Learning Curve Analyses for Left Bundle Branch Area Pacing with Conventional Stylet-Driven Pacing Leads.

Background: Physiological conduction system pacing has attracted attention to overcome the dyssynchrony problems of conventional right ventricular pacing (RVP). Left bundle branch area pacing (LBBAP), which complements short combing of His bundle pacing (HBP), has emerged and has proven its efficiency and safety. In addition, initial experiences of LBBAP were mainly using lumen-less pacing lead, and the feasibility of stylet-driven pacing lead (SDL) was also established. The purpose of this study is to evaluate the learning curve for LBBAP using SDL. Methods: The study enrolled 265 patients who underwent LBBAP or RVP performed by operators without previous LBBAP experience at Yonsei University Severance Hospital in Korea between December 2020 and October 2021. LBBAP was performed using SDL with an extendable helix. The learning curve was evaluated by analyzing fluoroscopy and procedure times. And, before and after reaching the learning curve, we evaluated how much the time required for the LBBAP differed from the time required for the RVP. Results: LBBAP was successful in 50 of 50 (100.0%) patients left bundle branch pacing was successful in 49 of 50 (98.0%). In 50 patients who underwent LBBAP, mean fluoroscopy and procedural times were 15.1 ± 13.5 minutes and 59.9 ± 24.8 minutes, respectively. The plateau of fluoroscopy time reached in the 25th case and the plateau of procedure time reached in the 24th case. Conclusion: During the initial experience with LBBAP, fluoroscopy and procedural times improved with increasing operator experience. For operators who were experienced in cardiac pacemaker implantation, the steepest part of the learning curve was over the first 24-25 cases. It is shorter than the previously reported learning curves of HBP.