart failure: results of the LIMIT-CHF study

Abstract

Purpose: To assess the usefulness of intra-thoracic impedance monitoring (IIM) alerts in guiding medication therapy in chronic heart failure (CHF) patients (pts) to prevent HF hospitalisations/unplanned visits.

Methods: CHF pts with OptiVol® or CorVue™ capable ICDs were randomised to either the active group (IIM alarm turned on and diuretic dose increased by 50% for one week) or the control group (IIM alarm turned off). The primary endpoint was the number of HF hospitalisations per pt at 1 year. The NYHA class, 6 minute walk test (6MWT), BNP and Minnesota Living with HF (MLWHF) questionnaire score were collected at baseline and follow-up (f-up).

Results: 80 pts were included and 71 reached 1 year f-up (7 pts died, 1 pt was lost at f-up and 1 pt was excluded from analysis since the congestion data were not collected by the device). The baseline characteristics and study outcomes are shown in the Table. After a median f-up of 13 months (IQR 12-14), there were 1.72±1.45 alerts in the active group vs. 1.13±1.0 in the control group, p=0.07. In the active group 60.9% (42/69) of alerts led to increasing the diuretic dose. There was a total of 11 HF hospitalisations in the active group vs. 6 in the control group without significant differences in the number of episodes per pt (0.28±0.85 vs. 0.15±0.43, p=0.95). There were no unplanned HF visits in the active group vs. 0.08±0.27 per pt in the control group, p=0.08. There was a trend towards reduction in HF related quality of life scores in the active group.

Conclusions: In this study IIM did not reduce emergency treatment of HF however it seems to have a positive impact on quality of life. This technology may have a useful role in managing HF pts with implantable devices.

P522
Bundle branch blocks are due to longitudinal dissociation in the His bundle: Resolution of BBB by permanent His bundle pacing

Abstract

Introduction: Focal disease in the main body of the His bundle (HB) is the cause for majority of bundle branch block (BBB) patterns on EKG. Temporary distal HB pacing (HBP) has previously been shown to correct LBBB in high number of patients. Anecdotal reports have confirmed abolition of BBB by permanent HBP. The aim of our study is to report the incidence of correction of BBB during permanent HBP in patients undergoing pacemaker (PM) implantation.

Methods: Permanent HBP was attempted in 205 patients referred for PM implantation. Non-consecutive patients with QRS duration (d) ≥110 ms and BBB were included in the study. Patients with normal QRS or CHB were excluded. HBP was performed using the Medtronic SelectSecure 3830 pacing lead. Baseline QRSd, paced QRSd, correction of BBB and HB pacing threshold were recorded.

Results: Fifty-eight patients met the inclusion-exclusion criteria. Mean age 73.2±12 yr; men 64%, HTN 83%, DM 28%, CAD 36%, AF 41%, SSS 38%, AV disease 62%, RBBB 36, LBBB 17, IVCD 5). Permanent HBP was successful in correcting BBB in 48 (83%) patients. Underlying BBB was corrected by HBP in 33 of 36 (92%) patients with RBBB; 14 of 17 (82%) patients with LBBB; 1 of 5 (20%) patients with IVCD. Baseline QRSd improved from 142±16 ms to 125±16 ms. HBP threshold at implant was 1.6±1.2 V @ 0.5 ms.

Conclusions: Permanent HBP acutely corrected underlying BBB in the vast majority of patients with right or left BBB (47 of 53, 89%) compared to only 1 of 5 (20%) patients with IVCD. This suggests that focal disease in the main HB is the cause for BBB in the patients referred for PM implantation.This may have significant implications for pacing patients with heart failure.

Selective His bundle and RB Capture

P523
Age and gender features in pediatric patients with paroxysmal supraventricular tachycardia

Abstract

Purpose: The aim of the study was to assess the role of pediatric age and gender on the onset and the electrophysiological type of the paroxysmal supraventricular tachycardia (SVT).

Methods: 406 children (255 (62,8%) boys and 151 (37,2%) girls) underwent cardiac examination and were diagnosed with paroxysmal SVT. Tachycardia mechanism was verified during transesophageal pacing study in the vast majority of cases. 220 children underwent intracardiac electrophysiologic study and radiofrequency catheter ablation.

