The diagnostic and prognostic value of predischarge exercise echocardiography (echo) was assessed prospectively in 36 patients with unstable angina soon after stabilization on medical treatment. Two-dimensional echo was performed at rest and immediately after a symptom-limited exercise test. Patients with previous myocardial infarction, coronary revascularization, left bundle-branch block and dilated cardiomyopathy were excluded. Left ventricular regional wall motion was analyzed visually and a wall motion score index (WMSI) was derived. Patients were followed prospectively for an average period of 26 months (range 16-34 months). The study end points were a new cardiac event defined as acute myocardial infarction or a need for coronary revascularization because of a recurrence of severe medically refractory angina. Sixteen patients (44%) had positive exercise electrocardiography (ECG), while exercise echo was positive in 22 patients (61%). Of 28 patients undergoing coronary angiography, 23 had significant coronary artery disease (CAD). The sensitivity of exercise ECG in detecting CAD was 61% while the corresponding result was 83% for exercise echo. Cardiac events occurred in 21 patients (58%). Exercise ECG was positive in 12 of these patients (57%), while a positive exercise echo was found in 17 patients (81%). There were significantly more patients with positive exercise echo among patients experiencing cardiac events than among those without cardiac events (p less than 0.01). In patients with CAD, WMSI decreased significantly after exercise (p less than 0.05). Exercise WMSI was also significantly lower in patients with CAD than in those without CAD (p less than 0.02). Exercise WMSI also discriminated patients with cardiac events from those without such events (p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)