Syncope overview
Syncope Microchapters |
Diagnosis |
---|
Treatment |
Case Studies |
Syncope overview On the Web |
American Roentgen Ray Society Images of Syncope overview |
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]
Overview
Syncope (IPA: Template:IPA and Template:IPA), is a sudden, and generally momentary, loss of consciousness, or blacking out caused by the Central Ischaemic Response, because of a lack of sufficient blood and oxygen in the brain. The first symptoms a person feels before fainting are dizziness; a dimming of vision, or brownout; tinnitus; and feeling hot. Moments later, the person's vision turns black, and he or she drops to the floor (or slumps if seated in a chair). If the person is unable to slump from the position to a near horizontal position, he or she risks dying of the Suspension trauma effect. More serious causes of fainting include cardiac (heart-related) causes such as an abnormal heart rhythm (an arrhythmia), where the heart beats too slowly, too rapidly or too irregularly to pump enough blood to the brain. Some arrhythmias can be life-threatening. Other important cardio-vascular conditions that can be manifested by syncope include subclavian steal syndrome and aortic stenosis.