It can be frightening to learn that your child has a congenital heart defect. But these are relatively common, affecting almost one in every 100 newborns in the United States. Advances in medical knowledge and diagnostic technologies can provide very detailed information regarding structural heart abnormalities.
Although nothing can be guaranteed with 100 percent certainty, most kids with heart problems can enjoy happy and healthy futures.
What Causes Congenital Heart Defects?
The human heart begins to form as a single tubular structure at about the fourth week of pregnancy. By the eighth week, this tube will gradually increase in length, eventually twisting upon itself. A wall, or septum, grows to divide the upper (atrial) and lower (ventricular) chambers into left and right sides. Four valves made of tissue develop, which keep blood moving forward through the cardiac chambers, lungs and body as the heart pumps.
Multiple genetic and environmental factors interact to alter the development of the heart during the early stages of a fetus' development (the first eight to nine weeks during pregnancy). Sometimes, the cause of a congenital heart defect is known. Certain environmental exposures during the first trimester of pregnancy may cause structural abnormalities (including anticonvulsant medications such as phenytoin, the dermatological medication isotretinoin or lithium salts for manic-depressive illness).
Uncontrolled diabetes, alcohol or drug abuse or exposure to industrial chemicals during pregnancy also can increase the risk of congenital heart malformations. Some chromosome abnormalities, in which there is an extra or missing chromosome (or part of a chromosome) are associated with congenital heart disease. But most of the time, the specific cause of congenital heart disease is unknown.
Over the past 25 years, advances in ultrasound imaging techniques have led to sophisticated tools such as fetal echocardiography, making it possible for many congenital heart malformations to be diagnosed as early as the 12th to 20th week of pregnancy. Such imaging has reassured many parents-to-be that their baby's heart is normal. For others, it has offered an opportunity to know long before the birth that there's a malformation. This gives the family and doctors the ability to make well-informed decisions about the best treatment options.
Heart Problems Before Birth
Because the placenta (and not the fetus' lungs) does the work of exchanging oxygen and carbon dioxide, it is possible for even severe developmental abnormalities of the heart to exist without causing difficulties for the fetus. Such abnormalities may become important only after circulation transitions to the newborn state after birth (when the umbilical cord is clamped at the time of delivery, the placenta is no longer involved in the baby's circulation).
The newborn becomes dependent upon the lungs and circulatory system for the oxygen and blood flow needed to survive outside of the womb. The right side of the heart receives oxygen-poor blood flowing back from the body and pumps it to the lungs, where the circulating blood picks up more oxygen. The left side of the heart receives oxygen-rich blood from the lungs and pumps it out to the body.
Signs and Symptoms
After birth, the first sign of congenital heart disease is often the presence of a heart murmur. A murmur in itself is not a disease, but simply a sound. As the heart pumps blood, it sometimes creates vibrations that are heard through the doctor's stethoscope as a noise or murmur.
Not all heart murmurs are signs of abnormalities -- in fact, heart murmurs usually don't indicate the presence of any heart problem. Sometimes, a doctor can determine with the stethoscope alone whether a particular murmur is a sign of heart disease. In other cases, additional tests -- such as chest X-rays, electrocardiograms (EKGs) or echocardiograms -- will help determine the exact nature of a murmur.
Although many children with minor forms of congenital heart disease may not require any treatment, some can have serious symptoms early on that will require medical or surgical treatment within the first year of life. One such symptom can be breathing difficulties from lung congestion. This is usually the result of excessive blood flow from the left side to the right side of the heart through abnormal connections between the two sides of the circulation, such as holes in the heart (as in ventricular septal defect, atrial septal defect, atrioventricular canal and patent ductus arteriosus).
Or the congestion could be the result of obstructions to blood flow on the left side of the heart, resulting in a backup of blood in the blood vessels returning blood from the lungs (such as in aortic stenosis, coarctation of the aorta and hypoplastic left heart syndrome). The shortness of breath in these babies may interfere with their ability to feed and may result in an inability to gain weight adequately. Such babies may require medical treatment or a procedure such as surgery or cardiac catheterization within the first weeks of life.
Other symptoms of congenital heart disease relate to an inadequate amount of oxygen carried within the blood. These infants usually appear to have blue skin, a condition called cyanosis. This can be due to an obstruction of blood flow to the lungs (such as in tricuspid atresia or pulmonary atresia) or due to a hole within the heart that allows oxygen-poor blood to flow from the right to the left side of the heart and out to the body (such as in total anomalous pulmonary venous return or Ebstein's anomaly). It can also be related to an abnormal positioning (transposition) of the arteries leaving the heart. In any of these cases, less red oxygenated blood comes from the lungs and more blue unoxygenated blood is carried to the body, causing the blue skin color.
Treatment for Congenital Heart Defects
Congenital (meaning present at birth) defects usually are treated with surgery, catheter procedures and sometimes medication. A combined approach using both surgery and catheterization is most common. Thanks to advances in pediatric heart surgery and interventional catheterization, nearly every form of congenital heart disease can be treated with the expectation of a good outcome.
Cardiac surgery and cardiac catheterizations are now performed on younger children -- in fact, it's common for them to be done during infancy or even the newborn period, which has many long-term advantages.
Kids with congenital heart disease are at risk for bacterial endocarditis, an infection of the tissue that lines the heart and blood vessels. This serious illness requires prolonged treatment with intravenous antibiotics in a hospital setting.
Children with types of congenital heart disease that cause cyanosis should receive antibiotics before procedures that could introduce bacteria into the bloodstream, including dental work or surgery in places in the body where bacteria tend to grow (such as the mouth or gastrointestinal tract). Antibiotics also might be recommended after heart surgery for kids who have artificial heart valves or have had endocarditis before.
Most children with heart problems, however, do not need premedication with antibiotics. The pediatric cardiologist will be familiar with the latest guidelines and can make recommendations based on the specific cardiac diagnosis, as well as procedure in question.
If You Suspect a Problem
Although sudden serious downturns during or after cardiac treatment aren't common, you should watch for certain signs that could signal a need for medical attention. If your child appears to be working harder than normal to breathe, call your doctor right away.
Other signs that warrant immediate medical attention include:
* a bluish tinge or color (cyanosis) to the skin around the mouth or on the lips and tongue * an increased rate of breathing or difficulty breathing * poor appetite or difficulty feeding (which may be associated with color change) * sweating while feeding * failure to thrive (failure to gain weight or weight loss) * decreased energy or activity level * prolonged or unexplained fever
Call the doctor immediately if your child has any of these symptoms.
Caring for Your Child
Parenting kids with heart defects includes learning about basics like feeding, giving medicines and watching for signs of trouble, but it also involves encouraging kids to become involved in their own care.
Because most congenital heart defects are now treated during infancy, it's often necessary to explain to an older child what happened in the past. When your child is old enough to understand, explain why he or she has a surgical scar, needs to take medication or has to visit the pediatric cardiologist. Describe the treatment in a way your child can understand and don't try to hide the details.
If kids believe they have a role in their care, they're likely to be more confident and positive. Your doctor may be able to suggest ways to discuss these issues.
Participation in some physical activities might be limited, but kids can still play and explore with friends. Always check with the cardiologist about which activities your child should or should not be doing. Certain competitive sports could be restricted, for example.
Although it's tempting for parents to be overly protective, sheltering kids can make them feel isolated and stigmatized -- which might do more harm than a heart defect in the long run. So do everything you can to make sure your child leads as normal a life as possible.