Atrial Flutter Ablation in the iCMR

Inclusion Criteria: * Patient indicated for type I atrial flutter ablations with at least 1 documented episode of type I atrial flutter within 6 months (180 days) of enrollment * Patient 18 years and older Exclusion Criteria: * Contraindications for MRI procedures * Patients who cannot have anti-arrhythmic drugs (class I or class III) prescribed for the treatment of type I atrial flutter stopped on the day of the procedure * Previous CTI ablation procedures * Myocardial infarction within 60 days of enrollment * Current unstable angina * Cardiac surgery within 90 days of enrollment * Any cerebral ischemic event (including transient ischemic attacks) within 6 months (180 days) of enrollment * Thrombocytosis or thrombocytopenia * Contraindication to anticoagulation therapy * Currently documented intracardiac thrombus or myxoma * Implantation of permanent leads of an implantable device in or through the right atrium within 90 days of enrollment * Prosthetic valve through which the catheter must pass * Interatrial baffle or patch through which the catheter must pass * Moderate or severe tricuspid valve regurgitation or stenosis * Uncompensated congestive heart failure * Active systemic infection * Pregnancy or if subject plans to become pregnant during the trial * Uncontrolled hyperthyroidism * Any other significant uncontrolled or unstable medical condition * Enrollment in any concurrent study without Imricor written approval * Life expectancy of less than or equal to 2 years (730 days) per physician opinion