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

Advanced analysis of spontaneous baroreflex sensitivity, blood pressure and heart rate variability in patients with dilated cardiomyopathy

2002 ◽  
Vol 102 (4) ◽  
pp. 465 ◽  
Author(s):  
Hagen MALBERG ◽  
Niels WESSEL ◽  
Annett HASART ◽  
Karl-Josef OSTERZIEL ◽  
Andreas VOSS
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Heart Rate Variability ◽  
Dilated Cardiomyopathy ◽  
Baroreflex Sensitivity ◽  
Advanced Analysis ◽  
Spontaneous Baroreflex

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.

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.

scholarly journals Artifacts in dependency structures of Portapres® signals

2019 ◽  
Vol 2 (1) ◽  
Author(s):  
Marko Mozetić ◽  
Tamara Škorić ◽  
Jelena Antelj ◽  
Katarina Otašević ◽  
Branislav Milovanović ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Baroreflex Sensitivity ◽  
Pulse Interval ◽  
Signal Acquisition ◽  
Non Invasive ◽  
Complex Procedure ◽  
Sequence Method ◽  
Copula Density ◽  
Spontaneous Baroreflex ◽  
Dependency Structures

Portapres® is a unique device that reliably accomplishes a challenging task of continuous and non-invasive recording ofblood pressure (BP) waveforms in moving subjects. The complex procedure of Portapres® signal acquisition includes periodic changesof cuffed fingers to avoid pain and stress, as well as the blood pressure correction due to the increasing and decreasing elevation of armposture. Due to these procedures, the recorded waveforms are corrupted. The aim of this paper is to analyze the influence of inevitableartifacts on parameters obtained from the blood pressure waveforms. The analyzed waveforms are obtained from healthy volunteers atBezanija Kosa Hospital, Belgrade. The parameters include systolic blood pressure (SBP) and pulse interval (PI) extracted byBeatscope® software. The interrelationship of SBP and PI signals forms a major cardiovascular feedback – baroreflex. It can beanalyzed using the sequence method for spontaneous baroreflex sensitivity, but the tools that reveal more profound dependencystructures include cross-approximate and cross-sample entropy, as well as the copula structures. The influence of artifacts, inevitable inPortapres® signals, is the main goal of this study. The analyses revealed that automatic artifact correction induced no significantchanges considering the statistical moments and the baroreflex sensitivity; the same applies to the copula density and rank tests. Theentropy analysis, however, turned out to be extremely sensitive so its implementation in Portapres® signal analysis is not recommended.

Change in spontaneous baroreflex control of pulse interval during heat stress in humans

2003 ◽  
Vol 95 (5) ◽  
pp. 1789-1798 ◽  
Author(s):  
Kichang Lee ◽  
Dwayne N. Jackson ◽  
Douglas L. Cordero ◽  
Takeshi Nishiyasu ◽  
Jochen K. Peters ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Heat Stress ◽  
Stroke Volume ◽  
Linear Relationship ◽  
Baroreflex Sensitivity ◽  
Pulse Interval ◽  
Baroreflex Control ◽  
Arterial Blood ◽  
Transfer Function Analysis ◽  
Spontaneous Baroreflex

Spontaneous baroreflex control of pulse interval (PI) was assessed in healthy volunteers under thermoneutral and heat stress conditions. Subjects rested in the supine position with their lower legs in a water bath at 34°C. Heat stress was imposed by increasing the bath temperature to 44°C. Arterial blood pressure (Finapres), PI (ECG), esophageal and skin temperature, and stroke volume were continuously collected during each 5-min experimental stage. Spontaneous baroreflex function was evaluated by multiple techniques, including 1) the mean slope of the linear relationship between PI and systolic blood pressure (SBP) with three or more simultaneous increasing or decreasing sequences, 2) the linear relationship between changes in PI and SBP (ΔPI/ΔSBP) derived by using the first differential equation, 3) the linear relationship between changes in PI and SBP with simultaneously increasing or decreasing sequences (+ΔPI/+ΔSBP or -ΔPI/-ΔSBP), and 4) transfer function analysis. Heat stress increased esophageal temperature by 0.6 ± 0.1°C, decreased PI from 1,007 ± 43 to 776 ± 37 ms and stroke volume by 16 ± 5 ml/beat. Heat stress reduced baroreflex sensitivity but increased the incidence of baroreflex slopes from 5.2 ± 0.8 to 8.6 ± 0.9 sequences per 100 heartbeats. Baroreflex sensitivity was significantly correlated with PI or vagal power ( r2 = 0.45, r2 = 0.71, respectively; P < 0.05). However, the attenuation in baroreflex sensitivity during heat stress appeared related to a shift in autonomic balance (shift in resting PI) rather than heat stress per se.

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
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