Platypnea-orthodeoxia syndrome in patients presenting enlarged aortic root: case report and literature review.

We describe herein a case of a patient who, when in orthostatic positions, had severe hypoxemia and ventilatory dysfunction. Although the severity of symptoms required hospitalization in an intensive care setting, the initial tests only identified the presence of enlarged aortic root, which did not explain the condition. The association of these events with an unusual etiology, namely intracardiac shunt, characterized the diagnosis of platypnea-orthodeoxia syndrome. The literature review shows that, with advancing research methods, there was a progressive increase in the identification of this condition, and this association should be part of the differential diagnosis of dyspnea in patients with enlarged aortic root.