Tetralogy of Fallot
What is tetralogy of Fallot?
The tetralogy of Fallot is a birth defect consisting of 4 problems with the heart:
- Ventricular septal defect, which is a hole between the 2 lower heart chambers (the ventricles)
- Infundibular stenosis, which is a narrowing under or at the pulmonary valve. (The pulmonary valve is the opening between the right ventricle and the pulmonary artery. The pulmonary artery carries blood to the lungs.) This defect can also involve the lung arteries.
- An enlarged right ventricle.
- A misaligned aorta that sits just over the hole between the ventricles. The aorta is the artery that normally carries oxygen-rich blood from the left ventricle to the rest of the body.
Because of the hole between the ventricles, oxygen-rich blood mixes with oxygen-poor blood. Also, less blood can reach the lungs because of the narrowing of the pulmonary valve and lung arteries. These defects make the right ventricle work extra hard. It gets bigger and thicker. Because some of the oxygen-poor blood will flow through the aorta to the body, the skin of children with tetralogy of Fallot often looks blue (a problem called cyanosis).
How does it occur?
Babies with this condition are born with it. What causes it is not known.
What are the symptoms?
Children with this birth defect often look blue. The blueness may appear at birth or soon after. Babies may have spells during which they turn blue, breathe rapidly, and cry. They may pass out. During exercise, older children who have not had surgery often become short of breath and may tire easily. They may squat during exercise to help them catch their breath. These symptoms happen because the children are not getting enough oxygen. Not enough blood is flowing to the lungs to pick up the oxygen their body needs
How is it diagnosed?
This birth defect causes an unusual sound in the heart, which your healthcare provider can hear with a stethoscope. It is called a heart murmur. A heart murmur is an extra sound made between heartbeats. These murmurs are caused by the blood leaving the heart through the narrowed lung artery.
Your provider will order a cardiac ultrasound (echocardiogram) to make the diagnosis. An echocardiogram uses sound waves to make pictures of the heart.
How is it treated?
First a heart catheterization may be done to get a more exact idea of the heart's structure. A heart (cardiac) catheterization is a procedure in which a thin tube is passed through a blood vessel and into the heart to check the heart.
To correct the problem, surgery is done to close the hole between the two lower heart chambers. This usually requires a patch of synthetic material such as Dacron.
The surgeon will also relieve the narrowing at the pulmonary valve. This may be done in several ways:
- The pulmonary valve may be replaced with a new artificial or tissue valve.
- The surgeon may enlarge the area of narrowing of the heart with a patch of synthetic material or a thin layer of tissue from the membrane surrounding the heart (the pericardium).
- If a baby is too sick or the pulmonary arteries are too small for corrective surgery, a small tube is placed between one of the arteries of the aorta and the pulmonary artery. This tube is called a shunt. It lets blood enter the lungs and allows the lung arteries to grow until corrective surgery can be done at a later time.
How long will the effects last?
After surgery, most children are able to do all normal things, including sports. Some children need to limit their activities. Some may need to take medicine to control their heart rate and to help their heart pump better. Later in life, they may have abnormal heart rhythms. They may need to take antibiotics before dental work and some other procedures to prevent infection of the heart.
Children with tetralogy of Fallot should see a cardiologist who specializes in congenital heart disease regularly for the rest of their lives.
Written by Reginald L. Washington, MD, FAAP, FACC, for RelayHealth.
Published by RelayHealth.
Last modified: 2009-09-02
Last reviewed: 2009-04-28
This content is reviewed periodically and is subject to change as new health information becomes
available. The information is intended to inform and educate and is not a replacement for medical
evaluation, advice, diagnosis or treatment by a health care professional.