Termination of Persistent Atrial Fibrillation by Catheter Ablation

Inclusion Criteria: 1\. Aged 18 to 80 years old; 2. Persistent AF; 3. Nonresponse or intolerance to ≥1 antiarrhythmic drug. Exclusion Criteria: 1. With uncontrolled congestive heart failure; 2. Having significant valvular disease and/or prosthetic heart valve(s); 3. With myocardial infarction or stroke within 6 months of screening; 4. With Significant congenital heart disease; 5. Ejection fraction was \<40% measured by echocardiography; 6. Allergic to contrast media; 7. Contraindication to anticoagulation medications; 8. Severe pulmonary disease e.g. restrictive pulmonary disease, chronic obstructive disease (COPD); 9. Left atrial (LA) thrombus measured by pre-procedure transesophageal echocardiography; 10. Having any contraindication to right or left sided heart catheterization; 11. Previous atrial fibrillation ablation; 12\. Presence of an implanted cardioverter-defibrillator; 13. Any cardiac surgery within the past 2 months; 14. Poor general health; 15.Life expectancy less than 6 months.