Patent foramen ovale presenting as platypnea-orthodeoxia: diagnosis by transesophageal echocardiography.

Platypnea-orthodeoxia is a rare syndrome that is often associated with interatrial shunting through a patent foramen ovale or atrial septal defect. We describe the case of a 65-year-old woman with progressive dyspnea and hypoxia when standing and walking, which was relieved by assuming the recumbent position. The diagnosis was confirmed by tilt-table transesophageal echocardiography demonstrating a large right-to-left shunt through a patent foramen ovale while the patient was in a semiupright position and no significant shunt while in a recumbent position. This case demonstrates that platypnea-orthodeoxia caused by a patent foramen ovale can be clearly demonstrated by the technique of contrast transesophageal echocardiography performed on a tilt table.