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 ofventricular pacing(VP)> 40%, including (a)Third-degree AV block; (b) Second degreeAV 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 studycenters.

• f. Subject or authorized legal guardian or representative has signed and dated thestudy 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 ontime 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 venacava, etc), or AV block resulting from: (a) Hypertrophic cardiomyopathy(HCM)vpost (modified) Morrow surgery, (b) ventricular septal defect repair; and those who areunlikely to achieve successful LBBAP procedure.