What is a VSD (Ventricular Septal Defect)?

A ventricular septal defect (VSD) is one of the most common congenital heart defects. A wall or septum divides the ventricles, the pumping chambers of the heart. In some developing hearts, the septum does not completely divide the two ventricles. A hole in the septum is classified as a ventricular septal defect. Many may have heard the term a "hole in the heart," which usually refers to a VSD.

If a VSD is fairly large, it can cause almost immediate problems to the affected newborn. VSDs create problems because the blood returning to the lungs in the right ventricle mixes with the oxygenated blood in the left ventricle. This can cause the right ventricle to overload and send too much blood to the lungs, causing very high blood pressure. If ignored, a VSD can cause a syndrome called Eisenmenger's, which results in early morbidity and is only reparable through a heart-lung transplant.

The mixed blood returning to the body from the left ventricle results in all the body's tissues and organs not getting enough oxygen. This can cause growth problems, difficulty feeding, and gradually an enlarged heart, due to the body's attempt to get more oxygen. Either ventricle may become enlarged from overflow.

Fortunately, the ventricular septal defect is often so small that it may not ever be noticed or treated. Often, a small VSD closes on its own without any type of medical intervention. Moderately sized VSDs are usually first noticed a few days after a child is born, although diagnosis can take longer depending on how much the ventricular septal defect is impacting the child's health. Many children with minor VSDs do not exhibit any symptoms or problems, but physicians may detect a heart murmur, which warrants further investigation.

When a ventricular septal defect is suspected, the child is generally referred to a pediatric cardiologist for further examination. The cardiologist will probably require a chest X-ray, an electrocardiogram (EKG), and an echocardiogram. The echocardiogram is basically a sonogram of the heart. All these tests are noninvasive and take little time to perform. If further examination of the size of the ventricular septal defect is needed, a cardiac catheterization may be performed.

With a moderately sized ventricular septal defect, most cardiologists prefer to wait and see if the hole closes on its own. This decision varies, however, and largely depends upon the health of the child. The bigger the hole, the more likely problems will occur.

If repair of the VSD is not immediate, the cardiologist may prescribe medications like digoxin to improve heart function and lasix to help reduce fluid overload. When a child cannot breast or bottle feed, high calorie formula can be administered through a nasal-gastric tube. A child with an unrepaired moderate or large VSD is more susceptible to lung infections, and care must be taken to avoid exposure to others who are ill.

If a ventricular septal defect is causing significant growth delays, or is creating too much pressure in the lungs, surgical repair provides an excellent outcome. The pediatric cardiothoracic surgeon will perform an open-heart procedure and suture or patch the holes with Gore-tex. Once surgery is performed, the child may be monitored once a year, but generally there are no limitations on activity or effects on quality of life. Most cardiologists, however, recommed that any child with a ventricular septal defect, repaired or otherwise, take antibiotics prior to any dental examinations to inhibit the potential growth of strep cells in the heart, a condition called bacterial endocarditis.

Though the surgery itself can be frightening and stressful to both parents and child, once over, the child should live a normal and healthy life. Symptoms prior to the surgery, like poor growth or feeding issues, generally resolve once the ventricular septal defect is closed. Closing a single VSD has a 99% rate of being uncomplicated.

In general, there is no known cause for a VSD. Children with Down's Syndrome are more likely to have VSDs, as are children with Noonan's Syndrome. Maternal use of alcohol and cocaine have also been linked to a greater incidence of VSDs. However, in most cases of ventricular septal defect, there is no defining link to maternal behavior or related health issues.