Patent Foramen Ovale With Platypnea - Orthodeoxia Syndrome: A Case Report.

Platypnea-orthodeoxia syndrome (POS) is an extraordinary medical condition characterized by positional dyspnea (platypnea) and arterial desaturation or hypoxemia (orthodeoxia) in the setting of an upright position. The difficulty breathing is alleviated upon lying down. It is the opposite of orthopnea and is manifested by a decrease in oxygen saturation when changing from supine to an orthostatic position. POS can have an intracardiac or an extracardiac etiology. Herein we report a case of an 87-year-old man presenting with acute on chronic dyspnea who showed promising improvement in oxygen saturation after patent foramen ovale (PFO) closure.