Adenosine administration during hybrid atrial fibrillation ablation to test dormant pulmonary vein conduction

BACKGROUND: Adenosine administration after initial pulmonary vein isolation (PVI) reveals dormant conduction and predicts atrial fibrillation (AF) recurrence. Elimination of dormant conduction when present may increase a long-term success rate of AF ablation procedures. There are no studies till date using adenosine to reveal acute reconduction of pulmonary veins (PVs) after epicardial PVI during a hybrid AF ablation procedure. METHODS: We included 24 patients (21 male, 55 ± 9 years) undergoing hybrid ablation for symptomatic paroxysmal (n = 12) and persistent (n = 12) AF, using an epicardial bipolar radiofrequency clamp to perform PVI. All antiarrhythmic medications were discontinued 5 days prior to the procedure, except for patients on amiodarone. Thirty minutes after PVI and once sinus rhythm was obtained, a bolus of adenosine (12 to 36 mg) was administered intravenously. The subsequent response was assessed for each PV (n = 96) using an in situ circular mapping catheter. RESULTS: Dormant conduction (i.e., the reappearance of PV potentials during at least one beat) was seen in 1 out of 96 PVs (1%). If reconduction was seen, further endocardial ablation using a 3.5-mm irrigated tip catheter was performed until no more reconduction occurred after repeating the adenosine bolus. CONCLUSIONS: Adenosine administration after PVI with the use of an epicardial bipolar radiofrequency clamp in the setting of hybrid AF ablation reveals acute reconduction in 1% of the PVs.