[A rare and curable cause of acute respiratory insufficiency after a pneumonectomy. The platypnea-orthodeoxia syndrome by the reopening of the foramen ovale].

We describe a case of a 54 year old patient who had developed a right to left shunt due to a patent foramen ovale as a late consequence of a pneumonectomy; this was responsible for acute respiratory insufficiency and respiratory failure. This is a rare complication, but its clinical presentation as platypnea-orthodeoxia should lead to the correct diagnosis. The diagnosis can be rapidly confirmed by a non-invasive examination, namely contrast echocardiography, coupled with color doppler. The treatment is surgical with excellent results. The pathophysiological mechanism is also discussed.