Blood Pressure Responses to Active Orthostasis are not Related to Spontaneous Baroreflex Sensitivity

2001 ◽  
Vol 100 (s44) ◽  
pp. 5P-5P
Author(s):  
A Fender ◽  
J Tank
Keyword(s):  
Blood Pressure ◽  
Baroreflex Sensitivity ◽  
Blood Pressure Responses ◽  
Spontaneous Baroreflex

scholarly journals Implantation of Combined Telemetric ECG and Blood Pressure Transmitters to Determine Spontaneous Baroreflex Sensitivity in Conscious Mice

10.3791/62101 ◽  
2021 ◽  
Author(s):  
René D. Rötzer ◽  
Verena F. Brox ◽  
Konstantin Hennis ◽  
Stefan B. Thalhammer ◽  
Martin Biel ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Baroreflex Sensitivity ◽  
Spontaneous Baroreflex

Aldosterone blunts the baroreflex response in man

1998 ◽  
Vol 95 (6) ◽  
pp. 687-692 ◽  
Author(s):  
K. M. YEE ◽  
A. D. STRUTHERS
Keyword(s):  
Blood Pressure ◽  
Animal Models ◽  
Sodium Nitroprusside ◽  
Baroreflex Sensitivity ◽  
Crossover Fashion ◽  
Healthy Male ◽  
Double Blind ◽  
Resting Blood Pressure ◽  
Blood Pressure Responses

1. Recent animal evidence suggests that aldosterone, like angiotensin II, may possess detrimental autonomic modulating properties. Aldosterone has been shown to impair the baroreflex response in animal models. This study is designed to test the hypothesis that aldosterone directly attenuates the baroreflex in vivo in man. 2. Fourteen healthy male volunteers [mean age (S.D.) 25 (9) years] received intravenous d-aldosterone (12 pmol·min-1·kg-1) and 5% dextrose (vehicle) in a double-blind crossover fashion, co-infused with incremental doses of intravenous phenylephrine and sodium nitroprusside. Aldosterone had no significant effect on resting blood pressure, heart rate or baroreflex response to sodium nitroprusside. However, reflex responses to phenylephrine were impaired with aldosterone (P< 0.01) while blood pressure responses were unaltered. Baroreflex sensitivity was significantly blunted in the aldosterone group [8.36±2.19 versus 10.12±2.27 ms/mmHg; P< 0.04]. 3. This study confirms previous observations from animal models that aldosterone impairs the baroreflex response. High aldosterone levels may contribute to the baroreflex dysfunction in cardiovascular diseases such as hypertension and heart failure.

Critical Appraisal of Indices for the Assessment of Baroreflex Sensitivity

1997 ◽  
Vol 36 (04/05) ◽  
pp. 246-249 ◽  
Author(s):  
P. Castiglioni ◽  
G. Mancia ◽  
G. Parati ◽  
A. Pedotti ◽  
M. Di Rienzo
Keyword(s):  
Blood Pressure ◽  
Baroreflex Sensitivity ◽  
Critical Appraisal ◽  
Spectral Estimation ◽  
Respiratory Frequency ◽  
Pulse Interval ◽  
Alpha Coefficient ◽  
Before And After ◽  
Reliable Parameter ◽  
Spontaneous Baroreflex

Abstract:The sequence technique and the spectral estimation of the alpha coefficient are currently employed for the assessment of “spontaneous” baroreflex sensitivity (BRS). The comparison of performance and effectiveness of these techniques is obtained by the analysis of systolic blood pressure (SBP) and pulse interval (PI) tracings recorded in conscious cats before and after baroreceptor denervation. Results indicate that (1) the average BRS estimates obtained by the sequence technique and by the alpha coefficient at the respiratory frequency are similar, (2) the alpha coefficients computed at the respiratory frequency tend to be higher than alpha coefficients estimated at 0.1 Hz, and (3) in spite of what is traditionally claimed, the PI-SBP coherence does not seem to represent a reliable parameter to enhance the specificity of the spectral estimate, because coherence values often remain above the 0.5 threshold also after baroreceptor denervation.

