Although no ablation system is yet approved in patients with persistent AF, these patients are increasingly undergoing ablation. Many investigators feel that these patients have more atrial disease and thus PVI alone is insufficient in these patients. As a result, it is common for these patients to undergo additional ablation, which is often quite extensive and exposes patients to proarrhythmia. Commonly utilized strategies include linear lesions (left atrial roof; mitral isthmus line), ablation of complex fractionated atrial electrograms (CFAEs), left atrial appendage isolation and/or even right atrial ablation. For years, the investigators have been concerned about the adverse effects of this additional ablation. The investigators postulated that the "answer" is not more ablation but trying to "reverse remodel" patients with persistent AF back to a paroxysmal form, whereby PVI alone would again be justified and sufficient. The efficacy of such a strategy has previously been demonstrated.