Een ongebruikelijke oorzaak van acute desaturatie

An unusual cause of acute desaturation A 61-year-old man presented with symptoms of rapidly increasing dyspnea, chest pain and significant hypoxemia for which the initial investigations revealed no clear explanation. There was a remarkable improvement of the saturation in supine position. A contrast transesophageal echocardiography established the presence of a patent foramen ovale (PFO), which was successfully closed via a percutaneous transcatheter. Platypnoea-orthodeoxia syndrome (POS) is a rare entity characterized by the presence of arterial hypoxemia in upright position with resolution of the hypoxemia in supine position. It is most frequently caused by a PFO. A PFO is, however, merely an essential precondition and the development of POS nearly always requires the presence of other (functional) factors.