The purpose of this study is to evaluate the safety and efficacy of conduction system pacing (CSP) using left bundle branch pacing (LBBP) and atrioventricular junction (AVJ) ablation in patients with end-stage heart failure and permanent atrial fibrillation (AF). Participants who are candidates for heart transplantation or left ventricular assist device (LVAD) implantation will be randomized to either the SYNC group (ICD implantation combined with LBBP and AVJ ablation) or the control group (ICD implantation only). The investigators will compare clinical outcomes, including mortality and heart failure hospitalization, between the two strategies over a 1-year follow-up period.