LAUSR

Abstract Funding Acknowledgements Type of funding sources: None. Background Automatic capture algorithms periodically measure the minimal quantity of current needed for pacing, self-adjusting output to guarantee consistent myocardial capture, enhancing patient safety in case of an unexpected rise in threshold and reducing current drain. Left bundle branch area pacing (LBBAP) is an emerging conduction system pacing (CSP) technique which overcomes technical issues and weaknesses of pure Hisian pacing. Purpose The aim of our study was to evaluate safety and efficacy of automatic threshold algorithms in a population of patients with LBBAP. Methods We prospectively enrolled patients receiving LBBAP with different companies which provide LBBAP material) and we evaluated automatic capture threshold algorithms safety and accuracy at 24 hours and at 3 months after implantation. Moreover, when available, home monitoring was used for follow up. Results We included 45 consecutive patients who underwent LBBAP from January 2022 to August 2022. At 24 hours, mean manual LBBAP threshold was 0.5±0.2 V at 0.4 msec, while automatic LBBAP threshold was 0.5±0.3 V at 0.4 msec (p = 0.30). At 3 months mean manual LBBAP threshold was 0.6±0.2V at 0.4 msec vs 0.6±0.2V at 0.4 msec (p = 0.25). Sensing and impedance measures where optimal at 24 hours and improved during 3 months follow up, respectively from 13.7±4.8 mV to 13.9±4.8 mV (p = 0.6) and from 460.1±130 Ohm to 417.1±96.2 Ohm (p = 0.1). Conclusion Automatic threshold algorithms are able to effectively measure LBBAP capture threshold both in the acute phase and during follow up. The possibility to safely use automatic threshold algorithms, thus preserving battery and protecting patients against possible future threshold rises, represents another advantage of LBBAP.