Twenty-six patients with unstable angina pectoris had biplane left ventricular (LV) angiograms and coronary arteriograms (CAGs) initially and at a median of 1 year following randomization to medical (15 patients) or surgical 11 patients) therapy. Left ventricular segmental wall motion was analyzed by a digital computer yielding segmental ejection fraction for 10 zones along the LV perimeter. Baseline and follow-up CAGs were analyzed simultaneously by one observer, and changes in LV segmental coronary perfusion were estimated. Left ventricular angiograms were analyzed separately from CAGs and independently of knowledge of changes in estimated segmental coronary perfusion. Left ventricular segmental wall motion was more frequently improved in surgical patients than in medical patients. Furthermore, in surgical patients there was a significant correlation between changes in LV segmental wall motion and perfusion to LV segments supplied by the left anterior descending coronary artery, whereas no such correlation for any segment was found in the medical group. Thus, this prospective randomized study suggests that, in patients with unstable angina, coronary revascularization may significantly improve LV segmental wall motion compared to medically treated patients. In the surgical group, improvement in LV wall motion relates to improvement in coronary perfusion to the segments supplied by the left anterior descending artery.