Tetralogy of Fallot is a problem with the heart’s structure that
is present at birth. This defect changes the normal flow of blood
through the heart. Tetralogy of Fallot is a combination of four
defects:
- A hole in the wall between the ventricles (two lower
chambers of the heart), called a ventricular septal defect.
- Narrowing of the tube that carries blood from the heart to
the lungs, called pulmonary stenosis.
- The aorta (the tube that carries oxygen-rich blood to the
body) grows from both ventricles, rather than from the left
ventricle only.
- A thickened muscular wall of the right ventricle, called
right ventricular hypertrophy.
Blood from both ventricles is pumped throughout the body,
including some blood that is oxygen poor. This can result in too
little oxygen in the blood during certain times. Infants and young
children with tetralogy of Fallot often have blue- or
purplish-looking skin color, called cyanosis, because of oxygen-poor
blood.
At birth, infants might not have blue-looking skin, but later might
develop sudden episodes (called "Tet spells") of bluish skin during
crying or feeding.
To learn more about tetralogy of Fallot click on one of the
following links or scroll down the page.
What We Know About Tetralogy of Fallot
- How often does tetralogy of Fallot occur?
- What problems do people with tetralogy of Fallot have?
What We Still Do Not Know About
Tetralogy of Fallot
- What causes tetralogy of Fallot?
- Can tetralogy of Fallot be prevented?
Resources for Families and Individuals
Affected by Anencephaly
| What
We Know About Tetralogy of Fallot |
How often does tetralogy of Fallot occur?
CDC estimates each year that about 1,575 babies in the United States
are born with tetralogy of Fallot (1). In other words, about 4 out
of every 10,000 babies born in the United States each year are born
with tetralogy of Fallot.
What problems do people with tetralogy of Fallot have?
Many babies with this condition will have to have surgery to correct
it. Babies who have surgery usually do well. Unfortunately, without
surgery, death usually occurs before the person reaches 20 years of
age.
People who have continuing, severe leakage of the pulmonary valve
might need to have the valve replaced. In addition, babies should
have a follow-up visit with a cardiologist to monitor for
life-threatening arrhythmias (irregular heart rhythms).
Following are just a few of the issues that people with tetralogy of
Fallot might have to face.
- Children with this condition might need to limit their
physical activity, especially in competitive sports.
- People with tetralogy of Fallot are at increased risk for
developing endocarditis (an infection of the inner layer of the
heart).
- People with repaired tetralogy of Fallot have a higher risk
of heart rhythm disturbances, called arrhythmias. Sometimes
these can cause dizziness or fainting. Medicine or medical
procedures might be needed to address these issues.
- People with tetralogy of Fallot can have delayed growth and
development.
- People with tetralogy of Fallot can have seizures during
periods when insufficient oxygen is being carried in the blood.
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| What
We Still Do Not Know About Tetralogy of Fallot |
What causes tetralogy of Fallot?
A specific cause for tetralogy of Fallot is unknown. Indeed,
scientists generally agree that multiple causes seem to be involved.
For example, mothers who experience rubella or other viral illnesses
during pregnancy have a higher risk of having a baby with tetralogy
of Fallot. In addition, scientists have found that mothers with poor
nutrition, a history of alcohol use, or diabetes, or who are older
than 40 years of age might have a higher risk for having a baby with
tetralogy of Fallot.
We at CDC work with many other researchers to study risk factors
that can increase the chance of having a baby with tetralogy of
Fallot, as well as outcomes of babies with the defect. Following are
examples of what our research has found:
- The rate of tetralogy of Fallot has been increasing from
year to year (2).
- The environment, specifically carbon monoxide, might be a
risk factor for having a baby with tetralogy of Fallot (3),
although more research is needed.
- There is a higher risk for tetralogy of Fallot among White
babies than babies of other races or ethnicities (2).
- No strong link exists between caffeine use by a mother and
risk for tetralogy of Fallot (4).
Can tetralogy of Fallot be prevented?
There is no known way to prevent the defect, but some of the
problems later in life that are associated with having it can be
prevented or improved if the defect is found early.
Even so, mothers can take steps before and during pregnancy to
have a healthy pregnancy. Such steps include taking a daily
multivitamin with folic acid (400 micrograms), not smoking, and not
drinking alcohol during pregnancy.
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|
Resources for Families and Individuals Affected by Tetralogy
of Fallot |
American Heart Association
National Heart, Lung, and Blood Institute
Mayo Clinic
American Congenital Heart Association
Medline
References
- Canfield MA, Honein MA, Yuskiv N, Xing J, Mai CT, Collins
JS, et al. National estimates and race/ethnic-specific variation
of selected birth defects in the United States, 1999-2001. Birth
Defects Res Part A Clin Mol Teratol. 2006;76(11):747–56.
- Botto LB, Correa A, Erickson JD. Racial and temporal
variations in the prevalence of heart defects. Pediatrics. 2001;
107(3):1-8
- Gilboa SM, Mendola P, Olshan AF, Langlois PH, Savitz DA,
Loomis D, et al. Relation between ambient air quality and
selected birth defects, seven county study, Texas, 1997-2000. Am
J Epidemiol. 2005; 162(3):238-52.
- Browne ML, Bell EM, Druschel CM, Gensburg LJ, Mitchell AA,
Lin AE, et al. Maternal caffeine consumption and risk of
cardiovascular malformation. Birth Defects Res A. 2007;
79:533-43.
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Date:
March 11, 2009
Content source: National Center on Birth Defects and Developmental
Disabilities
