Congenital heart defects are heart problems that are present at birth. They result when the heart does not develop normally before birth. Approximately 1% of infants are born with one or more heart or circulatory problems. Because most of these babies grow to adulthood, there are now about one million adults in the United States with congenital heart disease. People with congenital heart defects can live full and healthy lives.
What Causes Congenital Heart Disease?
In most cases, the causes of congenital heart defects are unknown. Researchers suspect that heart defects can be caused by a genetic abnormality or that defects can result when the developing fetus is exposed to infections, toxic substances, or drugs. Families can rarely predict or prevent congenital heart defects. Nonetheless, pregnant women should do all they can to ensure the health of their babies, like avoiding alcohol, drugs, and exposure to German measles and environmental toxins.
Most congenital heart defects are detected while the child is still very young, but some children live with a defect for years before it is diagnosed. In some cases, a congenital heart defect is discovered before the baby is born. All defects cannot be diagnosed before birth because the heart continues to develop in the days after a baby is born.
Types of Congenital Heart Defects
There are many different types of congenital heart defects. More than one defect may be present at the same time. Other defects—and there are dozens of types—may involve missing, unconnected, or misplaced arteries; underdeveloped or missing valves; and narrowed or blocked blood vessels. Some of the well-known defects include:
- Atrial Septal Defect (ASD)
- Ventricular Septal Defect (VSD)
- Atrioventricular Canal Defect
- Patent Ductus Arteriosus
- Aortic Stenosis
- Pulmonary Stenosis
- Ebstein’s Anomaly
- Coarctation of the Aorta
- Tetralogy of Fallot (Blue Baby Syndrome)
- Transposition of the Great Arteries
- Persistent Truncus Arteriosus
- Tricuspid Atresia
- Pulmonary Atresia
- Total Anomalous Pulmonary Venous Connection
- Hypoplastic Left Heart Syndrome
To find or confirm congenital heart disease, doctors may use a history and physical examination, chest x-rays, electrocardiogram (ECG), echocardiogram, exercise testing, heart catheterization, electrophysiology studies (EPS), and magnetic resonance imaging (MRI).
Most congenital heart disorders can be corrected or improved with surgery, but some do not require any treatment. Many types of congenital heart disease can cause major problems starting immediately or soon after birth. Some of them may even lead to irreversible changes that might prevent surgical correction later in life. Therefore, the trend is to operate on children with congenital heart disease at earlier ages. Most operations can fix the problem, but continuing medical care is generally needed following the procedure. Heart rhythm disorders and endocarditis remain potential threats, even years later.
Some operations are palliative, meaning the problem is not fixed, but adjustments are made to let the circulation work as well as possible under the circumstances. Palliation is done at a young age to allow the heart and circulation to develop enough so a reparative operation can be done later. Sometimes a palliative operation is all that can be done.
Congenital heart defects can be so severe that life cannot be maintained, or they can be so mild that trouble is not even suspected. Sometimes these abnormalities never do cause problems. Other times they become more abnormal with aging and then cause problems. For example, a child with a bicuspid aortic valve may have satisfactory function of the valve. As the child ages, the valve may thicken and calcify and lead to narrowing (stenosis), or it may retract and result in backward leakage (regurgitation). These changes may not produce symptoms until middle age or later.
Many congenital heart defects can be surgically repaired at a young age. Sometimes the doctor may recommend waiting for a time before repairing a defect. Reasons for this delay include the following:
- The problem will not get any worse by waiting for a limited time.
- The operation will be easier on the baby at an older age.
Some congenital problems are very hard to diagnose without some difficult, risky, and expensive tests, which are done only if there is a high suspicion of an abnormality. If the defect is not causing obvious problems, the likelihood increases that it might be overlooked at routine examinations.
With some congenital defects, such as ventricular septal defect, if an operation to close the defect is postponed too long, the damage can be so severe that an operation to correct the problems is no longer helpful because of the high pressure in the pulmonary artery.
Texas Heart Institute www.texasheartinstitute.com/HIC/Topics/Cond/CongenitalHeartDisease.cfm
Mayo Clinic www.mayoclinic.org/congenital-heart/index.html
Medline Plus www.nlm.nih.gov/medlineplus/congenitalheartdisease.html
The American College of Cardiology Foundation www.acc.org/media/patient/chd/chd.htm#Congenital
Adult Congenital Heart Association www.achaheart.org/resource
The Texas Adult Congenital Heart Center (TACH Center) offers services for adult congenital heart disease patients www.bcm.edu/baylorclinic/services/cardiology/cardio_tach.cfm