The invention relates to a system (100) for visualizing a cardiac parameter at a plurality of positions in a myocardium and at a plurality of stress levels, the system comprising a determination unit (110) for determining a value of the cardiac parameter at a position from the plurality of positions in the myocardium and at a stress level from the plurality of stress levels on the basis of stress level cardiac functional data, and a visualization unit (120) for visualizing the determined value of the cardiac parameter by displaying a point in a viewing plane. The visualized points are defined by their polar coordinates in a polar coordinate system in the viewing plane. A radial coordinate of the point visualizes the determined value of the cardiac parameter. An angular coordinate of the point visualizes an angular coordinate of the position in the myocardium in a cylindrical coordinate system. Thus, the system allows easy numerical comparison of local myocardial contractions at different stress level values.
