Focal ablation for atrial tachycardia from the double-exit of the Marshall bundle inducing atrial fibrillation.

Atrial fibrillation (AF) from the ligament/vein of Marshall (LOM/VOM) has previously been described. We report the case of a 23-year-old woman with an antiarrhythmic drug-resistant AF induced by two distinct atrial tachycardias (ATs). Focal ablation of these ATs from the double-exit of the Marshall bundle using a three-dimensional map eliminated AF triggering, even though pulmonary vein electrical isolation is the cornerstone for paroxysmal AF. Such mechanisms are important as triggering factors to plan ablation for paroxysmal AF. Focal ablation for triggering and inducing AF, originating from the double-exit of the Marshall bundle may be effective in eliminating AF in young patients.