What is Congenital Heart Disease?

Congenital Heart Disease is the term used to describe abnormal development of the heart before birth that results in structural defects in the heart. This problem in development can be very minor and result in simple defects (for example a hole between the pumping chambers) or can be very complex. Eight of every one thousand children are born with a congenital heart defect. Congenital heart defects usually develop before the end of the first trimester of pregnancy.

 

How is Congenital Heart Disease Identified?

Because of the range of defects, how and when a child is diagnosed with a congenital heart defect varies. In some patients it is obvious at the time of birth. In others, the defect is not diagnosed until adulthood. Some children are noted to have a problem from birth due to cyanosis (blue coloring), heart failure (with difficulty breathing), or a heart murmur. Other children may not be diagnosed until much later in life. Later diagnosis may occur because the problem is so subtle it is difficult to discern. It can also occur because of changes that occur in newborns and infants over time which mask any symptoms. During the first six months of life, the pressure in the blood vessels of the lungs falls when compared to the pressure in the blood vessels of other body organs. In some heart defects, symptoms don’t show up until the pressure in the lung blood vessels has fallen.

 

The most common way to diagnose a congenital heart defect is by your physician hearing a murmur (a sound inside the chest due to abnormal blood flow in the heart). But even murmurs can be normal variations and are not always diagnostic of a heart defect. Other diagnostic studies will be conducted as needed to determine if your child has congenital heart disease.

 

Did I Cause the Heart Defect?

Many parents are concerned that they "did something" or "didn't do something" that caused a problem in the development of their child. At this point we do not know what causes congenital heart disease. The cause may be due to many things (multifactorial) including genetics, environmental exposure, infections etc. We know that there is some kind of genetic link, as we see certain heart defects more commonly in specific chromosomal syndromes (such as Down Syndrome). We also know there is a small but increased chance of other family members having similar heart problems. Heart defects can occur if the mother is exposed to certain viruses (such as Rubella or German measles) during pregnancy. And certain drugs are associated with an increased chance of heart defects (such as alcohol, anticonvulsants, and lithium). The interaction between these factors and others we don’t even know yet may lead to cardiac defects. How that happens is still not known.