Pranav Bhagirath

110 Chapter 6 data is usually not merged with the Electrical Anatomical Mapping (EAM) systems. The integration of pre-procedurally (non-invasively) acquired data (i.e. MRI-based anatomical and pre-existing scar road map) may result in shorter durations of the invasive, X-ray-based conventional procedures. The use of iCMR would allow these advantages although reduced procedure times might not be seen initially because of the learning curve of doing the procedures in a new environment. Procedural radiation The use of electro-anatomical mapping systems has led to some reduction in radiation exposure form the historically high doses seen in electrophysiology procedures. There are in addition several new developments that focus on further reduction of radiation exposure. A recent example is the MediGuide™ (St. Jude Medical Inc., St. Paul, MN, USA) system, a novel 4-dimensional electromagnetic catheter tracking technology. It allows visualization of catheters inside angiographically derived left atrium models and pre- recorded cine-loops. The system is aimed to reduce radiation exposure by limiting fluoroscopy duration. Although, studies illustrate that EP procedures significantly benefit from this technology 14, 15 , it still awaits widespread clinical implementation. However, iCMR would completely eliminated radiation exposure even in long complex cases. Therapeutic efficacy Particular ablation procedures such as atrial fibrillation and ventricular tachycardia ablations are often associated with one or more redo procedures. Recent studies, based on MRI techniques including T2 and LGE have proposed an explanation for this phenomenon 9, 12 . During radio-frequency ablation there is formation of edema and necrosis 9, 16 . Post-ablation, edema gradually disappears and gaps between adjacent ablation lesions become apparent. These gaps or areas with incomplete isolation result in recurrence of arrhythmia. Identification of gaps in advance may facilitate redo procedures substantially ( figure 1 ) 12 . However, this requires a robust imaging strategy for gap identification. Furthermore, the integration of the generated gap information needs to be easily integrated into the EAM system. Current EAM systems unfortunately do not offer this functionality. It is safe to conclude that despite various technological advances, there is substantial need for further improvements in the current EP and ablation treatment and evaluation strategy. To a large extent, these developments (e.g. improved procedural guidance, reduction of radiation exposure and evaluation of procedural efficacy) could theoretically be achieved by operating in an iCMR environment.