Randomized Evaluation of Redo Ablation Procedures of Atrial Fibrillation with Focal Impulse and Rotor Modulation Guided Procedures (Redo-FIRM)

1. Male or female 18 - 80 years of age.
2. Has at least one (1) episode of spontaneous persistent or paroxysmal atrial fibrillation documented by rhythm strip/ ECG following the most recent ablation.
3. Had one (1) previous AF ablation after 01 January 2013, but NOT within the last 3 months. Detailed documentation of the previous ablation strategy is required.
4. Oral anticoagulation required with either Novel Oral Anticoagulant (NOAC) or Warfarin (in the case of Warfarin, therapeutic INR >= 2.0 for at least three weeks prior to randomization) for those subjects who meet two or more of the following criteria:
a. Age 65 years or older
b. Diabetes
c. Coronary artery disease (CAD)
d. Congestive heart failure
e. Hypertension with systolic>165 mm Hg
5. Willingness and able to remain on anti-coagulation therapy for a minimum of 3 months post procedure for all subjects and at least 12 months post procedure if the patient is on anti-coagulation pre-procedure or has CHADS2 score >= 2 (or CHADs-Vasc score >1).
6. Left atrial diameter < 6.0 cm via transthoracic echo or transesophageal echo; or <6.5 cm via CT or MRI up to 6 months pre-procedure with documented image of largest dimension, or intra-procedural ICE or atrial angiogram if CT/MRI not available.
7. Willingness, ability and commitment to participate in baseline and follow-up evaluations without participation in another clinical trial which may confound the results of this study, unless approved by the Sponsor.
8. Informed consent in writing from patient.

1. Presence of structural heart disease of clinical significance including:
a. Coronary artery disease with either:
o Coronary artery bypass surgery (CABG) within the last six months, or
o Stable/unstable angina or ongoing myocardial ischemia
b. Congenital heart disease where either the underlying abnormality or its correction prohibits or increases the risk of ablation.
2. NYHA Class IV.
3. Ejection fraction < 35% (within previous 6 months).
4. Previous AF ablation within the last 3 months.
5. ASD closure device, LAA closure device, prosthetic mitral or tricuspid valve, or permanent pacemaker.
6. History of myocardial infarction (MI) within the past three (3) months.
7. Contra-indication to Heparin and Warfarin/other novel oral anticoagulants (e.g. dabigatran, rivaroxaban, apixaban).
8. Diagnosed atrial myxoma.
9. Any concomitant arrhythmia or therapy that could interfere with the interpretation of the results from this study.
10. Untreatable allergy to contrast media.
11. Severe electrolyte abnormalities at time of the ablation procedure or atrial fibrillation secondary to electrolyte imbalance, thyroid disease, or reversible non-cardiac cause.
12. Atrial fibrillation from a reversible cause (e.g., surgery, hyperthyroidism, pericarditis).
13. History of pulmonary embolus within one year of enrollment.
14. Acute pulmonary edema.
15. Atrial clot/thrombus on imaging such as on a trans-esophageal echocardiogram (TEE) performed within 72 hours of the procedure if deemed appropriate by investigator.
16. Any history of a cerebrovascular disease (including stroke or TIA) within the past 6 months.
17. Any anticipation of cardiac transplantation or other cardiac surgery within the next 12 months.
18. Significant pulmonary disease, (e.g. restrictive pulmonary disease, constrictive or chronic obstructive pulmonary disease) or any other disease or malfunction of the lungs or respiratory system that produces severe chronic symptoms and significantly increases risk to sedation or anesthesia.
19. Acute illness or active systemic infection or sepsis.
20. Any history of blood clotting abnormalities or bleeding abnormalities.
21. Life expectancy of less than 12 months.
22. Any Intramural thrombus, tumor, or other abnormality that precludes catheter introduction or safe manipulation.
23. Women known to be pregnant.