The Study for Evaluate of Safety and Efficacy of Vein of Marshall RF Ablation

Inclusion Criteria: Men and women who are at least 20 years of age (80 years of age or older for geriatric patients). Patients requiring electrode ablation because of persistent arrhythmia despite use of antiarrhythmic drugs for more than 6 weeks Patients diagnosed with persistent atrial fibrillation after 2 consecutive electrocardiograms or 24-hour Holter test performed at least 1 week apart. Patients who have been on anticoagulants for more than 6 weeks or have taken equivalent safety measures. Patients with no evidence of intracardiac thrombus on transesophageal echocardiography or equivalent cardiac imaging (Cardiac CT) performed within 48 hours. Patients who have made a voluntary decision to participate in this study and have given written informed consent. Patients who are able to understand, follow instructions and participate for the full duration of the study. Exclusion Criteria: Patients whose computed tomography (CT) or antecedent venography demonstrate that Marshall's veins are less than 1 mm in diameter and less than 15 mm in length. Patient whose Marshall vein was confirmed to be less than 1 mm in diameter and less than 15 mm in length through computed tomography (CT) or total venogram. Patients who previously had atrial fibrillation ablation or Maze surgery Patients with a diagnosis of acute coronary syndrome within 3 months or who have undergone a stenting procedure or coronary artery bypass grafting in a coronary artery proximal to the anticipated procedure route at the time of the study. Patients with severe heart failure and those suffering from cardiogenic shock Those who are with less than 40% emissions Those with less than 40% of the ejection fraction Patients with hypertrophic cardiomyopathy Patients who have contraindications to contrast medias or anticoagulants Patients with evidence of intra-atrial thrombus on imaging studies performed within 1 month of the procedure Patients with evidence of blood clots in the atrium on imaging tests performed within 1 month of the procedure. Patients who have intracardiac malignant tumors and a life expectancy of 12 months or less Subjects with severe renal dysfunction (creatinine cleararnce < 30ml/min) Pregnant women, nursing mothers, and women who are planning to become pregnant or who may become pregnant during the study but are not using medically acceptable contraception Participation in other clinical trials within 30 days prior to screening Patients who participated in other clinical trials within 30 days prior to screening. In addition to the above, those who have clinical findings that the principal investigator or person in charge deems inappropriate for this study based on medical judgment. In addition to the above, those who have clinically signifcant findings that are considered inappropriate for this study as determined medically by the principal investigator or person in charge.