A quantitative technique that aligns the diastolic and systolic silhouettes was used to assess left ventricular function (wall thickening and endocardial wall motion) from two-dimensional echocardiographic studies for every 2 degrees of arc of the left ventricular circumference in canines. Thirty-two dogs were studied before and at specific intervals up to 14 days after either temporary or permanent occlusion of the left anterior descending coronary artery. Decreased systolic wall thickening and frank systolic thinning were observed in the ischemic/infarcted region 90 min and 6 hr after occlusion; endocardial motion showed the abnormally contracting segment less clearly. Partial recovery was seen in both groups of animals but to a greater degree in those with temporary occlusion. The technique was useful for assessing sequential changes in wall motion.