It begins to form long before you can hear it beat. In about the third week of pregnancy, the heart begins to develop from a single tube. As the weeks pass, the thin tube flowers into the chambers, walls and valves of a working heart. But sometimes something goes wrong and a congenital heart defect results.
About eight in 1,000 babies are born with congenital heart disease (CHD). While the cause of most defects is rarely discovered, sometimes CHD is traced to a chromosomal abnormality, fetal exposure to drugs and alcohol or a viral disease contracted by the mother.
Any part of the heart or cardiovascular system can be affected by congenital problems. Among the most common consequences of CHD are:
- Abnormal blood flow through the heart, caused by defects such as atrial septal defect (ASD) and ventricular septal defect (VSD). Commonly referred to as holes in the heart, septal defects occur when the opening in the wall that divides the heart into left and right chambers fails to close at birth. ASD occurs in the heart’s upper chambers, VSD in the lower chambers.
- Obstructed blood flow in the heart or nearby blood vessels. This is caused by a defect such as coarctation of the aorta, which occurs when the artery carrying blood from the heart to the rest of the body is pinched. In that case, blood flow to the lower body is blocked and pressure builds in the upper body.
- Abnormal circulation caused by incomplete development of the heart. In rare cases, the positions of the pulmonary artery and the aorta are switched—a malformation called transposition of the great vessels. When that happens, blood is pumped back to the body without passing through the lungs. Infants born with this defect look blue and need immediate medical attention.
Good diagnostic tools and regular checkups can help doctors detect congenital heart disease early on. And noninvasive tests such as echocardiography and magnetic resonance imaging make diagnosis after birth painless.
Treatment of CHD depends on the type and extent of the defect. Sometimes, monitoring alone is required. A hole in the heart, for example, may heal on its own. More often, however, medication is needed to make the heart muscle stronger, and sometimes surgery is necessary.
New, nonsurgical procedures to repair ASD and VSD are also on the horizon. One promising technique seals the hole with an expandable double-disk device. And because ultrasound exams can help detect CHD before a baby is even born, increasing use of in-utero operations is likely in the future.