Neurally mediated syncope

Zagga M, Massumi A. Neurally mediated syncope. Tex Heart Inst J 2000 27 268-272. 

Syncope is the abrupt and transient loss of consciousness due to a temporary reduction in cerebral blood flow. It is associated with an absence of postural tone and followed by a rapid and usually complete recovery. Syncope may be both benign or the only warning before an episode causing sudden death (1). Recurrent episodes of syncope may result from a variety of disorders, all of which cause a temporary reductiou iu cerebral blood flow sufficient to disturb the normal functions of the brain. Neurocardiogenic (vasovagal) syncope is the most common of a group of reflex (neurally mediated) syncopes, characterized by a sudden failure of the autonomic nervous system (ANS) to maintain blood pressure, and occasionally heart rate, at a level sufficient to maintain cerebral perfusion and consciousness (2-4). Syncope accounts for 3.5% of all emergency room visits and 1-6% of all hospital admissions annually in the USA (5). 

Table 13.2 Indications for permanent pacing in hypersensitive carotid sinus syndrome and neurally mediated syncope.

Neurally mediated syncope with significant bradycardia reproduced by a bead-up tilt with or without isoproterenol or other provocative maneuvers. (Level of evidence B)... 

Grimm W, Degenhardt M, Hoffman J, et al. Syncope recurrence can better be predicted by history than by head-up tilt testing in untreated patients with suspected neurally mediated syncope. Eur. Heart. J. 18, 1465-1469 (1997). 

Foglia Manzillo G, Giada F, Gaggioli G et al. Efficacy of tilt training in the treatment of neurally mediated syncope a randomized study. Europace 6, 199-204 (2004). 

Brignole M Randomized clinical trials of neurally mediated syncope. J. Cardiovasc. Electrophysiol. 14, S64-S69 (2003). 

Brignole M, Menozzi C, Gianfranchi L, Lolli G, Bottoni N, Oddone D A controlled trial of acute and long-term medical therapy in tilt-induced neurally mediated syncope. Am. J. Cardiol. 70, 339-342 (1992). 

Madrid AH, Ortega J, Rebollo JG et al. Lack of efficacy of atenolol for the prevention of neurally mediated syncope in a highly symptomatic population a prospective, double-bhnd, randomized and placebo-controlled study. J. Am. CoU. Cardiol. 37, 554-559 (2001). 

McLeod K, Wilson N, Hewitt J et al. Cardiac pacing for severe childhood neurally mediated syncope with reflex anoxic seizures. Heart 82, 721-725 (1999). 

---