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.