Patent foramen ovale and pulmonary embolism. An underestimated co-morbidity following cardiac surgery.

When pulmonary embolism occurs in the presence of a patent foramen ovale the sudden increase in the right heart pressure can open the defect and could cause right to left atrial shunting. This may further aggravate the already existing hypoxemia, and the direct communication between the venous and the arterial circulation increases the risk of paradoxical embolization. In this paper we present a case of postoperative pulmonary embolization in a patient with patent foramen ovale, and the effects of these co-existing conditions are reviewed. In the cardiac surgical literature such a complication has not yet been described.