Results: 257 (63,3%) children had atrioventricular (AV) reentrant tachycardia with accessory pathways (AVRT) and 149 (36,7%) had AV nodal reentrant tachycardia (AVNRT). In 257 (170 (66,1%) boys and 87 (33,9%) girls) children with AVRT manifesting WPW syndrome was diagnosed in 106 (41,2%), intermittent–in 31 (12,1%), latent–in 11 (4,3%), concealed–in 109 (42,4%) patients. There were 85 (57%) boys and 64 (43%) girls with AVNRT. Children's age ranged from 0,2 to 17,9 years (12,4±3,5 years) at the moment of tachycardia identification. Three age periods were identified to have higher frequency of paroxysmal tachycardia manifestation: the first year of life, 7 years and 10-15 years. AVRT was 1,7 times more frequent than AVNRT. However, AVNRT was the most frequent tachycardia type in children of 7-8 years of age (58,5% vs. 36,3% in all of the children respectively, p=0,02), as well as in girls ≥13 years old (63,6% girls vs. 28,2% boys in this age-group respectively, p=0,005). AVRT in boys occurred twice as frequently as AVNRT with the frequency of boys in the group of children with WPW syndrome increasing with age (53,8% in ≤10 years age group compared to 74,5% in >10 years age-group, p=0,004). Conduction properties of the accessory pathways (AP) became poor over time in girls: maximal AP conduction rate decreased (r=-0,4; p=0,04) and there was a tendency for AP effective refractory period (ERP) increase (r=0,3; p=0,08). In boys, the conductive properties of the AP were stable and remained virtually unchanged with age. In children older then 13 years with AVNRT differences between fast pathway ERP and slow pathway ERP were more significant in contrast to younger children; this age group was predisposed to dual AV nodal physiology detection and AVNRT development.

Conclusions: Gender and age of pediatric patients affect the timing and the type of paroxysmal SVT development, likely stemming from gender difference in age-related changes of electrophysiological properties of AV conduction. Certain age periods carry high-risk probability in tachycardia manifestation.

P524
Exercise stress test in diagnostics of long QT syndrome in young athletes

Abstract

Background: It is known that stress tests may help to diagnose long QT syndrome (LQTS) without genetic testing. But it seems to be a big problem in to make an accurate LQTS diagnosis in young athletes, because many of them have got acquired QT prolongation.

Aim: to develop new additional simple methods of noninvasive LQTS diagnostics in athletes.

Methods: 100 healthy children and 220 athletes (footballers, gymnasts, biathlonists, hockey players, short-trekkers) including 168 boys 11-15 years old were examined using a bicycle test by Bruce protocol: incessant stage 25 Wt stepping test with synchronic ECG recording and manually evaluated durations of RR and QT interval and its derivatives–corrected QT interval, calculated by Basett and Fridericia formulas (QTc, FQTc), QTc and FQTc interval dispersion. Intervals estimation at rest, during exercise and at minutes 3-4 of recovery period.

Results: Young athletes had lower heart rate (HR) at rest with gradual increase at physical load, while untrained children had a “jerky” HR growth, but at maximal loading (150 Wt) HR in both groups did not differ. Athletes had higher values of QT interval duration at rest and at initial load stages (25-50 Wt), due to myocardial hypertrophy and bradycardia. At peak load significant QT reduction (QT “hyperadaptation”) occurred in athletes, while in untrained group minimal QT were noted during recovery. QTc interval duration calculated by Bazett's formula in both groups were somewhat increasing at the first load stage, beginning to decrease at the second exercise step, going down beyond the original level at load peak and resuming the initial level by minute 4 of the recovery. Maximal QTc was recorded at 25 Wt load, not exceeding 450-460 ms in untrained and 460-470 ms in sportsmen. Inadequate QT shortening (QTc at peak load > 400ms), absence of QTc restoration to the initial value by early recovery (QTc at min 4 of recovery > 450ms), and significant QTc prolongation (difference between maximal and minimal QTc during exercise and recovery > 80 ms) revealed signs of myocardial electric instability and required further examination for LQTS diagnostics. While 3 criteria had been used, LQTS (verified by genetic tests) were diagnosed in one girl.

