The medical termsyncopeis derived from the Greek word “synkoptein,‘’ the original meaning of which was “to cut short.‘’ Because it is both a symptom and a sign, the physican may often find the evaluation of syncope a difficult and frustrating endeavor. Over the course of the past decade it has become apparent that transient alterations in autonomic nervous system activity, resulting in hypotension and bradycardia, are common causes of syncope. At the same time it has become apparent that these are a heterogenous group of disorders which, while sharing some characteristics, are nonetheless distinct maladies. This article attempts to briefly review our current understanding of these disorders and suggests guidelines on their diagnosis and management.