Paradoxical embolism. A diagnostic challenge and its detection during life.

Two cases of paradoxical embolism, one with recurrent cerebral embolism and one with brachial and coronary embolism and both associated with pulmonary embolism, were diagnosed during life. Although there was neither pulmonary hypertension nor intracardiac shunt present at the time of cardiac catheterization in both cases, the presence of a patent foramen ovale with an interatrial right-to-left shunt was demonstrated by a simple ascorbate dilution technique following a Valsalva maneuver. Each patient was treated by surgical interruption of the inferior vena cava and did well. Paradoxical embolism should be included in the differential diagnosis of arterial embolism for which there is no obvious source, especially when there is also evidence of venous thrombosis or pulmonary embolism.