Conclusions: Inadequate QTc shortening both at the peak of exercise and in early recovery periodas well as in combination with significant QTc prolongation during exercise test required additional examination for inherited or acquired LQTS diagnostics. These indices in combination with the other Schwartz criteria, were noted to be additional criteria of LQTS diagnostics in athletes.

P525
Pre-existing right axis deviation in patients with verapamil sensitive idiopathic left ventricular tachycardia

Abstract

Background: The origin of verapamil sensitive idiopathic left ventricular tachycardia (VS-ILVT) is usually located at Purkinje network in the left posterior fascicle. VS-ILVT can be successfully treated using catheter ablation at left ventricular mid-septal region. QRS axis in ECG often changes to rightward after successful catheter ablation.

Purpose: The purpose of this study is to clarify whether patients with VS-ILVT have a right axis deviation (RAD) prior to catheter ablation.

Methods: This study included 12 patients (28±12 years, range 10-57, 8 male) with VS-ILVT which was confirmed during catheter ablation. The QRS axis in 12-lead ECG during sinus rhythm were analyzed prior to catheter ablation, and were compared with 40 control patients (54±16 years, range 21-89,17 male) without structural heart disease.

Results: ECG axis prior to catheter ablation was significantly deviated to rightward in patients with VS-ILVT compared with control patients (78.9±30.9° vs 44.5±40.1° p=0.005), and QRS axis was over 90°in 6 of 12 patients with VS-ILVT (Figure). Successful ablation of VS-ILVT was achieved in 11 patients at left ventricular mid-septal region. ECG axis was further deviated to rightward in 5 of 11 patients, and the deepening or newly appearance of Q wave in inferior leads was recognized in 8 of 11 patients after a successful catheter ablation.

Conclusion: Patients with VS-ILVT had a significant RAD in a 12-lead ECG at baseline. This finding might be caused by the pre-existing degeneration of Purkinje network at the left posterior fascicle which may be the cause of VS-ILVT.

P526
Incidence and characteristics of tachyarrhythmias in young patients presented with acute myocarditis

Abstract

Purpose: Acute myocarditis may be associated with life threatening tachyarrhythmias and a poor outcome. The purpose of our study was to define the incidence and clinical characteristics of tachyarrhythmias in young patients with acute myocarditis.

Methods: We retrospectively reviewed all patients under 25 years of age who received a clinical or biopsy proven diagnosis of acute myocarditis from October 2002 to December 2014 at a tertiary care institution. Clinically significant tachyarrhythmias (CSTs) were defined as requiring treatment with antiarrhythmic medications and/or defibrillation.

Results: Seventy patients met the inclusion criteria (76% male, 22.4 ± 3.5 years). The diagnosis of myocarditis was made clinically with 43% (n=30) confirmed with biopsy. Eighteen patients required intubation and 38 were treated with inotropes. There were 18 patients with CSTs (4 supraventricular, 3 non-sustained VT, 11 sustained VT/VF). Cardioversion or defibrillation was required in 10/18 (55%). Patients with CSTs were more likely to have been treated with inotropes (16/18, 89%) than those without tachyarrhythmias. Twenty patients required mechanical support (IABP ,n=16,ECMO n=3,Impella n=1). Patients with CSTs were more likely to require mechanical support as compared to patients without. Twenty-two patients were transplanted and five died . Patients with CSTs were more likely to experience death or transplant as compared to patients without CSTs. When controlling for age and ejection fraction, CSTs remain a predictor of death or transplant. Left ventricular ejection fraction was an independent predictors of CSTs, while gender, CRP, ESR, and troponins were not.

Conclusion: Patients with acute myocarditis have a considerable incidence of clinically significant tachyarrhythmias. The morbidity and mortality is significantly higher in patients with tachyarrhythmias.

P527
Advancement in engineering technology with the potential to replace the 12 Lead ECG for rhythm management

Abstract

The 12 lead ECG is a routine bedside tool in cardiovascular assessment. A 12 lead ECG requires training to perform as well as further specialist analysis to interpret the cardiac rhythms. The standard 12 lead ECG is also limited by the time needed to undertake the screening, as it requires patient compliance and removal of upper garments.

