Recurrences of atrial fibrillation (AF) after catheter ablation are frequently associated with recovery of conduction between the pulmonary veins (PV) and the atrium. The recovery of PV conduction could be explained by the presence of dormant conduction between the PV and the atrium. Adenosine can be used during AF ablation procedures to reveal transient re-conduction of the isolated pulmonary vein (dormant PV conduction). We prospectively evaluate the utility of iv adenosine to guide elimination of dormant PV conduction by additional radiofrequency (RF) applications during AF ablation procedures. Thirty-four consecutive patients (30 male; age 51+/−8 years) referred for catheter ablation of drug-refractory AF (Paroxysmal 31/Persistent 3) were studied. Electrical PV isolation (PVI) was performed using Irrigated-tip radiofrequency (RF) ablation and was guided by a circular mapping catheter. After PVI, the presence of dormant conduction in each vein was assessed by injection of 12 mg of adenosine. If dormant conduction was present, additional RF energy was delivered at sites of transient re-conduction. Abolition of the dormant conduction was then demonstrated by repeated injections of adenosine. The recurrence rate of arrhythmia after one procedure was evaluated. The results were compared to an historical control group comprising the previous 34 consecutive patients who underwent PVI without the use of adenosine. Electrical PVI was achieved in 100% of PV’s and all 34 patients underwent the adenosine evaluation. Dormant PV conduction was observed in 17/34 patients and could be eliminated in all by additional RF delivery. Procedural and fluoroscopy times were 163±30 and 49±13 minutes, respectively. After a mean follow-up of 8.0±3.1 months, 6/34 (18%) patients experienced AF recurrence with 28/34 (82%) remaining free of arrhythmia without the use of antiarrhythmic drugs. When compared to the 14/34 patients (41%) from the historical control group who had AF recurrence, a significant reduction was observed (P<0.01). The use of adenosine to guide elimination of dormant PV conduction increases the success rate of AF ablation procedures. This needs to be evaluated in a randomized multicenter trial.
Dormant Conduction: It Is Time to Wake Up
