The objective of this safety and feasibility study is to assess whether the endocardial creation of electrically nonconductive lesions via PEF catheter ablation applied using the FARAPULSE Cardiac Ablation System Plus is a feasible and safe treatment for PersAF and associated AFL

This is a prospective, multi-center safety and feasibility study in subjects with persistent AF. Subjects will undergo percutaneous PEF ablation for pulmonary vein isolation as well as cavotricuspid isthmus interruption and other left atrial ablations at the investigator's discretion. Subjects will then be followed at 30 days, 60 ± 15 days, 6 months and 12 months for adverse events, recurrence of arrhythmia after a 90 day blanking period and other relevant outcome measures.

Key Inclusion Criteria: Patients are required to meet all the following inclusion criteria to participate in this study:

• Age 18-75 Patients with documented drug-resistant symptomatic persistent AF

  1. Patient is refractory or intolerant to at least one Class I/III antiarrhythmic agent.
  2. ECG-documented first episode of persistent AF, lasting longer than 7 days but not longer than 365 days
  3. Holter within 90 days prior to the Enrollment Date demonstrating 24 hours of continuous AF 3. Patient participation requirements:
  1. Lives locally
  2. Is willing and capable of providing Informed Consent to undergo study procedures
  3. Is willing to participate in all examinations and follow-up visits and tests associated with this clinical study.

Exclusion Criteria:

Subjects will be excluded from participating in this study if they meet any one of the following exclusion criteria:

1. AF that is:

   1. Paroxysmal (longest AF episode < 7days)
   2. Longstanding (has persisted > 12 months or that does not respond to cardioversion if < 12 months)
   3. Secondary to electrolyte imbalance, thyroid disease, alcohol abuse or other reversible / non-cardiac causes

2. Left atrial anteroposterior diameter ≥ 5.5 cm as documented by transthoracic echocardiography (TTE) or computed tomography (CT)

3. Any of the following cardiac procedures, implants or conditions:

   1. Clinically significant arrhythmias other than AF, AFL or AT
   2. Hemodynamically significant valvular disease
   3. Prosthetic heart valve
   4. NYHA Class III or IV CHF
   5. Previous endocardial or epicardial ablation or surgery for AF
   6. Atrial or ventricular septal defect closure
   7. Atrial myxoma
   8. Left atrial appendage device or occlusion
   9. Pacemaker, implantable cardioverter defibrillator or cardiac resynchronization therapy devices
   10. Significant or symptomatic hypotension
   11. Bradycardia or chronotropic incompetence
   12. History of pericarditis
   13. History of rheumatic fever
   14. History of congenital heart disease with any residual anatomic or conduction abnormality

4. Any of the following within 3 months prior toenrollment:

   1. Myocardial infarction
   2. Unstable angina
   3. Percutaneous coronary intervention
   4. Heart surgery (e.g. coronary artery bypass grafting, ventriculotomy, atriotomy)
   5. Heart failure hospitalization
   6. Stroke or TIA
   7. Clinically significant bleeding
   8. Pericarditis or pericardial effusion
   9. Left atrial thrombus

5. History of blood clotting or bleeding abnormalities.

6. Contraindication to, or unwillingness to use, systemic anticoagulation

7. Contraindications to CT or MRI

8. Sensitivity to contrast media not controlled by premedication

9. Women of childbearing potential who are pregnant, lactating or not using birth control

10. Medical conditions that would prevent participation in the study, interfere with assessment or therapy, significantly raise the risk of study participation, or confound data or its interpretation, including but not limited to

    1. Body mass index (BMI) > 40
    2. Solid organ or hematologic transplant, or currently being evaluated for an organ transplant
    3. Severe lung disease, pulmonary hypertension, or any lung disease involving abnormal blood gases or significant dyspnea
    4. Renal insufficiency with an estimated creatinine clearance <30 mL/min/1.73 m2, or any history of renal dialysis or renal transplant
    5. Active malignancy or history of treated cancer within 24 months of enrollment
    6. Clinically significant gastrointestinal problems involving the esophagus, stomach and/or untreated acid reflux
    7. Clinically significant infection
    8. Predicted life expectancy less than one year

11. Clinically significant psychological condition that in the investigator's opinion would prohibit the subject's ability to meet the protocol requirements

12. Current or anticipated enrollment in any other clinical study

13. Employment by FARAPULSE or the same hospital department or office of any investigator, or a family member of any of the preceding groups.

14. Use of amiodarone after day of index ablation procedure. Patients will cease use of amiodarone on or before the date of the index ablation procedure.

12 months