Jpn. J. Pharmacol. 72, 355-364 (1996)
New Algorithms for Real-Time, 24 hr Continuous and Noise-Adjusted Power
Spectral Analysis of Heart Rate and Blood Pressure Fluctuations in Conscious
Rats
Ryuji Nagai and Shinya Nagata
Department of Pharmacology I, Discovery Research Laboratories I, Dainippon
Pharmaceutical Co., Ltd., Enoki 33-94, Suita, Osaka 564, Japan
Abstract: The effective combination of C + + and assembler could
realize real-time power spectral analysis of various fluctuation indexes
simultaneously. The blood pressure (BP) waveform indexes (WIs) analyzed
simultaneously were heart rate (HR), systolic blood pressure (SBP), mean
blood pressure (MBP) and diastolic blood pressure (DBP). Power amplitudes
(very low frequency, VLFamp; low frequency, LFamp; and high frequency, HFamp)
were evaluated by accurate BP waveform recognition, accurate automatic rejection
of outliers, baseline adjustment in periodograms and digital filtering of
each amplitude. In the in vivo experiments, the amplitudes were changed
in a dose-dependent manner by methylatropine (HR-VLFamp, HR-LFamp and HR-HFamp),
phentolamine (HR-LFamp, SBP-VLFamp, SBP-LFamp and SBP-HFamp) and propranolol
(HR-LFamp and SBP-LFamp). The absolute correlation coefficients of the amplitude
and the change in each parameter were more than 0.96. In conclusion, this
real-time, noise-adjusted power spectral analysis system for investigating
HR and BP fluctuations enabled us to accurately evaluate autonomic nerve
activity in conscious rats. Moreover, unlike other systems, this system
was able to detect the biphasic changes in SBP-HFamps caused by phentolamine.
Keywords: Digital filter, Periodogram, Sympathetic nerve function, Parasympathetic
nerve function, Autonomic nerve
Copyright© The Japanese Pharmacological Society 1996
[Back to TOC]