Ventricular septal defect


The most common congenital heart defect known as ventricular septal defect (VSD) cause a hole in the wall (septum) that divide the lower chambers (ventricles) of the heart. The hole allows the blood to flow from the left to the right chamber of the heart which cause the heart to work harder since the oxygen-rich blood is returned to the lungs rather than to the rest of the body.

A minor VSD may close on its own without any intervention and may not cause any issues. The doctor will regularly evaluate if the hole closes on its own or if any symptoms have developed. If the hole becomes bigger, it may need to be intervene early during childhood through a surgery to avoid difficulties and further complications.


The symptom of VSD may be present at birth or may not appear until in childhood depending on the size of the hole and other associated heart defects. The signs and symptoms vary depending on the size of the hole.

Signs and symptoms of a VSD in infant can include:

  • Poor feeding
  • Fast breathing or breathlessness
  • Tiredness

Sign and symptoms of a VSD in adulthood can include:

  • Shortness of breath
  • Heart murmur

Seek medical help if the baby or child experience the following:

  • Getting tired or exhausted quickly when eating or playing
  • Not gaining weight
  • Breathless when eating or crying
  • Fast breathing or shortness of breath
  • Rapid or irregular heartbeat
  • Fatigue or weakness


The cause of congenital heart defects is still unknown. The problem may arise during early development of the heart which can be affected by several risk factors such as genetics, mother’s diet and medicine intake during pregnancy and the environment. Some children can have other heart defects along with VSD.

It is during fetal development that the wall (septum) designed to separate the two lower chambers of the heart (right and left ventricles) and it fails to form which leads to ventricular septal defect.
In a baby with a normal heart, the left side of the heart pumps oxygen-rich blood to the rest of the body while the right side only pumps blood to the lungs to get oxygenated blood. In a child with VSD, the blood can flow from the left ventricle to the right ventricle and into the lungs. This raises blood pressure and leads to extra blood flow in the lung arteries which requires the heart and lungs to work harder than usual.

VSDs can exist in different locations in the wall between ventricles. The hole or opening could be one or more and of different sizes.

VSDs can also develop from complications of a heart surgery or after experiencing a heart attack which usually occurs as we grow older.

Risk factors

Ventricular septal defects can occur in families with known genetic syndromes such as Down syndrome. If you have a known risk for a heart defect, a genetics specialist can provide you with assessment and recommendations to further understand the risks associated with this condition.