Implantable defibrillator with left ventricular assist device compatibility

Abstract

Implanted defibrillator (ICD) and HeartMate-II (Thoratec, Pleasanton, CA, USA) left ventricular assist device (LVAD) incompatibilities have been reported. In order to show which ICD would function regularly in Heart Mate II recipients, we conducted a systematic review of 39 consecutive patients with implanted ICD and HeartMate-II from our institution's LVAD registry. Forty-six ICDs were identified without device interactions in most ICD devices. However, loss of ICD to programmer telemetry was observed in four patients with V-193, V-196 and V-350 (St Jude Medical, Sunnyvale, CA, USA) and one patient with an Ovatio DR (Sorin, Milan, Italy) requiring ICD replacement. The majority of all investigated ICDs operated without LVAD to ICD interaction. However, surgeons implanting the Heart Mate II in ICD patients should be aware of possible interactions and incompatible devices should not be recommended in HeartMate-II recipients.

1. Introduction

Left ventricular assist device (LVAD) implantation has become an alternative treatment option to urgent heart transplantation in end-stage heart failure patients with marked improvement of patient functional status as well as quality of life [1]. Ventricular arrhythmias have been reported in a high amount of LVAD recipients in retrospective observations of pulsatile LVAD device recipients with only little hemodynamic impairment in most patients during LVAD support [2,3]. The role of ventricular arrhythmias in smaller modern LVAD devices with continuous blood flow on the other hand remains unclear, since passive pulmonary perfusion and left ventricular filling may be impaired during arrhythmia. ICD therapy has become the treatment of choice for prevention of sudden cardiac death due to ventricular tachyarrhythmias in heart failure patients [4]. Many patients receiving an LVAD already have an ICD implanted or receive ICD implantation following LVAD implantation. Three case reports about interactions between an ICD and LVAD have been previously reported [5–7]. Incompatibility of the HeartMate-II LVAD (Thoratec, Pleasanton, CA, USA) and the Atlas V-193 ICD (St Jude Medical, Sunnyvale, CA, USA) lead to loss of ICD to programmer telemetry during LVAD support, requiring surgical ICD replacement. Another case was reported recently with an incompatible Ovatio VR single-chamber ICD implanted at the left pectoral region (Sorin, Milan, Italy), where normal ICD telemetry could be restored by displacement of the device and leads to the right pectoral region [7]. ICD incompatibility was caused by electromagnetic interference from the LVAD impairing telemetry communication from ICD to programmer [5,7].

2. Methods and results

Addressing the question of device compatibility, we conducted a review of all ICD devices implanted in LVAD recipients in our institution's LVAD registry, identifying 39 patients, who received LVAD implantation between July 2005 until January 2009 with the HeartMate-II and had ICD protection. Forty-six ICD devices were identified as presented in Table 1 . This number exceeded the number of patients due to device replacement operations for battery depletion in four patients. All patients had transvenously implanted endocardial ICD leads. We identified four ICDs which had to be replaced for device incompatibility, leading to loss of ICD to programmer telemetry immediately after implantation of the LVAD. These were one Atlas VR V-193, one Epic+HF V-350 and one Epic+VR V-196 (all St Jude Medical, Sunnyvale, CA, USA) and one Ovatio DR (Sorin, Milan, Italy). All four devices operated without error after explantation. Programming was unchanged to settings before LVAD implantation and when stored electrograms were printed and evaluated, it became apparent, that one device had sensed and treated ventricular tachycardia correctly by overdrive pacing during the incompatible period (Epic+HF V-350). However, except for lacking telemetry, no changes in ICD programming were documented and device function was not inhibited by electromagnetic interference. No artefact sensing was documented in ICD episode storage suggesting induction of noise sensing by HeartMate-II electromagnetic emission. Device incompatibility with loss of ICD to programmer telemetry was independent of LVAD settings. Different settings of LVAD revolutions per minute (RPM) could not restore ICD telemetry in any ICD case, while one previously implanted cardiac pacemaker in a HeartMate-II recipient (Affinity DR, St Jude Medical, Sunnyvale, CA, USA) could be successfully interrogated and programmed at 8200 RPM with loss of telemetry at 9400 RPM and 11,000 RPM with regular pacemaker function documented by ECG.

3. Discussion

The use of implantable defibrillators in HeartMate-II recipients is feasible without device interactions in most ICD generators investigated in our population. Loss of ICD to programmer telemetry could be observed in patients with HeartMate-II and St Jude Medical ICD devices, Atlas VR V-193, Epic+VR V-196 and Epic+HF V-350 and the Sorin Ovatio DR. All of the above incompatible ICDs use electromagnetic wands, which are placed near the device. None of the described incompatible devices had wireless telemetry features. Wireless radio telemetry was only available for a small number of devices, but this feature was not systematically investigated. Electromagnetic emission from the HeartMate-II LVAD interacts with the ICD to programmer telemetry [5]. This is likely to be associated with the electromagnetic wavelength of telemetry communication used in the incompatible device's telemetry, because newer generation devices from St Jude Medical work well using different telemetry frequency.

Implantation of the above-mentioned incompatible devices may therefore not be recommended in patients with implanted HeartMate-II or candidates for HeartMate-II implantation. Surgeons implanting the HeartMate-II LVAD should be aware of possible loss of ICD telemetry. We recommend deactivation of ICD tachycardia detection before LVAD implantation by programming instead of perioperative application of a permanent magnet for temporary inactivation, especially if one of the above ICDs is present before LVAD implantation. Alternative ICD devices should be used in LVAD patients who require ICD protection in order to prevent device incompatibility. Alterations in LVAD RPM settings may be tried in incompatible devices for restoration of ICD telemetry function. However, ICD device replacement will be necessary if unsuccessful. We would prefer ICD device replacement with a device known to be compatible in incompatible chronic ICD carriers over ICD and lead displacement as previously reported [7], since ICD lead revision may cause further complications in this population of progressive heart disease and rigorous anticoagulation.

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