Coronary sinus atrial septal defect

This code describes a congenital heart defect where there is an abnormal communication between the coronary sinus and the left atrium, often due to an unroofed coronary sinus. This defect allows shunting of blood from the left atrium into the coronary sinus and then into the right atrium, bypassing the systemic circulation.

Use this code when documentation clearly indicates a diagnosis of a coronary sinus atrial septal defect. This diagnosis is typically made through echocardiography or cardiac catheterization, identifying the specific anatomical anomaly.

• Differentiate from other types of atrial septal defects (e.g., ostium secundum, ostium primum) which have distinct ICD-10-CM codes.
• Ensure the documentation specifies "coronary sinus" to support accurate code assignment.
• Consider sequencing with other congenital anomalies if present, following ICD-10-CM guidelines for multiple congenital malformations.