Influence of aging on cardiac baroreflex sensitivity determined non-invasively by power spectral analysis

2001 ◽  
Vol 100 (3) ◽  
pp. 267 ◽  
Author(s):  
Gianfranco PICCIRILLO ◽  
Mauro CACCIAFESTA ◽  
Emanuela VIOLA ◽  
Elvira SANTAGADA ◽  
Marialuce NOCCO ◽  
...  
2008 ◽  
Vol 115 (11) ◽  
pp. 1527-1536 ◽  
Author(s):  
C. Friedrich ◽  
H. Rüdiger ◽  
C. Schmidt ◽  
B. Herting ◽  
S. Prieur ◽  
...  

1995 ◽  
Vol 88 (1) ◽  
pp. 103-109 ◽  
Author(s):  
Peter Sleight ◽  
Maria Teresa La Rovere ◽  
Andrea Mortara ◽  
Gianni Pinna ◽  
Roberto Maestri ◽  
...  

1. It is often assumed that the power in the low-(around 0.10 Hz) and high-frequency (around 0.25 Hz) bands obtained by power spectral analysis of cardiovascular variables reflects vagal and sympathetic tone respectively. An alternative model attributes the low-frequency band to a resonance in the control system that is produced by the inefficiently slow time constant of the reflex response to beat-to-beat changes in blood pressure effected by the sympathetic (with or without the parasympathetic) arm(s) of the baroreflex (De Boer model). 2. We have applied the De Boer model of circulatory variability to patients with varying baroreflex sensitivity and one normal subject, and have shown that the main differences in spectral power (for both low and high frequency) between and within subjects are caused by changes in the arterial baroreflex gain, particularly for vagal control of heart rate (R—R interval) and left ventricular stroke output. We have computed the power spectrum at rest and during neck suction (to stimulate carotid baroreceptors). We stimulated the baroreceptors at two frequencies (0.1 and 0.2 Hz), which were both distinct from the controlled respiration rate (0.25 Hz), in both normal subjects and heart failure patients with either sensitive or poor baroreflex control. 3. The data broadly confirm the De Boer model. The low-frequency (0.1 Hz) peak in either R—R or blood pressure variability) was spontaneously generated only if the baroreflex control of the autonomic outflow was relatively intact. With a large stimulus to the carotid baroreceptor it was possible to influence the low-frequency R—R but not low-frequency blood pressure variability. This implies that it is too simplistic to use power spectral analysis as a simple measure of autonomic balance its underlying modulation is more complex than generally believed. 4. It may be that power spectral analysis is more a sensitive indicator of baroreflex control, particularly of vagal control, than direct evidence of autonomic balance. of course, there is often a correlation between the gain of the reflex and the autonomic balance of vagus and sympathetic. These considerations may help our understanding of some conditions, such as exercise or heart failure, when the power spectral analysis method fails to identify increased sympathetic discharge; this failure may partly be explained by the decrease in baroreflex sensitivity which occurs in these two conditions.


2009 ◽  
Vol 25 (3) ◽  
pp. 315-324 ◽  
Author(s):  
Constanze Friedrich ◽  
Heinz Rüdiger ◽  
Claudia Schmidt ◽  
Birgit Herting ◽  
Silke Prieur ◽  
...  

2001 ◽  
Vol 100 (3) ◽  
pp. 267-274 ◽  
Author(s):  
Gianfranco PICCIRILLO ◽  
Mauro CACCIAFESTA ◽  
Emanuela VIOLA ◽  
Elvira SANTAGADA ◽  
Marialuce NOCCO ◽  
...  

Aging reduces cardiac baroreflex sensitivity. Our primary aim in the present study was to assess the effects of aging on cardiac baroreflex sensitivity, as determined by power spectral analysis (α index), in a large population of healthy subjects. We also compared the α indexes determined by power spectral analysis with cardiac baroreflex sensitivity measured by the phenylephrine method (BSphen). We studied 142 subjects (79 males/63 females; age range 9–94 years), who were subdivided into five groups according to percentiles of age (25, 50, 75 and 95). Power spectral analysis yields three α indexes: an α low-frequency (LF) index of cardiac baroreflex sensitivity that ranges around 0.1 Hz; an α high-frequency (HF) index reflecting cardiac baroreflex sensitivity corresponding to the respiratory rate; and α total frequency (α TF), a new index whose spectral window includes all power in the range 0.03–0.42 Hz. Spectra were recorded during controlled and uncontrolled respiration. Under both conditions, all three α indexes were higher in the youngest age group (⩽ 34 years old) than in the three oldest groups. Notably, α TF was significantly higher in younger subjects than in the three oldest groups [14±1 ms/mmHg compared with 9±1 (P < 0.05), 8.1±1 (P < 0.001) and 8.1±1 (P < 0.05) ms/mmHg respectively]. BSphen showed a similar pattern [12±1 ms/mmHg compared with 8±0.5 (P < 0.001), 6±0.5 (P < 0.05) and 6±1 (P < 0.05) ms/mmHg respectively]. No significant differences were found for cardiac baroreflex sensitivity among the three oldest groups. All α indexes were correlated inversely with age. The index yielding the closest correlation with BSphen was α TF (r = 0.81, P < 0.001). Cardiac baroreflex sensitivity in normotensive individuals declines with age. It falls predominantly in middle age (from approx. 48 years onwards) and remains substantially unchanged thereafter. The elderly subjects we selected for this study probably had greater resistance to cardiovascular disease that is manifested clinically, with preserved cardiac baroreceptor sensitivity.


Diabetes ◽  
1992 ◽  
Vol 41 (5) ◽  
pp. 633-640 ◽  
Author(s):  
F. Bellavere ◽  
I. Balzani ◽  
G. De Masi ◽  
M. Carraro ◽  
P. Carenza ◽  
...  

Author(s):  
Soon Young Kwon ◽  
Chung Yill Park ◽  
Jung Wan Koo ◽  
Hyeon Woo Yim ◽  
Kang Sook Lee

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