Author + information
- Received November 25, 2019
- Revision received April 2, 2020
- Accepted April 3, 2020
- Published online July 20, 2020.
- Weijian Huang, MDa,b,∗∗ (, )
- Shengjie Wu, MDa,b,∗,
- Pugazhendhi Vijayaraman, MDc,∗,
- Lan Su, MDa,b,
- Xueying Chen, MDd,
- Bingni Cai, MDe,
- Jiangang Zou, MDf,
- Rongfang Lan, MDg,
- Guosheng Fu, MDh,
- Guangyun Mao, PhDi,
- Kenneth A. Ellenbogen, MDj,
- Zachary I. Whinnett, BM BS, PhDk and
- Roderick Tung, MDl
- aDepartment of Cardiology, First Affiliated Hospital of Wenzhou Medical University, Wenzhou, China
- bKey Lab of Cardiovascular Disease of Wenzhou, Wenzhou, China
- cGeisinger Heart Institute, Wilkes-Barre, Pennsylvania
- dDepartment of Cardiology, Zhongshan Hospital of Fudan University, Shanghai Institute of Cardiovascular Diseases, Shanghai, China
- eDepartment of Cardiology, Xiamen Cardiovascular Hospital, Xiamen University, Xiamen, China
- fDepartment of Cardiology, Jiangsu Province Hospital, Nanjing, China
- gDepartment of Cardiology, Nanjing Drum Tower Hospital, the Affiliated Hospital of Nanjing University Medical School, Nanjing, China
- hDepartment of Cardiology, Sir Run Run Shaw Hospital, affiliated to Medical College of Zhejiang University, Hangzhou, China
- iSchool of Environmental Science & Public Health, Wenzhou Medical University, Wenzhou, China
- jDepartment of Cardiology, Virginia Commonwealth University Health System, Richmond, Virginia
- kNational Heart and Lung Institute, Imperial College London, London, United Kingdom
- lUniversity of Chicago Medicine, Center for Arrhythmia Care, Pritzker School of Medicine, Department of Medicine, Section of Cardiology, Chicago, Illinois
- ↵∗Address for correspondence:
Dr. Weijian Huang, Department of Cardiology, First Affiliated Hospital of Wenzhou Medical University, Key Lab of Cardiovascular Disease of Wenzhou, Nanbaixiang, Wenzhou 325000, China.
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.
- cardiac resynchronization therapy
- heart failure
- His bundle pacing
- left bundle branch block
- left bundle branch pacing
- left conduction system
↵∗ Drs. Huang, Wu, and Vijayarman contributed equally to this work and are joint first authors.
This research was funded by the Key Research and Development Program of Zhejiang (2019C03012) and the Major Project of the Science and Technology of Wenzhou (ZS2017010). Dr. Vijayaraman is a speaker and a consultant for Medtronic; has received research and fellowship support from Medtronic; is a consultant to Boston Scientific, Abbott, Biotronik, and Merrit Medical; and has a patent pending for a His bundle pacing delivery tool. Dr. Ellenbogen is a speaker for Medtronic; and has received research and fellowship support from Medtronic. Dr. Whinnett is a speaker for Medtronic and Boston Scientific. Dr. Tung is a speaker and a consultant for Boston Scientific, Medtronic, Biotronik, and Abbott. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose.
The authors attest they are in compliance with human studies committees and animal welfare regulations of the authors’ institutions and Food and Drug Administration guidelines, including patient consent where appropriate. For more information, visit the JACC: Clinical Electrophysiology author instructions page.
- Received November 25, 2019.
- Revision received April 2, 2020.
- Accepted April 3, 2020.
- 2020 American College of Cardiology Foundation
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