VDDR pacing after His-bundle ablation for paroxysmal atrial fibrillation: a pilot study.

His-bundle ablation followed by pacemaker implantation is today a widely accepted therapeutic choice when drug refractoriness of symptomatic AF is evident. The selection of pacing mode in patients suffering from paroxysmal AF is still controversial. Preservation of AV synchrony is an attractive option in patients with paroxysmal AF who undergo His-bundle ablation. The purpose of this study was to examine prospectively the contribution of VDDR pacing for preservation of AV synchrony. After His-bundle ablation a VDDR pacing system was implanted in 17 patients with paroxysmal AF, and all antiarrhythmic drugs were withdrawn. The endpoint of the study was defined as the onset of chronic AF. To document the onset of chronic AF 48-hour Holter recordings were made every 6-8 weeks. After a mean followup of 18.2 (range 14-21) months, VDDR pacing is still operative in 13 patients (77%). Four patients developed chronic AF after a mean follow-up of 6 months. Of several baseline characteristics, only the intraatrial P wave at implantation was significantly smaller in patients developing chronic AF than in patients in whom the VDDR mode is still operative. This pilot study suggests that VDDR pacing is an attractive pacing method for patients with paroxysmal AF after His-bundle ablation. A low intraatrial P wave electrogram at implant was associated with a higher risk for the development of chronic AF.