Positional Changes in Right Atrial Pressure Before and After PFO Closure in Platypnea-Orthodeoxia Syndrome

Platypnea-orthodeoxia syndrome (POS) is a rare condition; however, the number of reported cases has been increasing in recent years. We present a case of POS caused by a patent foramen ovale (PFO), where oxygen saturation and right atrial pressure were measured in both the supine and the sitting positions before and after PFO closure. After closure, oxygen desaturation during postural changes resolved, but the increase in right atrial pressure persisted. Reports of right atrial pressure measurement in POS are rare. To the best of our knowledge, this is the first case in which right atrial pressure was measured both before and after PFO closure. Changes in right atrial pressure, in addition to postural blood flow alterations, contribute to the pathophysiology of POS in certain cases. Understanding individual case variations is crucial for effective management.