Objective: To investigate serial assessments of systolic coronary flow reversal in the infarct related artery for predicting poor left ventricular functional recovery after reperfused acute myocardial infarction. Setting: Regional hospital. Patients and methods: 49 patients with anterior acute myocardial infarction had transthoracic Doppler echocardiography to record coronary flow velocity in the left anterior descending coronary artery immediately after successful primary coronary angioplasty (day 0), and at 48 hours, one week, and three weeks. Main outcome measures: Coronary flow velocity at each time point; regional wall motion score index (RWMSI) at day 0 and at three weeks. Irreversible dysfunction was defined as a decrease in RWMSI to < 0.22. Results: Measurements of coronary flow velocity could be made in 45 patients. Patients were divided into three groups: no systolic flow reversal (group 1, n = 27), systolic flow reversal observed only on day 0 (group 2, n = 8), and systolic flow reversal persisting until 48 hours (group 3, n = 10). Although baseline RWMSI was similar among the three groups, the value at three weeks was significantly higher in group 3 than in the other two groups. In predicting irreversible dysfunction, the persistence of systolic flow reversal up to 48 hours had a higher positive predictive value (100%) than the presence of systolic flow reversal on day 0 (67%, p < 0.04). The negative predictive value of systolic flow reversal at 48 hours (83%) was comparable in accuracy to the presence of systolic flow reversal on day 0 (85%, NS). Conclusions: In reperfused anterior acute myocardial infarction, serial assessment of coronary flow velocity in the left anterior descending coronary artery is feasible using transthoracic Doppler echocardiography, and the persistence of systolic flow reversal at 48 hours is a more specific marker of irreversible dysfunction than peak creatine kinase or diastolic deceleration time.