Syndrome de platypnée-orthodéoxie associé à une embolie paradoxale liée à la persistance d'un foramen ovale perméable

Platypnea-orthodeoxia syndrome (POS) is the association of dyspnea (platypnea) and drop of the O2 saturation (orthodeoxia) in the upright position, which are relieved by recumbency. POS is most often due to a patent foramen ovale (PFO) with a coexistent functional defect. It affects patients over 50 years old. The diagnosis is simple and relies on measuring the O2 saturation in the supine and the upright position and an echocardiography showing the functional defect. The recommended treatment is the closure of the PFO when present. We describe the case of a patient who suffered a stroke due to a paradoxical embolism through a PFO causing severe POS.