Clinical Autonomic Research

, Volume 21, Issue 3, pp 133–141

Low frequency power of heart rate variability reflects baroreflex function, not cardiac sympathetic innervation

  • Faisal Rahman
  • Sandra Pechnik
  • Daniel Gross
  • LaToya Sewell
  • David S. Goldstein
Research Article

DOI: 10.1007/s10286-010-0098-y

Cite this article as:
Rahman, F., Pechnik, S., Gross, D. et al. Clin Auton Res (2011) 21: 133. doi:10.1007/s10286-010-0098-y



Power spectral analysis of heart rate variability is used to assess cardiac autonomic function. The relationship of low frequency (LF) power to cardiac sympathetic tone has been unclear. We reported previously that LF power may reflect baroreflex modulation. In this study we attempted to replicate our findings in additional subject cohorts, taking into account possible influences of respiration and using different methods to measure baroreflex-cardiovagal gain (BCG).


We assessed relationships of LF power, including respiration-adjusted LF power (LFa), with cardiac sympathetic innervation and baroreflex function in subjects with or without neuroimaging evidence of cardiac sympathetic denervation.


Values for LF power at baseline supine, seated, and during the Valsalva maneuver were compared between subject groups with low or normal myocardial concentrations of 6-[18F]fluorodopamine-derived radioactivity. BCG was calculated from the slope of cardiac interbeat interval vs. systolic pressure during Phase II of the Valsalva maneuver or after i.v. nitroglycerine injection (the Oxford technique).


LF and LFa were unrelated to myocardial 6-[18F]fluorodopamine-derived radioactivity. During sitting rest and the Valsalva maneuver logs of LF and LFa correlated positively with the log of Phase II BCG (r = 0.61, p = 0.0005; r = 0.47, p = 0.009; r = 0.69, p < 0.0001; r = 0.60, p = 0.0006). Groups with Low BCG (≤3 ms/mmHg) had low LF and LFa regardless of cardiac innervation. The log of LF power during supine rest correlated with the log of Oxford BCG (r = 0.74, p < 0.0001).


LF power, with or without respiratory adjustment, reflects baroreflex modulation and not cardiac sympathetic tone.


Power spectral analysis Heart rate variability Sympathetic Parasympathetic Autonomic 



Baroreflex-cardiovagal gain


High frequency


Adjusted high frequency power


Low frequency


Adjusted low frequency power

Copyright information

© Springer-Verlag (outside the USA) 2011

Authors and Affiliations

  • Faisal Rahman
    • 1
  • Sandra Pechnik
    • 1
  • Daniel Gross
    • 1
  • LaToya Sewell
    • 1
  • David S. Goldstein
    • 1
  1. 1.Clinical Neurocardiology SectionNational Institute of Neurological Disorders and Stroke, National Institutes of HealthBethesdaUSA

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