Ostium secundum type atrial septal defect

This code identifies a congenital heart defect characterized by an opening in the atrial septum, specifically in the area of the foramen ovale. This defect allows oxygenated blood from the left atrium to mix with deoxygenated blood in the right atrium, leading to a left-to-right shunt.

Use this code for patients diagnosed with an atrial septal defect (ASD) that is explicitly documented as an ostium secundum type. Documentation should clearly specify the type of ASD, often identified through echocardiography or cardiac catheterization reports.

• Differentiate from other types of ASDs (e.g., ostium primum, sinus venosus) which have distinct codes.
• Ensure the documentation specifies "ostium secundum" to avoid coding a generic or unspecified ASD.
• Consider sequencing this code as a primary diagnosis if it is the main reason for the encounter, or as a secondary diagnosis if it is a co-morbidity.