This is a prospective, randomized multi center study comparing two catheter ablation strategies (pulmonary vein isolation (PVI) versus PVI plus low voltage areas (LVA) guided for ablation in patients with symptomatic persistent and long standing persistent atrial fibrillation (AF) who were unresponsive to at least one Class I or III antiarrhythmic agents, or it is the patient´s decision to receive ablation as first line therapy. Patients with documented persistent AF who are eligible for participation in the study, and gave a written informed consent, will be randomized between two groups prior to the procedure: PVI and PVI+LVAs guided radiofrequency catheter ablation.