This is a single-arm clinical trial evaluating the efficacy and safety of left atrial isolation achieved by catheter ablation in patients with persistent atrial fibrillation with severe atrial fibrosis.

This is a single-arm clinical trial. Patients with persistent atrial fibrillation with severe atrial fibrosis are enrolled as subjects to conduct left atrial isolation by catheter ablation. Postoperative recurrence rate and other indicators are analyzed to evaluate the efficacy and safety of left atrial isolation achieved by catheter ablation in patients with persistent atrial fibrillation with severe atrial fibrosis.

Inclusion Criteria:

1. Aged 18 to 80 years old
2. Persistent AF with severe atrial fibrosis and left atrial anterioposterior diameter > 50mm
3. Nonresponse or intolerance to ≥1 antiarrhythmic drug
4. CHA2DS2-VASc ≥ 3 and HAS-BLED < 3

Exclusion Criteria:

1. With uncontrolled congestive heart failure;
2. Having significant valvular disease;
3. Having moderate-to-severe pulmonary hypertension;
4. With myocardial infarction or stroke within 6 months of screening;
5. With Significant congenital heart disease;
6. Ejection fraction was <40% measured by echocardiography;
7. Allergic to contrast media;
8. Contraindication to anticoagulation medications;
9. Severe pulmonary disease e.g. restrictive pulmonary disease, chronic obstructive disease (COPD);
10. Left atrial thrombus;
11. Having any contraindication to right or left sided heart catheterization