Radiofrequency Ablation of the Distal Vein of Marshall Prior to Ethanolization

CASE SUMMARY: A woman with atrial fibrillation underwent radiofrequency ablation combined with vein of Marshall (VOM) ethanol infusion. To prevent ethanol-induced sinus node injury via the distal VOM, we performed targeted radiofrequency ablation to occlude the distal VOM before ethanol infusion. No sinus arrest or atrioventricular block occurred. Pulmonary vein isolation was successfully achieved, and atrial fibrillation terminated during the procedure. TAKE-HOME MESSAGES: Sinus node and atrioventricular node injury are rare but critical complications of VOM ethanol infusion. Preemptive occlusion of the distal VOM by radiofrequency ablation before ethanol infusion can reduce the risk of conduction system injury.