Benefit of Complex Fractionated Atrial Electrograms Elimination in Atrial Fibrillation Ablation

Inclusion Criteria: * Patients with persistent (more than 7 days, or less than 7 days needing pharmacologic or electric cardioversion) * Presence of atrial fibrillation at the beginning of the procedure Exclusion Criteria: * Hypo or hyperthyroidism * Persistent long-lasting or non-defined duration atrial fibrillation * Hypertrophic myocardiopathy * Implantable defibrillation or pacemaker implanted * Moderate or severe mitral valve disease or mitral prosthetic valve * Ejection fraction less than 30% * Left atrial anteroposterior diameter more than 50 mm. * Previous atrial fibrillation ablation * Contraindication to anticoagulation * Left atrium thrombus * Current infective disease or sepsis * Pregnant women * Current unstable angor * Acute myocardial infarction in last 3 months * Atrial fibrillation secondary to ionic disturbance, thyroids disease or secondary to any other reversible or non cardiovascular disease * Reduced expectancy of life (less than 12 months) * Patient participating in another clinical study that investigates a drug or device * Psychologically unstable patient or denies to give informed consent * Any cause that contraindicate ablation procedure or antiarrhythmic drug