The feasibility and efficacy of His-Purkinje conduction system pacing in patients with permanent atrial fibrillation and chronic heart failure indicated for cardiac resynchronization therapy

Background: The aim is to study the feasibility and efficacy of His-Purkinje conduction system pacing (HPCSP) in cardiac resynchronization therapy (CRT) candidates of chronic heart failure with permanent atrial fibrillation (AF). Subjects and Methods: Patients with chronic heart failure and permanent AF (n = 16) were enrolled from the Department of Cardiology, Zhongshan Hospital of Fudan University, from September 2017 to April 2019 in this observational case study. The patients with chronic heart failure (left ventricular ejection fraction [LVEF] <40%) and permanent AF with low ventricular rate were indicated for CRT implantation. The study was approved by the Institutional Ethical Committee of Zhongshan Hospital of Fudan University, China. At baseline, 13 cases had narrow QRS duration (<120 ms) and 3 cases had left bundle branch block with QRS duration >120 ms. HPCSP lead connected to the RA port of the generator was implanted together with conventional biventricular pacing (BVP) and was programmed as HPCSP postprocedure. QRS durations were measured and compared during intrinsic, BVP, and HPCSP. Pacing parameters were measured and compared during postimplantation immediately and 6 months postimplantation. Echocardiogram parameters, New York Heart Association (NYHA) class, and 6-min walking distance (6MWD) were collected and compared between baseline and 6 months postimplantation. Results: QRS durations were significantly different during HPCSP compared with BVP (P < 0.0001). Pacing parameters including threshold and R wave amplitude were not significantly different during postimplantation immediately and 6 months postimplantation, whereas impedance was significantly different (P = 0.028). LVEF, left atrial diameter, left ventricular end-diastolic diameter, left ventricular end-systolic diameter, mitral regurgitation, tricuspid annular plane systolic excursion, pulmonary artery systolic pressure, and the percentages of moderate-to-severe mitral regurgitation and tricuspid regurgitation were not significantly different between baseline and 6 months postimplantation, whereas NYHA class and 6MWD were significantly different (P < 0.0001). Conclusion: HPCSP was feasible and effective in CRT candidates of chronic heart failure with permanent AF and low ventricular rate. It could significantly reduce QRS duration as compared to BVP. Moreover, although LVEF was not obviously improved, the pacing parameters were stable and NYHA class and 6MWD were improved during HPCSP at 6-month follow-up.