Congenital Heart Disease

What is congenital heart disease?

Congenital means present at birth. A congenital heart disease occurs when the heart, or blood vessels near the heart, do not develop properly before birth.

Around 500 — 600 babies are born with congenital heart defects in Ireland every year. In most cases, it is unknown why they occur.

Congenital heart disease can also be referred to as congenital cardiovascular disease or a congenital heart defect.

What happens if there is a congenital heart disease?

If a person has congenital heart disease, one of three things will normally happen:

  • The defect will obstruct the flow of blood in the heart (or vessels near the heart).
  • The defect will cause the blood to flow through the heart in an abnormal pattern.
  • In some rare cases, the left or right side of the heart doesn't develop properly.

What is the difference between cyanotic and acyanotic heart defects?

With cyanotic (blue) heart defects, the blood that is pumped around the body contains less-than-normal levels of oxygen. This causes the skin to appear bluish in colour, a condition known as cyanosis.

The most common type of cyanotic heart defect is termed tetralogy of Fallot (see diagram). This can result in for example, stenosis (narrowing) at or just beneath the pulmonary valve. This narrowing partially blocks the flow of blood from the right side of the heart to the lungs.

As a result of this condition, cyanosis may appear soon after birth, in infancy or later in childhood. In some children, the cyanosis may become severe, resulting in rapid breathing and possibly even unconsciousness.

Most children with this condition have open-heart surgery before they start going to school.

Acyanotic (pink) heart defects do not generally cause the infant or child to go blue. An example is coarctation of the aorta. The aorta is the main artery responsible for carrying blood from the heart to the rest of the body. Coarctation results in the aorta being constricted or pinched. This obstructs the blood flow mostly to the lower part of the body. It also increases blood pressure above the constriction.

With this condition symptoms usually do not show at birth, however they can begin to emerge as soon as a week after birth. A child with severe coarctation should have surgery in early childhood, after which, long-term follow up is necessary.

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