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

Background: Little is known about the durability of left atrial (LA) lesions created by ethanol infusion in the vein of Marshall (EIVM). Aims: To assess the persistence of LA lesions created by EIVM by electro-anatomical mapping at repeated catheter ablation for recurrent atrial tachycarryhymia (AT). Methods: We included consecutive patients who underwent EIVM for persistent atrial fibrillation (AF) or perimitral left atrial flutter (PLMAF) (index procedure) and repeated CA for recurrent AT or AF in a single center between January 2019 and April 2020. Acute EIVM effect was assessed at the index procedure by comparing the area of bipolar voltage <0.05mV in the vein of Marshall (VOM) region before and immediately after EIVM. Long-term EIVM effect was assessed by comparing this area in the VOM region at the redo procedure versus at the index procedure. Results: 24 consecutive patients (mean age 68.6{plus minus}6.1 years, 58% men) underwent a redo procedure after previous EIVM for persistent AF (n=21; 88%) or PMLAF (n=5; 21%). In each patient, the EIVM-related lesion persisted, with a chronic scar in the VOM region (median 13.1cm2 [interquartile range (IQR) 8.1-15.9] vs. 12.4cm2 (IQR 7.6-15.7) acutely, respectively. One quarter of patients (9/20) had late MI reconnection, which was located at the mitral annulus 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 MI are located at the edge of the scar and in the coronary sinus.