Vein of Marshall ethanol infusion: First-step or adjunctive choice for perimitral atrial tachycardia?

Perimitral atrial tachycardia (PMAT) is the most frequent type of iatrogenic atrial tachycardia (AT) after atrial fibrillation (AF) ablation. Vein of Marshall ethanol infusion (EIVOM) is a promising technique in mitral isthmus (MI) ablation.A total of 165 patients with PMAT were divided into three groups according to ablation strategies, including RF only group (n = 89), RF-EIVOM group (initial RF ablation with adjunctive EIVOM, n = 28), and EIVOM-RF group (first-step EIVOM with touch-up RF ablation, n = 48). Acute and follow-up procedure outcomes were evaluated.PMAT terminated in 89.9%, 89.3%, and 93.7% of patients in RF only, RF-EIVOM and EIVOM-RF groups, respectively (p = .715), with complete MI block achieved in 80.9%, 89.3%, and 95.8% of patients (EIVOM-RF vs. RF only, p = .012). First-step utilization of EIVOM was associated with a significant shortening of RF ablation time at MI (EIVOM-RF 2.1 ± 1.3 min, RF only 7.9 ± 5.9 min, RF-EIVOM 6.8 ± 5.8 min; p .001) and a decrease in the proportion of patients need ablation within coronary sinus (CS, EIVOM-RF 14.6%, RF only 61.8%, RF-EIVOM 64.3%; p .001). After a mean follow-up of 12.1 ± 6.2 months, AF/AT recurred in 39 (43.8%), 6 (21.4%), and 12 (25.0%) patients in RF only, RF-EIVOM, and EIVOM-RF group (RF-EIVOM vs. RF only, p = .026; EIVOM-RF vs. RF only, p = .022).EIVOM was associated with an enhanced acute MI block rate as well as reduced AF/AT recurrence. First-step utilization of EIVOM promises to significantly simplify the RF ablation process.PMAT is the most common type of iatrogenic AT after AF ablation procedures. EIVOM contributed to a higher acute MI block rate and lower arrhythmia recurrence risk during follow-up. First-step utilization of EIVOM significantly reduced the need for radiofrequency ablation at MI and inside CS with the advantage of creating a homogenous, transmural lesion and eliminating epicardial connections.