The purpose of this study it to learn whether pulmonary vein isolation (PVI) along with isolation of the posterior left atrial wall (PWI) in the region of the pulmonary venous component will reduce the likelihood of atrial fibrillation (AF) recurrence in patients with persistent atrial fibrillation at 12 months, after a single ablation procedure, in comparison to PVI alone.

The investigator hypothesizes that the combination of PVI + PWI will result in a significant reduction in recurrence of atrial fibrillation at 12 months after ablation.

Patients with persistent atrial fibrillation will be enrolled in this multi-center, randomized, prospective, single-blinded study. After catheter ablation (isolation) of the pulmonary veins (PVI) and while still in the cardiac electrophysiology laboratory, all patients will be randomized to either PVI alone or the combination of PVI + posterior left atrial wall isolation (PWI). For patients randomized to PVI, their ablation procedure will be completed at that time. For those patients randomized to PVI + PWI, they will have additional ablation to achieve PWI.

All study patients will have the same follow-up after their ablation procedure, including clinic visits at 3, 6, and 12 months and a heart event monitor for 7-14 days before these visits. An echocardiogram (heart ultrasound) is performed at 6 to 12 months after the ablation. Blood thinners are recommended for two months after ablation and then the need for continued use of blood thinners will be based on individual patient's medical history, stroke risk and the decision of the study doctor. Information about the patients' medical history, heart arrhythmias and atrial fibrillation will be collected during the study which will be analyzed.

Inclusion Criteria:

• Consistent with the current definitions, all patients with Persistent AF must exhibit an episode of continuous AF that is sustained >7 days.
• Patients must have symptomatic Persistent AF refractory or intolerant to at least one class I or class III antiarrhythmic drug
• Males and females with an age >18 years undergoing a first-time catheter ablation of AF; prior ablation of a right atrial cardiac arrhythmia (i.e., typical right atrial flutter) is permitted
• All patients must understand the requirements of the study and be willing to comply with the post-study follow-up requirements
• Patients must have documented episode of AF greater than 7 days in the year prior to the procedure

Exclusion Criteria:

• History of long-standing persistent AF
• Any reversible cause of AF (post-operative, thyroid disorder, etc.)
• Patients with cerebral ischemic events (stroke or transient ischemic attack), myocardial infarction or unstable angina in the previous 2 months
• Patients with any corrected or uncorrected congenital heart disease
• Patients with a history of hypertrophic cardiomyopathy
• Patients with cardiomyopathy and a left ventricular ejection fraction <40%
• Congestive heart failure, class IV
• Left atrial (LA) diameter >55 mm (parasternal long axis view)
• Patients with left atrial thrombus
• Women who are known to be pregnant or have had a positive β-HCG (human chorionic gonadotropin) test 7 days prior to procedure
• Patients whose life expectancy is <1 year
• History of left-sided left atrial ablation (catheter or surgically-based)
• Mental impairment precluding the patient from providing informed consent or completing appropriate follow-up