All Children's Hospital Logo

Health Information

Search Health Information   


What is syncope?

Syncope is a temporary loss of consciousness and muscle tone caused by inadequate blood supply to the brain. Syncope is better known as fainting.

Syncope accounts for 3 percent of emergency room visits and 6 percent of hospital admissions, according to the American Heart Association.

What causes syncope?

The common reason behind each syncopal or 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. Types of syncope include:

Some children have abnormalities of the structures of the heart that can cause syncopal episodes. Heart defects causing "outflow obstruction" may produce fainting because they restrict the blood flow to the body out of the left ventricle. Aortic stenosis and hypertrophic cardiomyopathy diminish the blood flow from the left ventricle through the aorta, and children with these problems may experience syncope.

Irregular or rapid heart rhythms can also trigger syncope. When the heart beats rapidly or irregularly, the ventricles have less time to fill with blood before it is time to pump whatever blood is within them to the lungs or to the body. Not as much blood as normal leaves the heart and flows through the aorta with these abnormal rhythms, and the body reacts to the diminished blood flow to the brain by fainting.

Yet another cause of syncope can be an inflammation of the heart muscle known as myocarditis. The heart muscle becomes weakened and is not able to pump as well as normal. The body again reacts to decreased blood flow to the brain by fainting.

Other situations or illnesses that can cause syncope include, but are not limited to, the following:

What are the symptoms of syncope?

The following are the most common symptoms of syncope. However, each child may experience symptoms differently. Also, the symptoms of syncope may resemble other conditions or medical problems. Consult your child's physician for a diagnosis.

Some children will experience presyncope, which is the feeling that they are about to faint. Your child may be able to tell you that he/she is "about to pass out," "feels like I might faint," "feels like the room is spinning," or "feels dizzy." These sensations usually occur immediately before fainting occurs. There may be enough warning to enable your child to sit or lie down before loss of consciousness occurs; this can prevent injuries that may occur due to falling during syncope.

In other instances, the child will have no presyncopal sensations, but will simply faint.

Should my child be seen by a physician after fainting?

Some types of syncope are caused by a serious problem, so it is recommended that your child be seen by a physician to determine the reason of all fainting spells.

How is the cause of syncope diagnosed?

Your child's physician will obtain a medical history and perform a physical examination. The details about the syncopal episodes are helpful in pinpointing the cause: how often they occur, what activity your child was participating in prior to fainting, if there were any presyncopal sensations, and other symptoms provide useful information. Blood pressure may be taken in sitting and standing positions to check for orthostatic hypotension.

Other diagnostic tests may include:

Treatment for syncope:

Specific treatment for syncope will be determined by your child's physician based on:

For vasovagal syncope, avoiding the situations that trigger the episodes is recommended.

For illnesses causing syncope, such as irregular heart rhythms or epilepsy, medications may be prescribed by your child's physician to help control the disease.

With outflow obstructions, surgical repair of the heart problem may be indicated. Consult your child's physician regarding specific information for your child.

Click here to view the
Online Resources of Cardiovascular Disorders

Additional Info

Pocket Doc Mobile App
Maps and Locations (Mobile)
Programs & Services
For Health Professionals
For Patients & Families
Contact Us
Find a Doctor

All Children's Hospital
501 6th Ave South
St. Petersburg, FL 33701
(727) 898-7451
(800) 456-4543

Use Normal Template
© 2015 All Children's Hospital - All Rights Reserved