Clinical Efficacy of Left Bundle Branch Area Pacing for Patients With Permanent Atrial Fibrillation and Heart Failure

Inclusion Criteria: * Adult patients aged more than 18 years old * Patients diagnosed with heart failure (LVEF\<50%) and have received optimal medical therapy for at least 3 months * Patients with permanent atrial fibrillation (QRS duration \<130ms) which need ventricular pacing, including: 1. LVEF\<50%, NYHA II-IV, drug-refractory atrial fibrillation with the fast ventricular rate, planned atrioventricular nodal ablation due to 1). anticipated low success rate of atrial fibrillation catheter ablation or 2). patients refused to receive catheter ablation or 3). refused to receive another catheter ablation after a previous history of failed procedures 2. LVEF\<50%, NYHA II-IV, atrial fibrillation with slow ventricular rate, anticipated ventricular pacing burden ≥ 40% * Written informed consent was provided Exclusion Criteria: * expected survival time is less than 12 months * Prior history of mechanical tricuspid valve replacement and/or congenital heart disease (including dextrocardia, transposition of the great arteries, single left persistent left superior vena cava, etc.) * Plan for PCI or CABG due to unstable angina or myocardial infarction in 3 months * Surgery is required within 1 year due to severe structural heart disease * Pregnancy, planned pregnancy or heart transplant * Prior history of HCM and/or ventricular septal defect repair, who are unlikely to achieve successful LBBAP procedure. * Failure of lead placement due to abnormal anatomy of the coronary sinus or enlarged right atrium, which makes it unable to switch from one pacing modality to another