AORTIC ATHEROEMBOLISM Microemboli or macroemboli from atherosclerotic plaque and thrombus in the aorta are important causes of cerebral and systemic embolization. Cerebral atheroembolism suggests the source of embolic material is intracardiac or is in the ascending aorta and/or transverse aortic arch. Lower extremity atheroembolism is caused most commonly by abdominal aortic aneurysm or diffuse atherosclerotic disease. Unilateral blue toes suggest that the embolic source is distal to the aortic bifurcation. Atheroembolism is characterized by livedo reticularis, blue toes, palpable pulses, hypertension, renal insufficiency, increased erythrocyte sedimentation rate, and eosinophilia (transient) (Fig. 1). Atheroembolism can occur spontaneously or be due to medication (warfarin or thrombolytic therapy), or to angiographic or surgical procedures. Thoracic aortic atherosclerotic plaque is most accurately assessed with TEE. Plaque thickness more than 4 mm or mobile thrombus (of any size) are associated with an increased risk of embolism (Fig.2).Severe aortic atherosclerosis is present in approximately 27% of patients with previous embolic events and is also a strong predictor of coronary artery disease.