Ablation of Fibrotic Areas in Patients With Persistent Atrial Fibrillation.

Brief summary: The objective of this study is to compare two different ablation strategies in participants with persistent atrial fibrillation and fibrotic areas in the left atrium. The participant will be randomized to pulmonary vein isolation or pulmonary vein isolation plus ablation of fibrotic areas.

Inclusion Criteria: 1. ECG-documented persistent or long-standing persistent atrial fibrillation according to European Society of Cardiology (ESC) definition 2. Symptoms e. g. palpitations, dyspnea, tiredness that is due to the atrial fibrillation. 3. Suitable candidate for catheter ablation. 4. Tried one or more antiarrhythmic drugs or unwilling to try antiarrhythmic drugs 5. Age ≥18 years. Exclusion Criteria: 1. LA dimension \>55 mm as determined by an echocardiography within the previous year 2. Acute coronary syndrome or coronary artery bypass surgery within 12 weeks 3. Severe aortic or mitral valvular heart disease using the ESC guidelines 4. Congenital heart disease 5. Prior surgical or percutaneous AF ablation procedure or atrioventricular-nodal ablation 6. Medical condition likely to limit survival to \< 1 year 7. New York Heart Association (NYHA) class IV heart failure symptoms 8. Contraindication to oral anticoagulation 9. Renal failure requiring dialysis 10. AF due to reversible cause 11. Pregnant and fertile women without anticonception 12. History of non-compliance to medical therapy 13. Unable or unwilling to provide informed consent