emergency medicine at ncemi   More Emergency Medicine Resources
Back to table of contents

1.01 Vasovagal Syncope (Faint, swoon)


The patient experiences a brief loss of consciousness, preceded by a sense of anticipation. First, there is a period of sympathetic tone, with increased pulse and blood pressure, in anticipation of some stressful incident, such as bad news, an upsetting sight, or a painful procedure. Immediately following the stressful occurrence, there is a precipitous drop in sympathetic tone, pulse and blood pressure,causing the victim to fall down or lose consciousness. Transient bradycardia and few clonic limb jerks may accompany vasovagal syncope, but there are usually no sustained palpitations, arrhythmias or seizures, incontinence, tongue biting, or injuries beyond a contusion or laceration from the fall. Ordinarily, the victim spontaneously revives after spending a few minutes supine, and suffers no sequelae, and can recall the events leading up to the faint. The whole process may transpire in the ED, or a patient may have fainted elsewhere, in which case the diagnostic challenge is to reconstruct what happened and rule out other causes of syncope.

What to do:

What not to do:


Vasovagal syncope is a common occurrence in the ED. Observation of the sequence of stress, relief, faint makes the diagnosis, but, better yet, the whole reaction can usually be prevented. It should be noted that although most patients suffer no sequelae, vasovagal syncope with prolonged asystole can produce seizures as well as rare incidents of death. The differential diagnosis of a loss of consciousness is extensive and therefore loss of consciousness should not immediately be assumed to be due to vasovagal syncope.


Table of Contents
from Buttaravoli & Stair: COMMON SIMPLE EMERGENCIES
Longwood Information LLC 4822 Quebec St NW Washington DC 20016-3229 fax electra@clark.net
Emergency Medicine at NCEMI   More emergency medicine resources
Write to us at NCEMI
Craig Feied, MD
Mark Smith, MD
Jon Handler, MD
Michael Gillam, MD