What is Hole in the Heart?

When you hear something like a baby has a hole in her heart -- what do you understand? Does it mean, the heart has a hole on its wall? Well, for a layman, such kind of presumption is obvious, but being a science student, you must know what it means. 

Hole in a heart is associated with congenital heart defects. It means, such kind of problem occurs right from the childhood when a baby is born. It is a very severe heart problem, as it changes the normal flow of blood through the heart. In order to understand the defect, you must know the structure of heart. Mammals, like human beings have four chambered heart -- two auricles and two ventricles. Both auricles and ventricles are separated by a wall called septum. The right side of the heart, means the right auricle and right ventricle is responsible for carrying low-oxygen (impure) blood while the left auricle and left ventricle is responsible for carrying oxygenated (pure) blood. The septum prevents the mixing of pure blood with impure blood. 

A baby having a hole in her heart means that a hole is present between the septum of either the auricles or ventricles. When a hole is present between the auricles, it is called Atrial Septal Defect (ASD) and when a hole is present between the ventricular septum, it is called Ventricular Septal Defect (VSD). Because of the presence of a hole in either atrial or ventricular wall -- the pure blood mixes with the impure one. This leads to the circular of mixed blood throughout the body and into the cells and tissues.