Right ventricular pacing (RVP) causes left ventricular mechanical dyssynchrony by inducing electrical interventricular and intraventricular dyssynchrony. His bundle pacing may restore the the atrioventricular, interventricular and intraventricular electrical synchronization, however, Increased pacing threshold might result in the early depletion of the pacemaker, and finally brought on pacemaker replacement, which was one of the major causes of device infection. Pacing the left bundle branch beyond the conduction block site might achieve a low and stable output and narrow QRSd. The investigators were prepared to consecutively include patients with atrioventricular block, divided into the left bundle branch area pacing(LBBAP) group and the conventional right ventricular pacing group. The electrophysiological characteristics of LBBAP and right ventricular pacing were compared with ECG characteristics. The left and right ventricular synchrony and left and right cardiac function were evaluated by 3D ultrasound, and the short-term and long-term safety and efficacy of LBBAP were evaluated.

This study is intended to be included in Fuwai hospital for admission to the atrioventricular block, with permanent pacemaker implant indications recommended by current guidelines. Patients were assessed for preoperative electrocardiogram, quality of life scores, cardiac function, and left and right ventricular synchrony. Patients were followed up by regular outpatients. The electrocardiogram, quality of life score, echocardiographic function, left and right ventricular synchrony, pacing parameters and pacing ratio were evaluated immediately after surgery, 3 months, 6 months, and 12 months after surgery. At the same time, the left bundle branch area pacing success rate, complications during intraoperative and postoperative follow-up were recorded.

Inclusion Criteria:

1. Age over 18 years old;
2. Atrioventricular block patients with indication for permanent ventricular pacing;
3. LVEF> 40%;
4. With informed consent signed

Exclusion Criteria:

1. Persistent atrial fibrillation;
2. Moderate or more severe valvular disease;
3. Hypertrophic cardiomyopathy；
4. Myocardial amyloidosis；
5. With indication for CRT or ICD implantation according to the current guideline;
6. Poor condition of the acoustic window because of emphysema or other reasons;
7. Patients refused postoperative follow-up.

Consecutive AVB patients with indications for ventricular pacing according to 2013 ESC/EHRA Guidelines. Patients with persistent atrial fibrillation or indications for cardiac resynchronization therapy or implantable cardioverter defibrillator implantation , hypertrophic cardiomyopathy, myocardial amyloidosis, or refused postoperative follow-up were excluded. All patients should sign written informed consent for agreement of the implantation procedure.