NEUROGENIC SYNCOPE

Neurogenic syncope is one of the most frequent causes of recurrent syn cope in patients with structurally normal heart. The mechanisms leadin g to neurogenic syncope remain poorly understood. Evidence recently ob tained from several laboratories suggests that impaired arterial baror eflex adaptation to orthostatic stress, in addition to cessation of va soconstrictive sympathetic traffic, contributes to the development of hypotension and bradycardia that determine the vasovagal response. Neu rogenic syncope encompasses a wide range of reflexogenic syncope that includes the vasovagal type, micturition syncope, carotid sinus hypers ensitivity and post-prandial syncope. Head-up tilt testing has become the diagnostic tool of choice for the evaluation of patients with recu rrent neurogenic syncope, providing an acceptable sensitivity and high specificity that is largely dependent on the type of tilt protocol us ed to induce neurogenic syncope. This chapter will review the pathophy siology, diagnosis and therapeutic approach to the patient with neurog enic syncope.