This is a post-market study collecting real-world clinical data on safety, effectiveness and procedural success of Boston Scientific Cardiac Cryoablation System (POLARx™ System)

The study will collect real-world clinical data on safety, effectiveness and procedural success of Boston Scientific Cardiac Cryoablation System (POLARx™ System) when used to perform pulmonary vein isolation (PVI) in the ablation treatment of De Novo Atrial Fibrillation (AF).

Inclusion Criteria:

1. Subjects indicated for the treatment of AF with the cryoablation system;
2. Subjects who are willing and capable of providing informed consent;
3. Subjects who are willing and capable of participating in all testing associated with this clinical study at an approved clinical investigational center;
4. Subjects who are of legal age to give informed consent specific to the national law.

Exclusion Criteria:

1. Any known contraindication to an AF ablation or anticoagulation, including those listed in the IFU/Tenpubunsyo as legally approved conditions;
2. Any prior LA ablation;
3. AF secondary to electrolyte imbalance, thyroid disease, or any other reversible or non-cardiac cause;
4. Known or pre-existing severe Pulmonary Vein Stenosis;
5. Evidence of cardiac myxoma, LA thrombus or intracardiac mural thrombus;
6. Previous cardiac surgery (e.g. ventriculotomy or atriotomy, CABG, PTCA, PCI, ventricular fistula or atrial incision) and any surgery within 90 days prior to enrollment;
7. Any implanted cardiac device (e.g. PM, ICD, CRT, valve replacement, LAAO, etc) within 90 days prior to enrollment;
8. Any planned OR scheduled cardiac device procedure (e.g. PM, ICD, CRT, valve replacement, LAAO, etc) during and post PVI ablation (during and post-index procedure);
9. Any planned ablation in LA except PVI procedure and roof line ablation;
10. Any planned ablation in ventricles;
11. Subjects undergoing atrial septal defect patch or other surgical procedures at or near the atrial septal defect;
12. Subjects with severe valvular disease OR with a prosthetic - mechanical or biological - heart valve (not including valve repair and annular rings);
13. Presence of any pulmonary vein stents;
14. Subjects with active systemic infection;
15. Subjects that have vena cava embolic protection filter devices and/or known femoral thrombus;
16. Any previous history of cryoglobulinemia;
17. Subjects that are unable to undergo atrium access safely or operate in the atrium as per investigator's medical judgement;
18. Subjects with no vascular access or obstruction of the femoral vein;
19. Subjects with blood coagulation disorders or diseases;
20. Any prior history of documented cerebral infarct, TIA or systemic embolism (excluding a post-operative deep vein thrombosis (DVT)) ≤ 180 days prior to enrollment;
21. Subjects who are hemodynamically unstable;
22. The subject is unable or not willing to complete follow-up visits and examination for the duration of the study;
23. Subjects with life expectancy ≤ 1 year per investigator's medical judgement;
24. Women of childbearing potential who are, or plan to become, pregnant during the time of the study (assessment per investigator's discretion);
25. Subjects with unrecovered/unresolved Adverse Events from any previous invasive procedure;
26. Subjects who are currently enrolled in another investigational study or registry that would directly interfere with POLAR SMART study. Exception when the subject is participating in a mandatory governmental registry, or a purely observational registry with no associated treatments. Each instance must be brought to the attention of the sponsor for approval.

Subjects will be clinically indicated for PVI ablation procedure (in compliance with instructions for use (IFU)/Tenpubunsyo as legally approved conditions) for the treatment of paroxysmal AF.