Po-05-110 multi-contact lead to facilitate left bundle branch pacing

Left bundle branch pacing (LBBP) has emerged as a preferred physiological pacing approach, however it is constrained by difficult implantation techniques and inconsistent LBB capture. Therefore, to facilitate LBBP and to improve implantation success, a novel pacing lead specifically for cardiac conduction system pacing that addresses these limitations is necessary. Develop a multi-contact lead (MCL) to facilitate pacing the conduction system at low threshold. A novel lead with five contacts at the distal end was designed and prototyped with fine silver wire wrapped around a central stainless-steel shaft. Insulation was removed from the silver wire with an Ultraviolet laser. The contacts were spaced apart from each other at distances ranging from 0.2 mm to 1.0 mm. The MCLs were tested on five isolated, perfused adult canine hearts. The right ventricular (RV) septum was exposed by opening the RV and leads were inserted from the RV septum to near the left ventricular (LV) septal surface. A standard clinical lead (Medtronic 3830) was also implanted from the RV septal surface. RV apex pacing was performed with a pair of pacing wires. Pacing thresholds for LBB capture were determined and QRS duration was measured from the pseudo-ECG recorded in perfusion bath. LBB capture was achieved for the standard lead and all combinations of MCL. LBB capture threshold was lower for the lowest combination of contacts on MCL compared to the standard 3830 lead values (0.68 ± 0.3 V vs. 1.63 ± 0.7 V, respectively, P < 0.01, Fig A). LBB capture was verified by comparing the shortest MCL QRS duration in each study with sinus rhythm and right ventricular pacing QRS durations (63.8 ± 9.6, 56.4 ± 5.9, and 106.8 ± 16.7 ms, respectively, Fig B). The novel MCL has the potential to facilitate the physiologic pacing process of LBBP. MCL enables a narrowly paced QRS complex and a low pacing capture threshold with a high success rate.