Electrophysiological parameters and anatomical evaluation of left bundle branch pacing in an in vivo canine model

Abstract

Introduction: Left bundle branch pacing (LBBP), a form of conduction system pacing in addition to His bundle pacing (HBP), can potentially maintain left ventricular electrical synchrony with better sensing and a low and stable capture threshold. Methods:We performed both HBP and LBBP using a canine model (n = 3; male;weight 30-40 kg). The electrocardiogram (ECG), intracardiac electrogram characteristics, and pacing parameters were compared between HBP and LBBP. The hearts were isolated and stained by Lugol's iodine (5%) to assess the relative locations of the leads in relation to the conduction system. Results:The average potential to ventricle interval was longer with HBP compared to LBBP (26.67 ± 3.06 ms vs 12.67 ± 1.15 ms; P = .002). There were also notable differences in the pacing parameters between HBP and LBBP: R-wave amplitude (2.67 ± 0.42 mV vs 11.33 ± 3.06 mV; P = .008), pacing impedance (423.3 ± 40.4 vs 660.0 ± 45.8; P = .003), and threshold (2.30 ± 0.66 V/0.4ms vs 0.67 ± 0.15 V/0.4 ms; P = .014). The paced morphology of ECG was similar to the intrinsic with HBP while a right bundle branch block pattern was noted with LBBP. The anatomical evaluation revealed the location of the leads and the average lead depth was significantly more with LBBP as compared to HBP (12.33 ± 1.53 mm vs1.83 ± 0.29 mm; P < .0001). Furthermore, with LBBP, the tip of the lead helix was noted to be around the LBB. Conclusion:This in vivo canine model study confirms the significant differences between HBP and LBBP. Furthermore, this model provides a precise anatomic evaluation of the location and the depth of the leads in relation to the conduction system. K E Y W O R D S anatomical evaluation, canine model, conduction system pacing, electrocardiogram, His bundle pacing, left branch bundle pacing SUPPORTING INFORMATION Additional supporting information may be found online in the Supporting Information section. How to cite this article: Chen X, Jin Q, Li B, et al. Electrophysiological parameters and anatomical evaluation of left bundle branch pacing in an in vivo canine model.

How Electrode Position Affects Selective His Bundle Capture: A Modelling Study

“…The capture thresholds computed were close to the range of those observed clinically [18]- [23], although a bit low. We presented most results for a pulse of 1 ms duration while 0.5 ms is often used [23].…”

Feasibility and stability of left bundle branch pacing in patients after prosthetic valve implantation

“…New onset BBB developed frequently after TAVR or SAVR and associated with increased early and late all‐cause mortality 6 . It has been demonstrated that patients with typical‐BBB morphology could benefit from LBBP in terms of QRS correction 23,24 . In the present study, BBB correction via LBBP succeeded in all the four patients complicated with BBB after TAVR or SAVR with a low and stable capture threshold during follow‐up.…”

Procedure-Related Complications of Left Bundle Branch Pacing: A Single-Center Experience

“…LBB is a wide network beneath the endomyocardium of the left septum (18). Thus, positioning of the lead at this area could easily capture the left conduction system (8). In case of lead dislodgement and perforation, repositioning of the lead to a distal LBB area could probably prevent the recurrence of these complications because the original area might be injured by the lead, and the fixation of lead in posterior septum through the C315 His sheath is simple.…”

“…However, as a novel pacing technique, the safety of LBBP has not been well-documented. To capture the left conduction system, the LBBP lead should be screwed deep enough into the subendomyocardium of the left ventricle (8), which differs from the conventional right ventricular (RV) pacing lead. Consequently, unique procedure-related complications, such as interventricular septum perforation, lead dislodgement, septum injury, and lead fracture, of LBBP are observed.…”