Department of Cardiology, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China.
Clin Cardiol. 2020 Oct;43(10):1119-1125. doi: 10.1002/clc.23415. Epub 2020 Jul 8.
Mitral isthmus (MI) ablation was limited due to technical challenges in the index ablation for long-standing persistent atrial fibrillation (LPeAF). The role of adjunctive MI ablation was controversial.
MI block could be achieved in most patients undergoing repeat LPeAF ablation and was associated with favorable clinical outcomes.
Of 87 consecutively patients undergoing reablation for recurrent atrial tachyarrhythmias (ATa), 41 patients with residual MI conduction but without pulmonary vein reconnection or left atrial roof conduction were enrolled to treat recurrent atrial flutter (AFL) (n = 20) and AF (n = 21). After AFL ablation and AF cardioversion, MI conduction gaps (CGs) were mapped and closed.
MI line was successfully blocked in 37 (90.2%) of 41 patients after closing 1.4 ± 0.5 CGs (31 endocardial CGs and 16 epicardial ones) in the initial MI lines. CGs were more often located at the endocardial sites close to the lateral ridge between left atrial appendage and left-sided PVs, midportion of MI and at the epicardial breakthroughs within coronary sinus. At the end of 16.0 ± 1.9 months' follow-up, 31 (83.8%) of 37 patients with MI block and 1 of 4 patients without MI block were free of further recurrence of ATa off anti-arrhythmic drugs. MI block was positively associated with ATa-free survival by Cox's regression analysis (hazard ratio [HR]: 0.012, 95% confidence interval [CI]: 0.000-0.456, P = .02).
MI block could be achieved in the majority of patients during repeat ablation for LPeAF. MI block was associated with favorable clinical outcomes after LPeAF reablation.
由于在索引消融治疗长期持续性心房颤动（LPeAF）时存在技术挑战，因此二尖瓣峡部（MI）消融受到限制。附加 MI 消融的作用存在争议。
在接受重复 LPeAF 消融的大多数患者中可以实现 MI 阻滞，并与良好的临床结果相关。
在 87 例连续因复发性房性心动过速（ATa）接受再消融的患者中，41 例患者存在残留的 MI 传导，但不存在肺静脉再连接或左心房顶传导，入选该研究以治疗复发性房扑（AFL）（n = 20）和房颤（AF）（n = 21）。在消融 AFL 和 AF 复律后，对 MI 传导间隙（CGs）进行了标测和闭合。
在最初的 MI 线中闭合 1.4±0.5 CGs（31 个心内膜 CGs 和 16 个心外膜 CGs）后，成功阻断了 41 例患者中的 37 例（90.2%）的 MI 线。CGs 更常位于左心耳和左侧 PV 之间的左心房侧嵴附近的心内膜部位、MI 的中段和冠状窦内的心外膜突破处。在 16.0±1.9 个月的随访结束时，37 例 MI 阻滞患者中的 31 例（83.8%）和 4 例未行 MI 阻滞患者中的 1 例在无抗心律失常药物的情况下无 ATa 复发。Cox 回归分析表明，MI 阻滞与 ATa 无复发生存呈正相关（风险比[HR]：0.012，95%置信区间[CI]：0.000-0.456，P =.02）。
在 LPeAF 的重复消融过程中，大多数患者可以实现 MI 阻滞。MI 阻滞与 LPeAF 再消融后的良好临床结果相关。
