BACKGROUNDDelayed cure had been observed in recurrent cases after index ablation of atrial fibrillation (AF), however, its mechanism and incidence have not been elucidated in detail. This study aims to investigate the impact of different ablation strategies on the incidence of delayed cure and its possible mechanisms after trans-catheter ablation of AF.

METHODSOne hundred and fifty-one consecutive cases with highly symptomatic, drug refractory AF were included in this study [M/F = 109/42, mean age (56.0 +/- 11.2) (18 - 79) years]. Segmental pulmonary vein ablation (SPVA) was performed in 83 patients with the guidance of circular mapping catheter (SPVA Group), circumferential PV linear ablation (CPVA) was carried out in the rest 68 cases under the guidance of 3 dimensional mapping system in conjunction with circular mapping catheter (CPVA Group). Delayed cure was defined as that early recurrence of atrial tachyarrhythmias (AF, atrial tachycardia, or atrial flutter) after ablation procedure was no longer observed during subsequent follow-up, and stable sinus rhythm was maintained > or = 2 months.

RESULTSEarly recurrence of atrial tachyarrhythmias was detected in 41 cases from SPVA group and 23 cases from CPVA group, and delayed cure occurred in 21.9% (9/41) of the cases from SPVA group and 47.8% (11/23) of the cases from CPVA group, more delayed cure in later group was observed (P < 0.05). Meanwhile, patients in SPVA group took a longer time to achieve a delayed cure [(27.0 +/- 18.0) days vs (14.0 +/- 8.1) days, P < 0.05], and presented more recurrent episodes [(3.50 +/- 1.08) times a week vs (2.42 +/- 1.11) times a week, P < 0.05]. However, recurrent episodes after index ablation were markedly decreased in cases with delayed cure from both groups (P < 0.05).

CONCLUSIONSDespite of an early recurrence of atrial tachyarrhythmias after index ablation of AF, delayed cure occurs in a significant number of patients undergoing either SPVA or CPVA. However, different ablation strategies place different impact on the delayed cure, more delayed cure is obtained with CPVA approach, and the delayed cure occurs earlier with this approach; the average recurrent episodes before delayed cure are also less frequently detected in CPVA group compared with those in SPVA group.