Neurocardiogenic Syncope: What Role for Serotonin?

  • B. P. Grubb


Recurrent episodes of neurocardiogenic (or vasovagal) hypotension and bradycardia that are sufficiently profound to result in syncope, offer not only a diagnostic and therapeutic challenge to the clinician, but also a fascinating challenge to the physiologist who seeks to understand why these episodes occur. Beginning with Sir Thomas Lewis’ original description of the disorder, a number of individuals have speculated on the potential physiological mechanisms involved [1]. However, these speculations remained highly theoretical, as there existed no way to either confirm or deny them. This picture changed dramatically in 1986 when Kenny et al. in their landmark paper reported that head upright tilt-table testing could reliably induce episodes of neurocardiogenic syncope in predisposed individuals [2]. This newfound ability to reproducibly provoke these episodes in a controlled laboratory setting permitted detailed observations and recordings of multiple parameters to be made before, during and immediately following a syncopal event [3–5]. Thus, there has been a virtual explosion of data over the last several years concerning the pathophysiology of neurocardiogenic syncope [6]. These observations have accumulated a body of data suggesting that sudden fluctuations in the central nervous system neurotransmitter serotonin (5-hydroxytryptamine or 5-HT) may play a pivotal role in the production of the hypotension and bradycardia that characterizes neurocardiogenic syncope. This paper will review serotonin’s role in central nervous system function and cardiovascular regulation, present observations on its potential role in neurocardiogenic syncope, and lastly will review data on the clinical use of the serotonin reuptake inhibitors in the therapy of recurrent syncope.


Dorsal Raphe Nucleus Carotid Sinus Vasovagal Syncope Recurrent Syncope Neurocardiogenic Syncope 
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Copyright information

© Springer-Verlag Italia 1998

Authors and Affiliations

  • B. P. Grubb
    • 1
  1. 1.Cardiac Electrophysiology and Pacemaker LaboratoriesThe Medical College of OhioToledoUSA

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