VDDR PACING AFTER HIS-BUNDLE ABLATION FOR PAROXYSMAL ATRIAL-FIBRILLATION - A PILOT-STUDY

His-bundle ablation followed by pacemaker implantation is today a wide ly accepted therapeutic choice when drug refractoriness of symptomatic AF is evident. The selection of pacing mode in patients suffering fro m paroxysmal AF is still controversial. Preservation of AV synchrony i s an attractive option in patients with paroxysmal AF who undergo His- bundle ablation. The purpose of this study was to examine prospectivel y the contribution of VDDR pacing for preservation of AV synchrony. Af ter His-bundle ablation a VDDR pacing system was implanted in 17 patie nts with paroxysmal AF and all antiarrhythmic drugs were withdrawn. Th e endpoint of the study was defined as the onset of chronic AF, To doc ument the onset of chronic AF 48-hour Holter recordings were made ever y 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 develope d chronic AF after a mean follow-up of 6 months. Of several baseline c haracteristics, only the intraatrial P wave at implantation was signif icantly 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 paroxysma l AF after His-bundle ablation. A low intraatrial P wave electrogram a t implant was associated with a higher risk for the development of chr onic AF.