In the canine model there exist major differences in the velocity-displacement relationships of systolic contraction between normal and ischemic myocardium. These differences are noninvasively measurable in vivo from video recordings of the fluoroscopic image of the heart, and can be detected within the time period of one cardiac cycle. Velocity data is plotted against the corresponding wall displacement on orthogonal axes (phase-space), producing characteristic loops which give an immediate visual indication of myocardial dysfunction.