Cardiac paroxysmal orthodeoxia syndrome: A comprehensive process of this challenging disease starting from the clinical suspicion till the therapeutic procedure.
Peter Youssef, Florent Broussous
✦ AI-curated · Sources linked
Case in brief
An elderly patient presenting to the emergency department with a femoral neck fracture developed dyspnoea and refractory hypoxaemia when sitting upright, which resolved when recumbent. Pulmonary embolism and COVID-19 were excluded by contrast-enhanced chest CT and RT-PCR; ECG and transthoracic echocardiography were unremarkable. Positional symptoms prompted a bubble contrast echocardiogram, which demonstrated substantial right-to-left passage through a patent foramen ovale and a hyperdynamic interatrial septum. Urgent percutaneous PFO closure was followed by marked symptomatic improvement.
What made this case unusual
The positional hypoxaemia emerged during preoperative evaluation for a femoral neck fracture, while initial investigations—including routine transthoracic echocardiography—were unremarkable.
Diagnostic / clinical pearl
When dyspnoea and hypoxaemia appear upright and improve with recumbency, consider platypnea-orthodeoxia syndrome; a bubble contrast echocardiogram can reveal a PFO-related right-to-left shunt despite an unremarkable routine echocardiogram.
Why it matters
The case illustrates how careful attention to positional symptoms can redirect evaluation after more immediately suspected causes of hypoxaemia have been excluded.