RESTORE SR II is a feasibility study on the minimally invasive use of the AtriCure Bipolar System for PV Isolation on a beating heart for the treatment of all types of atrial fibrillation in a sole therapy operation (not concomitant to another cardiac operation).

Inclusion Criteria:

1. Male or female patient between 18 and 80 years of age

2. Patient with symptomatic AF and failure or intolerance of one or more Class I or Class III AADs and:

   • Who describes 3 or more symptomatic AF episodes during the 6 month period prior to enrollment, with at least 1 electrocardiographically documented episode of AF in the 4 months prior to enrollment or,
   • Who has documented AF within the 6 months proceeding enrollment that did not terminate spontaneously (including patients in continuous AF) or,
   • Who is unwilling or unable to take anticoagulants, with 3 or more symptomatic episodes during the 6 month period prior to enrollment with at least 1 electrocardiographically documented episode of AF in the 4 months prior to enrollment.

3. Left Atrial Size < 6 cm (determined by echocardiography performed within 60 days of enrollment), unless the LV dysfunction is thought to result (at least in part) from AF

4. Left Ventricular Ejection Fraction ≥ 30% (determined by echocardiography performed within 60 days of enrollment)

5. Patient is willing and able to provide written informed consent.

6. Patient has a life expectancy of at least 2 years.

7. Patient is willing and able to attend the scheduled follow-up visits.

8. Weight < 325 lbs

Exclusion Criteria:

1. Prior cardiac catheter ablation for the treatment of arrhythmia within 4 months
2. Prior cardiac surgery
3. Patients requiring any open heart procedure (e.g. CABG, valve replacement or repair, atrial septal defect repair, etc.)
4. Class IV NYHA heart failure symptoms, unless these symptoms are considered to be due to uncontrolled AF
5. Cerebrovascular accident within previous 6 months
6. Known carotid artery stenosis greater than 80%
7. Evidence of significant active infection
8. Patient unable to undergo TEE
9. Pregnant woman
10. Requires anti-arrhythmic drug therapy for the treatment of ventricular arrhythmia
11. Presence of thrombus in the left atrium
12. Patient has co-morbid condition that in the opinion of the investigator poses undue risk of general anesthesia or port access cardiac surgery
13. Patient is enrolled in another investigational study