A case of incidentally diagnosed platypnea-orthodeoxia syndrome (POS) that presented with no dyspnea
Hitomi Hiranoa Kenji Nemotob Yoko Edaa Kengo Nishinoa Takashi Matsudaa Takefumi Saitoa
aDepartment of Respiratory Medicine, National Hospital Organization Ibarakihigashi National Hospital
bNemoto Clinic
The patient was a 68-year-old man who was taking oral steroids for organizing pneumonia complicated by pulmonary emphysema. The patient experienced prolonged hypoxemia without dyspnea even after recovery from the pneumonia. A transthoracic echocardiogram and right heart catheterization confirmed an intracardiac shunt from the right to the left atrium. This was diagnosed as platypnea-orthodeoxia syndrome (POS) caused by a patent foramen ovale (PFO). In the present case, it was thought that the preexisting POS was revealed by the increased right-to-left shunting caused by the cardiac morphological changes following the reduction in circulating plasma volume due to pneumonia and steroid use. A worsening ventilation-perfusion imbalance due to pulmonary emphysema and organizing pneumonia may also have contributed to the manifestation of POS.
Patent foramen ovale (PFO) Right-left atrial shunt
Received 13 Oct 2022 / Accepted 19 Dec 2022
AJRS, 12(2): 102-106, 2023