Distinct propagation patterns of right pulmonary veins through multiple epicardial connections during right atrial pacing and sinus rhythm.

A 47-year-old man with symptomatic paroxysmal atrial fibrillation (AF) underwent AF ablation. Activation maps during right atrial pacing and sinus rhythm before the ablation revealed distinctive left atrial (LA) propagations with multiple LA breakthrough sites via epicardial connections. A wide area circumferential ablation was not able to achieve a right pulmonary vein (RPV) isolation and required an inner PV ablation to isolate the RPV. Activation maps during different rhythms before the ablation may be helpful to unmask multiple epicardial connections between the RPV and right atrium.