scholarly journals Simulation of autonomic blockade in mathematical model of cardiovascular regulation

Cardio-IT ◽  
2018 ◽  
Vol 5 (2) ◽  
pp. e0201
Author(s):  
Yurii M. Ishbulatov ◽  
Anatoly S. Karavaev
Keyword(s):  
Mathematical Model ◽  
Cardiovascular Regulation ◽  
Autonomic Blockade

Abstract 422: Cardiovascular Regulation in Mice with Overexpression of the Gene of Vesicular Acetylcholine Transporter (VAChT)

Hypertension ◽  
2014 ◽  
Vol 64 (suppl_1) ◽  
Author(s):  
Geisa C Tezini ◽  
Silvia Guatimosim ◽  
Diogo A Guimarães ◽  
Mauro Oliveira ◽  
Rubens Fazan ◽  
...  
Keyword(s):  
Baroreflex Sensitivity ◽  
Fold Increase ◽  
Cardiovascular Regulation ◽  
Transgenic Animal ◽  
Vesicular Acetylcholine Transporter ◽  
Wild Type ◽  
Autonomic Blockade ◽  
Release Of Acetylcholine ◽  
Cardiovascular Autonomic Regulation ◽  
Spontaneous Baroreflex

It was recently developed a transgenic animal model with overexpression of cholinergic neurotransmission. This mouse, named ChAT-ChR2-EYFP, has several extra copies of the vesicular acetylcholine transporter (VAChT) gene and exhibits three-fold increase in the release of acetylcholine. However, the consequences of overexpression of VAChT protein to the cardiovascular system have not yet been characterized. Therefore, we have investigated the effects of the overexpression of the gene of VAChT on arterial pressure (AP) and heart rate (HR) as well as the autonomic cardiovascular regulation. Mice were assigned into two groups: Wild-type (WT, n=7) and ChAT-ChR2-EYFP (n=7). These animals were anesthetized (isoflurane) and implanted with probes to record AP by telemetry. After 10 days, the mice had basal AP and HR recorded continuously. Assessment of the autonomic function was conducted throughout the following approaches: 1) cardiac sympathovagal balance evaluated by HR responses to methylatropine and propranolol; 2) overall HR variability; 3) spontaneous baroreflex sensitivity by the sequence analysis. ChAT-ChR2-EYFP mice showed lower basal HR (461±8 vs. 502±14 bpm, p<0.01) but similar AP as compared to WT mice. ChAT-ChR2-EYFP mice exhibited higher vagal tone (Δbpm, 169±14 vs. 117±6, p=0.03) and lower HR after double autonomic blockade (IHR, 456±8 vs. 509±11 bpm, p<0.001). HR variability was similar between groups (SDNN: 88±16 vs. 65±7 ms; RMSSD: 11.4±1 vs. 9.7±0.5 ms). However, the baroreflex sensitivity (7.5±1.5 vs. 4.1±0.5 ms/mmHg, p=0.05) was higher in ChAT-ChR2-EYFP mice. Altogether, the results show that the cardiovascular autonomic regulation of ChAT-ChR2-EYFP mice is characterized by higher parasympathetic tone, combined with a lower basal HR and IHR. Moreover, these mice present greater baroreflex sensitivity.

Lyapunov exponent calculations as independent indices of complexity of cardiovascular regulation during hemorrhage with autonomic blockade

2011 ◽  
Vol 26 (2) ◽  
pp. e10-e11
Author(s):  
J. Ward ◽  
W. Baker ◽  
K. Walker ◽  
J Salinas ◽  
L.C. Cancio ◽  
...  
Keyword(s):  
Lyapunov Exponent ◽  
Cardiovascular Regulation ◽  
Autonomic Blockade

A mathematical model of CO2 effect on cardiovascular regulation

2001 ◽  
Vol 281 (5) ◽  
pp. H2036-H2052 ◽  
Author(s):  
Elisa Magosso ◽  
Mauro Ursino
Keyword(s):  
Mathematical Model ◽  
Model Simulation ◽  
Cardiovascular Response ◽  
Cardiovascular Regulation ◽  
Neural System ◽  
Gas Content ◽  
Physiological Data ◽  
Specific Stimulus ◽  
Hypercapnic Hypoxia ◽  
Peripheral Chemoreflex

