TY - JOUR
T1 - Spectral analysis of sympathetic discharge, R-R interval and systolic arterial pressure in decerebrate cats
AU - Montano, Nicola
AU - Lombardi, Federico
AU - Gnecchi Ruscone, Tomaso
AU - Contini, Mauro
AU - Finocchiaro, Maria Luisa
AU - Baselli, Giuseppe
AU - Porta, Alberto
AU - Cerutti, Sergio
AU - Malliani, Alberto
PY - 1992
Y1 - 1992
N2 - In 19 decerebrate and artificially ventilated cats, we analyzed, with a power spectral methodology, the variability simultaneously present in R-R interval and in thoracic preganglionic sympathetic outflow. R-R interval was characterized, as already described in humans and other experimental preparations, by two rhythmic components occurring at a frequency of about 0.1 Hz (low-frequency, LF) and at one corresponding to respiratory rate (high-frequency, HF) which, in these experiments, was set at 0.32 Hz. Two similar rhythmic components were also present in the sympathetic discharge. Arterial pressure changes were produced by aorta or vena cava flow obstruction in order to produce reflex responses in sympathetic activity. Reflex sympathetic excitations induced an increase in the LF component of both R-R interval and sympathetic discharge variabilities, while the HF components were simultaneously reduced. In contrast, reflex sympathetic inhibitions were accompanied by a decrease in LF components of both variability signals, while the HF components were simultaneously increased. A significant and positive correlation was found between changes in impulse activity and the amplitude of LF component of either R-R interval or sympathetic discharge variabilities. These data support the hypothesis that the low-frequency component of R-R variability can be used as a marker of sympathetic modulation.
AB - In 19 decerebrate and artificially ventilated cats, we analyzed, with a power spectral methodology, the variability simultaneously present in R-R interval and in thoracic preganglionic sympathetic outflow. R-R interval was characterized, as already described in humans and other experimental preparations, by two rhythmic components occurring at a frequency of about 0.1 Hz (low-frequency, LF) and at one corresponding to respiratory rate (high-frequency, HF) which, in these experiments, was set at 0.32 Hz. Two similar rhythmic components were also present in the sympathetic discharge. Arterial pressure changes were produced by aorta or vena cava flow obstruction in order to produce reflex responses in sympathetic activity. Reflex sympathetic excitations induced an increase in the LF component of both R-R interval and sympathetic discharge variabilities, while the HF components were simultaneously reduced. In contrast, reflex sympathetic inhibitions were accompanied by a decrease in LF components of both variability signals, while the HF components were simultaneously increased. A significant and positive correlation was found between changes in impulse activity and the amplitude of LF component of either R-R interval or sympathetic discharge variabilities. These data support the hypothesis that the low-frequency component of R-R variability can be used as a marker of sympathetic modulation.
KW - Efferent sympathetic discharge
KW - Heart rate variability
KW - Power spectrum analysis
KW - Sympatho-vagal interaction
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U2 - 10.1016/0165-1838(92)90222-3
DO - 10.1016/0165-1838(92)90222-3
M3 - Article
C2 - 1401724
AN - SCOPUS:0026646612
VL - 40
SP - 21
EP - 31
JO - Journal of the Autonomic Nervous System
JF - Journal of the Autonomic Nervous System
SN - 0165-1838
IS - 1
ER -