At the onset of wall motion alterations during dobutamine echocardiographic stress testing, a steeper increase in the overall T-wave amplitude in the precordial leads was observed in 17 patients with baseline normal wall motion, electrocardiogram, and critical coronary stenoses compared with 11 control subjects. Eleven patients with increasing T-wave amplitude had localized apical dyssynergy, whereas 6 patients with downward displacement of the ST segment had widespread wall motion alterations also located at the basal and midsegments.