Pranav Bhagirath

175 A priori model independent inverse potential mapping: the impact of electrode positioning RESULTS Computer simulations 252 electrodes surrounding the thorax This electrode layout provided a high image quality ( figure5 a , video 1). Right ventricular breakthrough could be easily discerned. An overall high correlation ( R = 0.96; p < 0.01) with the source model was found. The correlationmap ( figure 5 b ) clearly demonstrated a reduced correlation in areas with increased electrode spacing. 62 electrodes surrounding the thorax This electrode configuration resulted in a poor image quality ( figure 5 d , video 2). Several gaps appeared in the epicardial potential map, indicating loss of information in these areas. A reduced overall correlation compared to the source model was found ( R = 0.92; p < 0.01) ( figure 5 e ). 62 electrodes concentrated (30mm inter-electrode distance) When concentrating all available electrodes on the anterior part of the thorax in the region directly overlaying the heart, a clinical relevant image of the potentials on the anterior epicardium was obtained ( figure 5 g , video 3). Figure 5 h shows that the correlation with the source model greatly improved ( R = 0.97; p < 0.01), compared to the configuration using 62 electrodes surrounding the thorax. 62 electrodes super-concentrated (20mm inter-electrode distance) By reducing the inter-electrode distance to 20 mm, image quality improved. The depolarisation front appeared to be more homogeneous ( figure 5 j , video 4). This was confirmed by a slightly higher correlation with the source model ( R = 0.98; p < 0.01), compared to that obtained using the 30 mm electrode spacing configuration. As can be observed in figure 5 k , IPM using the super-concentrated electrode configuration provided the highest correlation with the source model. Inverse reconstruction of recorded human data The BSP recording and MRI examination lasted approximately 60 min. Segmentation and data processing lasted approximately 150 min. Correlation coefficients between measured and reconstructed ECGs were >0.94 for all leads used in the inversion and >0.97 for 85 % of those leads.