Inferior sinus venosus atrial septal defect

This code describes a congenital heart defect where there is an opening in the atrial septum, specifically located at the inferior aspect of the sinus venosus. This defect is often associated with anomalous pulmonary venous return from the right lung, where the pulmonary veins drain into the inferior vena cava or right atrium instead of the left atrium.

Use this code when documentation clearly identifies an atrial septal defect (ASD) as being of the inferior sinus venosus type. This diagnosis is typically made through echocardiography, cardiac MRI, or cardiac catheterization. It is often identified in pediatric cardiology or adult congenital heart disease settings.

• Differentiate from other types of ASDs (e.g., ostium secundum, ostium primum) based on precise anatomical location.
• Always look for associated anomalous pulmonary venous return, which should be coded separately if present.
• Ensure the documentation specifies "inferior" sinus venosus, as there is also a superior sinus venosus type.