Syncope is another word for fainting or passing out. Someone is considered to have syncope if they become unconscious and then soon recover. Pre-syncope is the feeling that you are about to faint. Someone with pre-syncope may be lightheaded (dizzy) or nauseated, have a visual “gray out” or trouble hearing, palpitations or feel weak or suddenly sweaty. 

For most people, syncope occurs once in a great while, if ever, and is not a sign of serious illness. However, in others, syncope can be the first and only warning sign prior to an episode of sudden cardiac death. Syncope can also lead to serious injury.

Syncope occurs when there is not enough blood flow to the brain. There are many potential causes, but the most common one is a reflex syncope, also called neutrally mediated syncope, vasovagal syncope, vasodepressor syncope or, just common faint. It is the result of a response to some trigger consisting of a blood vessels dilation (widening) and decrease of the heart rate (bradycardia). This causes blood pressure to drop, so less blood flows to the brain and fainting (syncope) or near-fainting (pre-syncope) occurs. The most common triggers include seeing blood or having blood drawn, standing up or getting up quickly, standing upright for a long time, sudden pain or hit.

Many life-threatening conditions may express also as syncope. If severe and/or recurrent, syncope needs a cardiovascular evaluation to rule out life threatening underlying conditions.
An assessment for syncope consists of a outpatient appointment where a medical and family history will be obtained, you/your child will be examined and a set of test will be done. The basic tests include a set of blood tests (to exclude anemia, diabetes, infection), an electrocardiogram, an echocardiogram. A second line of treatments that could be considered includes a Holter and an exercise test.