What is congenital heart disease?
Congenital means inborn or existing at birth. The terms congenital heart defect and congenital heart disease are often used equally, but the word "defect" is more accurate. A congenital heart defect occurs when the heart or blood vessels near the heart don’t develop normally before birth. What causes congenital heart defects?
Congenital heart defects are present in about one percent of live births and are the most frequent congenital malformations in newborns. In most cases scientists don’t know why they occur. Sometimes a viral infection causes serious problems.
German measles (also called rubella) is an example. If a mother contracts German measles during pregnancy, it can interfere with the development of the baby’s heart or produce other malformations. Other viral diseases also may produce congenital defects.
Heredity sometimes plays a role in congenital heart disease. More than one child in a family may have a congenital heart defect, but this rarely occurs. Certain conditions affecting multiple organs, such as Down’s syndrome, can involve the heart too. Some prescription drugs and over-the-counter medicines, as well as alcohol and "street" drugs, may increase the risk of having a baby with a heart defect.
Other factors that affect the heart’s development are under study. The fact is that we don’t know what causes most congenital heart defects.
What are the types of congenital defects?
Most heart defects either 1) obstruct blood flow in the heart or vessels near it or 2) cause blood to flow through the heart in an abnormal pattern. Rarely defects occur in which only one ventricle (single ventricle) is present, or both the pulmonary artery and aorta arise from the same ventricle (double outlet ventricle). A third rare defect occurs when the right or left side of the heart is incompletely formed called a hypoplastic heart.
The following defects are described in this section:
(The AHA Web site has information on congenital heart defects in Spanish.)
Aortic stenosis (AS)
Atrial septal defect (ASD)
Atrioventricular (A-V) canal defect
Bicuspid aortic valve
Coarctation of the aorta ("Coarct")
Ebstein’s anomaly
Eisenmenger’s complex
Hypoplastic left heart syndrome
Patent ductus arteriosus (PDA)
Pulmonary stenosis (PS)
Pulmonary atresia
Subaortic stenosis
Tetralogy of Fallot
Total anomolous pulmonary venous (P-V) connection
Transposition of the great arteries
Tricuspid atresia
Truncus arteriosus
Ventricular septal defect (VSD)
Patent ductus arteriosus (P.D.A.)
This defect allows blood to mix between the pulmonary artery and the aorta. Before birth there’s an open passageway (the ductus arteriosus) between these two blood vessels. Normally this closes within a few hours of birth. When this doesn’t happen, however, some blood that should flow through the aorta and on to nourish the body returns to the lungs. A ductus that doesn’t close is quite common in premature infants but rather rare in full-term babies.
If the ductus arteriosus is large, a child may tire quickly, grow slowly, catch pneumonia easily and breathe rapidly. In some children symptoms may not occur until after the first weeks or months of life. If the ductus arteriosus is small, the child seems well. If surgery is needed, the surgeon can close the ductus arteriosus by tying it, without opening the heart. If there’s no other defect, this restores the circulati
