PARADOXIC EMBOLISM.

A case of paradoxic embolism is presented and the anatomic and physiologic factors in its occurrence are discussed. About 85 cases of this unusual phenomenon have been reported. In the majority of instances peripheral thrombo-phlebitis and pulmonary embolism and infarction precede para- doxic embolism. There is then an increase in pressure in the right auricle and and a fight to left shunt is produced. This opens an otherwise physiologically closed foremen ovale and permits an embolus to by-pass the pulmonary circulation and to be carried peripherally. In patients with congenital heart disease with fight to left shunts the same lack of the filtering effect of the pulmonary circulation is present. Bacteria are less completely removed from the blood stream because they, like the clots, can pass from the right to the left side of the heart. Organisms carried into the cerebral circulation may result in abscess either because brain tissue has poor resistance to infection primarily or secondarily due to previous vascular disturbance. The salient features of both brain abscess and peripheral embolism are presented to emphasize the differences between these two conditions which are often considered together for no other reason apparently than the fact that the term paradoxic is used in describing both. [ABSTRACT FROM AUTHOR]