Left ventricular thrombus (LVT) formation is a serious complication of anterior ST segment elevation myocardial infarction (MI) that impacts prognosis. LVT has been linked to blood stasis in the LV apex, but conventional predictors of LVT formation are limited. This study employed 4D-flow MRI as a new means of quantifying MI induced alterations in LV flow physiology. Among a mixed cohort of post-MI subjects and controls, 4D-flow MRI demonstrated MI to be associated with increased flow stagnance in the LV apex. These findings will inform use of 4D-flow MRI in future studies to predict longitudinal risk for post-MI LVT.