Quantitative analysis reveals influencing factors to facilitate successful anodal-ring capture in left bundle branch pacing

Abstract

Background and Aims Left bundle branch pacing (LBBP) maintains left ventricular synchrony but induces right ventricular conduction delay (RVCD). Although anodal-ring capture (ARC) during bipolar LBBP improves RVCD, it is not achieved in all patients receiving LBBP. This study aimed to analyze the factors influencing ARC implementation. Methods Patients receiving LBBP with intraoperative ARC testing were enrolled. Electrocardiographic parameters were measured, including stimulus-to-QRS duration (stim-QRSd), stimulus-to-left/right ventricular activation time (stim-LVAT/RVAT), and V6-V1 interpeak interval. The distribution of lead-tip sites was described as the corrected longitudinal and lateral distance (longit-/lat-dist). Relative angles of the LBBP lead were measured. Echocardiography in short axis view was used to measured the intra-septal lead length. Intergroup comparisons, correlation analysis, and stepwise logistic regression were performed. Results Totally 105 patients were included, among which 65 (62%) patients achieved ARC at a pacing output ≤ 5.0 V/0.5ms (average 3.1 V/0.5ms). ARC further shortened the stim-QRSd by 13.1 ± 7.5 ms. Better unipolar-ring (cathodal) threshold and R-wave sensing in LBBP-ARC group indicated the critical role of ring-septum contact in ARC. Longer corrected longit-dist and shorter corrected lat-dist of lead-tip sites were positively correlated with higher success likelihood of ARC, likely due to the greater relative angle in which the lead entering the septum and consequently the longer intra-septal lead length and better ring-septum contact. Conclusions This study elucidated the factors affecting the success likelihood of LBBP-ARC. These findings improve the understanding of LBBP-ARC, providing references for future research and clinical practice.

Conduction system pacing is superior to reduce the new-onset atrial fibrillation risk compared with right ventricular pacing: insights from pooled clinical evidence

“…Our findings should be further assessed in further multicenter randomized trials with longer follow-up and larger sample size. Second, accumulated studies suggested that LBBP achieved left ventricular synchrony but induced right ventricular conduction delay[32]. Bipolar LBBP was expected to improve the bi-ventricular electrical synchrony in comparison of unipolar LBBP, futher achieving more physiological conduction system activation[33].…”