The VARIFY study is designed to find out how durable pulmonary vein isolation (PVI) is after treatment with the VARIPULSE pulsed field ablation (PFA) system in patients with paroxysmal atrial fibrillation (AF). AF is a common heart rhythm disorder caused by abnormal electrical signals coming from the pulmonary veins. In a PVI procedure, these veins are electrically isolated to prevent AF from recurring. Sometimes, the veins reconnect over time, which can lead to a return of arrhythmia. PFA is a new, non-thermal technology that uses short electrical pulses to safely and precisely treat heart tissue, reducing the risk of damage to nearby structures. The VARIPULSE system is one of these new PFA platforms. In this study, 20 adult patients with paroxysmal AF will undergo PVI using the VARIPULSE system. After 2-3 months, each patient will have a second planned procedure to check whether the pulmonary veins remain isolated. Any reconnections found will be treated immediately. The main goal is to determine how often the pulmonary veins stay durably isolated after the initial VARIPULSE treatment. Secondary goals include assessing the amount of scar tissue in the left atrium, recording any complications, and evaluating rhythm outcomes after one year. The results will help determine how effective and reliable the VARIPULSE system is for long-term treatment of AF.

Rationale: Pulmonary vein isolation (PVI) is the cornerstone of atrial fibrillation (AF) ablation. Pulmonary vein reconnection is associated with recurrence of arrhythmia, thus, durable PVI during the index procedure is important. Recently, pulsed field ablation (PFA) has emerged as a novel nonthermal energy source with high procedural safety and efficacy for PVI. Irreversible electroporation is achieved by the delivery of rapid, high-voltage pulsed electrical fields. Considering differences in catheter design and PFA protocols, it is important to establish PVI durability of the different PFA platforms. In the VARIFY study we will analyze PVI durability of the VARIPULSE platform in patients with paroxysmal AF using a 2-3 months protocol-mandated remapping study regardless of arrhythmia recurrence. Currently, there are no data on PVI durability of the VARIPULSE platform using mandatory remapping. Objective: To assess PVI durability in patients with paroxysmal AF who undergo a firsttime PVI with the VARIPULSE platform. Study design: Prospective, single-center study. Study population: Twenty consecutive adult patients (≥18 years old) with paroxysmal AF who are scheduled to undergo PVI with the VARIPULSE platform. Intervention: Patients will undergo a second invasive procedure 2-3 months after the index PVI. During the second procedure PVI durability will be assessed using high-definition mapping. Any reconnection will be targeted to achieve complete PVI. Main study parameters/endpoints: The primary outcome is the incidence of PV reconnection at the repeat procedure. The secondary outcome include the area of low voltage in the left atrium at the repeat procedure. Nature and extent of the burden and risks associated with participation, benefit, and group relatedness: All patients will undergo a repeat invasive procedure. This second procedure is associated with a similar procedural risk as the first procedure. A potential benefit of a mandated repeat procedure is that early pulmonary vein reconnection is identified and treated. Early treatment of pulmonary vein reconnection is associated with a better arrhythmia outcome.

Inclusion Criteria: 1) History of symptomatic paroxysmal AF; 2) Participants who are indicated for a PVI according to the 2020 ESC guidelines for the diagnosis and management of AF; 3) Participants who are willing and capable of undergoing a mandatory repeat procedure 2-3 months after the index procedure; 4) Participants whose age is 18-80 years. 5) Participants who are willing and capable of providing informed consent.

Exclusion Criteria: 1) Any known contraindication to an AF ablation or anticoagulation; 2) History of previous LA ablation or surgical treatment of AF, atrial flutter, or atrial tachycardia; 3) AF secondary to electrolyte imbalance, thyroid disease, or any other reversible or non-cardiac cause; 4) Significant structural heart disease; 5) History of blood clotting or bleeding disease; 6) Severe kidney disease (glomerular filtration rate <30 ml/min/1.73 m2); 7) Stroke or transient ischemic attack <3 months prior to enrollment; 8) Active systemic infection; 9) Pregnant, lactating, or women of childbearing potential who are, or plan to become, pregnant during the time of the study; 10) Participants who are currently enrolled in another investigational study or registry that would directly interfere with the current study.