Atrial fibrillation treatments have a limited efficacy and often cause long-term side effects. This study aims to develop and validate an ECGI system to risk stratification in patients with persistent AF, identifying the mechanisms responsible for the maintenance and the best treatment for ending it.

The MAIN GOAL of this project is to clinically validate the technology for the noninvasive identification of the mechanisms responsible for maintenance of AF using ECGI. To achieve this goal, the investigators will analyze the efficacy of different treatment options in persistent AF patients as a function of the results of the ECGI. Mainly, patients will be evaluated attending to the complexity of the patterns obtained. Moreover, the investigators will evaluate the treatment benefit of performing guided-ablation in conjunction with pulmonary vein isolation as compared to pulmonary vein isolation only. These analyses will be performed in patients with persistent AF arriving at the clinic to determine treatment options. AF outcomes following the treatment assigned therapy will be evaluated at 6 months and 1 year after.

These parameters are obtained from the ECGI map: histogram of rotors (number of rotors and location), Highest and Lowest Dominant Frequency (Hz), rotor duration (ms), simultaneous rotors (number of rotors) and signal entropy (normalized).

Wide antrum circumferential pulmonary vein isolation with demonstration of bidirectional block will be performed using standard cooled-tip radiofrequency catheters or cryoballoon catheters.

Inclusion Criteria:

• Patients with paroxysmal AF symptomatic and refractory to at least one antiarrhythmic medication arriving in atrial fibrillation to the AF clinic.
• Patients with paroxysmal AF undergoing AF ablation in whom AF was induced at the EP laboratory.
• Patients with persistent AF or long-term persistent AF attending the AF clinic.
• Patients must be able and willing to provide written informed consent to participate in the study.
• Prior anticoagulation for> 4 weeks or transesophageal echocardiogram excluding intracardiac thrombi.

Exclusion Criteria:

Inclusion Criteria:

• Patients with paroxysmal AF symptomatic and refractory to at least one antiarrhythmic medication arriving in atrial fibrillation to the AF clinic.
• Patients with paroxysmal AF undergoing AF ablation in whom AF was induced at the EP laboratory.
• Patients with persistent AF or long-term persistent AF attending the AF clinic.
• Patients must be able and willing to provide written informed consent to participate in the study.
• Prior anticoagulation for> 4 weeks or transesophageal echocardiogram excluding intracardiac thrombi.

Exclusion Criteria:

• Patients with inadequate anticoagulation levels, left atrial thrombus, tumor, or another abnormality which precludes catheter introduction on TEE prior to the procedure.
• Patients with moderate-to-severe mitral regurgitation.
• Patients with contraindications to systemic anticoagulation with heparin or coumadin.
• Patients who are or may potentially be pregnant.
• Current enrollment in another investigational drug or device study.
• Pacemaker or Implantable Cardioverter Defibrillator.

AF patients manifesting atrial fibrillation at the AF clinic