In this prospective, randomised, controlled, unblinded,monocentric study, we aim to evaluate the safety and efficacy of higher power CLOSE-guided PVI in patients referred for a first ablation for paroxysmal AF. We aim to include 100 patients into two groups (1:1). The experimental group will receive AF ablation with 45 Watt and stricter stability criteria (3 mm for 3 seconds) compared to the control group which will receive AF ablation according to the standard CLOSE-protocol (35 Watt and stability criteria of 3 mm for 8 seconds).

BACKGROUND: In a population of paroxysmal AF 'CLOSE'-guided PVI (Target Ablation index (AI) >550 and >400 for anterior and posterior wall respectively, interlesion distance ≤6mm) has been shown to obtain single-procedure durable PV isolation. However, the optimal RF power and stability criteria is unknown.

OBJECTIVES: With this study, we aim at evaluation the efficacy and the safety of higher power (45 watts) and stricter stability criteria (3 mm for 3 sec) as compared to a standard CLOSE protocol (35 watts with stability of 3 mm for 8 sec) in patients referred for a first ablation for paroxysmal AF.

POPULATION: Eligible patients are patients with paroxysmal AF who are planned for a 'CLOSE'-guided PV isolation for paroxysmal AF. At the time of the procedrual planning, we will ask the patient his/her consent for collectio of data. We aim at including 100 patients.

Inclusion Criteria:

• All patients referred for symptomatic paroxysmal AF and without advanced structural heart disease
• Signed Patient Informed Consent Form
• Age 18 years or older
• Able and willing to comply with all follow-up testing and requirements

Exclusion Criteria:

• Persistent atrial fibrillation (history of AF>7days or history of cardioversion > 48h of AF)
• Previous ablation for AF
• LA antero-posterior diameter>50 mm (parasternal long axis view , PLAX)
• LVEF <35% (ejection fraction)
• AF secondary to electrolyte imbalance, thyroid disease, or reversible or non-cardiac cause
• CABG procedure within the last three months
• Awaiting cardiac transplantation or other cardiac surgery
• Documented left atrial thrombus on imaging
• Diagnosed atrial myxoma
• Women who are pregnant or breastfeeding
• Acute illness or active systemic infection or sepsis
• Unstable angina
• Uncontrolled heart failure
• Myocardial infarction within the previous two months
• History of blood clotting or bleeding abnormalities
• Contraindication to anticoagulation therapy (ie, heparin or warfarin)
• Life expectancy less than 12 months
• Enrollment in any other study evaluating another device or drug
• Presence of intramural thrombus, tumor or other abnormality that precludes catheter introduction