Atrioventricular node ablation and His bundle pacing.

Abstract

Atrioventricular node ablation (AVNA) and right ventricular pacing (RVP) are effective therapies for patients with atrial fibrillation (AF) and rapid ventricular rates. His bundle pacing (HBP) is a physiologic alternative to RVP. The aim of our study is to assess the feasibility and safety of HBP in patients undergoing AVNA and its effect on left ventricular (LV) function. Permanent HBP is the preferred form of ventricular pacing at our institute. Atrioventricular node ablation and HBP were performed in patients with AF and difficulty in rate control. His bundle pacing implant characteristics and thresholds were recorded. Fluoroscopic relationship of AVNA site to HBP lead electrodes was documented. Left ventricular ejection fraction (LVEF) and New York Heart Association (NYHA) functional class at baseline and during follow-up were assessed. Forty-two patients underwent HBP and AVNA: age 74 ± 11 years; men 45%; HTN 64%; DM 19%; CAD 36%; permanent AF 40%; cardiomyopathy 55%. His bundle pacing was successful in 40 of 42 patients (95%). Successful AVNA site was at or below the ring electrode in 22 (no acute change in HBP threshold); above the ring electrode in 13 and left side in 2 pts (acute increase in HBP threshold in 7 of 15 pts). Final HBP threshold at implant was 1 ± 0.8 V@1 ms and increased to 1.6 ± 1.2 V@1 ms during a mean follow-up of 19 ± 14 months. Left ventricular ejection fraction increased from 43 ± 13% to 50 ± 11% (P = 0.01). New York Heart Association functional status improved from 2.5 ± 0.5 to 1.9 ± 0.5 (P = 0.04). Atrioventricular node ablation and HBP were successful in 95% of patients. His bundle pacing lead characteristics remained relatively stable. Left ventricular ejection fraction improved significantly during follow-up. His bundle pacing is feasible, safe and effective in pts undergoing AVNA.