A Rare Complication of Vein of Marshall Ethanol Infusion: Prolonged Atrioventricular Block

Despite the general safety and efficacy of vein of Marshall ethanol infusion (VOM-EI) with few complications, prolonged atrioventricular (AV) block remains a rare but catastrophic complication.

A 66-year-old male patient suffered from symptomatic atrial flutter after the index procedure of radiofrequency catheter ablation for persistent atrial fibrillation. During the redo procedure, activation and entrainment mapping showed that atrial flutter was associated with the mitral isthmus. During the course of VOM-EI, a prolonged AV block lasting 15.8 seconds occurred but resulted in no sequelae during follow-up.

This case of prolonged AV block underscores that VOM-EI can trigger serious conduction complications, making continuous monitoring imperative.

Prolonged AV block is a rare but serious complication of VOM-EI, possibly resulting from ethanol-induced vagal activation or direct injury to conduction tissues. Individualized ethanol dosing and continuous monitoring of AV conduction are essential safety measures.