Although emerging evidence demonstrated that left bundle branch pacing (LBBP) is a promising alternative for patients with either a bradycardia or a heart failure pacing indication. However, a direct comparison of the safety, efficacy and LV systolic synchrony between LBBP and RVP regimens was rare. In this study, the investigators aim to conduct a comparison of the safety and effectiveness performance between these two pacing methods for patients with atrioventricular block (AVB). The investigators focused on AVB patients undergoing permanent pacemaker implantations from the 1st of January 2018 to the 18th of November 2021 at West China Hospital.