Residual conduction after pulmonary vein isolation with a circular multielectrode radiofrequency ablation catheter: the role of adenosine and orciprenalin during a prolonged observation time.

INTRODUCTION

Recurrences after pulmonary vein isolation (PVI) in patients (pts) with paroxysmal atrial fibrillation (AF) are mostly due to PV reconnection. The effect of adenosine, orciprenalin and their combination on left atrial PV conduction after PVI with a phased radiofrequency (RF) circular multielectrode ablation catheter (Pulmonary Vein Ablation Catheter, PVAC) was prospectively evaluated during a prolonged waiting time. In addition, it was assessed whether pharmacological reconnection characterizes veins requiring use of an irrigated catheter.

METHODS AND RESULTS

In 116 consecutive pts [age 62 (IQR:52,68) years, 46% female], PVI was achieved with the PVAC alone in 114/116 (98%) pts and 461/464 (99%) veins after a median of 26 (IQR:22,32) applications delivering 1782 s (IQR:1518,2197) of RF. Mostly transient PV reconnections were observed in 40/116 (34%) pts and 57/464 (12%) PVs, a median of 44 (IQR:30,58) min after initial isolation. Adenosine, alone (43/57, 75%) or during orciprenalin infusion (7/57, 12%), unmasked residual conduction in the majority of veins (50/57, 88%). Additional PVAC applications less frequently achieved permanent isolation in veins showing reconnection compared to those that didn't (52/57, 91% vs. 404/407, 99%; P < .001). All PVs that could not be isolated with the PVAC were successfully treated with a standard irrigated catheter.

CONCLUSIONS

After apparent PVI with the PVAC, drug-challenge after prolonged observation unmasked residual PV conduction in a significant number of pts, and adenosine was the most effective strategy. Drug-induced PV reconnection was difficult to treat with the PVAC. Whether this strategy improves clinical outcome of PVI with phased RF needs to be investigated.