What Are Congenital Heart Defects?

Heart defects that are present from birth are called congenital heart defects. The circulatory system of the foetus is a little different from that of the newborn. The foetus gets its oxygen supply and nutrition from the mother through the placenta.

The foetal heart does not have to perform certain functions as the lungs do not process air. At the time of birth, when the lungs fill with air, the newborn’s heart routs blood in a path similar to yours. This requires some changes in the heart and blood vessels near the heart. When these do not take place effectively, there are malformations in the heart leading to Congenital Heart Diseases.

What Causes Congenital Heart Diseases?

There is no definitive evidence yet. But the following are suspected to be contributing factors:

Genetic Disorders :

Viral infections like German Measles.

Intake of drugs/alcohol by the mother.

Types of Congenital Heart Defects :

Due to malformation of the heart two things can happen:

Too little blood from the heart reaches the lungs. So there is not enough oxygenated blood to keep the body energetic and robust. Mixing of the pure and impure blood due to defects in the structure of the heart or the blood vessels is also possible. The child’s skin, nail beds and lips get a bluish tinge. The malformations that cause this are called Cyanotic Disorders. Quite often babies with Cyanotic Diseases have multiple problems in the heart.

Too much blood can also flow from the heart to lungs due to defects in the heart. These defects are called Acyanotic Disorders.

The most common acyanotic disorders are:

Septal Defects

In the fetal heart there is an opening between the left and right atria called the foramen ovale, which allows blood to circulate more directly from the right atrium to the left atrium.

When the baby is born the foramen ovale closes. In a small percentage of babies it does not. This leads to what is called Atrial Septal Defect.(ASD).

Similarly, when there is a malformation in the wall between the left and right ventricle, causing a “ hole” in the septum in between the two lower chambers of the heart, it is called Ventricular Septal Defect(VSD).


ASD can be without symptoms. Common symptoms of septal defects could be one or more of the following:

  • The child’s height and weight are below normal.
  • Breathlessness
  • Irregular heartbeat
  • Fatigue
  • Poor Feeding


Sometimes the septal defects close on their own. However, if this does not happen surgery may be necessary.

Patent Ductus Arteriosus

Your pulmonary artery, which carries impure blood to the lungs, does not do so in the foetus. It carries pure blood. From here the pure blood is shunted to the aorta through a small tube called ductus arteriosus. When the child is born, The ductus arteriosus closes. When it does, the condition is called Patent Ductus Arteriosus(PDA)

A child with PDA is likely to have the following symptoms:

  • Breathing difficulties
  • Heart murmur
  • Change in heart rate


The first option the doctor considers is to see if it will close on its own.

Medication can be used to narrow the duct.

If neither is effective, surgery or catheterisation may be necessary. A small cut is made in the chest and the tube is tied off. Or a coil is inserted through a catheter and placed on the ductus arteriosus to grip it close.

( Source: webhealthcentre.com)