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What is ventricular septal defect?

Ventricular septal defect (VSD) is a common structural heart disease that can be present at birth: a hole or defect in the septum (wall) that divides the two lower chambers of the heart (ventricles). In a fetus, the right and left ventricles of the heart are not separate. As the fetus grows, a wall forms and separates the two ventricles. If the wall does not completely form, a hole, or VSD, remains.

Depending on the size of the hole, the heart may pump harder to deliver enough blood to the body, causing higher pressure in the heart and possibly even enlargement. This defect causes blood to flow across the hole from the left pumping chamber (left ventricle) to the right pumping chamber (right ventricle) and into the lungs. In a bigger VSD, this extra blood pumped into the lung arteries can cause lung congestion and permanent damage over time.


In some cases, newborns with this congenital heart defect may be asymptomatic, because it’s not necessary for the heart and lungs to work harder, and the hole eventually can close as the wall continues to grow after birth. Some babies may display symptoms a few weeks after birth. However, if the hole is large, the baby often has symptoms related to heart failure. The most common symptoms of VSD are:

  • Shortness of breath
  • Fast breathing
  • Hard breathing
  • Paleness
  • Failure to gain weight
  • Fast heart rate
  • Sweating while feeding
  • Frequent respiratory infections


The cause of VSD in children is unknown, but genetic factors possibly are involved.


Your doctor can detect a VSD with a stethoscope, which will hear a loud heart murmur.


Some smaller VSDs will close spontaneously without surgical intervention, but there is no medication or procedure that can speed up this process or make the VSD smaller. Some VSDs can be managed adequately with medical therapy until they become smaller on their own.

Left untreated, large ventricular septal defects can cause pulmonary hypertension, and therefore require surgical treatment. To close this type of VSD and prevent serious problems later, open-heart surgery may be required in infancy or childhood, even in patients with few symptoms, to prevent complications.

Babies with severe symptoms need VSD repair within the first few months. Medicines temporarily may allay symptoms, but do not cure the VSD or prevent permanent damage to the lung arteries. If an infant is very ill, or has more than one VSD or a VSD in an unusual location, a temporary procedure (pulmonary artery banding) can be performed to relieve symptoms and high pressure in the lungs.

What to expect after treatment

When the VSD is small or has been closed with surgery, no special precautions are necessary. There is no increased risk if the child engages in normal physical activity.

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