Tetralogy
of Fallot occurs in approximately 3 to 6 per 10,000 births (about 3,000
babies a year) within the United States and represents 5-7% of
congenital heart defects. It occurs slightly more often in males than
in females. It's cause is thought to be due to environmental or genetic
factors or a combination. It is associated with chromosome 22 deletions
and DiGeorge Syndrome.
As classically described, Tetralogy of Fallot involves four malformations which present together:

1.
Ventrical Septal Defect (VSD) - a hole between the two bottom chambers (ventricles) of the heart
2.
Pulmonary Stenosis - a narrowing of the pulmonary valve
3.
Overridding Aorta - when the aortic valve connects not only to the left ventricle (normal) but to the right ventricle as well
4.
Right Ventricular Hypertrophy - the right venticle is more muscular
than normal, causing a characteristic boot-shaped appearance
These defects can cause:
- less blood flow to the lungs
- mixing of oxygen-rich (red) and oxygen-poor (blue) blood insode the heart
- low levels of oxygen in the blood (*this causes skin, fingertips, or lips to have bluish tint...cyanosis)
Symptoms in infant:- Rapid breathing
- Cool and clammy skin
- Pale skin color
- Poor feeding because the baby tires easily while nursing
- Poor weight gain
- Fussiness or irritability
- Heart murmur - first sign
- Cyanosis - second sign (TOF causes the most cases of cyanosis/"blue-baby")
Some
babies with Tetralogy of Fallot have what are called tetralogy
"spells." A "spell" occurs when there is a sudden drop in the oxygen
level in the blood. This causes the baby to become very blue. The baby
may also:
- Have a hard time breathing
- Become very tired and limp
- Not respond to your voice or touch
- Become very fussy
- Have a seizure
The cause of these "spells" is not known. They can happen when the baby:
- Is upset
- Has a low red blood cell count (anemia)
- has a lack of enough fluids
Helping to prevent "spells"- Lower baby's anxiety or stress
- Try to predict what the baby needs to stop or lessen crying
If your baby has a tetralogy "spell", you should:
- Bring the baby's knees up tight against the baby's chest (the knee-chest position).
- Attempt to calm the baby.
- Call 9-1-1 (USA) or 999 (UK) if your baby's symptoms do not immediately improve
Even
if the baby's symptoms improve at home without emergency treatment, you
should still contact your doctor to report the "spell"
NutritionBabies
with tetralogy of Fallot can tire while nursing or feeding. You may
need to feed your baby more often. Some babies also need extra
nutrition. This is given as a supplement or an extra feeding. These
feedings usually are formulas that give the baby extra calories. Many
babies need extra vitamins or iron. Your child's doctors will decide
what extra nutrition your baby might need
SURGERYEvery
infant or child with Tetralogy of Fallot needs surgery, usually within
the first year of life. Because of advances in surgery and treatment,
many children born with tetralogy of Fallot have successful surgery and
live to adulthood
Temporary OperationSome
babies are too weak to have open-heart, corrective surgery. In small
and very blue infants, a shunt operation may be done first to provide
adequate blood flow to the lungs. The shunt is built between the aorta
and the pulmonary artery. This lets the baby grow big and strong enough
to have a full repair. The shunt is removed when a complete repair is
done. After surgery, some babies may need medicines to help keep the
new blood pathway open.
Complete RepairComplete
repair tends to be done early in life. Once it was more common to do a
temporary operation first and a complete repair later in childhood.
Surgery to repair the defects of Tetralogy of Fallot involves:- closing
the ventricular septal defect with a patch which stops the mixing of
blood between chambers (the oxygen-rich blood now flows out of the
heart only to the body and the oxygen-poor blood goes to the lungs)
- opening
the right ventricular outflow tract by removing some thickened muscle
below the pulmonary valve (this improves the flow of oxygen-poor blood
to the lungs so that it can pick up more oxygen)
- opening or
widening the pulmonary valve and enlarging the peripheral pulmonary
arteries that go to both lungs Sometimes a tube is placed between the
right ventricle and the pulmonary artery. This is sometimes called a
Rastelli repair
LONG-TERMCardiology CareLong-term
follow up studies show that patients with TOF are at risk for sudden
cardiac death and for heart failure. Therefore, lifetime follow-up care
by a pediatric cardiologist is recommended to monitor these risks and
to recommend treatment, such as interventional procedures or
re-operation, if it becomes necessary
MedicationsSome patients with TOF need medicine to control symptoms.
*It is important to check with your doctor before changing or stopping any medicines.
Additional SurgerySome teenagers and adults may need additional surgery to repair or replace the pulmonary valve.
Endocarditis PreventionPeople
with tetralogy of Fallot are at increased risk for developing
endocarditis. People with unrepaired and partially repaired tetralogy
will need antibiotics to prevent endocarditis before certain dental
procedures. If your tetralogy of Fallot has been repaired, your
cardiologist will let you know if you need to continue to receive these
routine antibiotics.
Heart Rhythm DisturbancesPeople
with repaired tetralogy of Fallot have a higher risk of heart rhythm
disturbances called arrhythmias. These can originate from the atria or
the ventricles. Sometimes they may cause dizziness or fainting. You may
need medicine to control them. A cardiologist can decide if you need
any medicines. In rare cases, you may need a procedure in the cardiac
catheterization laboratory or the operating room to eliminate these
arrhythmias and control symptoms. Some people with TOF may need a
pacemaker or defibrillator to help stop or control irregular
heartbeats. Your cardiologist will discuss with you the need for any
additional surgeries.
StatisticsApproximately
25% of untreated patients with TOF die within the first year of life,
40% by 4 years, 70% by 10 years, and 95% by 40 years.
Would you like to do a virtual surgery? This is the same technique that was used years ago on a child with TOF![Thank you Saving Little Hearts. (repost)
On
November 29, 1944, a gravely ill nine-pound baby named Eileen Saxon was
wheeled into an operating room at Johns Hopkins Hospital. She was to
become the first recipient of the Blalock-Taussig shunt, a new
operation designed to save "blue babies." Eileen's blue complexion and
severe weakness came from a congenital, fatal heart malformation called
Tetralogy of Fallot.
A pediatrician at Johns Hopkins, Dr. Helen
Taussig, had approached Dr. Alfred Blalock to suggest a surgical remedy
for the condition. They came up with a radical idea -- to bypass the
malformation altogether. Vivien Thomas set up experiments in the lab to
develop the procedure before it was first performed.
Now you can
enter the operating room and don surgeon's scrubs. You'll have the same
set of tools used by the original Hopkins surgical team.
http://www.pbs.org/wgbh/amex/partners/breakthroughs/b_surgeon.html]
Many thanks to Vanessa at CHD Heart Foundation for writing this article.