The Vision-MR Ablation Catheter will be used in conjunction with the following investigational products: Advantage-MR EP Recorder/Stimulator, Vision-MR Ablation Cable Set, Vision-MR Diagnostic Cable, the interventional MRI Suite (iSuite) image guidance and mapping system, and a dStream Interface (dSIF-FE). With the exception of iSuite and dSIF-FE, which are manufactured by Philips, Imricor will provide all investigational devices used in the study.