Congenital means “present from birth.” Congenital heart problems are the most common birth defect, occurring in almost one percent of all births. There many types of congenital heart disorders. Some may cause no problems at all, and some may be almost immediately fatal. Usually doctors do not know why congenital heart defects occur. They can be genetic, but it is not likely that more than one sibling will have a heart defect. An infection like rubella that occurs while the mother is pregnant can cause a malformation of the heart. The heart is fully formed by the fourth month of pregnancy, so infection is only a likely cause if it occurred during the first trimester. Conditions like Down’s Syndrome, which affects other organs, can also affect the heart. Drugs, prescription or illegal, including alcohol, taken during pregnancy, can also lead to defects.
The most common congenital heart disorders are:
Stenosis: Stenosis can occur on the right or left side of the heart. When it occurs on the right side, which feeds blood to the lungs via the pulmonary artery, it is called pulmonary stenosis. On the left side, which feeds blood to the rest of the body via the aorta, it is called aortic stenosis. Stenosis refers to an obstruction of either the pulmonary artery or the aorta. Usually, the obstruction occurs in the valves. When the pulmonary valve, which connects the right ventricle to the pulmonary artery, is affected, the condition is called pulmonary valve stenosis. When it occurs in the aortic valve, which connects the left ventricle to the aorta, it is called aortic valve stenosis.
Septal defects: Septal defects are problems with the walls (septa) between either the two atria or the two ventricles. The hole allows blood to bypass the normal circulation and travel straight from one side of the heart to the other. This provides excess work for the side of the heart with the extra blood. Usually the blood flow is from left to right, which means that oxygentated blood meant for the body instead goes to the lungs. There is then an excess of blood in the lungs, and a lack of blood and oxygen going to the rest of the body. When the defect occurs in the septum between the atria, it is called an atrial septal defect. When it occurs between the ventricles, it is called a ventricular septal defect.
Coarctation of the aorta: Blood pumped by the left ventricle travels through the aorta to the head, arms, abdomen and legs. A coarctation is a narrowing in the artery that obstructs blood flow. Because it forces the left ventricle to work harder than it is supposed to, it can cause heart failure. Sometimes this heart failure is severe enough to require emergency treatment in the first few days of an infant’s life.
