Durability of Left Atrial Lesions After Ethanol Infusion in the Vein of Marshall

Objectives: The aim of this study was to assess the persistence of left atrial (LA) lesions created by ethanol infusion in the vein of Marshall (EIVM) by electroanatomical mapping on repeat catheter ablation for recurrent atrial tachyarrhythmia.

Background: Little is known about the durability of LA lesions created by EIVM.

Methods: The study included consecutive patients who underwent EIVM for persistent atrial fibrillation or perimitral LA flutter (index procedure) and repeat catheter ablation for recurrent atrial tachyarrhythmia or atrial fibrillation at a single center between January 2019 and April 2020. The acute effect of EIVM was assessed at the index procedure by comparing the area of bipolar voltage <0.05 mV in the vein of Marshall (VOM) region before and immediately after EIVM. The long-term effect of EIVM was assessed by comparing this area in the VOM region between the redo procedure and the index procedure.

Results: Twenty-four consecutive patients (mean age 68.6 ± 6.1 years, 58% men) underwent redo procedures after previous EIVM for persistent atrial fibrillation (n = 21 [88%]) or perimitral LA flutter (n = 5 [21%]). In each patient, the EIVM-related lesion persisted, with a chronic scar in the VOM region (median 13.1 cm² [interquartile range: 8.1-15.9 cm²] vs 12.4 cm² [interquartile range: 7.6-15.7 cm²] acutely, respectively). One quarter of patients (9 of 20) had late mitral isthmus reconnection, which was located at the mitral annular edge or in the coronary sinus.

Conclusions: Atrial lesions created by EIVM are durable, which reinforces the efficacy profile of EIVM. Reconduction sites in the mitral isthmus are located at the edge of the scar and in the coronary sinus.