HP_0012668 (Vasovagal syncope) can be described as follows. A vasovagal episode or vasovagal syncope is the most common form of reflex syncope. Reflex syncope is a general term used to describe types of syncope resulting from a failure in autoregulation of blood pressure, and ultimately, in cerebral perfusion pressure resulting in transient loss of consciousness. The mechanisms responsible for this are complex and involve both depression of cardiac output as well as a decrease in vascular tone. Also known as: Neurocardiogenic syncope, Reflex syncope, Situational syncope, Vasovagal episode.