The RhythmPadII is a novel ECG device which obtains six-lead ECGs, without requiring the patient to undress. The system uses advanced technology comprising of capacitively coupled electric potential sensors to optimise the signal to noise ratio during sensing, replacing conventional copper electrode sensors.

The aim of the SL-AF trial was to assess the ability of the RhythmPadII device to diagnosis dysrhythmias.

Methods: 171 patients attending clinics for routine 12-lead ECGs were screened in a prospective study.

Simultaneous recording of the RhythmPadII 6-lead ECG was undertaken sequentially from the standard 12-lead ECG.

The 12-lead ECGs and 6-lead ECGs were analysed by a Cardiologist, who was blinded to each set of ECGs and the automated diagnostic report produced by the RhythmPadII device.

Patient feedback was also obtained via a qualitative questionnaire.

Results: The RhythmPadII device successfully obtained 98.2% (168/171) multi lead ECGs.

84.2% of 12 lead ECGs showed normal sinus rhythm (NSR) with 7.6% sinus bradycardia, 3.5% atrial fibrillation and 2.3% sinus tachycardia. 1.8% were other types.

Blinded analysis of the multi lead rhythms showed 98.4% sensitivity for NSR, and over 96% specificity for sinus bradycardia, sinus tachycardia and atrial fibrillation, when compared to the 12 lead ECGs.

Automated analysis of the multi lead rhythms showed 92% sensitivity for NSR, and 100% sensitivity for atrial flutter, and 92% for sinus bradycardia, when compared to the 12-lead ECGs.

There was excellent patient feedback for the RhythmPadII. 97.6% patients felt the novel device was comfortable and recommended it. Comments centred around use of ease and lack of invasiveness for the patient.

Conclusion: The results show that the RhythmPadII utilises novel engineering technology to provide a reliable alternative to the standard 12-lead ECG in the detection and diagnosis of cardiac rhythms. The RhythmPadII has the potential for widespread utilisation, as it is quick, comfortable, and no undressing is required. Our findings demonstrate that this novel ECG technology may be effectively employed for screening for arrhythmias, including atrial fibrillation.

P528
Time course and characteristics of tachyArrhythmias

Abstract

Purpose: Ventricular tachyarrhythmia (VTA) have been frequently reported after implantation of left ventricular assist devices but there is no information on supraventricular tachycardias. The goal of this study was to examine not only the frequency but also characteristics of (supra)ventricular ectopic beats ((S)VEB), atrial flutter (AFL)/fibrillation (AF) and ventricular tachycardias (VT) after implantation of the Heartmate II.

Methods: Continuous rhythm registrations were obtained from 8 patients (7 male; 43±12years) during the first 5 days after Heartmate II implantation. Hospital records were analysed to examine late post-operative tachyarrhythmia. Hemodynamic parameters (mean arterial pressure(MAP), right atrial pressure(RAP), heart rate(HR) and ST-deviation(d-ST)) prior to VT episodes were compared with sinus/pacing rhythms (reference periods).

Results: VT (N=6), AF (N=3) and AFL (N=1) were pre-operatively present in 6 patients. VEBs were post-operatively observed in all patients. Frequent single VEBs (>10/H,N=90.111), V-couplets, V-runs, single SVEBs, SV-couplets, SV-runs occurred in respectively 42.2%, 34%, 20%, 3.9%, 2.6% and 1.4% of the recording time. Prior to VT episodes (N=121), MAP decreased, HR, d-ST increased and RAP remained unaltered. Postoperatively, 5 patients developed either VT (N=2), AF (N=1) or both VT/AF (N=2) during a follow-up of 18±14 months. PoVT were initiated by either by single VEBS (28%), V-couplets (15%),V-run (46%) or suddenly (11%).

Conclusion: Both atrial and ventricular tachyarrhythmia are frequently observed in patients after Heartmate II implantation despite improvement in cardiac hemodynamics caused by cardiac unloading.

