Assessment of autonomic function in humans by heart rate spectral analysis

Am J Physiol. 1985 Jan;248(1 Pt 2):H151-3. doi: 10.1152/ajpheart.1985.248.1.H151.


Spectral analysis of spontaneous heart rate fluctuations were assessed by use of autonomic blocking agents and changes in posture. Low-frequency fluctuations (below 0.12 Hz) in the supine position are mediated entirely by the parasympathetic nervous system. On standing, the low-frequency fluctuations increase and are jointly mediated by the sympathetic and parasympathetic nervous systems. High-frequency fluctuations, at the respiratory frequency, are decreased by standing and are mediated solely by the parasympathetic system. Heart rate spectral analysis is a powerful noninvasive tool for quantifying autonomic nervous system activity.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adult
  • Atropine / pharmacology
  • Autonomic Nerve Block
  • Autonomic Nervous System / physiology*
  • Heart Rate* / drug effects
  • Humans
  • Male
  • Posture
  • Propranolol / pharmacology
  • Spectrum Analysis / methods


  • Atropine
  • Propranolol