Interactions between two simultaneous tachycardias within an electrically isolated pulmonary vein

Pulmonary vein (PV) arrhythmogenicity underlying the maintenance of atrial fibrillation (AF) may be explained by three mechanisms: enhanced automaticity, triggered activity, and reentry. There are only a few reports describing sustained PV tachycardias (PVT) following electrical disconnection from the left atrium, in which the electrophysiological features are most consistent with a reentrant mechanism. We describe the case of a patient with paroxysmal AF demonstrating PVT within an isolated PV with high-density mapping revealing two different PVTs interacting in a "ping-pong" manner.