Prospective, Multicenter, Investigation of the Adagio Cryoablation System in Subjects With Atrial Flutter

Inclusion Criteria: * Two symptomatic episodes of typical AFl (or chronic atrial flutter) during the one-year period prior to enrollment. This may include typical AFl occurring while receiving anti-arrhythmic drug (AAD) therapy for non-AFl tachyarrhythmia, including atrial fibrillation (AF). * At least one episode of typical (clockwise or counterclockwise) atrial flutter documented by 12 lead electrocardiogram (ECG) within 6 months prior to enrollment. * Subject has been diagnosed with symptomatic AFl * Subject is at least 18 and ≤75 years of age. * Subject is able and willing to give informed consent Exclusion Criteria: * Intra-cardiac thrombus has not been eliminated in subjects exposed to less than 4 weeks of therapeutic anticoagulation and a TEE (trans-esophageal echocardiogram) and/or CT did not conclusively rule out thrombus * Subject developed persistent AF at least once in history (electrical or pharmacological cardioversion after 48h or episode duration \>7 days). Subject had any previous left atrial ablation. * Subject had any previous cardiac surgery, e.g. prosthetic valves, except in the case of an isolated coronary bypass surgery performed more than three months prior to the procedure. * Subject has permanent pacemaker or defibrillator implant. * Subject has 2° type II, 3° degree atrioventricular (AV) block or left/right bundle branch block pattern * Subject has unstable angina pectoris. * Subject has history of previous myocardial infarction (MI) or percutaneous intervention during the last three months or planned in the next 3 months. Subject has symptomatic carotid stenosis. * Subject has chronic obstructive pulmonary disease with detected pulmonary hypertension or any other evidence of significant lung disease. * Subject has any contraindication for oral anticoagulation. * Subject has any history of previous transient ischemic attack (TIA) or stroke. * Subject has known intra-cardiac thrombus formation. * Subject has any significant congenital heart defect corrected or not (except for patent foramen ovale that is allowed). * Subject has evidence of congestive heart failure (NYHA class II, III or IV) in sinus rhythm. * Subject has hypertrophic cardiomyopathy. * Subject has abnormal long or short QT interval, signs of Brugada syndrome, known inheriting ion channel disease on the family, arrhythmogenic right ventricular dysplasia. * Subject has sarcoidosis. * Subject has myxoma. * Subject has thrombocytosis (platelet count \> 600,000 / μl) or thrombocytopenia (platelet count \<100,000 / μl). * Subject has any untreated or uncontrolled hyperthyroidism or hypothyroidism. * Subject has renal dysfunction with glomerular filtration rate \< 60 ml/min/1.72m2. * Subject has a reversible causes for AF like alcoholism. * Subject is a pregnant woman or woman of childbearing potential not on adequate birth control: only woman with a highly effective method of contraception \[oral contraception or intra-uterine device\] (who must have a negative pregnancy test within 1 week of randomization) or sterile woman can be enrolled. * Subject is a breastfeeding woman. * Subject has an active systemic infection. * Subject is unwilling or unable to comply fully with study procedures and follow-up due to any disease condition, which can raise doubt about compliance and influencing the study outcome especially any kind of cancer requiring ongoing in-hospital treatment, severe bleeding in history or a suspected pro-coagulant state. * Legal incapacity or evidence that a subject cannot understand the purpose and risks of the study or inability to comply fully with study procedures and follow up. * Subject has a life expectancy of ≤ 1 year. * Subject is participating in any other clinical study