Macro-reentrant atrial tachycardia conducting through a left superior vena cava after catheter ablation in a patient with paroxysmal atrial fibrillation.

A left superior vena cava can be a cause of cardiac rhythm or conduction abnormalities, and can also be the arrhythmogenic source of atrial fibrillation (AF) with connections to the coronary sinus and left atrium. In the present study, we report a case with a macro re-entrant atrial tachycardia that coursed through the left superior vena cava after a previous AF ablation, which successfully ablated paroxysmal AF.