Diagnosis and pathophysiology of paradoxical embolism

Three cases of paradoxical embolism are presented. Although most systemic emboli originate in the heart, detection of other sources is aided by venography of the lower extremities, indocyanine green-dye curve studies of the inferior vena cava, obtaining right heart pressures, oximetry, and pulmonary angiography. Forty per cent of 55 patients reviewed had repeat episodes of systemic embolism and 2 of the 3 proved cases of paradoxical embolism had repeat episodes. Prolonged anticoagulant therapy may prevent recurrence.