AUTHOR=Ye Yang , Wu Shengjie , Su Lan , Sheng Xia , Zhang Jiefang , Wang Bei , Sharma Parikshit S. , Ellenbogen Kenneth A. , Su Yangang , Chen Xueying , Fu Guosheng , Huang Weijian 

TITLE=Feasibility and Outcomes of Upgrading to Left Bundle Branch Pacing in Patients With Pacing-Induced Cardiomyopathy and Infranodal Atrioventricular Block

JOURNAL=Frontiers in Cardiovascular Medicine

VOLUME=Volume 8 - 2021

YEAR=2021

URL=https://www.frontiersin.org/journals/cardiovascular-medicine/articles/10.3389/fcvm.2021.674452

DOI=10.3389/fcvm.2021.674452

ISSN=2297-055X

ABSTRACT=His bundle pacing (HBP) can reverse left ventricular (LV) remodeling in patients with right ventricular (RV) pacing induced cardiomyopathy (PICM), but may be unable to correct infranodal atrioventricular block (AVB). Left bundle branch pacing (LBBP) results in rapid LV activation and may be able to reliably pace beyond the site of AVB. Our study was to assess the feasibility, safety and outcomes of permanent LBBP in infranodal AVB and PICM patients. Patients with infranodal AVB and PICM that underwent LBBP for cardiac resynchronization therapy（CRT）were included. Clinical evaluation, echocardiographic and electrocardiographic assessments were recorded at baseline and follow-up. Permanent LBBP upgrade was successful in 19 of 20 patients with a median follow-up duration of 12 months. QRS duration (QRSd) increased from 139.3 ±28.0 ms at baseline to 176.2 ± 21.4 ms (P<0.001) with RVP and was shortened to 120.9 ±15.2 ms after LBBP (P <0.001). The mean LBBP threshold was 0.7 ± 0.3 V@0.4ms at implant and remained stable during follow-up. The LVEF increased from 36.3 ± 6.5% to 51.9 ±13.0 % (P<0.001) with LVESV reduced from 180.1 ± 43.5 to 136.8 ± 36.7 ml (P<0.001) during last follow-up. LBBP paced beyond the site of block which results in a low pacing threshold with a high success rate in infra-nodal AVB patients. LBBP improved LV function with stable parameters over the 12 months, making it a reasonable alternative to cardiac resynchronization pacing via a coronary sinus lead in infranodal AVB and PICM patients.

Keywords: cardiac pacing; atrioventricular block (AVB); pacing-induced cardiomyopathy (PICM); heart failure (HF); His bundle pacing (HBP); left bundle branch pacing (LBBP); cardiac resynchronization therapy (CRT)；