Abstract
Introduction: Conduction system pacing (CSP) includes His bundle pacing (HBP) or left branch branch area Pacing (LBBAP) is cardiac physiologic pacing. CSP has emerged as a safe and effective alternative to traditional right ventricular pacing in patients with atrioventricular block.
Objective: This study evaluates the safety, feasibility and effectiveness of CSP in patients with atrioventricular block indicated for permanent pacemaker implantation.
Methods: This is an interventional study without a control group. Patients with AV block indicated for permanent pacemaker implantation underwent His bundle pacing or left bundle branch area pacing. The safety and efficacy of CSP were assessed.
Results: CSP was performed in 43 patients with a success rate of 36/43 (83.7%), including 7/10 (70%) for HBP and 29/33 (87.7%) for LBBAP. The QRS duration at baseline was 100 ± 11 ms versus 123 ± 10.3 ms (p < 0.001) compared to 119 ± 38 ms and 122.5 ± 10 ms (P = 0.339) during HBP and LBBAP, respectively. HBP had a higher pacing threshold at implantation compared to LBBAP (1.2 ± 0.6 V/1ms vs 0.86 ± 0.3 V/0.4ms, P = 0.024), but it remained stable during follow-up. Left ventricular ejection fraction (LVEF) improved from 51 ± 15.5% before implantation to 56 ± 12.6% at the end of the study (P = 0.004), with a more significant improvement in patients with heart failure before implantation. The incidence rates of lead dislodgement and pacemaker infection were 1/36 (2.7%) and 1/36 (2.7%), respectively.
Conclusion: CSP was successfully performed in 83.7% of patients with low complication rates and low pacing threshold and stable thresholds during follow-up. CSP improves LVEF, especially in patients with pre-existing heart failure.