A ventricular septal defect (VSD) is a hole between the right and left pumping
chambers of the heart.
The heart has four chambers: a right and left upper chamber called an atrium and
a right and left lower chamber called a ventricle.
In the normal heart, the right and left chambers are completely separated from
each other by a wall called a septum. The right atrium is separated from the
left atrium by the atrial septum and the right ventricle is separated from the
left ventricle by the ventricular septum.
It is normal for all infants to be born with a small hole between the two atria,
which usually closes within the first few weeks of life.
Normally there is no hole between the two ventricles, but some infants are born
with these holes called ventricular septal defects.
Ventricular septal defects are among the most common congenital heart
defects, occurring in between 0.1 percent to 0.4 percent of all live births and
makes up about 20 percent to 30 percent of congenital heart lesions.
Ventricular septal defects are probably one of the most common reasons for
referral of an infant to a cardiologist.