Dobutamine echocardiography was performed on 297 patients after acute myocardial infarction to assess the prognostic value of dobutamine-induced hypotension in patients with left ventricular dysfunction. Patients were divided into two groups according to ejection fraction (group I, ejection fraction <0.45, n = 123; group II, ejection fraction > or =0.45, n = 174) and were followed for 20+/-8 months. Hypotension was defined as a decrease in systolic blood pressure > or =20 mm Hg, compared with baseline values. The incidence of hypotension was similar in groups I and II (23.6% vs. 18.4%, P = 0.28), and the hypotension was not related to positive dobutamine echocardiography. Univariate analysis showed that the development of hypotension was associated with a higher incidence of cardiac death in group I but not in group II. Multivariate analysis showed that dobutamine-induced hypotension was an independent predictor only for cardiac death in group I and was not related to any other cardiac events in either group. In conclusion, the development of hypotension during dobutamine stress can identify a subgroup with poor ventricular functional reserve and at high risk for cardiac death among patients complicated with left ventricular dysfunction.