Stability of the heart rate power spectrum over time in the conscious dog

Abstract

The purpose of this experiment was to test the stability of the heart rate (HR) power spectrum over time in conscious dogs. HR was recorded for 1 h for each of six animals on 2 days. A Fast Fourier transform was used to derive the HR power spectrum for the 12 contiguous 5-min epochs comprising the 1-h recordings. Changes in frequency and amplitude of the various spectral peaks were quantitatively examined. We confirm the presence of two major concentrations of power centered around 0.02 (low frequency peak) and 0.32 Hz (high frequency peak). However, we observed variations in these spectral peaks, especially their amplitudes, both within each hour and from day 1 to day 2. The amplitudes of these two spectral peaks tended to vary reciprocally. HR power spectra based on 5 min of recorded data were also derived from an additional eight animals in both the lying and standing positions; the power spectra from these short recordings were sufficiently sensitive to detect redistributions in power due to changes in posture in all eight dogs. We conclude that: 1) data should be recorded for relatively long periods (e.g., 1 h) to characterize the HR power spectrum; 2) some variability in frequency and amplitude will persist across spectra even when based on longer data bases; 3) care should be taken to ensure that the subject's behavioral state is stable within the recording period; 4) shorter (e.g., 5 min) data bases are not suitable except for detecting relatively robust changes in the HR power spectrum.

Assessing positive emotional states in dogs using heart rate and heart rate variability

“…In this latter comparison, as expected [25,44], we observed an activation of sympathetic tone in conjunction with a withdrawal of parasympathetic tone during testing. This was indicated by an increase in HR and LF:HF ratio and a decrease in RMSSD, HF, and LF.…”

“…Most studies on HRV in dogs [22,23,24] split the spectra in three bands according to fixed frequencies: VLF (0-0.04 Hz), LF (0.04-0.15 Hz) and HF (0.15-0.5 Hz). We find this division strict and arbitrary because the peak position varies due to changes in heart rate and respiratory frequency [25]. As a result, the upper tail of the LF peak could be >0.15 and the HF peak could extend beyond 0.5 Hz.…”

Validity and reliability properties of canine short-term heart rate variability measures—a pilot study

“…Hence, research within different disciplines (i.e., anthrozoology; biomedicine; behavior science; physiotherapy; veterinary medicine) will probably continue to observe individual differentiations in response to varying interventions (Koolhaas et al, 2010). To use HRV measures in single-case experimental designs, the testretest reliability (i.e., repeatability) of short-term HRV measures has to be further explored in dogs (Sandercock et al, 2005;Brown et al, 1989). There is a need for a study design other than ours for the purpose of assessing the test-retest reliability and confounding variables in canine short-term HRV analysis.…”

Intracavernosal pressure characteristics analyzed by power spectral density for identifying the phase of penile erection

“…Each segment overlapped the previous segment by 50%. The linear trend within each time window was removed to avoid its contribution to the very-low-frequency power, 19 and a Hamming window was applied in the time domain to attenuate the leakage effect. 20 The application of a windowing function in signal processing involves adding zero values outside of a particular chosen interval.…”