Cavotricuspid isthmus ablation guided by real-time magnetic resonance imaging.

Magnetic resonance imaging (MRI) has evolved as a standard cardiac imaging technique. Interventional procedures guided by real-time MRI may derive potential benefit from a fluoroscopy-free working environment, more detailed insights into the target anatomy, and additional information on organ tissue properties relevant for pathomorphology as well as therapy delivery. Electrophysiological (EP) procedures in a magnetic resonance (MR) scanner require new workflows with different, MR safe, interventional materials and hardware setup, different approaches to intracardiac orientation and catheter tracking, and an adapted patient management. Recently, invasive diagnostic EP procedures have been described in animal studies and in a clinical setting.1,2 Actual catheter ablation has so far only been reported in a limited number of animal series.3 Hereby, we report on a MRI-guided cavotricuspid isthmus ablation. A 74-year-old man without structural heart disease was admitted with documented episodes of paroxysmal symptomatic typical right atrial flutter. At the ablation procedure the patient presented in sinus rhythm. The patient was enrolled into a clinical study approved by the local ethics committee and by the German Federal Institute for Drugs and Medical Devices (BfArM). He provided written and verbal informed consent. In this study, we used MR conditional catheters (Vision, Imricor Medical Systems, Burnsville, MN) and an MR conditional EP recording system (Bridge MR EP Recording System, Imricor Medical Systems, Burnsville, MN). The material is designed for use in 1.5 T closed bore scanners and imposes no limitations on the catheter trajectory, scanner landmark, or patient position. The catheter allows for all clinical scan protocols and is safe for use in normal and first level controlled operating modes. ### MR Conditional Catheters Although the appearance and functionality are similar to conventional ablation catheters, the design of the MR conditional catheter differs substantially. All ferromagnetic materials are removed to eliminate the potential for force and torque …