Correlation of the Arrhythmia Mechanism and Substrate to Ablate Persistent Atrial Fibrillation Study

Inclusion Criteria: * Age ≥18 years and ≤ 80 years; * Symptomatic persistent AF AND clinically indicated for AF catheter ablation * At least one episode of AF lasting more than 7 days, documented on 12-lead ECG, Holter monitor, 2-week loop monitor or trans-telephonic monitor (TTM) within 12 months of enrollment in the study * Able to provide informed consent. Exclusion Criteria: * History of previous catheter or surgical ablation for AF * Presence of intracardiac thrombus * contraindication to systemic oral anticoagulation therapy * Subjects with reversible causes of AF * Antero-posterior left atrial dimension \> 60 mm on echocardiography * Severe valvular disease (mitral/aortic stenosis or regurgitation); * Subjects that are pregnant or breastfeeding; * Chronic kidney disease and creatinine clearance \<50ml/min. * Contraindication to MRI Imaging (e.g. permanent pacemaker, metallic implants, etc)