Cineventriculo- and echocardiographic studies of left-ventricular cavity demonstrated an increase in the deep diameter and the thinning and outward displacement of the posterior wall during the isovolumic systole in normal subjects. This change of shape was however uncommon and, if present, less pronounced in 19 patients with marked coronary heart disease (CHD). In normal subjects, posterior wall movement amplitude was always greater than that of the anterior wall, whereas in coronary patients left-ventricular wall movement amplitudes were always similar. It is assumed that the lateral posterior wall displacement is due to a later myocardial activation in this area, while the absence of such movements is attributed to increased volume of ventricular cavity. The ratio of left-ventricular diameter to posterior wall thickness was actually below 3 in all normal subjects and above 3 in most of the coronary patients.