Cardiac Return Current

Visualization of the return current in the chest (Utah Torso data set) obtained by forward calculation. The boundary values for this computation are provided by measurements of the electrical potential done by B. Taccardi on the cardiac surface. The computation itself was carried out by F. Sachse. A smooth electric current field was derived from the electric potential. Then stream stream surfaces were computed along that current. The stream surfaces are started along isopotential lines on the surface of the heart and advected until they return to the heart, following the typical bent shape induced by the dipolar sources in the heart. The color coding shows the distortion of the parameterization of the start curve. The strength of these images is to improve on previous visualizations based on streamlines since whole volumes can now be identified, and to offer a means to better understand the relationship between in- and outflow of the electric current on the surface of the heart. Additionally, an LIC representation of the electric current was calculated constrained to the cardiac surface.