P529
Effect smoothness priors regularization on quantitative estimate of heart rate variability parameters of normal subjects

Abstract

Purpose: Standard short-term (SST) (5-minutes) heart rate variability analysis (HRVa) in the frequency-domain (FD) implies the assumption of stationarity during the sampled intervals. Among detrending methods to remove slow non-stationary trends from the HRV signal before analysis the freeware Kubios software includes the "smoothness priors" (SP) regularization method, which is basically a time-varying high pass filter with adjustable cut-off frequency. We evaluated the effects of SP on quantitative estimate of linear and non-linear HRV parameters of healthy subjects (HV), using the freeware software Kubios 2.1, (Biosignal Analysis and Medical Imaging Group, Department of Physics, University of Kuopio, Finland.

Methods: 24-hours 12-lead Holter ECG recorded in 40 HV (mean age: 42±18). HRV analyzed in the awake (rest and activity) and sleep (NREM and REM) conditions, with Kubios 2.1. SSTHRVa according to ESC recommendations, in the time-domain (TD), frequency-domain (FD), and with non-linear (NL) methods [Poincaré plot (PP), Recurrence plot (RP), Detrended fluctuation analysis (DFA), Approximate entropy (AE), Sample entropy SE), Correlation dimension (CD)].

Results: At univariate analysis, SP induced statistically significant (p< 0.05) changes of TD: TINN (decreased) and SDNN/RMSSD ratio (decreased), and NL: RP (decreased); AE and SE (increased) parameters, but with different effects between NREM and REM sleep conditions. In the FD, VLF power (decreased), HF power (increased) and total power (decreased) were affected by SP, w/out significant changes of LF/HF ratio, in all conditions. All parameters with and w/out SP remained optimally correlated (Pearson R²: between 0.8 and 1, p<0.00001) with the exception of VLF frequency peaks. At multivariate analysis, only mean heart rate, LF and HF power in relative or normalized units, LF/HF ratio and NL PP sd2 and sd1/sd2 ratio, were independent identifiers of different physiological conditions (awake state, physical activity and sleep not affected by the use of SP.

Discussion: Slow linear or more complex trends within the analyzed time series are among artifacts inducing non-stationarity that can alter SSTHRVa and should be removed before the analysis. In this study Kubios SP regularization method (lambda =400) removed most VLF spectral power and enhanced significantly the HF and power, but without significant changes of LH/HF ratio, one of the usually accepted index of sympathovagal balance. However other TD and NL parameters were differently affected under different physiological conditions. Thus further research is deserved to guide appropriate use od SP.

P530
Utilization of echocardiographic tissue deformation imaging to differentiate idiopathic VT from ARVC

Abstract

Background: Differentiation of ventricular tachycardia with structural normal heart (idiopathic VT) from arrhythmogenic right ventricular cardiomyopathy (ARVC) is challenging especially in early stages. We sought to compare myocardial deformation imaging parameters in both conditions.

Methods: From 5/2010 to 5/2014, we recruited 13 ARVC patients diagnosed by the modified Task force criteria, 14 idiopathic VT patients (RV origin) and 16 controls. We performed standard transthoracic echocardiography to measure RV dimensions and systolic function (table), 2D speckle tracking to calculate strain and strain rate from the basal, mid and apical RV free wall segments.

Results: RV dimensions were significantly increased and RV function parameters were significantly reduced in the ARVC group. Strain and strain rate values were significantly lower in mid and apical segments of RV free wall in ARVC patients. (table)

Conclusion: Deformation imaging shows regional RV abnormalities in ARVC patients that are significantly different from idiopathic VT patients. This imaging modality has the potential to differentiate the two conditions.

P531
Usefulness of 7-days Holter monitoring in patients after pulmonary vein isolation- assessment of silent atrial fibrillation recurrences

Abstract

Atrial fibrillation (AF) is one of the most common arrhythmias observed in cardiological practice and is responsible for substantial morbidity and mortality. Pulmonary vein isolation (PVI) is a radiofrequency catheter ablation technique widely used in treatment of patients with AF, the effectiveness of PVI in patients with AF is still under intensive investigation. It is also well known, that a follow up based only on clinical symptoms has a limited value, the presence of asymptomatic (silent) AF after ablation procedure has been reported in many papers. Therefore, prolonged Holter recording seems to be very accurate method in the assessment of silent AF recurrences in such patients.

