AUTHOR=Zhang Lu , Jiang Longfu , Luo Binbin , Shen Jiabo , Wu Hao , Zeng Weifang 

TITLE=Six transition patterns and seven capture types in different left bundle branch bipolar pacing configurations

JOURNAL=Frontiers in Cardiovascular Medicine

VOLUME=Volume 11 - 2024

YEAR=2024

URL=https://www.frontiersin.org/journals/cardiovascular-medicine/articles/10.3389/fcvm.2024.1430529

DOI=10.3389/fcvm.2024.1430529

ISSN=2297-055X

ABSTRACT=This study aims to explore the different transition patterns and capture types during two bipolar pacing tests based on the selective left bundle branch (LBB) capture determined by the continuous pacing and recording technique.Sixty-seven patients completed two unipolar and two bipolar pacing tests based on selective LBB capture during screwing-in for left bundle branch pacing (LBBP) using the continuous pacing and recording technique. The electrophysiological characteristics and potential mechanism of different pacing configurations were further evaluated in this study.We found six transition patterns and derived seven capture types in two bipolar pacing tests according to the analysis of continuous electrocardiogram and electrogram changes. Compared with the conventional configuration of "Tip-Ring+" bipolar pacing, "Ring-Tip+" testing had lower threshold for simultaneous capture of LBB, left and right ventricular septum myocardium (1.57 V vs 2.84 V at 0.5 ms) and was the only configuration to yield the peculiar "LBBP+ right ventricular septum pacing (RVSP)" capture type.In this study, we observed for the first time that the "Ring-Tip+" bipolar pacing allows for a lower clinically applicable pacing threshold for simultaneous capture of LBB, left Zhang et al. 3   and right ventricular septum myocardium, and the peculiar "LBBP+ RVSP" capture type. This may be a more advantageous physiological pacing configuration, warranting further investigation and application in the future.Based on the specific selective LBB capture, We first found six transition patterns and derived 7 capture types in two bipolar pacing tests due to the different thresholds of LBB, left ventricular septal myocardial (LVSM) and right ventricular septal myocardial (RVSM).Compared with the conventional configuration of "Tip-Ring+" bipolar pacing, "Ring-Tip+" testing had lower threshold for simultaneous capture of LBB, left and right ventricular septum myocardium (1.57 V vs 2.84 V at 0.5 ms) and was the only configuration to yield the peculiar "LBBP+ RVSP" capture type. More pacing strategies should be released and investigated to achieve the best physiological pacing according to the individualized electrophysiological characteristics of patients.