Role of adenosine

Abstract

Typical vasovagal syncope differs from other neurally mediated reflex syncopes not only in terms of its precipitating factors (fear, strong emotion, etc.), which constitute predefined diagnostic criteria, but also in the variety of its clinical features. The presence of a trigger of a recognizable type is important for the diagnosis of reflex syncope (in which case the general term ‘situational syncope’ is often employed) [1]. Most variants are in fact named for their triggers, such as cough syncope, micturition syncope, swallow syncope, etc. Except for the presence of a trigger, autonomic activation is an important clue to diagnose vasovagal syncope in adolescents and most adults, with the exception of the elderly in whom the autonomic activation is less noticeable and therefore causes fewer warning symptoms.