title: Unique very low-frequency heart rate variability during deep sleep in humans.
abstract: We investigate heart rate variability (HRV) in the very low-frequency (VLF) range (0.003-0.04 Hz) during deep sleep in good sleepers. Spectral analysis of HRV during deep sleep reveals consistent peaks at <0.04 Hz. By using wavelet analysis, we find both stationary and nonstationary periodic patterns in the VLF range, the presence of which has been discussed but has not been fully established to date. Although the mechanism(s) behind the unique VLF oscillations remain to be fully explored, we conjecture that there is an endogenous rhythmic component in human HRV in the VLF range. Further, our results also suggest a need for caution in the interpretation of the VLF spectral power in HRV during deep sleep.
authors.affiliation: Department of Neurology and Neurosciences, New Jersey Medical School, The University of Medicine and Dentistry of New Jersey, Newark 07101, USA.
authors.forename: Fumiharu
authors.initials: F
authors.lastname: Togo
authors.forename: Ken
authors.initials: K
authors.lastname: Kiyono
authors.forename: Zbigniew Romuald
authors.initials: ZR
authors.lastname: Struzik
authors.forename: Yoshiharu
authors.initials: Y
authors.lastname: Yamamoto
mesh_terms: D000222:Adaptation, Physiological / Q000502:physiology; D000328:Adult; D000465:Algorithms; D001683:Biological Clocks / Q000502:physiology*; D003936:Diagnosis, Computer-Assisted / Q000379:methods*; D004562:Electrocardiography / Q000379:methods*; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D008297:Male; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012890:Sleep / Q000502:physiology*