To evaluate prolonged diastolic dysfunction in acute coronary syndrome, mitral inflow velocities and left ventricular wall motion were examined with pulsed-wave Doppler and two-dimensional echocardiography in 14 patients with successful reperfusion, 8 patients without reperfusion after acute myocardial infarction, and in 10 patients with prolonged angina. Early peak flow velocity and the ratio of early to atrial peak flow velocity increased gradually both after the onset of acute myocardial infarction with reperfusion and cessation of angina pectoris. However, in acute myocardial infarction without reperfusion, early peak flow velocity and the ratio of early to atrial peak flow velocity decreased significantly. Atrial peak flow velocity remained unchanged in acute myocardial infarction with reperfusion, while it was decreased in angina pectoris on the seventh day. Regional systolic dysfunction abated gradually in acute myocardial infarction with successful reperfusion, and regional systolic dysfunction was not detected in angina pectoris on the third day. Thus, abnormalities in left ventricular early diastolic filling persisted for several days after reperfusion in acute myocardial infarction or cessation of angina. Left ventricular late filling remained unchanged in acute myocardial infarction, whereas, in angina pectoris, a compensatory increase in late filling diminished gradually with an increase in early filling. These results indicate that there are different types of recovery process after diastolic filling abnormalities in patients with acute coronary syndrome.