Common Atrium Concurrent with Atrioventricular Septal Defect: A Case Report

Common atrium accounts for 0.5% to 1% of congenital heart diseases. It is characterized by the atria septum's complete absence and atrioventricular canal defect. It may occur as an isolated malformation or associated with other extracardiac anomalies. Untreated cases are at risk of developing pulmonary hypertension. We present a case of an 18-month-old female baby with a recurrent chest infection, central cyanosis, and echocardiographic features of the common atrium concurrent with atrioventricular canal defect and features of pulmonary hypertension.