Effects of Low-Intensity Exercise Conditioning on Blood Pressure, Heart Rate, and Autonomic Modulation of Heart Rate in Men and Women with Hypertension

2009 ◽  
Vol 11 (2) ◽  
pp. 129-143 ◽  
Author(s):  
Lien P.T. Hua ◽  
C. Ann Brown ◽  
Sylvia J.M. Hains ◽  
Marshall Godwin ◽  
Joel L. Parlow
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Diastolic Blood Pressure ◽  
Baroreflex Sensitivity ◽  
Autonomic Modulation ◽  
Men And Women ◽  
Low Intensity ◽  
Walking Program ◽  
Spontaneous Baroreflex ◽  
Low Intensity Exercise

Untreated hypertension increases cardiovascular risk 2-fold to 3-fold, leading to serious cardiovascular problems that include left ventricular hypertrophy, stroke, ischemic heart disease, myocardial infarction, vascular disease, renal disease, and death. Exercise conditioning is recommended as one of the initial treatments for hypertension. The purpose of this pretest—posttest study was to quantify the effects of a 12-week home-based low-intensity exercise conditioning (walking) program in hypertensive men and women on systolic and diastolic blood pressure, heart rate, and autonomic modulation of heart rate. A total of 20 mildly hypertensive men and women who were assigned to a structured exercise (walking) program were compared with a control group of 20 nonexercising mildly hypertensive participants. Electrocardiographic heart rate and R-R interval data and beat-by-beat arterial blood pressure data were collected continuously for 10 min with participants in the supine and standing postures and during low-intensity steady-state exercise. The results show that systolic and diastolic blood pressure and R-R interval decreased and spontaneous baroreflex sensitivity increased in the exercise group. The decline in blood pressure was significant statistically and clinically. The increase in spontaneous baroreflex sensitivity indicates that the ability of the cardiovascular system to respond rapidly to changing stimuli improved after the 12-week walking protocol. The low-intensity exercise conditioning program achieved a training effect in this population.

Reduced baroreflex sensitivity in elderly humans is not due to efferent autonomic dysfunction

1999 ◽  
Vol 98 (1) ◽  
pp. 103-110 ◽  
Author(s):  
D. O'MAHONY ◽  
C. BENNETT ◽  
A. GREEN ◽  
A. J. SINCLAIR
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Baroreflex Sensitivity ◽  
Reflex Response ◽  
Cognitive Stress ◽  
Age Related ◽  
Cold Face ◽  
Blood Pressure Responses ◽  
Age Range ◽  
Cold Face Test

A progressive decline in baroreflex sensitivity (BRS) is a characteristic feature of human aging, the basis of which is poorly understood. The purpose of the present study was to determine whether alterations in efferent baroreflex function might contribute to the age-related decrease in BRS. We studied 10 healthy young (mean age 30.5 years; age range 22–40 years; six male) and 10 healthy elderly (mean age 70.7 years; age range 67–75 years; five male) volunteers. We tested efferent cardiac vagal function using the bradycardiac response to the cold face test, and efferent sympathetic function using heart rate and blood pressure responses to four stress tests: (i) low-level cognitive stress, (ii) high-level cognitive stress, (iii) hand immersion in ice water (cold pressor test) and (iv) isometric sustained hand-grip. Haemodynamic responses to these stresses are mediated via efferent baroreflex pathways, whereas the afferent components of each reflex response are independent of afferent baroreflex pathways. BRS was measured from simultaneous Finapres-derived continuous blood pressure and digital ECG R–R interval data using the sequence analysis paradigm. As expected, BRS was significantly reduced in the elderly group (7.29±0.74 ms/mmHg; mean±S.E.M.) compared with the young group (13.84±1.13 ms/mmHg; P < 0.001). However, neither the bradycardiac responses to the cold face test nor the efferent sympathetically mediated heart rate/blood pressure responses to the stress test battery were significantly different between the young and elderly groups. We conclude that the age-related decrease in BRS is not attributable to impairments in the efferent sympathetic or parasympathetic system components of the baroreceptor reflex pathway.

scholarly journals Arterial baroreflex function in older adults with neurocardiogenic syncope

2009 ◽  
Vol 32 (3) ◽  
pp. 191 ◽  
Author(s):  
Kenneth M Madden ◽  
Chris Lockhart
Keyword(s):  
Blood Pressure ◽  
Older Adults ◽  
Baroreflex Sensitivity ◽  
Arterial Baroreflex ◽  
Neurocardiogenic Syncope ◽  
Baroreflex Function ◽  
Large Numbers ◽  
Falls In Older Adults ◽  
Spontaneous Baroreflex ◽  
Arterial Baroreflex Sensitivity

