Impact of Left Bundle Branch Area Pacing vs. Right Ventricular Pacing in Atrioventricular Block (LEAP-Block)

Inclusion Criteria: * a. Adult patients aged 18-90; * b. AV block patients with ventricular pacing indications and the expected rate of ventricular pacing(VP)\> 40%, including (a)Third-degree AV block; (b) Second degree AV block (type II); (c) intermittent advanced AV block with expected VP\>40%; (d)Symptomatic first degree AV block and PR interval on ECG ≥ 250ms; * c. The subject is able to receive a pectoral implant; * d. The subject is willing and able to comply with the protocol; * e. The subject is expected to remain available for follow-up visits at the study centers. * f. Subject or authorized legal guardian or representative has signed and dated the study Subject Informed Consent Exclusion Criteria: * a. Baseline echocardiographic assessment of patients with impaired LV function (LVEF\<50%); * b. Having difficulties in follow-up: Those who cannot accept 2-year follow-up on time due to physical condition or other reasons; * c. Patients with persistent atrial fibrillation; * d. Pacemaker replacement without new implanted ventricular electrodes; * e. Patients with implantable cardioverter-defibrillator (ICD) indications; * f. Surgery is required within 1 year due to severe structural heart disease; * g. Patients with tricuspid mechanical valve replacement, or congenital heart disease (including transposition of the great arteries, or permanent left superior vena cava, etc), or AV block resulting from: (a) Hypertrophic cardiomyopathy(HCM)vpost (modified) Morrow surgery…