Question: What is a congenital heart defect and what causes it? How common is it? Can it affect risk for developing heart disease either as a child or as an adult?
Answer: The heart has four chambers with four valves. And there are walls separating the chambers. Most heart defects affect the walls between the chambers, or the heart valves. Only about 25 percent will cause symptoms and need treatment.
We don't really know the cause of congenital heart defects. We do believe that there are both genetic factors, and that means a defect in a gene or a part of a gene that leads to development of the heart defect, and also environmental factors -- exposure to infectious agents or exposure to certain toxic agents, or even not receiving pre-natal vitamins. If someone wants to prevent a heart defect, all they can do is make sure they receive pre-natal vitamins, they don't smoke, and they try to lead a healthy lifestyle during pregnancy. Beyond that, there's not really much a parent can do to prevent a heart defect in their child.
Using echocardiography, we can diagnosis heart defects, especially the serious ones, by about 20 weeks of pregnancy. So if there's a family history of a heart defect in another child, or perhaps the mother has a heart defect, or the father, it's recommended that the mother be screened and the baby be looked at with echocardiography target="_blank"anywhere from 18 to 20 weeks of pregnancy. If a heart defect is found on echocardiography in a baby that's still in the womb, we can make plans for delivery and for taking care of the baby at the time of birth.
Children that are born with congenital heart defects often have to have surgery, and some children have multiple operations. I'm often asked whether that can affect their risk of having heart disease later in life. The fact is we don't know the answer to that. We don't believe that it does. We still think the usual risk factors: obesity, hypertension, smoking, genetics, diabetes -- those are the things that affect the risk for developing heart disease, and we think those are much more important than any history of congenital heart defects or prior surgery. But we're concerned about the patients that have had multiple surgeries, because sometimes it's a little bit harder to distinguish symptoms from coronary artery disease from symptoms related to their congenital heart defect, so we watch them more closely.