A Multicenter Study of the Electrical Characteristics and Short-Term Outcomes of the Aveir VR Leadless Pacemaker

BackgroundThe Aveir leadless pacemaker employs an active fixation method, enabling real-time monitoring of electrical parameters during implantation. However, comprehensive studies regarding the electrical parameters during this procedure are rare. ObjectiveThis study aims to analyze the electrical characteristics to further guide the implantation strategy and improve device stability and safety. MethodsThis multi-center retrospective study enrolled 119 patients (mean age 70.18 years; 59.58% female) who received the Aveir VR leadless pacemaker from November 2024 to May 2025 across ten centers in China. Intraprocedural variations in commanded electrogram (CEGM), current of injury (COI), impedance, pacing threshold, and sensing parameters were meticulously documented. ResultsCEGM mapping demonstrated various morphologies (R, RS, QR, QRS, and QS) aiding localization. During fixation, 58.82% of patients exhibited an increased COI from mapping to 0.5 turns, which was associated with reduced short-term pacing thresholds. From 0.5 to 1 turn, 52.94% showed further COI increases. ROC analysis revealed that an impedance increase has predictive value for short-term pacing thresholds, with an AUC of 0.634 and a cut-off value of 230 {Omega} (sensitivity 0.622, specificity 0.41). Lead stability showed a moderate correlation with impedance increase ({rho}=0.44, P<0.001), while the correlation with COI was weak. ConclusionDuring Aveir implantation, CEGM variations guide site localization. Initial COI increases (0-0.5 turns) are linked to optimal short-term thresholds. Monitoring impedance increase is vital, as a threshold of 230 {Omega} serves as a key indicator of device stability and fixation quality.