Syncope in Children
What is syncope?
Syncope is a brief loss of consciousness and muscle tone that can occur when not enough
blood gets to the brain. Syncope is commonly called fainting. In most children, it’s
usually harmless. But in a few children, syncope is serious. This is usually because
of a heart problem, or sometimes a neurological problem.
What causes syncope?
The common reason behind each fainting episode is a temporary lack of oxygen-rich
(red) blood getting to the brain. However, many different problems can cause a decrease
in blood flow to the brain. Some causes of syncope include:
- Vasovagal syndrome (or neurocardiogenic syncope). A sudden drop in blood pressure with or without a decrease in heart rate. It is caused
by a problem with the nerves controlling the heart and blood vessels. This is the
most common cause of syncope and can follow periods of extreme emotion.
- Arrhythmia. A heart rate that is too slow, too fast, or too irregular to keep enough blood flow
to the body, including the brain. This is a fairly rare cause of syncope.
- Structural heart disease (muscle or valve defects). There may be problems with the heart muscle or one or more of the heart valves. This
may cause a decrease of blood flow to the body, including the brain. Inflammation
of the heart muscle known as myocarditis can also cause fainting. The heart muscle
becomes weak and is not able to pump as well as normal. The body again reacts to decreased
blood flow to the brain by fainting.
- Orthostatic hypotension. This is a drop in blood pressure that occurs when a person has been standing for a
while, or changes from a sitting to a standing position. Blood pools in the legs, preventing
a normal amount of blood from being pumped to the brain. This brief drop in blood
flow to the brain causes a person to faint. This more commonly occurs in senior adults.
Other situations or illnesses that can cause syncope include:
- Head injury
- Inner ear problems
- Low blood sugar
- Breath holding episodes
- Brain mass
- Aneurysm or abnormality of the blood vessels of the brain
- Having a bowel movement
What are the symptoms of syncope?
Some children will have symptoms before they faint. A child may have:
- Changes in his or her vision
- Cold, damp skin
There may be enough warning signs that your child will have time to sit or lie down
before fainting occurs. This can prevent injuries that may happen because of falling
during syncope, such as head injury.
How is syncope diagnosed?
The healthcare provider will ask about your child’s symptoms and health history. He
or she will give your child a physical exam. Helpful details you can provide include answers
to these questions:
- How often does syncope occur?
- What your child was doing before the syncope?
- Did your child had any symptoms before the syncope?
- What did he or she ate before the syncope?
- What happened during and after the syncope?
- Was the syncope witnessed?
- How long did the period of loss of conscious persist after syncope?
The provider will check your child's blood pressure and heart. Your child’s blood
pressure is usually checked more than once in different positions. It may be taken while
your child is lying down sitting, and standing. The provider will look for changes
in blood pressure that occur with orthostatic hypotension.
Often your child will not need any tests. If your child's provider thinks there may
be a serious problem, he or she may refer you to a pediatric cardiologist. This is
a doctor with special training to treat heart problems in children. He or she may
order tests, such as:
- Electrocardiogram (ECG). This test records the electrical activity of the heart. It shows any abnormal rhythms
(arrhythmias) and problems with heart function.
- Tilt table test. This test checks a child's blood pressure and heart rate while he or she is in different
- Holter monitor. This test uses a portable monitor that your child wears for 24 hours or longer. It
is used to evaluate irregular, fast, or slow heart rhythms while your child does his
or her normal activities, even while away from the provider's office.
- Echocardiogram (echo). This test studies the heart's function. It uses sound waves (ultrasound) to make a
moving picture of the heart and heart valves, pumping function, and blood flow through
How is syncope treated?
After an episode of syncope, your child should lie down for 10 to 15 minutes. Or,
your child can sit with his or her head between the knees. Give your child a drink
Work with your child's healthcare provider to figure out the cause and ways to prevent
If a heart problem is the cause of syncope, the pediatric cardiologist will figure
out what treatment is needed.
Occasionally, the problem can also be due to a brain problem and may require consultation
with a pediatric neurologist.
What are the complications of syncope?
Most syncope in children is harmless. In a small number of children, serious heart
problems may be the cause of syncope. Sudden death can occur.
Can I help my child prevent passing out?
To prevent passing out caused by dehydration:
- Stay hydrated. Be sure your child stays well hydrated. Encourage him or her to drink
plenty of water.
- Increase salt intake. Try non-fat salty snacks such as pretzels or crackers.
If passing occurs when standing too long:
- Advise your child not to lock his or her knees when standing.
- Advise your child to promote blood flow by relaxing and tightening the leg muscles.
If your child has passed out upon standing:
- Make sure your child sits up slowly, lets his or her legs hang off the bed, and tell
him or her to wiggle the toes and take a few deep breaths before standing up.
If your child feels like he or she may pass out, advise him or her to sit or lie down
When should I call my child's healthcare provider?
Call your child's provider if he or she has syncope, especially if:
- It continues even with preventive efforts
- It occurs with irregular heartbeats
- It occurs with exercise
- You have a family history of syncope
- There is no known cause
- It occurs unpredictably and in dangerous situations
- Injuries occur afterwards
Key points about syncope
- Syncope is a brief loss of consciousness and muscle tone. It’s caused when the brain
doesn’t get enough blood.
- It is usually harmless, but in a small number of children, it is caused by a heart
- Syncope is usually diagnosed with a health history and physical exam, including checking
blood pressure and heart rate.
- If there is no serious cause, syncope is managed by finding the cause and learning
ways to prevent it.
Tips to help you get the most from a visit to your child’s healthcare provider:
- Know the reason for the visit and what you want to happen.
- Before your visit, write down questions you want answered.
- At the visit, write down the name of a new diagnosis, and any new medicines, treatments,
or tests. Also write down any new instructions your provider gives you for your child.
- Know why a new medicine or treatment is prescribed and how it will help your child.
Also know what the side effects are.
- Ask if your child’s condition can be treated in other ways.
- Know why a test or procedure is recommended and what the results could mean.
- Know what to expect if your child does not take the medicine or have the test or procedure.
- If your child has a follow-up appointment, write down the date, time, and purpose
for that visit.
- Know how you can contact your child’s provider after office hours. This is important
if your child becomes ill and you have questions or need advice.