Reply to Hanke et al.

I thank Hanke et al. for their interest and comments [1] about our recently published article of randomized comparison of left atrial (LA) and biatrial radiofrequency ablation [2]. This letter is in response to their comments.

1. The aim of LA ablation combined with cavotricuspid isthmus ablation is to achieve a totally bidirectional conduction block of LA. In our study, LA ablation lesions include isolation of the pulmonary veins, the mitral isthmus, the inter-atrial septum, the LA roof, the coronary sinus and cavotricuspid isthmus. Calò et al. also designed LA ablation combined with cavotricuspid isthmus [3]. Actually both of these were not the LA ablation alone. By using the terms LA and biatrial ablation is confusing indeed, but they were just different strategies. As the mechanism of AF, the concept of ‘trigger and substrate’ with left atrium as the predominant site for AF still remains valid. Most of atrial tachycardia following AF ablation arises from the LA. Patients may also experience typical atrial flutter arising from the cavotricuspid isthmus of AF [4]. Although bipolar ablation system has a better transmurality, there is still a conduction gap which may exist in mitral isthmus between LA and right atrium. So the LA combined with cavotricuspid isthmus ablation also could prevent atrial tachycardia after AF ablation.

2. As for the nomenclature, ‘long-standing persistent’ and ‘surgical ablation procedure’ are more appropriate than ‘permanent’ and ‘modified Maze procedure’, respectively in our study.

3. AF recurrence in the early postoperative period is not related to long-term success, but early recurrence of AF carries an independent risk of treatment failure and is necessary to be described in the result [5]. We evaluate the efficacy of AF ablation from the results of 24 h Holter after three months. The data of early AF recurrence might be valuable for the further study about the relationship between the early and the late recurrence of AF.

4. Although long-term continuous rhythm surveillance as well as usage of a defined nomenclature might be of an additional benefit, 24 h Holter monitoring is an acceptable minimal monitoring strategy for patients enrolled in a clinical trial and is recommended at three to six months intervals for one to two years following ablation. But it will increase the medical cost to the patient after valve and ablation surgery, especially in a developing country. Also in our opinion, pure sinus rhythm after AF ablation shows no clinic significance. For instance, if AF/flutter/tachycardia episode is present and lasts for only 30 s per year, does that means the AF ablation failed or is it necessary that we should do medical intervention with it?

References