Type : Phenotype or locus, molecular basis unknown;
Alternative titles and symbols : Syncope, familial neurocardiogenic;
Description : Vasovagal syncope (VVS) is an exaggerated tendency toward the common faint caused
by a sudden and profound hypotension with or without bradycardia. Several lines of
evidence indicate central and peripheral abnormalities of sympathetic function. Newton
et al. (2005) stated that a definitive diagnosis of VVS is made only when a patient
has reproduction of symptoms in association with hypotension or bradycardia. The head
up tilt (HUT) test is the investigation carried out to induce these hemodynamic changes
(Parry and Kenny, 1999). This disorder may be the same as Streeten-type orthostatic
hypotensive disorder (143850).;