PRACTICALLY every instance of embolism implies a sudden occlusion of the aortic bifurcation by an embolus which has its origin in the left side of the heart. A few exceptions to this rule have been reported. These include rare emboli which have their origin from thrombi or arteriosclerotic plaques.1 Even more rare are paradoxical emboli from the right side of the heart.2 To the best of our knowledge none of the survival cases (table) includes these unusual conditions. Therefore, consideration need be given only to emboli arising in the left side of the heart and lodging at the aortic bifurcation.
The condition of aortic embolus is rare, and it is difficult to obtain an over-all picture of its frequency. In this community of some two thousand hospital beds, saddle embolus of the aorta is recorded as a diagnosis approximately three times each year. This incidence approximates that given by others.3