[Platypnea-orthodeoxia syndrome in Spain]

Platypnea orthodeoxia (PO) syndrome is characterized by dyspnea and orthostatic hypoxemia. Various cardiac and noncardiac conditions responsible for the pathophysiological mechanisms involved in the syndrome are found during differential diagnosis. We searched the records of Hospital Universitario Miguel Servet in Saragossa for confirmed cases of PO syndrome diagnosed between January 2002 and June 2014 and found 4 cases. Three were secondary to rightto- left shunt by way of a patent foramen ovale. The fourth was secondary to an intrapulmonary vascular shunt in the context of hepatopulmonary syndrome. A total of 129 titles on PO syndrome were indexed in MEDLINE between 1979 and April 2013; 77% were published in the last 10 years. PO syndrome is under diagnosed. The evident increase in incidence in recent years is probably attributable to better diagnostic techniques.