The electrophysiological characteristics and ablation strategies of epicardial mitral isthmus-dependent atrial flutter mediated by the Marshall ligament
Gao Mingyang
Huang Lihong
Lai Yiwei
Guo Qi
Li Xu
Dong Jianzeng
Sang Caihua
Ma Changsheng
Abstract：Objective To describe the electrophysiological characteristics and ablation strategies of epicardial mitral isthmus-dependent atrial flutter(AFL)mediated by the Marshall ligament.Methods A retrospective study was conducted on 38 patients who underwent atrial fibrillation ablation and developed recurrent AFL radiofre-quency ablation between January 2022 and June 2023 at the Arrhythmia Center,Beijing Anzhen Hospital,Capital Medical University.All patients were diagnosed intraoperatively with epicardial mitral isthmus-dependent AFL mediated by the Marshall ligament through high-density mapping.Intraoperative mapping characteristics,ablation method and follow-up results were analyzed.Results The 38 patients in this study included 30 cases of counter-clockwise reentry around the mitral valve,5 cases of clockwise,and 3 cases of bi-atrial reentry.In all cases,activation mapping demonstrated a"pseudo-focal"activation pattern,with breakthrough points typically located at the ridge between the left pulmonary veins and the left atrial appendage or posterior to the previous endocardial mitral isthmus ablation line.Twenty patients(52.6％)had AFL terminated by ethanol infusion of the vein of Marshall.During a follow-up period of(18±9)months,4 patients(10.5％)experienced recurrences of atrial fibrillation or atrial tachycardia post blanking period.Conclusion Epicardial mitral isthmus-dependent AFL mediated by the Marshall ligament often presents with counterclockwise rotation and has a characteristic activation pattern.ablation can effectively terminate this type of AFL,with a low long-term recurrence rate.
Keywords：Atrial flutterCatheter ablationMitral isthmusMarshall vein
Publication Date：2024-11-08
Online Publishing Date：2026-09-14(First online date of this platform, not the publication date of the document)
Pages：4( 1606-1609 )