Pranav Bhagirath

213 General discussion The pilot study evaluating the IPM algorithm for reconstructing sinus rhythm, revealed the first point of atrial activation near the crista terminalis of the superior vena cave into the right atrium. The first point of ventricular epicardial breakthrough was located at the right ventricular free wall. These findings corresponded to the anatomically known location of the sinus node and where the moderator band attached to the ventricular myocardium 27 . The use of MRI is unique and enables visualization and incorporation of tissue- characteristics in computational meshes. In addition, an integrated IPM and simulation based approach facilitates a comprehensive assessment of arrhythmias and underlying substrate. These two factors significantly contribute towards the clinical applicability of this workflow and offer a unique environment for the development and evaluation of patient tailored therapeutic strategies. Subsequently, using this workflow, a comparison between the boundary element model (BEM) and finite element model (FEM) was performed. Body volume potential computation using the finite element model proved to be efficient if the number of bounding surfaces between organs taken into account was high. In addition, using the FEM rather than the BEM enabled the incorporation of different anisotropies, local tissue characteristics and sigma gradients over different regions. From a computational standpoint, computing a potential field by means of the FEM was not a problem. The computation time of a 240,000 points potential field was approximately 3 minutes. Graphics processorswith hundreds of computation units combinedwith quad coremain CPU’s are becoming available at consumer prices. Generally available FEM packages are able to benefit from this just by setting some parameters and do not require custom coding. While the performance gains by computing the FEM in parallel may easily be tenfold. The same workflow was utilized to investigate the optimal positioning of 62 torso electrodes for IPM. Computer simulations were used to gain insight and predict probable image quality of different electrode configurations and demonstrated that an anterior view of the epicardial potentials could be reconstructed at a high resolution using only 62 anterior electrodes with an inter-electrode distance of 20mm. These findings demonstrate that the proposed FEM based whole-heart computational workflow offers an integrated platform for cardiac electrical assessment using IPM and simulations. The IPM algorithm can accurately reconstruct reliable cardiac activation