The purpose of this clinical study is to evaluate the and performance of the Imricor Medical Systems, Inc. (Imricor) MR Ablation Catheter when used with related accessories for the treatment of type I atrial flutter. The Vision Ablation Catheter and its accessories have been designed for use under fluoroscopic or magnetic resonance guidance. The study will be a single center study conducted at the Leipzig University Hospital Heart Center in Germany. The study population will consist of adult patients requiring ablation for type I atrial flutter.