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