A system for the production of a four dimensional (moving three dimensional) human epicardial left ventriculogram, modelled and highlighted to show regional wall motion changes, is described. The moving image is derived by fitting a surface to the three dimensional coordinates of coronary artery bifurcations. These are determined by analysis of digitised biplane coronary cineangiograms. This image system not only provides a unique 3-D view of left ventricular activity but might also provide measures of cardiac dynamics such as, stroke volume and velocity of wall movement. The system is not fully automated although operator interaction may be minimised. Further work on vessel tracking systems is required before full automation is possible.