Multiple electrode leads facilitate left bundle branch area pacing: A concept evaluation study

Left bundle branch area (LBBA) lead placement relies on single-electrode pacing guided by electrocardiogram markers during transeptal advancement. We hypothesize that multiple electrodes on a lead tip facilitate LBBA pacing.

This study aimed to develop and evaluate a multielectrode lead (MEL) with dimensions and electrical properties similar to clinically relevant lumenless leads (LLLs) for use in LBBA pacing.

Insulated 125 μm silver wires were fixed along a 3-dimensional printed MEL shaft. Wires were wrapped circumferentially at distal, medial, and proximal sites (0.4 mm apart), secured with polyimide, and deinsulated by sanding. The MEL tip was cut into a bevel shape to facilitate septal insertion. MEL has 5.4 mm² surface area across the 3 electrodes vs LLL's 3.6 mm² surface area. MELs and LLLs were inserted at up to 3 LBBA sites in perfused canine hearts (n = 4), totaling 9 sites. Impedance, pacing threshold, and shortest QRS duration at each insertion site were recorded and compared.

MEL and LLL had similar impedance and capture voltages. MEL's multiple pacing options evoked QRS morphology changes with pacing output and location. MEL more often detected a narrower QRS at insertion than LLL (LLL, 114 ms; quartile [Q]1-Q3, 98-120 ms; MEL, 82 ms; Q1-Q3, 68-98 ms; P = .03) and recorded QRS durations similar to sinus rhythm, suggesting MEL may better facilitate physiological pacing.

MELs more often evoked electrocardiogram markers indicative of conduction system capture during LBBA pacing, suggesting that MELs may streamline implantation, reduce lead repositioning, and advance conduction system pacing strategies.