Reflex syncope (Q41448)

Reflex syncope is a transient loss of consciousness with spontaneous recovery and associated with loss of postural tone. Reflex syncope is the most common form of syncope and can occur in individuals with normal autonomic function. The mechanism is believed to be related to blood pooling in the legs followed by reduction in blood return to the heart which triggers a sympathetic tone increase. Vigorous cardiac contractions with an underfilled ventricle are hypothesized to cause reflex loss of sympathetic tone and vagotonia.