Frequency analysis of heart rate variability in monkeys: Comparison of the results with two different settings of frequency bandwidths

<p>Frequency analysis of heart rate variability is used as a method of estimating the autonomic nervous system activity. This frequency analysis requires the use of species-appropriate low-frequency (LF) and high-frequency (HF) bandwidths, but different bandwidths have been used between monkey studies. The aim of this study was to perform frequency analysis by 2 different bandwidth settings used in monkey studies and compare to clear the characteristics of each setting. Atropine (ATR, 1 mg/kg), atenolol (ATE, 1 mg/kg), clonidine (CLO, 0.1 mg/kg), or saline as the control were injected to 4 telemetered monkeys. Frequency of HRV was analyzed by both settings used in Champeroux et al. (C setting: 0.04–0.10 Hz for LF and 0.10–0.5 Hz for HF) and Shivy et al. (S setting: 0.01–0.2 Hz for LF and 0.2–0.8 Hz for HF). The expected hemodynamic changes at these agents were observed for at least 4 hours postdose. In control baseline, total power (TP) and HF values were similar by the 2 settings, but LF values were more than 4 times higher with the S setting than with the C setting and therefore also a higher LF/HF ratio. Both settings showed that ATR significantly decreased both LF and HF values, LF/HF ratio significantly increased, and CLO obviously decreased both LF and LF/HF. On the other hand, there were no clear changes in any parameter with ATE. It was confirmed that drug-induced change pattern of each parameter and the statistical test results were broadly similar for the 2 settings, though the ratio of LF value to TP differed largely between the 2 settings.</p>