Purpose: Neurocardiogenic syncope (formerly vasovagal) accounts for large numbers of falls in older adults and the mechanisms are poorly understood. This study examined the differences in baseline arterial baroreflex function in older adults with and without a neruocardiovascular response to orthostatic stress. Methods: Subjects were divided into two groups based on the presence (TT+ group) or absence (TT- group) of a neurocardiovascular response to upright tilting (70 degree head-up tilt for 10 minutes after 400 micrograms of sublingual nitroglycerin). A neurocardiovascular response was defined as presyncopal symptoms (lightheadedness) in association with at least a 30 mm Hg decrease in blood pressure. Before being divided into groups, baroreflex function was assessed using the spontaneous baroreflex method (baroreflex sensitivity, BRS). This method involves the analysis of “spontaneous” swings in blood pressure and heart rate that are mediated by the arterial baroreflexes. Results: 42 older adults (mean age 70.3±0.7 yr) were recruited, of which 18 were in the TT+ and 24 were in the TT- group. At baseline, the TT+ group demonstrated increased arterial baroreflex sensitivity in response to negative blood pressure sequences only (BRSdown, 11.2±1.9 vs. 7.3±1.0 ms/mm Hg, P=0.011). During tilt, the TT+ group demonstrated a much larger decrease in overall arterial baroreflex sensitivity than the TT- group (-6.8±1.2 vs. –3.2±0.9 ms/mm Hg, P=0.012). There was a negative correlation between BRSdown and length of tilt table test (r=-0.329, P=0.041) in the TT+ subjects. Conclusion: Older adults with neurocardiogenic syncope have exaggerated arterial baroreflex sensitivity at baseline.

Autonomic Cardiovascular Regulation in the Newborn

2012 ◽  
pp. 201-221
Author(s):  
Peter Andriessen
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Baroreflex Sensitivity ◽  
Heart Rate Response ◽  
Function Analysis ◽  
Feedback System ◽  
Cardiovascular Regulation ◽  
Interval Change ◽  
Method Transfer ◽  
Spontaneous Baroreflex

This paper reviews the baroreflex mediated heart rate response in human infants with a focus on data acquisition, signal processing and autonomic cardiovascular modeling. Baroreflex mediated heart rate response is frequently used as an estimate of autonomic cardiovascular regulation. Baroreflex mediated heart rate response may be viewed in terms of a negative-feedback system. To study fluctuations in this feedback system, continuous registration of ECG and blood pressure waveforms are required. From these waveforms, time series of R-R interval and blood pressure values are derived. This paper focus on spontaneous baroreflex sensitivity (e.g., R-R interval change per unit of arterial blood pressure change, ms/mmHg) calculated from cross-spectral analysis of spontaneous occurring changes in R-R interval and blood pressure. Despite different methodology (sequence method; transfer function analysis; head-up tilt) there is fairly good agreement of spontaneous baroreflex sensitivity values during homeostasis. Preterm infants and term newborns have values of 2-4 and 10-15 ms/mmHg, respectively. These values are much lower than found in adults, approximately 25 ms/mmHg. The clinical relevance of a limited baroreflex function may be that acute perturbations of the cardiovascular system are poorly counteracted and may result in poor cerebral perfusion.

scholarly journals Noninvasiveassessment of spontaneous baroreflex sensitivityin pregnancy

2008 ◽  
Vol 14 (1) ◽  
pp. 49-52
Author(s):  
F. Gugova ◽  
O. V. Mamontov ◽  
O. Bogomolova ◽  
E. Y. Petrenko ◽  
A. O. Konradi
Keyword(s):  
Blood Pressure ◽  
Early Pregnancy ◽  
Baroreflex Sensitivity ◽  
Autonomic Function ◽  
Late Pregnancy ◽  
Normal Pregnancy ◽  
Orthostatic Tolerance ◽  
Baroreflex Function ◽  
History Of ◽  
Spontaneous Baroreflex

The aim of the present study was to investigate evolution of autonomic function during normal pregnancy without history of hypertension. 23 women of mean age 27,4±4,4 yrs on 12-14 weeks of gestation were examined. Spontaneous baroreflex function (BRS) was analyzed by Finometer device with beat-to-beat blood pressure registration. All measurements were performed at supine rest and 5 minute passive tilt (70). Baroreflex was calculated by sequence technique. 12 women were studies second time on 26-30 week of pregnancy. A normal or increases values of spontaneous baroreflex were observed in early pregnancy with e significant reduction of baroreflex sensitivity during tilt. In late pregnancy restoration of the orthostatic tolerance was accompanied by decrease of BRS.

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