Understanding Heart Disease -- the Basics
Congenital Heart Disease continued...
The exact causes of congenital heart defects are generally hard to pin down; the mother's genes and environmental factors may both contribute. Chromosome abnormalities, including the one that causes Down syndrome, have been linked to many congenital heart defects. Infections contracted during pregnancy by the mother, such as rubella, may also result in congenital heart defects for the child. Congenital heart defects range widely in their effects. Some are apparent immediately, but others do not produce noticeable symptoms until adulthood.
Among the most common congenital heart defects are septal defects, or holes in septum, the wall dividing the left and right sides of the heart. If a septal defect is big enough to cause problems, it can be patched surgically or with a minimally invasive catheter-based procedure. Another frequently seen defect is pulmonary stenosis, a condition in which the pulmonary valve is so narrow that blood flow to the lungs is restricted. With surgery, the valve can be pried open or replaced. In some babies, a small fetal blood vessel known as the ductus arteriosus fails to close at birth as it should. This condition, known as patent ductus arteriosus, allows some blood that is headed for the body via the aorta to leak back into the pulmonary artery, placing the heart under added strain. This problem can also be corrected surgically or sometimes with medication.
Some congenital heart defects are so extensive that they result in so-called ''blue babies,'' in whom some oxygen-poor blood flows to body tissues instead of to the lungs. The excess of poorly-oxygenated blood gives the baby a bluish tinge. Unless treated, infants with this condition would not survive for any extended period.
Fortunately, surgery can successfully correct many of these conditions.