This study is a prospective, randomized controlled, single-blind, multicenter study design. To evaluate the safety and efficacy of traditional pulmonary vein isolation (PVI) alone and PVI combined with Bachmann bundle ablation on persistent atrial fibrillation.

According to the treatment strategy, they were divided into two groups. Control group: circumferential PVI alone group (CPVI). Experimental group: CPVI combined with Bachmann bundle ablation group (CPVI-BBM).

Catheter ablation enhances the likelihood of maintaining sinus rhythm in patients with atrial fibrillation (AF); however, the procedural success rate remains suboptimal in individuals with persistent AF. Research indicates that the Bachmann bundle plays a significant role in the initiation and maintenance of AF. In a study utilizing a porcine model, Schwartzman et al. demonstrated that ablation at various sites within the right atrial septum-specifically, the fossa ovalis, the crista terminalis of the right atrium, and the coronary sinus ostium-can effectively disrupt left-right atrial conduction. This disruption occurs without impairing the conduction function of the atrioventricular node or inducing other atrial arrhythmias, although it does result in the cessation of electrical and mechanical activity in the left atrium. Kumagai et al. conducted radiofrequency ablation on the central portion of the Bachmann bundle on the epicardial surface of the canine heart, successfully blocking interatrial conduction and terminating AF. Electrophysiological mapping revealed an absence of activation entering the right atrium from the Bachmann bundle, and no evidence of the Bachmann bundle's involvement in the formation of a reentry loop was observed.This study seeks to examine the safety, efficacy, and long-term outcomes associated with the integration of circumferential pulmonary vein isolation (CPVI) and Bachmann bundle ablation in the management of persistent atrial fibrillation. Participants were allocated into two distinct groups based on the treatment strategy: the control group, which received pulmonary vein isolation alone (CPVI), and the experimental group, which underwent a combination of pulmonary vein isolation and Bachmann bundle ablation (CPVI-BBM).

Inclusion Criteria:

1. Subjects≥ 18 years old and ≤ 75 years old;
2. the subject was diagnosed with persistent atrial fibrillation (duration of ≥6 months and ≤ 3 years);
3. Able to understand the purpose of the trial, voluntarily participate in this study, the subject or his legal representative signed the informed consent form, and was willing to complete the follow-up according to the requirements of the protocol.

Exclusion Criteria:

1. Previous atrial fibrillation catheter ablation therapy, left atrial appendage closure or atrial fibrillation surgery;
2. atrial fibrillation secondary to electrolyte imbalances, thyroid disease or other reversible disease, or non-cardiac causes;
3. Left atrial or left atrial appendage thrombus (confirmed by esophageal ultrasound or CT examination);
4. Patients with pulmonary vein stenosis or pulmonary vein stents implanted;
5. Have had atrial septal repair or atrial myxoma;
6. Severe structural heart disease (such as moderate to severe mitral regurgitation, dilated cardiomyopathy, hypertrophic cardiomyopathy, severe heart valve disease);
7. Cardiac ultrasound showed that the diameter of the left atrium was ≥50mm
8. New York College of Cardiology (NYHA) cardiac function grades III and IV; LVEF<40%；
9. Those with cerebrovascular diseases (including stroke, transient ischemic attack) in the past 3 months;
10. Those who have had cardiovascular events in the past 3 months (including acute myocardial infarction, coronary intervention or heart bypass);
11. surgery, prosthetic valve replacement or repair, atrial or ventriculotomy;
12. Those with acute or severe systemic infection;
13. Combined with severe liver and kidney insufficiency (AST or ALT≥ 3 times the upper limit of normal; SCr>3.5mg/dl or Ccr<30ml/min);
14. Those with obvious bleeding tendency and hematologic diseases, or contraindications to anticoagulation;
15. Patients with malignant tumors and end-stage diseases with a life expectancy of < 12 months; After chemotherapy or radiotherapy for malignant tumors;
16. The subject is a female who is pregnant or lactating or cannot use contraception during the trial;
17. The subject has participated in clinical trials of other drugs or devices during the same period;
18. Abnormalities or diseases that, in the opinion of the investigator, should be excluded from the scope of enrollment in this study.