Tetralogy of Fallot, Pediatric
Tetralogy of Fallot is a combination of four heart defects that are present at birth (congenital). The condition develops between conception and the second month of pregnancy, while the heart is developing. Together, these defects cause problems in blood flow as well as low levels of oxygen in the blood.
The four heart defects that make up tetralogy of Fallot are:
Ventricular septal defect. This is a hole in the wall between the two lower chambers of the heart (ventricles). The hole allows blood with oxygen and blood without oxygen to mix.
Overriding aorta. This means that the main artery that leads away from the heart (aorta) is located in the wrong place. Normally, the aorta is attached to the left ventricle. In an overriding aorta, it is located between the ventricles and over the ventricular septal defect. An overriding aorta allows the oxygen-poor blood of the right ventricle to travel to the rest of the body.
Pulmonary stenosis. This is a condition in which the valve between the right ventricle and the artery that leads to the lungs (pulmonary artery) is too narrow. Pulmonary stenosis results in less blood moving to the lungs than is normal.
Right ventricular hypertrophy. This is an enlargement and thickening of the right ventricle. It occurs because the heart has to work harder than normal to move blood through the pulmonary artery. The pressure in the right ventricle causes it to become more muscular (it hypertrophies).
Tetralogy of Fallot is usually discovered within the first year of life when a health care provider hears an abnormal sound (heart murmur) when listening to the heart beat.
What are the causes?
The cause of this condition is not known. In some cases, it may be caused by genes that are passed down through families (inherited).
What increases the risk?
This condition is more likely to develop in:
Children with DiGeorge syndrome or Down syndrome.
Children whose mothers consumed a lot of alcohol during pregnancy.
Children whose mothers were over 40 years of age at the time of pregnancy.
Children whose mothers had poor nutrition or a viral disease such as rubella during pregnancy.
What are the signs or symptoms?
Symptoms of this condition include:
A bluish tint to the skin, fingertips, or lips (cyanosis).
Tiredness and limpness.
A lack of response when being talked to or touched.
When these symptoms occur suddenly, it is called a tetralogy spell. Tetralogy spells occur when there is a sudden drop in blood oxygen levels.
How is this diagnosed?
This condition is diagnosed with a test that uses sound waves to produce images of the heart (echocardiogram
). Additional tests may be ordered to confirm the diagnosis. They may include:
An exercise stress test. During this test, your child exercises or is given medicine to make the heart work harder and beat faster while heart tests are performed.
Electrocardiogram (ECG). This is a test that records the electrical impulses of the heart.
How is this treated?
This condition is treated with:
- Open-heart surgery. This surgery is done within the first year after birth:
To close the ventricular septal defect.
To widen the pulmonary artery.
To correct the problems that are caused by the other defects.
- Shunting. This temporary surgery is performed on children who cannot have open heart surgery for any reason, such as those who are very small for their age. The purpose of the surgery is:
To place a device called a shunt between the pulmonary artery and the aorta.
To create a pathway between the pulmonary artery and the aorta, allowing more blood to travel to the lungs.
Follow these instructions at home:
- If your child has a tetralogy spell:
Bring your child's knees up tight against his or her chest (the knee-chest position).
Attempt to calm your child.
If your child's symptoms do not improve immediately or if your child has cyanosis, call local emergency services (911 in the U.S.).
Tell all of your child's health care providers (including dentists) about your child's condition.
Consider having your child wear a medical alert bracelet or necklace. This tells anyone caring for your child in an emergency that your child has a heart condition.
Limit certain types of activities if told by your child's health care provider.
Consider getting counseling or joining a parental support group if you are feeling stressed or having trouble coping with your child's condition.
If your child had surgery, follow post-surgery care instructions.
Keep all follow-up visits as told by your child's health care provider. Your child will need to see a health care provider and heart specialist (cardiologist) regularly for life. This is important because your child's health care provider will check for new problems and make sure that any existing problems are under control.
Your child has difficulty breathing.
Your child becomes tired and limp.
Your child does not respond when being talked to or touched.
Your child is unusually fussy.
Your child has a seizure.
Your child has a bluish tint to the skin, fingertips, or lips (cyanosis). If your child has cyanosis, call local emergency services (911 in the U.S.).
Your child may have symptoms of tetralogy of Fallot until a corrective surgery is done.
This information is not intended to replace advice given to you by your health care provider. Make sure you discuss any questions you have with your health care provider.