Platypnea-Orthodeoxia Syndrome Revealing a Patent Foramen Ovale in a Middle-Aged Woman

Abstract Platypnea-orthodeoxia syndrome is a rare condition characterized by dyspnea and arterial desaturation that worsen in the upright position and improve when supine. We report the case of a 53-year-old woman with significant obesity, hypertension, dyslipidemia, and a history of two ischemic strokes, admitted for refractory hypoxemia. Clinical examination revealed dyspnea and desaturation in the sitting position, with improvement when lying down, showing a 7% difference in oxygen saturation. Transesophageal echocardiography (TEE) identified a patent foramen ovale (PFO). Percutaneous closure of the PFO was successfully performed. Follow-up transthoracic echocardiography showed no residual shunt. Clinical evolution was favorable, with complete resolution of dyspnea, and no recurrence during follow-up.