Purpose: The purpose of the study was to analyze the occurrence of AF episodes in standard 24-hours and continuous 7-days Holter recordings performed in patients after PVI.

Methods: The study population consisted of 75 highly symptomatic patients (52 men, age 51±9 years, all EHRA III) qualified to PVI. Patients with the left ventricle dysfunction or structural heart disease had been excluded from the study. During the follow-up 20 patients received beta-blokers, 4- amiodarone, and 14- other antiarrhythmic (mostly I class). Holter recordings were performed 6-9 months (median 7 months) after the procedure - continuous 7-days recording (H7) using Reynolds Pathfinder 700 system. Episode of AF was registered when the duration was >30 sec. Two AFs were regarded as one episode when the duration of sinus rhythm between them was <30 sec. We analyzed the presence of AF in the first day of Holter monitoring and in the entire recording (H7). Patients were asked to maintain a log of symptoms suggestive of AF, and the individual AF episode was classified as either symptomatic or asymptomatic.

Results: During the follow-up 40 patients (53%) (30 males, age: 52±10) were asymptomatic and free of AF episodes. AF episodes were found in 35 patients (47%) (22 males, age: 51±9 years). In AF+ group, 16 patients had AF in the first day of H7 and 34 patients had AF during the prolonged monitoring (between 2-7 day of H7), only one patient had AF in the first day of H7. Silent AF episodes were found in 8 patients (23%). All silent episodes were found during the prolonged monitoring (2-7 day of H7). There were also 5 patients, symptomatic during the follow-up, with no episodes of AF in 7 days Holter.

Conclusions: Continuous, 7-days ECG recording appears to be useful method in the assessment of AF occurrence in patients after PVI. It is a very useful tool in the detection of silent atrial fibrillation.

P532
Clinical profile and electrophysiological abnormalities of Adult Ebsteins anomaly

Abstract

Background: Ebstein's anomaly is a complex congenital anomaly with a broad pathologic-anatomical and clinical spectrum. Patients with Ebstein's anomaly who reach late adolescence and adulthood often have an excellent outcome. When Ebstein's anomaly presents in adults, the most common symptoms include exercise intolerance with dyspnea, fatigue, symptomatic arrhythmias and right-sided heart failure. Patients with mild Ebstein's anomaly may be asymptomatic with no functional limitation. adults often present with arrhythmias.

Methods: 40 cases of Ebstein's anomaly in adults with diverse presentations admitted in Cardiology department in different units of National Institute of Cardiovascular Diseases(NICVD), Dhaka from the period of August 2003 to December, 2013 were reported . Symptoms at their initial presentation along with radiography, electrocardiography, and echocardiography were analyzed.

Results: Among the 40 cases, male was 16 (40%) and female was 24 (60%), age group (16-55 years) mean age was 35 years, initial presenting feature requiring admission and cardiac evaluation was rhythm disturbances especially atrial arrhythmias (40%), (10%) cases WPW syndrome , junctional rhythm with intermittent sinus pauses (20%) and ventricular trigeminy (10%). Overt cardiac failure was the initial presentation in (10%patients), whereas 20% patients presented with NYHA functional class II dyspnoea and easy fatiguability. Rheumatic fever was present coexisting with Ebsteins anomaly in (5%). Two patients presented with congenital rubella syndrome with patent ductus arteriosus with Ebsteins anomaly. 5% patients who presented with inferior wall myocardial infarction on routine echocardiographic evaluation had Ebsteins anomaly. Two patients had cyanosis. Associated defects in these patients included ASD (25%), ASD with VSD (20%), PDA (5%) , RVOT aneurysm (5%), pericardial effusion (10%). All patients had low pressure tricuspid regurgitation (TR). Posterior leaflet displacement more than septal leaflet displacemenent was present in 20% patients. Anterior leaflet was not displaced in any of these patients. Celemajors index in most of the patients was in the range of (0.6-0.97). 3 patients had celemajor index of 1.5. Carpentier type 1 in 20% patients, in type II in 65% patients, type III in 10% patients, type IV in 5% patients. Cardiothoracic ratio ranged from 0.61 -0.71 and only one patient had a ratio of 0.85.

