Clinical features

• The main symptom is of sudden unexpected collapse and transient unconsciousness.
• Prior to a vasovagal faint the individual often experiences feelings of nausea, lethargy, dizziness, coldness with a cold sweat breaking out before losing consciousness.
• The individual may yawn uncontrollably with a vacant expression and marked pallor of the face and extremities.
• In those who have recurrent fainting there can be a brief period of pre-syncopal anxiety that can give warning of an impending attack.
• Vasovagal fainting usually occurs while the person is standing but can happen when seated.
• When fainting is associated with cardiac arrhythmia it is not so influenced by posture and can happen while seated. As a result the person either sinks to the ground falls or forward.
• The period of unconsciousness is usually brief, lasting less than one minute. It is sometimes accompanied by what appears to be a brief convulsion thatis due to anoxia (lack of oxygen) of the brain stem and not a true seizure.
• The victim usually reverts to normal consciousness very quickly and shows none of the after-effects of confusion, disorientation or automatic behaviour normally seen after an epileptic seizure. They may continue to look pale and feel ‘shaky’ for 10-15 minutes following the episode.