Platypnea-Orthodeoxia Syndrome Due to Sinus Venosus Atrial Septal Defect With Partial Anomalous Pulmonary Venous Return.

BACKGROUND

Platypnea-orthodeoxia syndrome is a rare cause of positional hypoxia resulting from right-to-left shunting, often associated with intracardiac defects and abnormal venous return.

CASE SUMMARY: A 68-year-old woman with progressive hypoxia presented with positional desaturation and was found to have a superior sinus venosus atrial septal defect with partial anomalous pulmonary venous return. After diagnosis via bubble echocardiography and cardiac magnetic resonance imaging, successful transcatheter closure was performed with resolution of hypoxia.

DISCUSSION: This case highlights the importance of considering platypnea-orthodeoxia syndrome in cases of unexplained hypoxia and demonstrates the role of advanced imaging and 3D modeling in planning successful transcatheter repair of complex congenital defects in older adults.

TAKE-HOME MESSAGES: When traditional workup for hypoxia is unrevealing, clinicians should consider consultation with adult congenital heart disease specialists for assistance in diagnosis and management of rare congenital heart defects. Multimodal imaging is important for procedural planning in transcatheter sinus venosus atrial septal defect closure.