Ethanol Infusion of Atrial Flutter Mediated by the Vein of Marshall.

BACKGROUND

Atypical atrial flutter (AFL) after atrial fibrillation (AF) ablation, particularly when mediated by epicardial structures such as the vein of Marshall (VOM), poses a therapeutic challenge.

CASE SUMMARY: A 64-year-old woman presented with recurrent AFL after AF ablation. High-density and entrainment mapping confirmed a macro-re-entrant circuit involving the VOM via epicardial conduction. After failed endocardial ablation, ethanol infusion into the VOM immediately terminated the tachycardia. At 1-year follow-up, the patient maintained sinus rhythm with a marked improvement in left ventricular ejection fraction (from 46% to 68%).

DISCUSSION: For postablation AFL, comprehensive mapping is crucial to identify epicardial substrates. VOM-mediated flutter can be effectively treated with ethanol infusion.

TAKE-HOME MESSAGE: This case underscores that VOM-mediated epicardial connections can sustain AFL after AF ablation, and targeted ethanol infusion is a highly effective therapeutic strategy.