Long-term benefits and feasibility of permanent left bundle branch pacing in patients with left bundle branch block

Objective To assess the long-term feasibility, safety and effectiveness of permanent left bundle branch pacing (LBBP) in patients with left bundle branch block (LBBB) . Methods Patients with LBBB who had implanted LBBP more than 2 years from Department of Cardiology, the First Affiliated Hospital of Wenzhou Medical University were included. The feasibility of the implantation method, the electrical characteristics and clinical efficacy of the left bundle branch were analyzed and evaluated. The main outcome measures were characteristics, QRS complex, pacing parameters, echocardiographic measurements, and New York Heart Association (NYHA) functional classification and electrode-related complications. Results A total of 11 patients were included, with mean age of (71.0±12.4) years and intrinsic QRS duration of (164.6±15.7) ms. Of them, 6 (54.5%) were selective LBBP and 5 were non-selective, with the paced QRS duration of (113.1±17.1) ms. The average follow-up duration was (32.5±12.1) months. The acute threshold and R-wave amplitude were (0.65±0.21) V/0.5 ms and (8.3±1.7) mV, respectively, which remained stable during the follow-up. In 7 patients who had left ventricular ejection fraction (LVEF) <50%, the LVEF improved from 34.0%±8.2% to 63.4%±9.8%, left ventricular end-systolic volume decreased from (127.6±65.3) ml to (37.2±13.9) ml and NYHA improved from 3.3±0.7 to 1.3±0.5 (P<0.05) . No adverse events such as electrode dislocation, loss of capture, increased threshold, perforation and stroke, rehospitalization for heart failure or death were observed. Conclusion Permanent LBBP can achieve LV synchrony in LBBB patients and is safe and effective during long-term follow-up. Key words: Bundle of His; Cardiac resynchronization therapy; Bundle branch block