Conclusion: Ebsteins anomaly in adults can have diverse presentations.Symptoms due to Electrophysiological events were more prevalent than due to hemodynamic disturbances.

P533
Bleeding risk in patients treated with dabigatran or vitamin K antagonist for non-valvular atrial fibrillation : a meta analysis of matched analysis in routine care settings

Abstract

Background: Large randomized controlled trials have found that in non-valvular atrial fibrillation (AF), new oral anticoagulants had a favourable risk-benefit profile, with significant reductions in stroke, mortality and intracranial haemorrhage, but increased gastrointestinal bleeding. The comparative safety of dabigatran vs. vitamin K antagonist (VKA) for treatment of AF in routine care settings is a matter of debate in several countries. Therefore, we performed a meta-analysis of studies available, specifically those in which a matched analysis on baseline characteristics was available.

Methods: A Medline search until January 2015 documented 1146 entries for dabigatran and bleeding. Only publications with at least 1000 patients, a follow-up period with recording of major bleeding events and adjusted comparison with baseline characteristics were considered. In order to avoid overlap between studies and repeated data, we removed studies with subsequent and/or larger analysis. Chi-square test was used to assess heterogeneity among studies. In the presence of statistical heterogeneity, we analyzed the data by using random-effects models.

Results: Eleven analyses with 375,603 patients were identified and included in the analysis. After adjustment performed in each study, patients were divided into three groups: dabigatran 110 mg users (n=18,213, 5%), dabigatran 150 mg users (n=97,634, 26%), and VKA users (n=259,756, 69%). During follow-up, major bleeding events occurred in 5,452 patients (1.5%). In the whole population of AF patients, adjusted hazard ratio (HR) for major bleeding was 0.76 (95% CI 0.67-0.86, p<0.0001) for dabigatran compared to VKA. The adjusted HR for major bleeding events was significantly lower for patients treated with dabigatran 110 mg twice daily (HR=0.84, 95% CI 0.73-0.95, p=0.007) and for those treated with dabigatran 150 mg twice daily (HR=0.71, 95% CI 0.59-0.87, p=0.0006) compared to VKA.

Conclusions: In patients with non-valvular AF seen in general clinical practice, dabigatran was independently associated with a lower incidence of major bleeding (regardless of the anatomical site) compared with warfarin. These findings were similar for the 110 mg and the 150 mg dabigatran doses.

P534
Influence of rivaroxaban in comparison to warfarin on the laboratory measurements of coagulation assays and the circadian variation in patients with non-valvular atrial fibrillation

Abstract

Background: Compared with warfarin (WR), rivaroxaban (RB) has a relatively short half-life and peak and a trough blood concentration throughout the day. The ROCKET-AF study showed that RB was non-inferior to warfarin for preventing thromboembolic events in patients with non-valvular atrial fibrillation (NVAF).

Objective: To clarify the influence of RB and WR on coagulation assays and the circadian variation.

Methods and Results: The study enrolled 28 consecutive NVAF patients administrated with RB (n=13) and WR (n=15). Blood samples were collected 4 times a day (6 AM, 11 AM, 3 PM, and 6 AM the next day) and the prothrombin time (PT), PT-INR, and protein C level were measured in each patient. The PTs measured at each time for WR were significantly higher than those for RB (23.4 vs. 13.4sec at 6AM, 23.6 vs. 15.0sec at 11 AM, 23.8 vs. 14.1sec at 3PM, and 24.0 vs. 13.3sec 6AM the next day, respectively, P<0.0001). The PT-INRs measured at each time for WR were significantly higher than those for RB (1.99 vs. 1.20 at 6AM, 2.00 vs. 1.32 at 11 AM, 2.02 vs. 1.27 at 3PM, and 2.03 vs. 1.19 at 6AM the next day, respectively, P<0.0001). In contrast, the protein C levels measured at each time for RB were significantly higher than those for WR (52.3 vs. 103.2% at 6AM, 55.7 vs. 102.1% at 11 AM, 53.1 vs. 100.2% at 3PM, and 51.0 vs. 104.1% at 6AM the next day, respectively, P<0.0001).

