Inclusion Criteria:
1. At least 18 years old (or older if required by local law)
2. Symptomatic, documented, drug-refractory paroxysmal or persistent atrial fibrillation (AF).
3. Willing and capable of providing written informed consent
4. Willing and able to comply with all follow-up assessments and study procedures at an approved investigational site
Exclusion Criteria:
1. Any of the following atrial conditions:
1. Left atrial anteroposterior diameter of at least 5.5 cm, or if not available, non-indexed volume greater than 100 mL
2. Any prior atrial endocardial, epicardial, or surgical ablation for atrial arrhythmia (excluding right-sided Supraventricular Tachycardia (SVT) or Cavo-Tricuspid Isthmus (CTI)-dependent flutter)
3. Any prior atrial surgery
4. Current atrial myxoma
5. Pulmonary vein abnormality, stenosis, or prior stenting (common and middle pulmonary veins allowed)
6. Current left atrial thrombus
2. Any of the following cardiovascular conditions:
1. History of sustained ventricular tachycardia or ventricular fibrillation
2. Atrial fibrillation secondary to reversible or non-cardiac causes (e.g., electrolyte imbalance, thyroid disease, alcohol)
3. Presence of any of the following cardiac devices or implants:
* Current or anticipated pacemaker, implantable cardioverter defibrillator, or cardiac resynchronization therapy device
* Current implantable loop recorder other than LUX-Dx
* Prior interatrial baffle or septal closure device/patch (Patent Foramen Ovale (PFO)or Atrial Septal Defect (ASD))
* Left atrial appendage closure or occlusion device
4. Clinically significant valvular disease, including:
* Any cardiac valve prosthesis, ring, repair, or clip
* Moderate to severe mitral stenosis
* Moderate to severe aortic stenosis
* Severe mitral regurgitation
* Severe tricuspid regurgitation
5. Hypertrophic or amyloid cardiomyopathy
6. Presence of Inferior Vena Cava (IVC) filter, inability to obtain vascular access, or contraindication to femoral access
7. Awaiting cardiac transplantation or other cardiac surgery within 12 months (left atrial appendage closure/occlusion procedures allowed no less than (≥) 60 days after index procedure)
8. Severe right ventricular dysfunction per investigator assessment
3. Any of the following congenital conditions:
1. Congenital heart disease with clinically significant residual anatomic or conduction abnormalities, or channelopathies
2. Known congenital methemoglobinemia
3. Known G6PD deficiency
4. Any of the following medical history conditions:
1. Solid organ or hematologic transplant, or under evaluation for transplant
2. History or current evidence of hemi-diaphragmatic paralysis or paresis
3. Prinzmetal angina or severe non-revascularizable coronary disease
4. Known coagulopathy or bleeding disorder
5. Renal insufficiency, history of dialysis, or renal transplant
6. Known allergic reaction to nitroglycerin (excluding hypotension)
7. Required use of phosphodiesterase inhibitors within 24 hours of the ablation procedure
8. Active spinal cord stimulator
5. Any of the following baseline conditions:
1. NYHA Class III or IV heart failure
2. Left ventricular ejection fraction (LVEF) less than 40% within 12 months
3. CHA2DS2-VASc score greater than or equal to 5
4. Body mass index (BMI) greater than 45.0
5. Contraindication to or unwillingness to use systemic anticoagulation peri-procedurally
6. Pregnant or lactating at time of procedure
7. Severe lung disease, pulmonary hypertension, or oxygen-dependent lung disease
8. Active malignancy (excluding squamous cell carcinoma)
9. Clinically significant gastrointestinal disease (e.g., severe or erosive esophagitis, uncontrolled reflux, gastroparesis, esophageal candidiasis, active gastroduodenal ulceration)
10. Known Active systemic infection
11. Life expectancy of less than 1 year
12. Concurrent enrollment in another investigational study or registry that may interfere with this study (exceptions include mandatory governmental registries or purely observational registries with sponsor approval)
6. Any of the following events within 90 days prior to consent:
1. Myocardial infarction, unstable angina, or coronary intervention
2. Pericarditis or symptomatic pericardial effusion
3. Gastrointestinal bleeding
4. Cardiac surgery
5. Stroke, Transient Ischemic Attack (TIA), or intracranial bleeding
6. Any active non-neurologic thrombus and/or thromboembolic event
7. Carotid stenting or endarterectomy
8. Heart failure hospitalization
9. Uncontrolled diabetes mellitus or HbA1c greater than 8.0%
7. Other conditions:
1. Unwillingness to receive, or unable to tolerate, a subcutaneous, chronically inserted ICM from the LUX-Dx family of devices
2. Any medical condition that, in the investigator's opinion, would interfere with study participation, increase risk, or affect data interpretation
