Abstract
A 72-year-old woman who suffered from paroxysmal atrial fibrillation for 6 years referred to our hospital. Although she became free from atrial fibrillation after two sessions of catheter ablation of electrical isolation of the pulmonary veins in March and December 2007, the paroxysmal atrial tachycardia recurred 4 months after the second ablation procedure. During the third ablation in April 2008, electrical reconnection was observed between the right inferior pulmonary vein and left atrium at baseline. Rapid intravenous administration of 20mg of adenosine triphosphate under continuous infusion of isoproterenol revealed transient reconnection between the right superior pulmonary vein and the left atrium. The P wave morphology of clinically detected atrial tachycardia was similar to that during pacing from the right superior pulmonary vein. Hence, the atrial tachycardia was considered to originate from the right superior pulmonary vein. After isolation of the right superior and inferior pulmonary veins, no electrical reconduction was observed with or without drug administration. She has been free from arrhythmia after the ablation for 16 months without antiarrhyrhmic drugs. Transient reconnection between the right superior pulmonary vein and the left atrium caused the clinical symptomatic tachycardia, which was revealed only by administration of adenosine triphosphate during catheter ablation. The functional conduction block between the pulmonary veins and the left atrium can occur in the chronic phase after catheter ablation, and adenosine triphosphate infusion is considered to be important to confirm complete conduction block even after multiple sessions of catheter ablation.
