Patent foramen ovale revealed by COVID-19 pneumonia

BACKGROUND: Platypnea-orthodeoxia syndrome (POS) is a rare condition characterized by dyspnoea (platypnea) and arterial desaturation in the upright position resolved in the supine position (orthodeoxia). Intracardiac shunt, pulmonary ventilation–perfusion mismatch and others intrapulmonary abnormalities are involved. CASE PRESENTATION: We report a case of POS associated with two pathophysiological issues: one, cardiac POS caused by a patent foramen ovale (PFO) and second, pulmonary POS due to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) interstitial pneumonia. POS has resolved after recovery of coronavirus disease 2019 (COVID-19) pneumonia. CONCLUSIONS: Right-to-left interatrial shunt and intrapulmonary shunt caused by SARS-CoV-2 pneumonia contributed to refractory hypoxemia and POS. Therefore, in case of COVID-19 patient with unexplained POS, the existence of PFO must be investigated.