Platypnea-Orthodeoxia: Patent Foramen Ovale Unmasked by Pulmonary Emboli

This report describes an 84 year old woman who presented with breathlessness from platypnea-orthodeoxia. This was due to a distortion of a patent foramen ovale by lower thoracic vertebral fractures which allowed a right-to-left intracardiac shunt. The right-to-left shunt was, in this case, triggered by small bilateral pulmonary emboli. Platypnea-orthodeoxia is rare, complex, and underdiagnosed. The pathogenesis requires an anatomical substrate for a shunt and a functional component that triggers reversal of the flow across it. Recognition is critical and may prevent provision of sedation, invasive ventilatory support, and vasopressor; all of which actually exacerbate right-to-left extrapulmonary shunt.