A rare dyspnea in internal medicine: platypnea-orthodeoxia after pneumonectomy

A right-to-left shunting across a patent foramen ovale is a rare cause of acute respiratory failure after pneumonectomy. We report two cases of posture dependent dyspnea (platypnea-orthodeoxia) secondary to postoperative right-to-left shunting across a patent foramen ovale. Both cases occurred three months after pneumonectomy, the first in a 63-year-old man and other in a 52-year-old man. A platypnea-orthodeoxia (dyspnea induced by the upright position with arterial deoxygenation relieved by recumbency) should lead to the diagnosis which is confirmed by echography or cardiac catheterization. The prognosis is good after surgical closure of the patent foramen ovale. The physiopathologic mechanism is poorly understood. We report two cases of platypnea-orthodeoxia.