Vasovagal fainting: Deconditioning an autonomic syndrome
1982; Elsevier BV; Volume: 23; Issue: 9 Linguagem: Inglês
10.1016/s0033-3182(82)73073-7
ISSN1545-7206
AutoresHenry H. Babcock, Douglas H. Powell,
Tópico(s)Heart Rate Variability and Autonomic Control
Resumo(continued) Regardless of its cause, fainting results from a complex series of physiologic interactions. Wright and asso ciates l reviewed the most frequently encountered types of fainting, one of which is particularly associated with an imbalance within the autonomic nervous system. This imbalance is precipitated by imagined or real exposure to bodily harm, to certain medical or surgical procedures, or to the sight of blood. Since it is mediated by the autonomic nervous system, this type of fainting has long been referred to as vasovagal syncope or vasovagal syndrome.2 The syndrome begins with giddiness, pallor, sweat ing, increased respiration, and nausea, and if unop posed by corrective action leads to loss of conscious ness. This series of physiologic events represents a two-phase response. 3 Following an aversive situation, there is an initial sympathetically mediated increase in blood pressure and in heart rate. In the service of homeostasis, parasympathetic impulses are mobilized, only to lead to overshooting in the opposite direction. This second phase of the reaction consists of a decrease in heart rate, a marked fall in blood pressure, and loss of consciousness. The present case report deals with an attempt to modify an example of this syndrome by covertly de sensitizing the autonomic nervous system response on which it is based.
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