The objective of this multicenter randomized study is to establish the effectiveness of treatment for paroxysmal atrial fibrillation (AF), in patients not previously treated with anti-arrhythmic drugs, by encircling the pulmonary veins with radiofrequency (RF) ablation, using the NaviStar® ThermoCool® catheter and the CARTO™ EP Navigation System. Effectiveness will be determined by comparing chronic success of ablation therapy versus anti-arrhythmic drug treatment, defined as patients with an absence of atrial tachycardias during 24 months of follow-up as determined by 7-days Holter and transtelephonic monitoring, and by 12-lead electrocardiogram (ECG) recordings.

This study is a prospective, randomized, multicenter clinical study that will enroll in its first phase 40 patients. The study will be performed in 3 European hospitals. Patients will be randomized to either the RF ablation strategy or to the medication arm.

Hypothesis:

As first line therapy, catheter ablation improves the long-term success, health-economic outcomes and is equally safe compared to the best anti-arrhythmic medication treatment in a selected group of patients with paroxysmal atrial fibrillation.

Primary endpoint:

• long-term success, defined as patients free from any atrial fibrillation during 24 months after initial study treatment as determined by 7-days Holter and transtelephonic monitoring and by 12-lead ECG recordings.

Secondary endpoints:

• AF burden: frequency and duration of episodes
• health-economic costs over 24 months
• serious adverse events
• Quality of Life scores, using SF-36 questionnaire

Inclusion Criteria:

• Informed consent obtained
• Two or more documented symptomatic paroxysmal atrial fibrillation episodes during the last 6 months. Episodes should last longer than 30 seconds.
• Patients should not be on anti-arrhythmic medication therapy (Class I, III or IV) for AF (other than for cardioversion) or are currently on antiarrhythmic drug (AAD) therapy for any other arrhythmia

Exclusion Criteria:

• Patients who had a previous ablation for atrial fibrillation
• Patients who had presence of severe valvular disease, myocardial infarction and/ or cardiomyopathy
• Patients with a left atrial size more than 50 mm
• Patients who had more than 2 cardioversions
• Patients who have a history of AF for less than 3 months or more than one year
• Patients with solely asymptomatic AF
• Patients who have AF episodes triggered by another uniform arrhythmia
• Patients who actively abuse alcohol or other drugs, which may be causative of AF
• Patients with a tumor, or another abnormality which precludes catheter introduction
• Patients with a revascularization or other cardiac surgery within 6 months before study treatment
• Patients in whom appropriate vascular access is precluded
• Patients with a contraindication to treatment with warfarin or other bleeding diathesis participants in another investigational clinical or device trial
• Patients who are inaccessible for follow-up psychological problem that might limit compliance
• Patients who cannot or will not fulfill the follow-up or protocol requirements
• Pregnant women
• Patients with severe chronic obstructive pulmonary disease
• Patients with Wolff-Parkinson-White (WPW) syndrome
• Patients with renal failure requiring dialysis
• Patients with hepatic failure