Bradycardia-Dependent Conduction Block Into Pulmonary Vein After Isolation
Pulmonary vein (PV) isolation is the cornerstone of ablation for the treatment of paroxysmal atrial fibrillation. Once PV isolation is achieved, multiple maneuvers may be used to assure durable effect, including pacing along the ablation line,1 adenosine challenge2 to uncover dormant PV conduction, and an appropriate waiting period after successful isolation.3 We describe a novel finding of transient PV reconnection by rapid pacing of the coronary sinus.
A 69-year-old man with symptomatic, drug-refractory, paroxysmal atrial fibrillation was referred for PV isolation. Echocardiography displayed a normal left ventricular ejection fraction with mild left atrial enlargement.
Antral isolation was performed in atrial fibrillation, first around the left PVs, followed by the right PVs. Ablation was performed with an open-irrigated ablation catheter (Thermocool SF, Biosense Webster, Diamond Bar, CA), guided by a 10-pole circular mapping catheter (Lasso, Biosense Webster, Diamond Bar, CA). During the right-sided lesion set, sinus rhythm resumed at …