A Differential Model of the Baroreflex Control of the Cardiovascular System During a Tilt Test

2006 ◽  
Author(s):  
K. Djabella ◽  
C. Medigue ◽  
M. Sorine
Keyword(s):  
Cardiovascular System ◽  
Tilt Test ◽  
Baroreflex Control ◽  
Differential Model

Ontogeny of the arterial and cardiopulmonary baroreflex during fetal and postnatal life

1997 ◽  
Vol 273 (2) ◽  
pp. R457-R471 ◽  
Author(s):  
J. L. Segar
Keyword(s):  
Nervous System ◽  
Angiotensin Ii ◽  
Cardiovascular System ◽  
Cardiovascular Function ◽  
Postnatal Life ◽  
Fetal Life ◽  
Arterial Baroreflex ◽  
Baroreflex Control ◽  
Autonomic Reflexes ◽  
Cardiopulmonary Baroreflex

The autonomic nervous system is intimately involved in regulating cardiovascular function. Sensing mechanisms dispersed throughout the circulation, including arterial baroreceptors, low pressure receptors, and chemosensitive receptors, continually evoke reflexes designed to maintain cardiovascular homeostasis. Although there is a growing body of knowledge regarding neural regulation of the adult cardiovascular system, characterization and understanding of these physiological systems during development is limited. This review highlights developmental changes in the arterial and cardiopulmonary baroreflex during fetal and postnatal life and contrasts the function of these responses with those seen in the adult. Baroreceptors are functional in the immature animal and reset toward higher pressure levels with maturation. In our ovine model, the sensitivity of the efferent limb of the baroreflex is greatest during fetal life and decreases with postnatal development. As in the adult, angiotensin II and arginine vasopressin interact with the sympathetic nervous system early during development to alter baroreflex control of the cardiovascular system. However, the extent to which these hormonal systems influence autonomic reflexes during the fetal and newborn period appears vastly different than in the adult. Endogenous angiotensin II significantly contributes to resetting of the arterial baroreflex early in life, whereas even high circulating levels of vasopressin have little effect on baroreflex function until adulthood. Finally, the ability of cardiopulmonary mechanoreceptors to regulate cardiovascular function is impaired early in development, in sharp contrast to the heightened sensitivity of the arterial baroreflex at this stage of maturation. The potential importance of these autonomic reflexes on cardiovascular function during the perinatal period is highlighted.

scholarly journals Integration of the baroreflex control mechanism in a heterogeneous model of the cardiovascular system

2012 ◽  
Vol 26 (S1) ◽  
Author(s):  
Luciano Gonçalves Fernandes ◽  
Paulo Roberto Trenhago ◽  
Pablo Javier Blanco ◽  
Raúl A Feijóo
Keyword(s):  
Cardiovascular System ◽  
Control Mechanism ◽  
Baroreflex Control ◽  
Heterogeneous Model

scholarly journals Mathematical modeling of the cardiovascular autonomic control in healthy subjects during a passive head-up tilt test

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Yurii M. Ishbulatov ◽  
Anatoly S. Karavaev ◽  
Anton R. Kiselev ◽  
Margarita A. Simonyan ◽  
Mikhail D. Prokhorov ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Cardiovascular System ◽  
Healthy Subjects ◽  
Low Frequency ◽  
Tilt Test ◽  
Peripheral Vascular ◽  
Control Loops ◽  
Head Up Tilt ◽  
Head Up Tilt Test

Abstract A mathematical model is proposed for the autonomic control of cardiovascular system, which takes into account two separated self-exciting sympathetic control loops of heart rate and peripheral vascular tone. The control loops are represented by self-exciting time-delay systems and their tone depends on activity of the aortic, carotid, and lower-body baroreceptors. The model is used to study the dynamics of the adaptive processes that manifest in a healthy cardiovascular system during the passive head-up tilt test. Computer simulation provides continuous observation of the dynamics of the indexes and variables that cannot be measured in the direct experiment, including the noradrenaline concentration in vessel wall and heart muscle, tone of the sympathetic and parasympathetic control, peripheral vascular resistance, and blood pressure. In the supine and upright positions, we estimated the spectral characteristics of the model variables, especially in the low-frequency band, and the original index of total percent of phase synchronization between the low-frequency oscillations in heart rate and blood pressure signals. The model demonstrates good quantitative agreement with the dynamics of the experimentally observed indexes of cardiovascular system that were averaged for 50 healthy subjects.

