Tetralogy of Fallot (TOF)

This page is dedicated to my friend Christy and her son TJ who both have Tetralogy of Fallot.
If you have any comments regarding any inaccuracies of this page, please email us with what is wrong, what you would put instead, and a reference so that we can check.

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.


The heart on the left is showing what a heart looks like with no defects.
The heart on the right is what the heart looks like with Tetralogy of Fallots

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”


Babies 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


Every 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 Operation

Some 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 Repair

Complete 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


Cardiology Care

Long-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


Some patients with TOF need medicine to control symptoms.
*It is important to check with your doctor before changing or stopping any medicines.

Additional Surgery

Some teenagers and adults may need additional surgery to repair or replace the pulmonary valve.

Endocarditis Prevention

People 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 Disturbances

People 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.


Approximately 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.


Many thanks to Vanessa at CHD Heart Foundation for writing this article.

NOTE: Christy had a cow valve replacement in December 2007 and has informed me “that if anyone would like to contact her in regard to Tetralogy of Fallots to contact her via her Facebook page called Zipper Club and anyone with 22q

If you would like to read Christy’s Personal Story

Related Links:

The British Heart Foundation are doing booklets for Parents of children to help understand their childs heart and the booklets are also for health professionals.

Here is the link for Tetralogy of Fallots

Disclaimer: The facts and opinions shown in this article are as accurate and up to date as possible, but are provided as general “information resources”, which may not be relevant to individual persons. This article is not a substitute for individual assessment and always take advice from a doctor who is familiar with the particular person.

Consult you or your child’s physician regard the specific outlook for you or your child.