Critical analysis of autoregressive and fast Fourier transform markers of cardiovascular variability in rats and humans
Braz. j. med. biol. res
;
42(4): 386-396, Apr. 2009. graf, tab
Article
Dans Anglais
| LILACS
| ID: lil-509171
ABSTRACT
The autonomic nervous system plays an important role in physiological and pathological conditions, and has been extensively evaluated by parametric and non-parametric spectral analysis. To compare the results obtained with fast Fourier transform (FFT) and the autoregressive (AR) method, we performed a comprehensive comparative study using data from humans and rats during pharmacological blockade (in rats), a postural test (in humans), and in the hypertensive state (in both humans and rats). Although postural hypotension in humans induced an increase in normalized low-frequency (LFnu) of systolic blood pressure, the increase in the ratio was detected only by AR. In rats, AR and FFT analysis did not agree for LFnu and high frequency (HFnu) under basal conditions and after vagal blockade. The increase in the LF/HF ratio of the pulse interval, induced by methylatropine, was detected only by FFT. In hypertensive patients, changes in LF and HF for systolic blood pressure were observed only by AR; FFT was able to detect the reduction in both blood pressure variance and total power. In hypertensive rats, AR presented different values of variance and total power for systolic blood pressure. Moreover, AR and FFT presented discordant results for LF, LFnu, HF, LF/HF ratio, and total power for pulse interval. We provide evidence for disagreement in 23 percent of the indices of blood pressure and heart rate variability in humans and 67 percent discordance in rats when these variables are evaluated by AR and FFT under physiological and pathological conditions. The overall disagreement between AR and FFT in this study was 43 percent.
Texte intégral:
Disponible
Indice:
LILAS (Amériques)
Sujet Principal:
Système nerveux autonome
/
Analyse de Fourier
/
Bloc cardiaque
/
Hypertension artérielle
Type d'étude:
Étude pronostique
Limites du sujet:
Animaux
/
Femelle
/
Humains
/
Mâle
langue:
Anglais
Texte intégral:
Braz. j. med. biol. res
Thème du journal:
Biologie
/
Médicament
Année:
2009
Type:
Article
Pays d'affiliation:
Brésil
Institution/Pays d'affiliation:
Universidade de São Paulo/BR
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