(P16) Platypnea-Orthodeoxia Syndrome, an Unusual Cause of Dyspnea

Introduction: Platypnea-orthodeoxia syndrome is a rare disorder resulting from an interatrial shunt, such as patent foramen ovale (PFO) in this case, and functional component that promotes abnormal shunting when the patient rises to upright position.

Case Description: An 80-year-old female admitted to a skilled nursing facility (SNF) developed worsening shortness of breath. She had a known history of interstitial pulmonary fibrosis on 3L O2 as well as history of heart failure, CAD and recent history of DVT on apixaban. Patient reported to SNF staff concerns of increasing shortness of breath which worsened in the upright position. She was found to be hypoxic O2 around 80% despite increase in oxygen to 4L. She was sent to the emergency department and admitted. She was found to have profound platypnea an orthodeoxia upon admission. A TEE in 2012 did show atrial septal aneurysm with right-to-left shunt consistent with PFO with redemonstration in 2019 on TTE for which no interventions were considered as she was asymptomatic at the time. Echocardiogram was repeated in sitting and supine positions . In the sitting position, patient immediately became tachypneic and tachycardic. A large right-to-left shunt was observed with agitated saline injection. After discussions with pulmonology and cardiology, decision was made to close PFO. She had improvement in dyspnea post PFO closure. She was able to return to SNF in stable condition.

Discussion: Platypnea-orthodeoxia is a rare cause of positional dyspnea. Patients with PFO can develop a right-to-left shunt, which can be visualized with tilt-table contrast echocardiography. The shunt causes symptoms of dyspnea in upright position and relieved in recumbency, or platypnea, and oxygen desaturation accentuated by upright posture and improved by recumbency, or orthodeoxia. Treatment includes closure of the PFO to alleviate the shunt. Dyspnea is a frequent symptom described by residents in nursing facilities, and the differential can be broad. Although platypnea-orthodeoxia syndrome is rare, it should be considered when platypnea is present.