Cor biloculare

Cor biloculare is a rare congenital heart defect characterized by a two-chambered heart, typically consisting of a single atrium and a single ventricle. This malformation results from a failure of septation during cardiac development, leading to a common atrioventricular valve and significant mixing of oxygenated and deoxygenated blood. Patients often present with cyanosis and symptoms of heart failure.

This code is used when documentation clearly indicates a diagnosis of cor biloculare, a congenital anomaly where the heart has only two chambers. It is typically identified through echocardiography, cardiac MRI, or angiography. Use this code for the primary diagnosis when the patient is being treated for this specific congenital heart defect.

• Ensure documentation explicitly states "cor biloculare" or describes a two-chambered heart with a single atrium and ventricle.
• Do not confuse with other complex congenital heart defects that may have only two functional chambers but different anatomical structures (e.g., single ventricle with rudimentary atrium).
• Always code any associated congenital anomalies or complications, such as pulmonary hypertension or heart failure, in addition to this code.