Right to left shunt through a patent foramen ovale without pulmonary hypertension

This article describes a patient presenting with dyspnea and platypnea and whose only clinical finding was presence of patent foramen ovale with a right to left shunt, without pulmonary hypertension, characteristic of the rare Platypnea-Orthodeoxya Syndrome, with very interesting pathophysiological findings and with therapeutic alternatives not yet defined.