My mind is racing. what does it mean if a boy has atrioventricular septal defect?

AV canal: Atrioventricular canal is a very complex congenital endocardial cushion defect that consist of a primum atrial septal defect and a av canal type of ventricular septal defect. May be associated with a cleft mitral valve. Surgical repair is the treatment. The timing will depend on severity of shunting, the presence or absence of a concomitant right ventricular outflow obstruction and other factors.

AVSD: Also known as an av canal, it is a type of congenital heart defect. There is a an ASD and vsd together creating a defect (hole) in the center of the heart. There is also one common av valve , rather than 2 distinct valves (mitral and tricuspid valves). It is commonly but not necessarily associated with down syndrome. Surgical repair is usually required in infancy.