Conduction System Pacing Versus Biventricular Pacing After Atrioventricular Node Ablation

Implantation of permanent pacemaker with biventricular stimulation with or without defibrillator lead placement using standard techniques. The right ventricle lead will be positioned in the RV apex or septum, while the left ventricle lead will be delivered to the most appropriate coronary sinus tributary, preferably posterolateral or lateral vein.

Left bundle branch pacing (LBBP) will be the preferred pacing technique. In brief, after localizing the His bundle area the LBBP lead will be positioned approximately 1-1.5 cm distal to the His bundle position in the right ventricular septum. Before screwing the lead deep into the interventricular septum, the suitable position will be confirmed by fluoroscopic signs and adequate paced QSR morphology. Given that the pacing parameters with LBBP are typically low and stable, backup RV lead will not be mandatory. If LBBP will be unobtainable, His bundle pacing (HBP) implantation will be attempted. His bundle potential mapping will be performed with the use of the electrophysiological system and under fluoroscopic guidance. Distal HB potential with a large ventricular signal and a small atrial signal will be targeted before the pacing lead will be screwed into position. Backup RV lead will be mandatory for all patients receiving HBP devices.

Atrioventricular node ablation (AVNA) will be performed following pacemaker implantation (preferably during the same hospitalization). After femoral vein access will be obtained, the ablation catheter will be positioned to the presumed area of the AV node in the mid-septum under fluoroscopy. The location will be optimized according to the intracardiac electrograms. Ablation will be performed in a temperature-controlled mode. Successful AVNA will be recognized with an abrupt drop of heart rate to 40 bpm and will continue for 60 seconds thereafter.