Pranav Bhagirath

109 Interventional cardiac magnetic resonance imaging in electrophysiology: advances toward clinical translation INTRODUCTION Technical advances in cardiovascular electrophysiology (EP) have resulted in an increasing number of catheter ablation procedures reaching 200.000 in Europe for the year 2013 1 . These advanced interventions are often complex and time-consuming, and may cause significant radiation exposure 2 . Furthermore, a substantial number of ablation procedures remain associated with poor (initial) outcomes and frequently require one or more redo procedures 3 . Innovations in cardiac imaging and image guidance could help improve the results of ablation procedures 4 . Amongst the available imaging modalities, Cardiac Magnetic Resonance Imaging (CMR) can be considered the most comprehensive and suitable modality for the complete EP and catheter ablation process (including patient selection, procedural guidance and (procedural) follow-up) 5 . The unique ability of CMR including tissue characterization (e.g. T2 weighted imaging for edema visualization, Late Gadolinium Enhancement (LGE for necrosis quantification)) may be of advantage for the evaluation of lesion formation and therapeutic efficacy 6-9 . These benefits and the lack of radiation exposure inspired the development of hybrid fluoroscopy and CMR (XMR) suites 10 and dedicated interventional CMR (iCMR) units 11 . This review examines the requirements and clinical feasibility of a dedicated iCMR suite for EP procedures. First, the limitations of current EP procedures and ablation strategies are analyzed and the advantages of an iCMR suite for this purpose are discussed. Second, the clinical feasibility is examined by presenting the current challenges of working in an MRI environment. Safety, imaging and device related aspects are also reviewed. Finally, the requirements for implementing an iCMR suite and the current state of their developments is addressed. CURRENT CHALLENGES IN ELECTROPHYSIOLOGY There are different phases during the workup and follow-up of a diagnostic or ablative EP procedure. The limitation of the current strategy, including the role of fluoroscopy, in diagnosis and treatment of arrhythmias are discussed in the following paragraphs. Patient identification and procedure planning Imaging is considered a cornerstone of patient selection for ablation therapy 4 . Information about arrhythmic substrate can be acquired prior to the procedure using CMR. However, despite the proven usefulness 12, 13 , pre-procedurally acquired