Abstract
BACKGROUND: 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. OBJECTIVE: 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. METHODS: 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 mm(2) surface area across the 3 electrodes vs LLL's 3.6 mm(2) 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. RESULTS: 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. CONCLUSION: 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.