Weijian Huang1, Shengjie Wu2, Pugazhendhi Vijayaraman3, Lan Su2, Xueying Chen4, Bingni Cai5, Jiangang Zou6, Rongfang Lan7, Guosheng Fu8, Guangyun Mao9, Kenneth A Ellenbogen10, Zachary I Whinnett11, Roderick Tung12. 1. Department of Cardiology, First Affiliated Hospital of Wenzhou Medical University, Wenzhou, China; Key Lab of Cardiovascular Disease of Wenzhou, Wenzhou, China. Electronic address: weijianhuang69@126.com. 2. Department of Cardiology, First Affiliated Hospital of Wenzhou Medical University, Wenzhou, China; Key Lab of Cardiovascular Disease of Wenzhou, Wenzhou, China. 3. Geisinger Heart Institute, Wilkes-Barre, Pennsylvania, USA. 4. Department of Cardiology, Zhongshan Hospital of Fudan University, Shanghai Institute of Cardiovascular Diseases, Shanghai, China. 5. Department of Cardiology, Xiamen Cardiovascular Hospital, Xiamen University, Xiamen, China. 6. Department of Cardiology, Jiangsu Province Hospital, Nanjing, China. 7. Department of Cardiology, Nanjing Drum Tower Hospital, the Affiliated Hospital of Nanjing University Medical School, Nanjing, China. 8. Department of Cardiology, Sir Run Run Shaw Hospital, affiliated to Medical College of Zhejiang University, Hangzhou, China. 9. School of Environmental Science & Public Health, Wenzhou Medical University, Wenzhou, China. 10. Department of Cardiology, Virginia Commonwealth University Health System, Richmond, Virginia, USA. 11. National Heart and Lung Institute, Imperial College London, London, United Kingdom. 12. University of Chicago Medicine, Center for Arrhythmia Care, Pritzker School of Medicine, Department of Medicine, Section of Cardiology, Chicago, Illinois, USA.
Abstract
OBJECTIVES: The aim of this study was to assess the feasibility and efficacy of left bundle branch pacing (LBBP) using a novel intraseptal technique to deliver cardiac resynchronization therapy (CRT) in patients with left bundle branch block (LBBB) and nonischemic cardiomyopathy. BACKGROUND: His bundle pacing to correct LBBB is a viable alternative approach to achieve CRT but is limited by suboptimal lead delivery and high thresholds. METHODS: This was a prospective, multicenter study performed between June 2017 and August 2018 at 6 centers. Patients with nonischemic cardiomyopathy, complete LBBB, and left ventricular ejection fractions (LVEFs) ≤50% who had indications for CRT and/or ventricular pacing in whom LBBP was attempted were included. Success rates, QRS duration, LVEF, left ventricular end-systolic volume, and improvement in functional class were assessed. RESULTS: LBBP was successful in 61 of 63 patients (97%, mean age 68 ± 11 years, 52.4% men). During LBBP, QRS duration narrowed from 169 ± 16 to 118 ± 12 ms (p < 0.001). Pacing threshold and R-wave amplitude remained stable at 1-year follow-up compared with implantation values (0.5 ± 0.15 V/0.5 ms vs. 0.58 ± 0.14 V/0.5 ms and 11.1 ± 4.9 mV vs. 13.3 ± 5.3 mV, respectively). LVEF increased significantly (33 ± 8% vs. 55 ± 10%; p < 0.001), with a reduction in left ventricular end-systolic volume (123 ± 61 ml vs. 67 ± 39 ml; p < 0.001). LVEF had normalized (≥50%) in 75% of patients at 1 year. New York Heart Association functional class improved significantly from 2.8 ± 0.6 at baseline to 1.4 ± 0.6 at 1 year. No deaths or heart failure hospitalizations were observed during follow-up. CONCLUSIONS: LBBP is a feasible and effective method for achieving electric resynchronization of LBBB, with resultant improvements in left ventricular structure and function. Low and stable pacing thresholds may be advantageous over His bundle pacing for CRT in patients with LBBB and nonischemic cardiomyopathy.
OBJECTIVES: The aim of this study was to assess the feasibility and efficacy of left bundle branch pacing (LBBP) using a novel intraseptal technique to deliver cardiac resynchronization therapy (CRT) in patients with left bundle branch block (LBBB) and nonischemic cardiomyopathy. BACKGROUND: His bundle pacing to correct LBBB is a viable alternative approach to achieve CRT but is limited by suboptimal lead delivery and high thresholds. METHODS: This was a prospective, multicenter study performed between June 2017 and August 2018 at 6 centers. Patients with nonischemic cardiomyopathy, complete LBBB, and left ventricular ejection fractions (LVEFs) ≤50% who had indications for CRT and/or ventricular pacing in whom LBBP was attempted were included. Success rates, QRS duration, LVEF, left ventricular end-systolic volume, and improvement in functional class were assessed. RESULTS: LBBP was successful in 61 of 63 patients (97%, mean age 68 ± 11 years, 52.4% men). During LBBP, QRS duration narrowed from 169 ± 16 to 118 ± 12 ms (p < 0.001). Pacing threshold and R-wave amplitude remained stable at 1-year follow-up compared with implantation values (0.5 ± 0.15 V/0.5 ms vs. 0.58 ± 0.14 V/0.5 ms and 11.1 ± 4.9 mV vs. 13.3 ± 5.3 mV, respectively). LVEF increased significantly (33 ± 8% vs. 55 ± 10%; p < 0.001), with a reduction in left ventricular end-systolic volume (123 ± 61 ml vs. 67 ± 39 ml; p < 0.001). LVEF had normalized (≥50%) in 75% of patients at 1 year. New York Heart Association functional class improved significantly from 2.8 ± 0.6 at baseline to 1.4 ± 0.6 at 1 year. No deaths or heart failure hospitalizations were observed during follow-up. CONCLUSIONS: LBBP is a feasible and effective method for achieving electric resynchronization of LBBB, with resultant improvements in left ventricular structure and function. Low and stable pacing thresholds may be advantageous over His bundle pacing for CRT in patients with LBBB and nonischemic cardiomyopathy.
Keywords:
His bundle pacing; cardiac resynchronization therapy; heart failure; left bundle branch block; left bundle branch pacing; left conduction system
Authors: Nadeev Wijesuriya; Mark K Elliott; Vishal Mehta; Baldeep S Sidhu; Marina Strocchi; Jonathan M Behar; Steven Niederer; Christopher A Rinaldi Journal: Front Physiol Date: 2022-06-06 Impact factor: 4.755