Objective To explore the safety and efficacy of radiofrequency catheter ablation(RCFA)in patients with persistent atrial fibrillation(AF)/atrial flutter(AFL)and heart failure(HF)with left ventricular ejection fraction≤35%.Methods This study is a retrospective study.Patients with persistent AF/AFL and HF with left ventricular ejection fraction≤ 35%admitted to Beijing Anzhen Hospital from January 2018 to March 2024 were enrolled.The perioperative characteristics and complications changes in echocardiographic parameters,and follow-up outcomes were analyzed.Results A total of 45 patients were enrolled with a mean age of(56±13)years and a mean LVEF of(28±4)%.The ablation strategy was circumferential pulmonary vein isolation and empirical linear ablation.The operation time and fluoroscopy time were 120(120,163)min and 5(4,10)min respectively.The patients mainly underwent linear ablation including circumferential pulmonary vein isolation(38,84.4%),cavotricuspid isthmus(37,82.2%),roofline(34,75.6%),mitral isthmus(34,75.6%).21(46.7%)patients underwent ehtanol infusion into the vein of Marshall.24(53.3%)patients underwent electrocardioversion.All patients restored sinus rhythm immediately after RFCA and had no perioperative complications.After a median follow-up of 22.9(7.8,31.0)months,2 patients died of cardiovascular disease,1 patient underwent heart transplantation,14(33.3%)patients were readmitted for cardiovascular disease,and 10 patients(23.8%)had recurrence of AF.The mean LVEF of the 28 patients who obtained LVEF at the last follow-up increased from(28±4)%to(51±14)%,and the average improvement of LVEF was(23±13)%(P<0.0001).15 of these patients had complete recovery of left ventricular systolic function(LVEF≥ 50%).Conclusions RFCA is safe and effective for patients with persistent AF/AFL and HF with LVEF ≤ 35%,and can improve patient's cardiac function and significantly increase LVEF.