ACUTE embolic occlusion of the terminal aorta at its bifurcation is a common and life-threatening cardiovascular catastrophe. Aortic saddle embolus accounts for approximately 10% of all peripheral arterial emboli. It is invariably a reflection of severe, coexisting heart disease.
Physicians must be sufficiently familiar with the characteristic clinical manifestations of saddle embolus in order to reach the diagnosis promptly, recommend appropriate therapy, and avoid irreversible ischemic injury. Time is of the essence in the successful treatment of patients with this disease.
Pathogenesis
Sudden embolic occlusion of the terminal aorta is almost always caused by dislodged intracardiac mural thrombi, from either the left ventricle or left atrium. Perhaps the most common source of large emboli is the left ventricular chamber in patients who have had a recent myocardial infarction. Endocardial inflammation and roughening becomes the site for mural thrombosis. During early convalescence from infarction, such thrombi may become detached from the