Congenital heart diseases (CHD) are a group of conditions affecting the heart that develop during a pregnancy and exist from birth. CHDs are caused by malformations, where structures in the heart and the big blood vessels coming out of it, do not form properly and may be left with holes, with shunts, or with some portions missing entirely. CHDs are split into two types, cyanotic and acyanotic. The word “cyan” comes from the Greek word meaning “blue”, so cyanotic CHDs are those that lead to bluish skin in children, while acyanotic CHDs do not.
Cyanotic CHDs are more severe than acyanotic CHDs, and the blueing of the skin they cause indicates a lack of oxygen in the body. Unlike acyanotic CHDs, most cyanotic CHDs are fatal within the first year of life, if they are not treated. Acyanotic CHDs are less severe, not all of them require treatment, and they are more common than cyanotic CHDs.
The symptoms of congenital heart disease depend on whether or not it is cyanotic.
In cyanotic CHD, symptoms include:
In acyanotic CHD, symptoms include:
Both cyanotic and acyanotic CHDs can occur because of three broad causes – infections, genetic disorders, and the maternal environment. For example, Tetralogy of Fallot is a cyanotic CHD that can be due to Down syndrome (a genetic disorder), or in mothers with diabetes (the maternal environment), among other causes.
Patent Ductus Arteriosus, on the other hand, is an acyanotic CHD that can occur due to maternal alcoholism (the maternal environment) or rubella (an infection that a baby can get during pregnancy).
The risk factors of having a baby born with a congenital heart disease include:
Congenital heart diseases are often diagnosed in babies or young children, although it may take time for them to be noticed, and thus may be diagnosed in adulthood. Diagnosis starts with a doctor listening to the heart with a stethoscope. CHDs cause abnormal heart sounds, and these might be the first indication of CHD.
An echocardiography study may also be requested, which takes an image of the heart and can help to see abnormal movements or the location of structures. An EKG, which reads the electric activity of the heart, is also typically requested. Finally, a chest X-ray might be done to visualize the size and shape of the heart, in relation to the lungs.
The treatment of most acyanotic CHD is watchful waiting, or doing nothing and seeing if the heart defect will get better on its own. If acyanotic CHD causes symptoms, some medicines to reduce blood pressure or reduce the heart’s workload might be prescribed. Sometimes surgery is required for acyanotic CHD, especially if the heart defect is large.
Cyanotic CHD almost always requires surgery to fix the heart defect. These surgeries are typically done before a child is 1 years old.