The systolic ejection fraction has been the standard method for assessing left ventricular performance. However, it is evident that this measure of overall ventricular performance does not fully describe abnormalities in local myocardial performance characteristic of coronary artery disease. For example, areas of hypokinesis can frequently be found in subjects with normal ejection fraction. Several methods have been proposed for the study of local wall motion based on the change in the length of chords drawn to the endocardial silhouette from left ventricular single or bi-plane angiograms (1,2,3,4,5,6,7). More recently, Welch has suggested that the extent of local wall motion at midsystole is more often abnormal than the total shortening at end sys-stole in ischemic heart disease (8).