Atrial tachycardia after circumferential pulmonary vein ablation of atrial fibrillation: mechanistic insights, results of catheter ablation, and risk factors for recurrence.

目的：研究旨在明确房颤消融术后出现的房性快速心律失常的原因。

背景：患者在进行导管消融后会出现房性快速心律失常。

方法：观察了78名在接受肺静脉旁消融（CPVA）术后出现快速房性心律失常的患者。采用三位标测对房颤和房性心动过速的过程进行监测，来评价消融治疗引发房性心动过速的可能。

结果：共有155例出现AT，其中137名为再循环，18名为局灶性。进行最多的左房消融是针对僧帽瓣峡部，顶部和隔部。120名左房再循环AT中有115名跨越了之前的消融线，符合心脏缝隙连结理论。导管消融在78名患者中的60名中取得成功，在平均随访的13 +/- 10月内，60名在未使用抗心律失常治疗的情况下未出现AT/AF。再循环性隔部AT与复发有关(odds ratio 7.3; 95% confidence interval 1.5 to 36; p = 0.02)，但PV隔离的结果则较好(odds ratio 0.17; 95% confidence interval 0.04 to 0.81; p = 0.03)。

结论：大约90%的CPVA后AT与再循环有关，且多数都为与先前消融形成了缝隙所致。这些结果显示如果限制线性损伤和首次房颤手术中肺静脉旁不连续的情况，则可以降低发生这种情况的几率。

　　（来源：J Am Coll Cardiol. 2007 Oct 30）

Atrial tachycardia after circumferential pulmonary vein ablation of atrial fibrillation: mechanistic insights, results of catheter ablation, and risk factors for recurrence.

Division of Cardiology, University of Michigan Hospitals, Ann Arbor, Michigan, USA.

OBJECTIVES: The aim of this study was to determine the mechanism of atrial tachycardia (AT) that occurs after ablation of atrial fibrillation (AF).

BACKGROUND: Patients who undergo catheter ablation of AF may develop AT during follow-up.

METHODS: Seventy-eight patients underwent an ablation procedure for AT after circumferential pulmonary vein ablation (CPVA) for AF. The 3-dimensional maps from the AF and AT procedures were compared to determine whether AT arose from a prior ablation line.

RESULTS: A total of 155 ATs were mapped, and the mechanism was re-entry in 137 (88%) and focal in 18 (12%). The most common left atrial (LA) ablation targets were the mitral isthmus, roof, and septum. The critical isthmus in 115 of the 120 LA re-entrant ATs (96%) traversed a prior ablation line, consistent with a gap-related mechanism. Catheter ablation was successful in 66 of the 78 patients (85%). After a mean follow-up of 13 +/- 10 months, 60 of the 78 patients (77%) were free of AT/AF without antiarrhythmic medications. Re-entrant septal AT was associated with recurrence (odds ratio 7.3; 95% confidence interval 1.5 to 36; p = 0.02), whereas PV isolation during the AT procedure was associated with a favorable outcome (odds ratio 0.17; 95% confidence interval 0.04 to 0.81; p = 0.03).

CONCLUSIONS: Approximately 90% of ATs after CPVA are re-entrant, and nearly all are related to gaps in prior ablation lines. These findings suggest that the prevalence of these arrhythmias may be reduced by limiting the number of linear lesions, demonstration of linear block, and pulmonary vein disconnection during the initial AF procedure.