Conclusions: The protein C levels, physiological anticoagulant factor, for RB were constantly and significantly higher than those for WR throughout the day as opposed to PTs and PT-INRs. These findings may explain the specific lasting anticoagulant effect of RB, and not WR.

P535
Respirate Project-2: a telemedicine-based project for ICD-CRTD patients involving HF specialist and general practitioner

Abstract

Background: The effectiveness of telemedicine in heart failure is not established. Several studies showed that Remote Monitoring (RM) of Heart Failure (HF) patients (PTs) with implantable cardioverter-defibrillators (ICDs) or an ICD for resynchronization therapy (CRT-D) can improve PTs clinical outcome by reducing the time to clinical decision in response to clinical events, the number of emergency department in-office visits and the mean length of cardiovascular hospitalizations. RESPIRATE-1 was a Remote Patient Management (RPM) pilot-project that involved both HF specialists and primary physicians (PP) and enrolled only 4 patients with CHF implanted with a device. RESPIRATE -2 followed the same program but involved a greater number of PP and was supported by the local healthcare business of Bergamo.

Purpose: The primary aim of this project was to develop, implement, and test the feasibility and efficacy of RM program (telephone support, network care and device-assisted monitoring), involving HF specialist and PP.

Methods: HF specialist (hospital HF clinic) and PP (outpatient clinic), in order to share clinical data and to track and share clinical decisions, used a remote access technology. When appropriate, a teleconsultation between the patient and the physician or nurse was allowed.

Results: 10 PP were trained about HF management and RPM. 6 transmissions (tx) per PT are scheduled on a monthly basis from June 2014 to November 2014 and CareAlert tx are activated. PP was the first clinical data reviewer. Clinical actions, if needed, were assigned to the appropriate physician, following shared flow-chart. During the study we reported: 60 scheduled transmissions, all co-managed by PP and HF specialist, with no need for pt's hospital access. 7 Alert Tx: 3 due to ICD shock on VF, that required patient's hospitalization; 4 of these due to fluid accumulation, all managed by PP in outpatient clinic. The concept of RPM was perceived positively by patients and physicians.

Conclusion: A remote HF patient co-management with PP seems to be feasible but requests clear and simple flow-chart. The acceptance by patients and primary physicians is necessary for the implementation of RPM via implantable electronic devices as part of the out-patient HF-care program.

P536
Gender differences in antithrombotic therapy in Europe: observations from the GLORIA-AF registry program

Abstract

Purpose: Women with non-valvular atrial fibrillation (AF) are at higher risk of stroke than men. Previous studies suggest that women were often undertreated with vitamin K antagonists (VKAs), but gender-specific data on practice patterns following the introduction of non-VKA oral anticoagulants (NOACs) are limited. Our aim was to assess antithrombotic therapy by gender in patients with AF in Europe.

Methods: GLORIA-AF is a global registry of patients with newly diagnosed non-valvular AF at risk of stroke (CHA2DS2VASc score ≥1). We evaluated initial antithrombotic therapy in European patients enrolled in GLORIA-AF between Nov 2011 and Feb 2014.

Results: In total, 4703 patients (median age 73 years; women 47.2%) were included in the analysis. Among women with CHA2DS2VASc scores = 1 (low stroke risk), 71.4% (n = 55) received oral anticoagulants (OACs), 11.7% (n = 9) received acetylsalicylic acid (ASA), and 15.6% (n = 12) received no antithrombotic therapy. For women with one risk factor for stroke (CHA2DS2VASc score = 2), the corresponding figures were 89.0% (n = 274), 6.8% (n = 21) and 3.6% (n = 11), respectively. For men with one risk factor for stroke (CHA2DS2VASc score = 1), the corresponding figures were 85.3% (n = 400), 6.0% (n = 28) and 8.5% (n = 40), respectively. In each gender at each level of stroke risk besides males with CHA2DS2VASc scores ≥5, NOACs accounted for >50% of initial OAC prescriptions. Further data are presented in the figure.

Conclusions: In the first years of NOAC availability in Europe, women with AF had high rates of NOAC use, similar to rates observed in men