Abstract
BACKGROUND: Platypnea-orthodeoxia syndrome (POS) is a relatively uncommon clinical syndrome characterized by dyspnea and deoxygenation accompanying postural changes, such as sitting or standing from a recumbent position. CASE PRESENTATION: We describe the case of a 76-year-old woman who was hospitalized with dyspnea in the sitting position, which was relieved in the right lateral decubitus position. The patient was diagnosed with POS caused by a patent foramen ovale (PFO), dilation and elongation of the ascending aorta, and pectus excavatum. We performed PFO closure and replacement of the ascending aorta via median sternotomy. The patient's postoperative percutaneous oxygen saturation dramatically increased in the sitting position. CONCLUSIONS: Elongated and dilated ascending aorta and pectus excavatum with PFO may be risk factors for POS. In older patients, surgical intervention is an important treatment option for POS caused by cardiac and aortic comorbidities.