Comparison of electrical characteristics and pacing parameters of pacing different parts of the His-Purkinje system in bradycardia patients

We aimed to evaluate the electrical characteristics and pacing parameters at different locations of His-Purkinje system pacing. Patients who successfully underwent His-Purkinje system pacing with bradycardia indications from April 2018 to August 2019 were retrospectively analyzed according to the lead location confirmed by visualization of the tricuspid value annulus, postoperative echocardiography, and pacing electrocardiogram. The electrical characteristics and pacing parameters were compared among these patients. A total of 135 patients were retrospectively analyzed. Among them, 30 patients received atrial side HBP (aHBP group), 52 received ventricular side HBP (vHBP group), and 53 received left bundle branch pacing (LBBP group). The proportion of non-selective pacing was significantly lower in aHBP group (30.0%) than in vHBP (75.0%) and LBBP group (90.6%). LBBP had significantly shorter procedural and fluoroscopic duration than aHBP and vHBP. The capture threshold was significantly higher (1.07 ± 0.26 V/1.0 ms vs. 0.89 ± 0.22 V/1.0 ms vs. 0.77 ± 0.18 V/0.4 ms, P < 0.01, respectively), and the R-wave amplitude was significantly lower (3.71 ± 1.72 mV vs. 5.81 ± 2.37 mV vs. 10.27 ± 4.71 mV, P < 0.05 respectively) in aHBP group than those in the other two groups at implantation and during 3-month follow-up. No significant differences were observed in complications among groups during 3-month follow-up. VHBP and LBBP had better pacing performances than aHBP and might be more ideal pacing methods for bradycardia patients.