Left Bundle Branch Pacing of His-Purkinje Conduction System: Initial Experience

Abstract

Background: Conventional right ventricular pacing increases the risk of atrial fibrillation and heart failure in pacemaker patients. Stimulation of the left bundle branch (LBB) of the His-Purkinje system can prevent the unwanted outcomes of right ventricular pacing. Objective: To retrospectively analyze the intraoperative outcomes, electrocardiographic and clinical data from the initial follow-up of patients submitted to stimulation of the LBB. Methods: The electronic parameters of the implant and of possible early complications of 52 consecutive patients submitted to stimulation of the conduction system were evaluated. The adopted significance level was 0.05. Results: Fifty-two patients underwent left bundle branch stimulation, with 50 successful procedures; 69.2% of the patients were male, and the median and interquartile range of age at the time of implantation was 73.5 (65.0-80.0) years. The pre-implant QRS duration was 146 (104-175) ms and 120 (112-130) ms after the procedure. The left ventricle activation time was 78 (70-84) ms. The R-wave amplitude was 12.00 (7.95-15.30) mV, with a stimulation threshold of 0.5 (0.4-0.7) V x 0.4 ms and impedance of 676 (534-780) ohms. The procedure duration was 116 (90-130) min, and the fluoroscopy time was 14.2 (10.0-21.6) min. Conclusion: Cardiac stimulation of the His-Purkinje conduction system through the stimulation of the left bundle branch is a safe and feasible technique. In this study, it showed a high success rate, with low procedure and fluoroscopy periods, achieving adequate electronic measurements.