The aim of this study was to determine whether early assessment of left ventricular (LV) systolic and diastolic functions by pulsed wave Doppler tissue imaging predicts LV thrombus formation after acute anterior myocardial infarction. Echocardiography was performed in 87 consecutive patients with first acute anterior myocardial infarction within 24 hours after arrival to the coronary care department. Mitral inflow velocities and early diastolic (Em), late diastolic (Am), and peak systolic (SM) mitral annular velocities were measured. Em/Am and the ratio of early diastolic mitral inflow velocity to Em (E/Em), which is a reasonably good index for predicting elevated LV filling pressure, were calculated. To detect LV thrombus, 2-dimensional echocardiography was repeated on days 3, 7, 15, and 30. Patients were divided into two groups according to LV thrombus formation: group 1 (n = 29; aged 59 +/- 11 years; 4 women) with thrombus; and group 2 (n = 58; aged 57 +/- 9 years; 6 women) without thrombus. Members of group 1 had significantly lower Em, a lower SM, a lower peak systolic mitral annular velocity, and a lower Em/Am than those in group 2 (6.4 +/- 2.0 cm/s vs 8.9 +/- 2.7 cm/s, P <.001; 7.3 +/- 1.6 cm/s vs 8.6 +/- 1.7 cm/s, P =.001; 0.65 +/- 0.25 cm/s vs 0.89 +/- 0.27 cm/s, P <.001, respectively). The E/Em was significantly higher in group 1 than in group 2 (12.5 +/- 5.0 vs 7.2 +/- 2.8, P <.001). The sensitivity of an E/Em ratio greater than 9 in predicting LV thrombus formation was 69%, the specificity 79%, the positive predictive value 63%, and the negative predictive value 84%. Mitral annular velocities derived by pulsed wave Doppler tissue imaging are simple to obtain even in technically suboptimal studies, and can be used for predicting LV thrombus formation after myocardial infarction.