Fainting (“Syncope”) in Children
Basics of Fainting/Syncope
Syncope is a medical term used to describe a temporary loss of consciousness due to the sudden decline of blood flow the brain. In layman’s terms, syncope is commonly called fainting or “passing out.” If a child is about to faint, he or she will feel dizzy, lightheaded or nauseous. The child’s field of vision may “white out” or “black out.”
Fast Fact of Fainting/Syncope
- Syncope accounts for 1 percent to 3 percent of emergency room visits and 6 percent of hospital admissions, according to the American Academy of Family Physicians.
Causes of Fainting/Syncope
A temporary shortage of oxygen-rich (red) blood getting to the brain causes syncope, or fainting. Many different problems can decrease blood flow to the brain, including:
- Vasovagal syncope. When the vagus nerve is stimulated, it leads to a slowing of the heart rate and dilation of the body's blood vessels. With a slow heart rate and dilated blood vessels, less blood gets to the brain, causing a fainting spell. In susceptible people, pain and emotional stress can trigger vasovagal syncope, which is the most common type. The condition occurs more often in certain families.
- Orthostatic hypotension. This drop in blood pressure occurs after a person has been standing for a while, or after changing position from sitting to standing. Blood tends to pool in the legs, preventing a normal amount of blood from being returned to the heart, which in turn reduces the amount of blood that normally leaves the heart and goes to the body. After a momentary drop in blood flow to the brain, a child faints.
- Heart defects. Heart defects may cause fainting if they restrict the blood flow to the body from the left ventricle. Examples include aortic stenosis and hypertrophic cardiomyopathy.
- Irregular or rapid heart rhythms. When the heart beats rapidly or irregularly, the ventricles have less time to fill with blood before the blood is pumped to the lungs or body. During these abnormal rhythms, less blood than normal leaves the heart and flows through the aorta. The body reacts to this diminished blood flow to the brain by fainting.
- An inflammation of the heart muscle known as myocarditis. The condition weakens the heart muscle, making it unable to pump as well as normal. Again, the body reacts to this decreased blood flow to the brain by fainting.
Other situations or illnesses that can cause syncope include (but are not limited to):
- Head injury
- Inner ear problems
- Low blood sugar
- Breath holding episodes
Symptoms of Fainting/Syncope
Each child may experience symptoms of syncope differently. Because symptoms of syncope may resemble other conditions or medical problems, it is important to consult with a child's health care provider for a diagnosis.
Some children experience “presyncope”, a feeling that they are about to faint. A child may say he or she is "about to pass out," "feels like I might faint," "feels like the room is spinning," or "feels dizzy." These sensations usually occur right before fainting. There may be enough warning for a child to sit or lie down before fainting, which can prevent injury from a fall.
In other instances, children have no presyncopal sensations and simply faint.
Health Problems Associated with Fainting/Syncope
Some types of syncope are caused by a serious problem, so a child should be seen by a health care provider to determine the reason for the fainting spells.
Tests, Procedures and Diagnosis of Fainting/Syncope
To make a diagnosis, a child's health care obtains a medical history and performs a physical examination. Details about syncopal episodes — how often they occur, what activity a child was participating in prior to fainting, and any presyncopal sensations or other symptoms — are all useful information that can help a health care provider pinpoint a cause. In addition, blood pressure readings may be taken in sitting and standing positions to check for orthostatic hypotension.
Other diagnostic tests may include:
- Blood tests. These help evaluate potential culprits such as low blood sugar and dehydration.
- Electrocardiogram (ECG or EKG). This test records the electrical activity of the heart and shows abnormal rhythms (arrhythmias or dysrhythmias).
- Tilt table test. The child's blood pressure and heart rate are measured while lying down on a board and again after the board is tilted up.
- Holter monitor. A child wears this portable EKG machine for 24 hours or longer to evaluate irregular, fast or slow heart rhythms while engaging in normal activities.
- Echocardiogram (or “echo”). This procedure studies or evaluates the heart's function by using sound waves to produce a moving picture of the heart and its valves.
Treatment of Fainting/Syncope
A child’s health care provider determines a treatment plan for syncope based on:
- A child's age, overall health and medical history
- Severity and cause of the condition
- A child's tolerance for specific medications, procedures or therapies
- Expectations for the course of the condition
- Parents’ opinions or preferences
For vasovagal syncope, avoiding situations that trigger the episodes is recommended.
For illnesses causing syncope (such as irregular heart rhythms or epilepsy), a child’s health care provider may prescribe medications to help control the condition.
For outflow obstructions, surgical repair of the heart problem may be needed.
It is important to consult a child’s health care provider for specific information related to the child.