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79 Platypnea–orthodeoxia syndrome as an uncommon cause of dyspnoea in a nonagenarian with aortic dissection


 
 
 Platypnea–Orthodeoxia syndrome (POS) is an uncommon but challenging clinical condition characterized by positional dyspnoea (platypnea) and arterial desaturation (orthodeoxia) in the upright position that improve in the supine position. POS can occur insidiously, as progressive unexplained oxygen desaturation for months or years, or as acute life-threatening unexplained hypoxaemia. The most common cause is the presence of an intracardiac shunt (patent foramen ovale and other interatrial defects) associated with a secondary anatomic or functional defect that serve as substrate for a right to left intracardiac shunt leading to oxygen desaturation.
 
 
 
 Herein we present the case of a nonagenarian with a known history of ascending aortic aneurysm, that was admitted to the emergency department of our institution with a complaint of intermittent chest pain and dyspnoea. POS was then diagnosed, and the patient underwent a successful percutaneous closure with an Amplatzer™ device (25/25 mm) with minimal residual right-to-left shunt leading to a significant relief of the dyspnoea and improvement of arterial saturation. We also herein revise the clinical presentation, pathophysiology, diagnostic work-up, and management of patients with POS, aiming at increasing the awareness of this uncommon but often misdiagnosed treatable condition.
