Inclusion Criteria:

• Patient is greater than or = 18 years of age
• Patient has documented symptomatic paroxysmal atrial fibrillation (PAF) refractory to at least 1 antiarrhythmic (Class IA, IC, III) drug.
• Patient has episodes of symptomatic AF including, but not limited to, palpitations, lightheadedness, fatigue, dyspnea, and/or chest pain.
• A minimum of a 6-month history of symptomatic paroxysmal AF (documented by patient report in the medical record).
• A minimum of 2 discrete symptomatic paroxysmal AF episodes in the month prior to study entry. Paroxysmal AF rhythm must be documented by objective evidence (12-lead electrocardiogram [ECG], Holter monitor, event monitor, or other telemetry rhythm strip) with the presence of sinus rhythm and/or underlying rhythm between episodes.
• Patient has been informed of the nature of the study, agreed to its provisions, and provided written informed consent.

Exclusion Criteria:

• Patient had a cerebral vascular accident or transient ischemic attack within the previous 6 months.
• Patient had a myocardial infarction within the previous 6 weeks.
• Patient has underlying metabolic etiology related to AF (e.g., hyperthyroidism, metabolic disorder).
• Patient has significant underlying structural heart disease (e.g., valvular disease, presence of aneurysm, left ventricular hypertrophy) requiring surgical or procedural intervention.
• Patient with prior catheter ablation procedure for the treatment of AF within the previous 6 months.
• Patient has evidence of, or history of, 50% or more stenosis in any pulmonary vein.
• Patient had a previous thoracic procedure resulting in sternal opening and/or pericardial opening (e.g., surgical ablation, coronary artery bypass graft [CABG], or valve repair).
• Patient has a left atrial size > 6.0 cm measured on echocardiogram.
• Patient has a left ventricular ejection fraction (LVEF) < 35%.
• Patient requires treatment for CAD (coronary artery disease) or has untreated unstable angina.
• Patient has a presence of esophageal fistula or esophageal stricture, untreated esophagitis, varices, dysphagia, or odynophagia caused by anatomical abnormality or other diseases contraindicating transesophageal echocardiography.
• Patient has severe chronic obstructive pulmonary disease.
• Patient has a known allergy or contraindication to Coumadin (warfarin) therapy, or inability to comply with Coumadin (warfarin) therapy.
• Patient has a known allergy or contraindication to complying with antiarrhythmic (Class IA, IC, III) therapy.
• Patient has an acute illness or active systemic infection or sepsis.
• Patient has a co-morbidity with life expectancy of less than one year or protocol non-compliance that would limit follow-up.
• Patient is geographically remote and/or unable to return for follow-up examinations.
• Patient is pregnant or is planning to become pregnant during the study.
• Patient is enrolled in any concurrent study.