This is a gross external view of a heart showing very large left ventricle and very small right ventricle delineated by anterior descending branch of left coronary artery. This rare condition is known as hypoplastic right heart syndrome, a congenital heart defect in which the right ventricle of the heart fails to grow and develop appropriately. The ventricle's muscle structure is poor and underdeveloped and the ventricle cannot contain the proper amount of blood pumped from the right atrium. This condition needs immediate and emergency treatment, as the heart begins to fail almost immediately after birth.