Recurrent Persistent Atrial Fibrillation:In-situ Ablation Vs Extensive Ablation

Inclusion Criteria: 1. Age 18 years or older; 2) Diagnosed as recurrent PerAF according to the latest clinical guidelines; 3) Ineffective or intolerable to ≥1 anti-arrhythmia drug treatment; 4) the first ablation procedure was PVI and linear ablation; 5) consented to receive radiofrequency catheter ablation. Exclusion Criteria: * 1\) Recurrent atrial flutter/atrial tachycardia; 2) The first ablation procedure included extra-PV substrate ablation; 3) The first low voltage area\>30%; 4) Serious complications during the first procedure; 5) The first ablation was paroxysmal atrial fibrillation. 6) Uncontrolled congestive heart failure; 7) History of severe valve disease and/or prosthetic valve replacement; 8) Left atrial thrombus confirmed by preoperative esophageal ultrasound; 9) Severe congenital heart disease; 10) Severe lung disease; 11) Left atrial diameter ≥60mm; 12) Contraindications for cardiac catheterization; 13) Myocardial infarction or stroke within 6 months; 14) Contrast agent allergy; 15) The use of anticoagulant drugs is contraindicated; 16) Have performed any cardiac surgery within 2 months;17) life expectancy is less than one year, including factors such as physical inability to tolerate ablation or unstable disease conditions.