The effect of changes in arterial CO2tension on the cardiovascular system is analyzed by means of a mathematical model. The model is an extension of a previous one that already incorporated the main reflex and local mechanisms triggered by O2 changes. The new aspects covered by the model are the O2-CO2 interaction at the peripheral chemoreceptors, the effect of local CO2 changes on peripheral resistances, the direct central neural system (CNS) response to CO2, and the control of central chemoreceptors on ventilation and tidal volume. A statistical comparison between model simulation results and various experimental data has been performed. This comparison suggests that the model is able to simulate the acute cardiovascular response to changes in blood gas content in a variety of conditions (normoxic hypercapnia, hypercapnia during artificial ventilation, hypocapnic hypoxia, and hypercapnic hypoxia). The model ascribes the observed responses to the complex superimposition of many mechanisms simultaneously working (baroreflex, peripheral chemoreflex, CNS response, lung-stretch receptors, local gas tension effect), which may be differently activated depending on the specific stimulus under study. However, although some experiments can be reproduced using a single basal set of parameters, reproduction of other experiments requires a different combination of the mechanism strengths (particularly, a different strength of the local CO2mechanism on peripheral resistances and of the CNS response to CO2). Starting from these results, some assumptions to explain the striking differences reported in the literature are presented. The model may represent a valid support for the interpretation of physiological data on acute cardiovascular regulation and may favor the synthesis of contradictory results into a single theoretical setting.

scholarly journals Diagnostics of coupling between low-frequency loops in cardiovascular autonomic control in adults, newborns and mathematical model using cross-recurrence analysis

2019 ◽  
Vol 8 (4) ◽  
Author(s):  
Yurii M. Ishbulatov ◽  
Anton R. Kiselev ◽  
Elena N. Mureeva ◽  
Yulia V. Popova ◽  
Alexander V. Kurbako ◽  
...  
Keyword(s):  
Mathematical Model ◽  
Coupling Strength ◽  
Phase Synchronization ◽  
Low Frequency ◽  
Autonomic Control ◽  
Recurrence Analysis ◽  
Synchronization Index ◽  
Autonomic Blockade ◽  
The Mathematical Model ◽  
Newborn Children

The aim of study is to investigate effectiveness of cross-recurrence analysis for the detection of coupling between the loops of heart rate and vessel tone sympathetic control. The cross-recurrence analysis is applied to the interbeat intervals and photopletysmographic signals from the mathematical model of cardiovascular system and from adults and newborn children. The model is examined under the conditions of the four experiments: with fully operational autonomic control, autonomic control weakened by 40%, autonomic control weakened by 70% and autonomic blockade. The coupling is most pronounced in adult subjects and the model with fully operational autonomic control, while it is absent under the autonomic blockade. Autonomic control is also not fully developed in newborn children. As the result, smaller coupling strength is expected. The results of cross-recurrence analysis of the model and experimental data are compared with the results of coupling detection based on the analysos of phase synchronization. Synchronization index demonstrates good correlation with the coupling strength in the model and weak coupling in newborn children in relation to adult subjects. In both cases, no correlation is observed between the synchronization index and the results of cross-recurrence analysis.

Caffeine and Placebo Expectation

2007 ◽  
Vol 21 (2) ◽  
pp. 91-99 ◽  
Author(s):  
Yunfeng Sun ◽  
Yinling Zhang ◽  
Ning He ◽  
Xufeng Liu ◽  
Danmin Miao
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Sleep Deprivation ◽  
Cognitive Performance ◽  
Cognitive Functions ◽  
Cardiovascular Regulation ◽  
Double Blind ◽  
Positive Effects ◽  
Pressure Tests ◽  
Healthy Males

Abstract. Caffeine placebo expectation seems to improve vigilance and cognitive performance. This study investigated the effect of caffeine and placebo expectation on vigilance and cognitive performance during 28 h sleep deprivation. Ten healthy males volunteered to take part in the double-blind, cross-over study, which required participants to complete five treatment periods of 28 h separated by 1-week wash-out intervals. The treatments were no substance (Control); caffeine 200 mg at 00:00 (C200); placebo 200 mg at 00:00 (P200); twice caffeine 200 mg at 00:00 and 04:00 (C200-C200); caffeine 200 mg at 00:00 and placebo 200 mg at 04:00 (C200-P200). Participants were told that all capsules were caffeine and given information about the effects of caffeine to increase expectation. Vigilance was assessed by a three-letter cancellation test, cognitive functions by the continuous addition test and Stroop test, and cardiovascular regulation by heart rate and blood pressure. Tests were performed bihourly from 00:00 to 10:00 of the second day. Results indicated that C200-P200 and C200-C200 were more alert (p < .05) than Control and P200. Their cognitive functions were higher (p < .05) than Control and P200. Also, C200-P200 scored higher than C200 in the letter cancellation task (p < .05). No test showed any significant differences between C200-P200 and C200-C200. The results demonstrated that the combination of caffeine 200 mg and placebo 200 mg expectation exerted prolonged positive effects on vigilance and cognitive performance.

Mathematical model of hit phenomena and its application to movie advertisement

2008 ◽  
Author(s):  
Ishii Akira ◽  
Yoshida Narihiko ◽  
Hayashi Takafumi ◽  
Umemura Sanae ◽  
Nakagawa Takeshi
Keyword(s):  
Mathematical Model
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