Ventricular Septal Defect

What is Ventricular Septal Defect?

(© Competence Network for Congenital Heart Defects)

Ventricular means ‘of the ventricles’ - the pumping chambers of the heart.
Septal means ‘of the septum’ – the wall between the right and left sides of the heart. Defect means that there is something wrong, in this case it is a hole.
So a Ventricular Septal Defect (VSD) is a hole in the wall between the ventricles.

Because pressure is higher on the left side of the heart, some of the blood that should be pumped into the aorta leaks through the hole in the septum into the right ventricle. There it combines with the blue de-oxygenated blood and is pumped to the lungs.

In a small VSD there is only slightly more blood than normal being pumped to the lungs. This kind of hole usually closes by itself, although this may take some time and it may not close completely until adulthood. Small holes like these should not affect your child very much or make them ill.

If the heart has a large VSD, or multiple VSD’s there is much more blood than normal being pumped to the lungs. This means that the right ventricle has to work very hard to pump the extra blood. The increased flow of blood also travels at higher than normal pressure into the pulmonary artery and the lungs. At the same time, the left ventricle is losing blood to the right. It therefore has to pump harder to get enough blood into the aorta to supply the body’s needs. The overall effect is that both the heart and the lungs have to do more work than usual.

The VSD may be one of two or more heart defects. In some cases, the VSD is necessary for a circulation such as Pulmonary Atresia.


Sometimes a VSD is diagnosed during pregnancy on an ultrasound scan of the foetus. A VSD may also be diagnosed after birth, if your baby is showing symptoms. A large VSD will normally cause a baby to be breathless, have problems feeding and to be slow to put on weight. Babies with a VSD can also suffer from frequent chest infections.

The sound of the extra blood moving through the valve to the lungs can also be heard as a heart murmur. When a When a heart murmurs, doctors may use a number of tests to make a diagnosis including:


In some cases, the VSD will close over time and no treatment will be necessary. If doctors think this is going to happen, they will monitor the VSD to make sure it is diminishing in size and not affecting the child’s health in any way.
Sometimes it is necessary to operate to repair a VSD. This is open heart surgery, which means that the heart will need to be stopped and opened to repair it. A heart bypass machine will take over the job that the heart normally does.

The aim of the operation is to make the circulation of blood through the heart and lungs normal, so a patch is put over the hole between the ventricles.

For most children this surgery is low risk, but it can depend on how well your child is otherwise. The doctors will discuss risks with you in detail before asking you to consent to the operation. The length of time in hospital will usually be about a week, depending on how well the child is otherwise.

After Surgery

If the hole is near a valve, or there is any other problem in the heart, treatment can be more difficult, even if the VSD itself is quite small. It is not uncommon for a child to pick up an infection, such as a chest infection or infected wound, while undergoing treatment.

However, most children are much better, active, and gaining weight a few days after surgery. They will have a scar down the middle of the chest, and there may be small scars where drain tubes were used. These fade very rapidly in most children, but will not go altogether. Smaller scars on the hands and neck usually fade away to nothing.

Some of the following problems can occur after surgery or later in life:

  • A small amount of blood may still ‘shunt’ from left to right where the VSD is not completely closed. This should close by itself eventually.
  • The aortic valve may leak because of the abnormal blood flow and may need to be repaired at a later date.
Author(s): Children’s Heart Federation
Last updated: 2008-09-23