Endocardial Mapping With the CoreMap EP Mapping System

Inclusion Criteria:

1. Subject has persistent or long-standing persistent AF, at the discretion of theinvestigator (Phase 1 & 2)

2. Subject has PerAF with no history of prior AF ablation therapy (Phase 3)

3. Subject is 18 to 80 years of age

4. Subject has presence of AF-related symptoms and is scheduled for clinicallyindicated standard of care AF ablation to manage PerAF (Phase 2 or 3) orlong-standing PerAF (Phase 2)

5. Subject is able to provide written informed consent

6. Subject is able and willing to complete all study procedures

Exclusion Criteria:

1. Any of the following within three months of enrollment:

2. Myocardial infarction (MI)

3. Any surgical or percutaneous cardiac procedure including coronary interventionand cardiac ablation

4. Confirmed thrombus on imaging

5. Any of the following within six months of enrollment:

6. Cardiac surgery including coronary artery bypass grafting, ventriculotomy,atriotomy

7. Thromboembolic event (stroke)

8. Any of the following cardiac conditions:

9. New York Heart Association (NYHA) IV

10. Left ventricular ejection fraction (LVEF) < 30%

11. Left atrial diameter >55mm (anterioposterior) (Phase 3)

12. Carotid stenting or endarterectomy

13. Atrial or ventricular septal closure or left atrial appendage closure

14. Implanted permanent pacemaker, biventricular pacemaker, or any type ofimplantable cardiac defibrillator; loop recorders are permitted.

15. Presence of intramural thrombus, tumor (including atrial myxoma), or otherabnormality that precludes vascular access, catheter introduction, ormanipulation

16. Unstable angina

17. Prior mitral or tricuspid valve surgery, repair, prosthetic or mechanical valve

18. Moderate to severe mitral valve stenosis or other severe valvular disease

19. Any blood clotting or bleeding abnormalities

20. Contraindication to systemic anticoagulation

21. AF secondary to electrolyte imbalance, acute alcohol intoxication, or reversible ornon-cardiac cause

22. Body mass index (BMI) > 40 kg/m2

23. Severe pulmonary disease, pulmonary hypertension, or any chronic respiratorycondition

24. Renal failure requiring dialysis or transplant

25. Acute illness, active systemic infection, or sepsis

26. Active drug or alcohol dependency

27. Hypertrophic cardiomyopathy or cardiac amyloidosis

28. Cor pulmonale

29. Any contra-indication that may extend procedure time, at the discretion of theoperator

30. Any woman known to be pregnant or breastfeeding, or any woman of childbearingpotential who is not on a reliable form of birth regulation method or abstinence

31. Subject considered part of vulnerable population

32. Life expectancy less than one year

33. Employee of the study site or Sponsor

34. Subjects who are currently enrolled in another study that would directly interferewith this study