Permanent His bundle pacing improving cardiac function in the patients with chronic systolic heart failure

Objective To investigate the efficacy and safety of permanent His bundle pacing (HBP) in the patients with chronic heart failure (CHF) . Method We retrospectively collected data from 22 patients with CHF who underwent pacemaker implantation with permanent HBP in Wuhan Asia Heart Hospital from April 2013 to January 2018. The QRS duration, left ventricular end-diastolic diameter (LVEDD) , left ventricular ejection fraction (LVEF) , New York Heart Association functional class (NYHA class) , 6-minute walk distance (6MWD) of post-procedure were compared to the pre-procedure. Results Fourteen patients (63.6%) were received successfully permanent HBP. Thirteen patients were diagnosed as permanent atrial fibrillation, one with normal sinus rhythm. Eleven were succeeded in selective HBP, 3 were performed as nonselective HBP. The pacemaker generations included VVIR in 1 patient, DDDR in 1 patient, cardiac resynchronization therapy (CRT) pacemaker (CRT-P) in 6 patients, and CRT defibrillator (CRT-D) in 6 patients. Eight patients were given atrioventricular junction ablation in the same procedure. The time of total procedure was 1.5-5.5 (2.9±0.6) hours. The average period of follow-up was (18.6±10.7) months. The patients’ average HBP percentage was 96.4%±3.3%. The QRS duration of pre-procedure was (164.9±31.3) ms and was (126.7±15.0) ms of post-procedure (P=0.002) . There were significant improvements in LVEDD [ (6.9±1.0) cm vs. (6.3±1.1) cm, P=0.009] , LVEF [ (30.9±12.8) % vs. (40.1±13.3) %, P=0.012] , 6MWD [ (228±57) m vs. (414±45) m, P<0.001] and NYHA class (3.3±0.4 vs. 1.9±0.3, P<0.001) . The pacing thresholds [ (2.2±1.6) V/0.4 ms vs. (2.3±1.8) V/0.4 ms, P=0.9] , sensing [ (3.8±2.3) mV vs. (3.2±1.6) mV, P=0.22] , and impedance of HBP leads [ (530.7±74.4) Ω vs. (505.4±102.4) Ω, P=0.56] were comparable during the procedure as well as during follow-ups. Conclusion Permanent HBP improved cardiac function significantly in heart failure patients with dependence of right ventricular pacing and a part of CRT patients. Key words: His bundle pacing; Chronic heart failure; Cardiac resynchronization therapy