Platypnoea-orthodeoxia syndrome as an uncommon cause of dyspnoea: a literature review.

Platypnoea-orthodeoxia syndrome (POS) is an uncommon but challenging clinical condition characterised by positional dyspnoea (platypnoea) and arterial desaturation (orthodeoxia) in the upright position that improve in the supine position. Since its first description, many cases have been reported and many conditions have been associated with this syndrome. Herein, we review the clinical presentation, pathophysiology, diagnostic work-up and management of patients with POS, aiming to increase the awareness of this often misdiagnosed condition.