Background : The prognosis of patients with non-ischemic dilated cardiomyopathy (DCM) is variable. Clinical and echocardiographic variables have been used to predict prognosis in patients with DCM. The aim of this study was to investigate whether the contractile reserve on dobutamine stress echocardiography (DSE) could predict the myocardial contractile reversibility or prognosis in patients with recent-onset DCM. Method : High-dose DSE was performed in 22 patients with recently diagnosed DCM in incremental stages lasting 5 min each, with an initial dose of 5關g/kg/min, which was increased to 10 關g/kg/ min, then to 20 and 30 關g/kg/min, and finally to the maximum dose of 40 關g/kg/min. Left ventricular (LV) volume and ejection fraction (EF) was measured by Simpson���s biplane method. A follow-up echocardiography was done at 9짹6 months. Results : Fourteen patients were men and age was 46짹16 years. Resting LVEF, LV end-diastolic volume and LV end-systolic volume was 24짹6%, 174짹53 mL and 133짹44 mL. LVEF were increased to 31짹9% at low dose dobutamine and to 36짹9% at peak dose dobutamine stimulation. Follow-up LVEF was 39짹15% after 9짹6 months (Fig 1). Resting LVEF, LV volume, stroke volume, E/E���, Ees, Ea and VVID could not predict follow-up LVEF. However, LVEF, LV volumes, Ees and VVID at peak dose on high-dose DSE, not at low dose, was well correlated with follow-up LVEF, especially peak LVEF was most strongly correlated (Fig 2). During follow-up period, 3 died of cardiac causes and 5 readmitted for aggravation of heart failure. In patients with cardiac events, LVEF was lower, LV volumes were higher and changes of LVEF from resting to peak dobutamine were lower. Conclusion : High-dose DSE could predict late spontaneous improvement in cardiac function in patients with recent-onset DCM and had prognostic values for future cardiac events.