A prospective, single-arm, single-center study to evaluate the safety, performance, and effectiveness of the SpherePVI™ Catheter for treating paroxysmal AF.

Inclusion Criteria:

1. Symptomatic paroxysmal or persistent atrial fibrillation documented by:

   • A physician's note indicating recurrent AF
   • At least two electrocardiographically documented AF episodes within 12 months prior to enrollment

2. Failure or intolerance of at least one Class I-IV anti-arrhythmic drug.

3. Suitable candidate for catheter ablation.

4. Age ≥ 18 and < 75 years.

5. Able and willing to give informed consent.

6. Able and willing, and has ample means to comply with all pre-procedure, post-procedure and follow-up testing requirements

Exclusion Criteria:

Subjects will not be eligible for the study if any of the following criteria are met:

1. Continuous AF lasting more than 12 months (long-standing persistent AF).
2. AF secondary to electrolyte imbalance, thyroid disease, acute alcohol intoxication, or reversible or non-cardiac cause.
3. Previous left atrial catheter or surgical ablation (including septal closure or left atrial appendage closure).
4. Valvular cardiac surgical/percutaneous procedure (e.g., ventriculotomy, atriotomy, and valve repair or replacement and presence of a prosthetic valve).
5. Any carotid stenting or endarterectomy.
6. Any cardiac procedure (surgical or percutaneous) or percutaneous coronary intervention within 90 days prior to the initial procedure.
7. Coronary artery bypass graft (CABG) procedure within the 6 months prior to the index ablation procedure.
8. Awaiting cardiac transplantation or other cardiac surgery within 12 months following the initial ablation procedure.
9. Presence of any type of implantable cardiac defibrillator (with or without biventricular pacing function).
10. Documented thromboembolic event (stroke or transient ischemic attack) within the past 6 months (180 days).
11. Documented left atrial thrombus on imaging.
12. History of blood clotting or bleeding abnormalities.
13. Any condition contraindicating chronic anticoagulation.
14. Myocardial infarction (MI) within the 3 months (90 days) prior to the initial procedure.
15. Body mass index >40 kg/m2.
16. Left atrial diameter (anteroposterior) >50 mm for paroxysmal AF and >55mm for persistent AF.
17. Diagnosed atrial myxoma.
18. Left ventricular ejection fraction (EF) < 40%.
19. Uncontrolled heart failure or NYHA Class III or IV heart failure.
20. Rheumatic heart disease.
21. Hypertrophic cardiomyopathy.
22. Unstable angina.
23. Moderate to severe mitral valve stenosis.
24. Severe mitral regurgitation (regurgitant volume ≥ 60 mL/beat, regurgitant fraction ≥ 50%, and/or effective regurgitant orifice area ≥ 0.40cm2).
25. Primary pulmonary hypertension.
26. Significant restrictive or obstructive pulmonary disease or chronic respiratory condition.
27. Renal failure requiring dialysis.
28. Acute illness, active systemic infection, or sepsis.
29. Significant congenital anomaly or medical problem that, in the opinion of the investigator, would preclude enrollment in this study or compliance with follow-up requirements or would impact the scientific soundness of the clinical trial results.
30. Any woman known to be pregnant or breastfeeding, or any woman of childbearing potential who is not on a reliable form of birth regulation method or abstinence.
31. Current or anticipated participation in any other clinical trial of a drug, device, or biologic during the duration of the study, unless pre-approved by the Sponsor.
32. Presence of intramural thrombus, tumor, or other abnormality that precludes vascular access, catheter introduction, or manipulation.
33. Known drug or alcohol dependency.
34. Life expectancy less than 12 months.
35. Vulnerable subject.