Abstract 13804: Effect of Adenosine Triphosphate on the Automatic Electrical Activity in the Pulmonary Vein Isolated by Catheter Ablation: The Relationship Between Automatic Electrical Activity and Dormant Conduction
Recently, adenosine triphosphate (ATP) is used to examine the dormant conduction between the isolated pulmonary vein (PV) and left atrium (LA) after ablation of atrial fibrillation (AF). Although ATP was shown to have a proarrhythmic effect, its effect on the automaticity originating from the PV remains to be elucidated. The aim of this study was to clarify the effect of ATP on the automatic electrical activity in the pulmonary vein isolated by catheter ablation. The consecutive 90 AF patients (62 men; mean age, 58±10 years) in whom all 4 PVs were isolated by ablation were studied prospectively. There were 69 patients with paroxysmal and 21 with persistent AF. The end point of the PV isolation was the establishment of a bidirectional conduction block between the LA and PV. After the elimination of PV potential on the steerable circular catheter (Lasso catheter), the exit block was also confirmed by pacing inside the PV with a Lasso catheter. After successful PV isolation, dormant PV conduction and automatic electrical activity were identified by use of double (or single) Lasso catheters during injection of intravenous ATP (10 or 20mg). After rapid injection of ATP, dormant PV conduction was observed in 52 PVs of 39 patients (43.3%): 10 in the right superior PV, 9 in the right inferior PV, 21 in the left superior PV, and 12 in the left inferior PV. Automatic electrical activity was observed in 16 PVs of 13 patients (14.4%) after PV isolation: 4 in the right superior PV, one in the right inferior PV, 5 in the left superior PV, and 6 in the left inferior PV. Automatic electrical activity and dormant conduction manifested in the different PVs in all cases except for 2 in which they manifested in the same PV. In 11 of these 13 patients (85%), automatic electrical activity was eliminated by ATP. Thus, ATP suppresses automaticity in the PV, while re-inducing conduction from the left atrium to the isolated PV after AF ablation. ATP may not be suitable for inducing focal firing originating from the PV.
- © 2012 by American Heart Association, Inc.