Inclusion Criteria:

• Idiopathic paroxysmal symptomatic atrial fibrillation refractory to antiarrhythmic therapy
• Age 50 – 85 years
• Patient willing to participate in randomized trial and an invasive follow-up at month 3 (-6)
• Structural normal heart
• Patient willing and able to participate in 12 months follow-up period
• ECG documentation of atrial fibrillation (ECG, Holter, event recorders, etc) for at least one AF event in the prior year (related to symptomatic or asymptomatic episodes) with an average number of one episode per month
• Written informed consent of the patient

Exclusion Criteria:

• Patients who have had previous pulmonary vein ablation procedures Patients with atrial fibrillation secondary to a reversible cause
• Known presence of intracardiac or other thrombi
• Evidence of obstructive lung disease requiring bronchodilator therapy
• Pregnant females or those of child bearing potential who have not had a negative pregnancy test within 48 hours before treatment.
• Other medical illness (i.e. cancer, congestive heart failure) that may cause the patient to be non-compliant with the protocol, confound the data interpretation or is associated with limited life-expectancy (i.e., less than one year)
• History of bleeding diathesis or suspected pro-coagulant state contraindication to anticoagulation therapy
• Hyperthyroidism or hypothyroidism manifested clinically and in laboratory tests (TSH, T3, T4)
• Participation in a clinical trial within the last 30 days. Simultaneous participation in a registry (e.g. project AB1 of the AFNET) is permitted.
• Drug addiction or chronic alcohol abuse
• Legal incapacity, or other circumstances which would prevent the patient from understanding the aim, nature or extent of the clinical trial
• Evidence of an uncooperative attitude