Large Mobile Thrombus

In a 58-year-old woman with rheumatic heart disease and severe mitral stenosis, a thrombus is seen floating within the left atrial cavity on transesophageal echocardiography. The large size of the thrombus and the presence of severe mitral stenosis prevent it from migrating into the systemic circulation. See the NEJM article, “Mobile Large Left Atrial Thrombus“: