Division of Cardiac Electrophysiology, Houston Methodist DeBakey Heart and Vascular Center, Houston, Texas, USA.
Division of Cardiac Electrophysiology, Houston Methodist DeBakey Heart and Vascular Center, Houston, Texas, USA.
JACC Clin Electrophysiol. 2024 Nov;10(11):2420-2430. doi: 10.1016/j.jacep.2024.07.009. Epub 2024 Sep 11.
Reconnection of the mitral isthmus (MI) is common after radiofrequency ablation (RFA). Vein of Marshall ethanol infusion (VOMEI) expedites MI ablation, but long-term results are unclear.
This study sought to determine anatomic substrates of failed MI ablation, with and without VOMEI.
Consecutive VOMEI procedures were included (n = 231; of which 140 were de novo ablations and 91 were prior RFA failures (rescue VOMEI). MI conduction mechanisms were studied with vein of Marshall (VOM) electrograms obtained with a 2-F octapolar catheter, mapping, and differential pacing.
In rescue VOMEI, intact VOM electrograms showed epicardial connections, epi-endocardial dissociation, and VOM conduction in pseudo-MI block. After VOMEI, after a follow-up of 725 ± 455 days, 78 patients (33.7%) experienced recurrence. Of those, 36 (46%) had evidence of MI reconnection and 42 had other mechanisms. Of the 36 patients with MI reconnection, endocardial radiofrequency (RF) at the annular MI restored block in 16 (45%), and coronary sinus (CS) RF was required in 20 (55%). Post-VOMEI recurrence mechanisms included CS connection-dependent arrhythmias: CS-mediated perimitral flutter, CS-to-left atrium (LA) and CS ostial re-entry, and CS focal activity. Intraprocedural factors associated with MI reconnection included volume of ethanol delivered ≥4 mL (OR: 0.74; P = NS), CS ablation at VOMEI (OR: 4.05; P = 0.003), and age (OR: 1.06; P = 0.011).
MI reconnections after RFA are due to epicardial connections from VOM. Recurrences after VOMEI are due to incomplete annular MI RFA and CS arrhythmogenesis including CS-mediated perimitral flutter, CS-to-LA re-entry and CS focal activity. Adding complete CS disconnection to VOMEI may prevent recurrences.
射频消融（RFA）后常出现二尖瓣峡部（MI）再连接。Marshall 静脉乙醇输注（VOMEI）加速 MI 消融，但长期结果尚不清楚。
本研究旨在确定 VOMEI 有无情况下 MI 消融失败的解剖学基础。
连续纳入 VOMEI 程序（n=231；其中 140 例为初次消融，91 例为 RFA 失败后再次消融（挽救性 VOMEI）。采用 2-F 八极导管获取 Marshall 静脉（VOM）电图、标测和差频起搏研究 MI 传导机制。
在挽救性 VOMEI 中，完整的 VOM 电图显示心外膜连接、心内膜-心外膜分离和假性 MI 阻滞中的 VOM 传导。VOMEI 后，中位随访 725±455 天后，78 例患者（33.7%）复发。其中 36 例（46%）有 MI 再连接证据，42 例有其他机制。36 例 MI 再连接患者中，环形 MI 心内膜射频（RF）复律 16 例（45%），需行冠状窦（CS）RF 20 例（55%）。VOMEI 后复发机制包括 CS 连接依赖性心律失常：CS 介导的二尖瓣环周房扑、CS 至左心房（LA）和 CS 口部折返，以及 CS 局灶性活动。与 MI 再连接相关的术中因素包括输送乙醇量≥4ml（OR：0.74；P=NS）、VOMEI 行 CS 消融（OR：4.05；P=0.003）和年龄（OR：1.06；P=0.011）。
RFA 后 MI 再连接是由于 VOM 的心外膜连接。VOMEI 后复发是由于不完全的环形 MI RFA 和 CS 心律失常发生，包括 CS 介导的二尖瓣环周房扑、CS 至 LA 折返和 CS 局灶性活动。将完全 CS 分离加入 VOMEI 可能预防复发。
