Tetralogy of Fallot (TOF)

What is tetralogy of Fallot?

Tetralogy of Fallot is a type of congenital heart disease that is present at birth. Tetralogy is the medical term for four conditions that occur together.

A baby with tetralogy of Fallot has these four heart conditions:

1. Pulmonary stenosis - Narrows the pathway that carries blood from the heart to the blood vessels in the lungs.

2. Ventricular septal defect (VSD) - Causes an opening (hole) between the heart’s lower left and right pumping chambers (ventricles).

3. Ventricular hypertrophy - Thickens the heart muscle in the lower right ventricle.

4. Displaced aorta - Causes the aorta (the main blood vessel that carries blood to the body) to arise farther on the heart’s right side than usual.

What are the signs and symptoms of tetralogy of Fallot in infants?

Symptoms of tetralogy of Fallot typically appear within hours or days after birth. During a newborn screening, your child’s health care provider may detect a sound known as a heart murmur or your baby may have low oxygen saturation (oxygen level) in their blood.

If the pulmonary stenosis is severe, your baby’s skin, tongue and fingernails may look blue (cyanosis). Cyanosis occurs because not enough blood is going to the lungs to get oxygen. As a result, the blood that leaves the heart and flows through your child’s body is low in oxygen.

How is tetralogy of Fallot diagnosed in infants?

Doctors at our Fetal Heart Program may diagnose tetralogy of fallot during pregnancy. At Children’s Health, we use the most advanced cardiac imaging to pinpoint the severity of the four heart conditions. This information helps our doctors customize the most effective treatment plan for your child.

Your baby may get one or more of these diagnostic tests:

• Echocardiogram - An ultrasound of the heart

• Electrocardiogram (EKG) - A test that measures the heart’s electrical activity

• Chest X-ray - Images of the heart and chest

What causes tetralogy of Fallot?

Most congenital heart diseases like tetralogy of fallot happen for no known reason. They are not the result of something a woman does or doesn’t do during pregnancy.

Some children with tetralogy of fallot may also have Down syndrome or DiGeorge syndrome. These conditions are the result of a change in a child’s genetic makeup (chromosomes). Our heart specialists partner with Down or DiGeorge syndrome specialists at Children’s Health to provide comprehensive care for your child.

Risk factors

• Viral illness such as rubella during pregnancy

• Maternal alcoholism

• Family history of the condition

How is tetralogy of Fallot treated?

A baby with tetralogy of fallot needs corrective heart surgery. Our pediatric heart surgeons evaluate your baby’s unique heart anatomy and overall health to develop a treatment plan that offers the best outcomes.

Nonsurgical treatment

Infants with mild tetralogy of fallot don’t need immediate treatment. Newborns with a severe condition usually need treatment within one to two weeks after birth to help them grow and get stronger for the heart surgery. These treatments, which temporarily improve blood flow, include:

• IV medication. Your baby receives medicine through a blood vessel to help blood reach the lungs to pick up oxygen.

• Shunt procedure. Our doctors place a temporary tube (shunt) that carries blood from the heart to the lungs. We make a small incision and place the shunt through a blood vessel (cardiac catheterization).

Open heart surgery

Open-heart surgery to correct all four heart conditions typically takes place when a child is six to 12 months of age. Our heart surgeons successfully perform a large number of tetralogy of fallot procedures every year.

The surgery involves:

• Expanding the pathway that carries blood from the heart to the lungs

• Using a patch to close the hole in the heart

Your child’s symptoms should go away after heart surgery. As the blood flows properly to the lungs, your child will have enough oxygen in their blood to meet their body’s needs.

Learn more about valve-sparing repair of tetralogy of Fallot