Lam, AnnaAnnaLamKüffer, ThomasThomasKüffer0000-0003-3553-4945Hunziker Munsch, Lukas ChristophLukas ChristophHunziker MunschNozica, NikolasNikolasNozicaAsatryan, BabkenBabkenAsatryan0000-0002-0050-5717Franzeck, Florian MarkusFlorian MarkusFranzeckMadaffari, AntonioAntonioMadaffariHäberlin, Andreas David HeinrichAndreas David HeinrichHäberlin0000-0002-9283-0110Mühl, AlineAlineMühlServatius, Helge SimonHelge SimonServatius0000-0003-2887-8707Seiler, JensJensSeilerNoti, FabianFabianNotiBaldinger, Samuel HannesSamuel HannesBaldinger0000-0002-2296-4631Tanner, HildegardHildegardTannerWindecker, StephanStephanWindeckerReichlin, Tobias RomanTobias RomanReichlin0000-0002-7197-8415Roten, LaurentLaurentRoten0000-0002-0827-13292024-10-052024-10-052021-06https://boris-portal.unibe.ch/handle/20.500.12422/54308INTRODUCTION Chemical ablation by retrograde infusion of ethanol into the vein of Marshall (VOM-EI) can facilitate the achievement of mitral isthmus block. This study sought to describe the efficacy and safety of this technique. METHODS AND RESULTS Twenty-two consecutive patients (14 males, median age 71 years) with attempted VOM-EI for mitral isthmus ablation were included in the study. VOM-EI was successfully performed with a median of 4 ml of 96% ethanol in 19 patients (86%) and the mitral isthmus was successfully blocked in all (100%). Touch up endocardial and/or epicardial ablation after VOM-EI was necessary for 12 patients (63%). Perimitral flutter was present in 12 patients (63%) during VOM-EI and terminated or slowed by VOM-EI in 4 and 3 patients, respectively. The low-voltage area of the mitral isthmus region increased from 3.1 cm2 (interquartile range [IQR] 0-7.9) before to 13.2 cm2 (IQR: 8.2-15.0) after VOM-EI and correlated significantly with the volume of ethanol injected (p = .03). Median high-sensitive cardiac troponin-T increased significantly from 330 ng/L (IQR: 221-516) the evening of the procedure to 598 ng/L (IQR: 382-769; p = .02) the following morning. A small pericardial effusion occurred in three patients (16%), mild pericarditis in one (5%), and uneventful VOM dissection in two (11%). After a median follow-up of 3.5 months (IQR: 3.0-11.0), 10 of 18 patients (56%) with VOM-EI and available follow-up had arrhythmia recurrence. Repeat ablation was performed in five patients (50%) and peri-mitral flutter diagnosed in three (60%). CONCLUSION VOM-EI is feasible, safe, and effective to achieve acute mitral isthmus block.enatrial fibrillation atrial tachycardia ethanol infusion ligament of Marshall vein of Marshall600 - Technology::610 - Medicine & healtharticle10.48350/1609553392871110.1111/jce.15064