To determine the presence and prevalence of regional contraction abnormalities in patients with angina pectoris, radionuclide ventriculography gated to an electrocardiogram was carried out in 22 control subjects (group 1) and in 22 patients with angina pectoris (group 2) with isolated stenosis of the left anterior descending coronary artery. No patients had had previous myocardial infarctions. A computer program subdivided the left ventricle into four regions at a geometric centre, and time-activity curves (30-40 ms/frame) of the global, septal, apical, and lateral regions were computed. There was no significant difference in the ejection fraction in the global or in any of the regions between the two groups. End systole in each region occurred close to global end systole in both groups. In the global region the percentage stroke volume ejected during the first third of systole was not significantly less in group 2 than in group 1. Regional analysis of the segments perfused by the stenosed vessel showed that the percentage stroke volume ejected during the first third of systole in group 2 was significantly less in the septal region and in the apical region compared with that in group 1. In contrast, in the normally perfused lateral region, there was no significant difference in the percentage stroke volume at the first third of systole between the two groups. This indicates that early contraction abnormalities are present in the region perfused by the stenosed vessel in patients with angina pectoris without previous myocardial infarction. Thus analysing the regional change in left ventricular volume during ejection in patients with coronary artery disease can show localised areas of contraction abnormalities during early systole that are not apparent when ventricular contraction is assessed as a whole.