An adverse event (AE) is any untoward medical occurrence in a participant participating in a clinical study that does not necessarily have a causal relationship with the pharmaceutical/biological agent under study. The primary safety endpoint was the incidence of PAEs (within 7 days of the initial mapping and ablation procedure). PAEs included the following AEs: Atrio-esophageal fistula, cardiac tamponade/perforation, device or procedure related death, major vascular access complication/bleeding, myocardial infarction, pericarditis, phrenic nerve paralysis (permanent), pulmonary vein stenosis, stroke/cerebrovascular accident (CVA), thromboembolism, and transient ischemic attack (TIA).

Wave I and Wave II (Main Phase): The full analysis set (FAS) included all enrolled Wave I and Wave II (main phase) participants who had insertion of the study catheter (with or without delivery of pulse field ablation [PFA]); Wave II (Roll-in): The Roll-In analysis set (RI AS) included all Wave II (roll-in) participants who were enrolled in the roll-in phase and underwent ablation with the irreversible electroporation (IRE) ablation system.

Kaplan-Meier estimates of the success rate of freedom from primary effectiveness failure, that is, documented (symptomatic and asymptomatic) atrial arrhythmia (AF, AT, or AFL) recurrence based on electrocardiographic data (>=30 seconds on arrhythmia monitoring device) from Day 91 to Day 365 post index procedure, was reported. Acute procedural failure defined as failure to confirm entrance block in all PVs except those that are silent and/or cannot be cannulated post-procedure, use of a non-study catheter for PV isolation, or failure to have PFA delivery with the study catheter due to IRE system malfunctions, was also considered a long-term effectiveness failure.

Wave I and Wave II (Main Phase): The FAS included all enrolled Wave I and Wave II (main phase) participants who had insertion of the study catheter (with or without delivery of PFA); Wave II (Roll-in): The RI AS included all Wave II (roll-in) participants who were enrolled in the roll-in phase and underwent ablation with the IRE ablation system.

Number of participants who achieved acute procedural success were reported. Acute procedural success was defined as confirmation of entrance block in all clinically relevant targeted pulmonary veins (PVs) after adenosine/ isoproterenol challenge.

Wave I and Wave II (Main Phase): The FAS included all enrolled Wave I and Wave II (main phase) participants who had insertion of the study catheter (with or without delivery of PFA); Wave II (Roll-in): The RI AS included all Wave II (roll-in) participants who were enrolled in the roll-in phase and underwent ablation with the IRE ablation system.

Kaplan-Meier estimates of the success rate of freedom from primary effectiveness failure, that is, documented symptomatic re-occurrence of atrial arrhythmia (AF, AT, or AFL) episodes based on electrocardiographic data (>=30 seconds on arrhythmia monitoring device) from Day 91 to Day 365 post index procedure, was reported. Acute procedural failure defined as failure to confirm entrance block in all PVs except those that are silent and/or cannot be cannulated post-procedure, use of a non-study catheter for PV isolation, or failure to have PFA delivery with the study catheter due to IRE system malfunctions, was also considered a long-term effectiveness failure.

Wave I and Wave II (Main Phase): The FAS included all enrolled Wave I and Wave II (main phase) participants who had insertion of the study catheter (with or without delivery of PFA); Wave II (Roll-in): The RI AS included all Wave II (roll-in) participants who were enrolled in the roll-in phase and underwent ablation with the IRE ablation system.

Change from baseline in AFEQT total score was reported. The AFEQT questionnaire is an atrial fibrillation-specific health-related quality of life (HRQoL) questionnaire designed to assess the impact of atrial fibrillation on participants' HRQoL. The questionnaire includes 20 questions on a 7-point Likert scale. Questions 1-18 evaluate HRQoL and questions 19-20 relate to participants' satisfaction with treatment. Overall or subscale scores range from 0 to 100, where 0 corresponds to complete disability (or responding "extremely" limited, difficult or bothersome to all questions answered), while a score of 100 corresponds to no disability (or responding "not at all" limited, difficult or bothersome to all questions answered). Therefore, a positive change in score corresponds to improvement in QoL. Total score was calculated using AFEQT formula: 100 -([sum of severity for all questions answered - number of questions answered]*100 / total number questions answered*6).

The FAS included all enrolled Wave I and Wave II (main phase) participants who had insertion of the study catheter (with or without delivery of PFA). The RI AS included all Wave II (roll-in) participants who were enrolled in the roll-in phase and underwent ablation with the IRE ablation system. Here, 'N' (number of participants analyzed) indicates number of participants evaluable for this outcome measure. Here, 'n' (number analyzed) is defined as participants analyzed for specified timepoints.