Effects of Exercise Training on Baroreflex Control of the Cardiovascular System

2006 ◽  
Vol 940 (1) ◽  
pp. 338-347 ◽  
Author(s):  
EDUARDO MOACYR KRIEGER ◽  
GUSTAVO JOSÉ JUSTO SILVA ◽  
CARLOS EDUARDO NEGRÃO
Keyword(s):  
Exercise Training ◽  
Cardiovascular System ◽  
Baroreflex Control

scholarly journals A multiscale model of the cardiovascular system that incorporates baroreflex control of chronotropism, cell-level contractility, and vascular tone

2021 ◽  
Author(s):  
Hossein Sharifi ◽  
Charles K Mann ◽  
Jonathan F Wenk ◽  
Kenneth Campbell
Keyword(s):  
Kinetic Model ◽  
Arterial Pressure ◽  
Cardiovascular System ◽  
Vascular Tone ◽  
Molecular Level ◽  
Systolic Pressure ◽  
Systemic Circulation ◽  
Cell Level ◽  
Baroreflex Control ◽  
Level Function

Multiscale models of the cardiovascular system can provide new insights into physiological and pathological processes. Models that incorporate molecular-level effects may be particularly useful for clinical applications because they can predict the functional consequences of pharmaceuticals that modulate the properties of molecules and/or the rate at which they undergo reactions. PyMyoVent is a computer model that bridges from molecular to organ-level function and simulates a left ventricle pumping blood through the systemic circulation. Initial work with PyMyoVent focused on the End Systolic Pressure Volume Relationship and ranked potential therapeutic strategies by their impact on contractility. This manuscript extends PyMyoVent by adding baroreflex control of arterial pressure. The reflex algorithm is inspired by the underlying biology. It uses an afferent signal derived from arterial pressure to drive a kinetic model that mimics the net result of neural processing in the medulla and cell-level responses to autonomic drive. The kinetic model outputs control signals that are constrained between limits that represent maximum parasympathetic and maximum sympathetic drive and which modulate heart rate, intracellular Ca2+ dynamics, the molecular-level function of both the thick and the thin myofilaments, and vascular tone. Simulations show that the algorithm can regulate mean arterial pressure at set-points ranging from ~30 to ~150 mmHg as well as maintaining arterial pressure when challenged by rapid changes in blood volume or sudden increases in aortic resistance.

Impact of age on the vasovagal response provoked by sublingual nitroglycerine in routine tilt testing

2007 ◽  
Vol 113 (7) ◽  
pp. 329-337 ◽  
Author(s):  
Bart Verheyden ◽  
Janneke Gisolf ◽  
Frank Beckers ◽  
John M. Karemaker ◽  
Karel H. Wesseling ◽  
...  
Keyword(s):  
Vasovagal Syncope ◽  
Study Groups ◽  
Left Ventricular ◽  
Buffering Capacity ◽  
Tilt Test ◽  
Resistance Response ◽  
Baroreflex Control ◽  
Tilt Testing ◽  
Age Related ◽  
Vasovagal Response

NTG (nitroglycerine) is used in routine tilt testing to elicit a vasovagal response. In the present study we hypothesized that with increasing age NTG triggers a more gradual BP (blood pressure) decline due to a diminished baroreflex-buffering capacity. The purpose of the present study was to examine the effect of NTG on baroreflex control of BP in patients with distinct age-related vasovagal collapse patterns. The study groups consisted of 29 patients (16–71 years old, 17 females) with clinically suspected VVS (vasovagal syncope) and a positive tilt test. Mean FAP (finger arterial pressure) was monitored continuously (Finapres). Left ventricular SV (stroke volume), CO (cardiac output) and SVR (systemic vascular resistance) were computed from the pressure pulsations (Modelflow). BRS (baroreflex sensitivity) was estimated in the time domain. In the first 3 min after NTG administration, BP was well-maintained in all patients. This implied an adequate arterial resistance response to compensate for steeper reductions in SV and CO with increasing age. HR (heart rate) increased and the BRS decreased after NTG administration. The rate of mean FAP fall leading to presyncope was inversely related to age (r=0.51, P=0.005). Accordingly, patients with a mean FAP fall >1.44 mmHg/s (median) were generally younger compared with patients with a slower mean FAP-fall (30±10 years compared with 51±17 years; P=0.001). The main determinant of the rate of BP fall on approach of presyncope was the rate of fall in HR (r=0.75, P<0.001). It was concluded that, in older patients, sublingual NTG provokes a more gradual BP decline compared with younger patients. This gradual decline cannot be ascribed to failure of the baroreflex-buffering capacity with increasing age. Age-related differences in the laboratory presentation of a vasovagal episode depend on the magnitude of the underlying bradycardic response.

scholarly journals Baroreflex contribution to blood pressure and heart rate oscillations: time scales, time-variant characteristics and nonlinearities

2009 ◽  
Vol 367 (1892) ◽  
pp. 1301-1318 ◽  
Author(s):  
M Di Rienzo ◽  
G Parati ◽  
A Radaelli ◽  
P Castiglioni
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Cardiovascular System ◽  
Time Scales ◽  
Physiological Mechanism ◽  
Controversial Issues ◽  
Baroreflex Control ◽  
Nonlinear Characteristics ◽  
Baroreflex Function ◽  
Rate Oscillations

The aim of this paper is to highlight the aspects of the baroreflex control of the cardiovascular system that could be relevant to the analysis and modelling of cardiovascular oscillations and regulation. In particular, complex and/or controversial issues of the baroreflex control are addressed on the basis of results obtained in previous studies by others as well as by our group. Attention has been focused on time-variant and nonlinear characteristics of the baroreflex function and on the influence of this physiological mechanism on different frequency regions of blood pressure and heart rate spectra.

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