cardiovascular disorders
Syncope
Key Points
Syncope results from global central nervous system dysfunction, usually resulting from insufficient cerebral blood flow. Most syncope results from benign causes. Some less common causes involve cardiac arrhythmia or outflow obstruction and are serious or potentially fatal. Vasovagal syncope usually has an apparent trigger, warning symptoms, and a few minutes or longer of postrecovery symptoms. Syncope due to cardiac arrhythmias typically occurs abruptly and with quick recovery. If a benign etiology is not clear, driving and use of machinery should be prohibited until the cause is determined and treated—the next manifestation of an unrecognized cardiac cause may be fatal. Treatment is directed at the underlying disorder. 