Department of Cardiology, Tsuchiura Kyodo Hospital, Tsuchiura, Ibaraki, Japan.
Department of Cardiovascular Medicine, Tokyo Medical and Dental University, Tokyo, Japan.
J Cardiovasc Electrophysiol. 2021 Dec;32(12):3146-3155. doi: 10.1111/jce.15268. Epub 2021 Oct 28.
Catheter ablation for perimitral atrial tachycardia (PMAT) that persists despite lateral mitral isthmus (LMI) ablation is challenging. The aim of this study was to identify the role of the ligament of Marshall (LOM) in PMATs that persist after LMI conduction block has been created, and evaluate the validity of ethanol infusion into the vein of Marshall (VOM) as treatment.
Sixteen consecutive PMATs in 13 patients that persisted despite apparent LMI conduction block, which was confirmed by ultrahigh-resolution mapping and entrainment pacing along the mitral annulus, were analyzed. PMATs were classified into two types based on the location of the endocardial breakthrough site: those utilizing the LOM (n = 13), which had a breakthrough site along with the LOM, and those not utilizing the LOM (n = 3), which had a breakthrough site at an anterior or posterior side of the LOM. Of the 16 PMATs, 5 PMATs (31%) were not suitable for ethanol infusion into the VOM because the LOM was not involved in the tachycardia circuit or because of the anatomy of the VOM. Fourteen PMATs (88%) were successfully terminated solely by breakthrough site ablation. At a mean follow-up period of 12 ± 9 months, 10 (77%) patients have remained free from atrial tachyarrhythmias.
In cases of PMAT following LMI ablation, epicardial conduction over the LMI can occur independently of the LOM. Ethanol infusion into the VOM in such cases would not abolish residual epicardial conduction. The anatomy of the VOM can also preclude the use of this method.
尽管已经进行了外侧二尖瓣峡部（LMI）消融，但持续性的周边性心房性心动过速（PMAT）的导管消融仍然具有挑战性。本研究旨在确定Marshall 韧带（LOM）在 LMI 传导阻滞后仍然存在的 PMAT 中的作用，并评估Marshall 静脉（VOM）乙醇输注作为治疗方法的有效性。
分析了 13 例患者中 16 例持续性 PMAT，尽管明显存在 LMI 传导阻滞，但通过超高分辨率映射和沿二尖瓣环进行的起搏标测证实了这一点。根据心内膜突破部位的位置，将 PMAT 分为两种类型：利用 LOM 的 PMAT（n=13），突破部位与 LOM 一起，以及不利用 LOM 的 PMAT（n=3），突破部位在前或后 LOM 侧。在 16 例 PMAT 中，有 5 例（31%）不适合进行 VOM 乙醇输注，因为 LOM 未参与心动过速回路或由于 VOM 的解剖结构。14 例 PMAT（88%）仅通过突破部位消融成功终止。在平均 12±9 个月的随访期间，10 例（77%）患者未发生心房性心动过速。
在 LMI 消融后出现 PMAT 的情况下，LMI 上的心外膜传导可以独立于 LOM 发生。在这种情况下，VOM 内的乙醇输注不会消除残留的心外膜传导。VOM 的解剖结构也可能排除这种方法的使用。
