FEATURES OF CENTRAL HEMODYNAMICS OF YOUNG ADULTS DEPENDING ON VARIATIONS OF ACTUAL HEART RATE

Author(s):  
A.P. Spitsyn ◽  
N.E. Kushkova ◽  
E.V. Kolodkina

Indicators of systemic hemodynamics were evaluated. Those were blood pressure (BP), shock volume of the blood (SVB), peripheral vascular resistance (PVR), cardiac index (CI) and others. They were evaluated in 41 students. Their age was between 21 and 26 years. It was determined that the majority of central hemodynamics indicators importantly depend on the character of differences of actual frequency of heart rates and their meanings. The most important indicators of hemodynamics such as shock volume of the blood and heart index were lower and diastolic arterial blood pressure and peripheral vascular resistance were higher in people with heart rates higher than required normal heart rates. Important peculiarities of correlative interconnections between parameters of central hemodynemics depending on heart rates were revealed. The above peculiarities of hemodynemics depending on the character of differences of actual and normal heart rates confirm the importance of evaluation and understanding of such a simple parameter.

1984 ◽  
Vol 62 (2) ◽  
pp. 137-147 ◽  
Author(s):  
John X. Wilson

The mammalian renin–angiotensin system appears to be involved in the maintenance of blood volume and pressure because (i) sodium depletion, hypovolemia, and hypotension increase renin levels, and (ii) administration of exogenous angiotensin II rapidly increases mineralocorticoid and antidiuretic hormone production, transepithelial ion transport, drinking behavior, and peripheral vascular resistance. Are these also the physiological properties of the renin–angiotensin system in nonmammalian species? Signals for altered levels of renin activity have yet to be conclusively identified in nonmammalian vertebrates, but circulating renin levels are elevated by hypotension in teleost fish and birds. Systemic injection of angiotensin II causes an increase in arterial blood pressure in all the vertebrates studied, suggesting that barostatic control is a universal function of this hormone. Angiotensin II alters vascular tone by direct action on arteriolar muscles in some species, but at concentrations of the hormone which probably are unphysiological. More generally, angiotensin II increases blood pressure indirectly, by acting on the sympathetic nervous system. Catecholamines, derived from chromaffin cells and (or) from peripheral adrenergic nerves, mediate some portion of the vasopressor response to angiotensin II in cyclostomes, elasmobranchs, teleosts, amphibians, reptiles, mammals, and birds. Alteration of sympathetic outflow is a prevalent mechanism through which the renin–angiotensin system may integrate blood volume, cardiac output, and peripheral vascular resistance to achieve control of blood pressure and adequate perfusion of tissues.


1956 ◽  
Vol 186 (3) ◽  
pp. 525-528 ◽  
Author(s):  
G. B. Spurr ◽  
Steven M. Horvath ◽  
Enid Allbaugh Farrand

Chlorpromazine in doses of 2 and 5 mg/kg has been found to produce an initial hypotension in anesthetized dogs which was followed by return of the mean arterial blood pressure to near control levels. During the next 60–65 minutes there was a secondary decline in the pressure to hypotensive levels. Both an initial and secondary hypotension were the result of a decrease in peripheral vascular resistance.


1979 ◽  
Vol 236 (4) ◽  
pp. H592-H595
Author(s):  
C. S. Liang ◽  
D. Sprecher

beta-Phenylethylamine increased mean aortic blood pressure, total peripheral vascular resistance, left ventricular dP/dt, and (dP/dt)/P in chloralose-anesthetized dogs. Pretreatment with phentolamine reduced the increases in aortic blood pressure and total peripheral vascular resistance produced by beta-phenylethylamine, whereas, the effects of beta-phenylethylamine on left ventricular dP/dt and (dP/dt)/P were abolished by propranolol. beta-Phenylethylamine pretreatment, but increased both after phentolamine pretreatment. Furthermore, both the cardiac and vascular effects of beta-phenylethylamine were abolished by desipramine. These results indicate that beta-phenylethylamine exerts both positive inotropic and vasoconstrictory effects, probably by releasing endogenous norepinephrine from the adrenergic nerve endings.


2020 ◽  
Vol 87 (1-2) ◽  
pp. 47-52
Author(s):  
K. V. Serikov ◽  
L. M. Smyrnova ◽  
O. F. Dzygal

Objective. To raise the efficacy of treatment of arterial hypertension in patients, suffering ischemic cerebral stroke of the middle grade of severity on background of determination of hemodynamic variant of arterial hypertension. Materials and methods. Prospective nonrandomized investigation concerning 42 patients, suffering ischemic cerebral stroke of middle severity in accordance to the insult severity scale of National Institute of Health (National Institutes of Health Stroke Scale - NIHSS), was conducted. The patients’ middle age have constituted (69.4 ± 1.4) yrs. There were the central hemodynamic indices measured, the arterial hypertension hemodynamic variant determined, the oxygen and hemodynamic status estimated, and in accordance to the results obtained - the differentiated antihypertensive therapy was administered. All the patients were divided into three groups, depending on hemodynamical variant of arterial hypertension: the first group – patients with eukinetic variant, the second group – patients with hypokinetic variant, the third group – patients with hyperkinetic variant. Hemodynamical variant of arterial hypertension was determined in accordance to the referent level of cardiac index. The groups were representative in accordance to age, height, the body mass, the main and concurrent pathology and the cerebral affection degree. Results. In the patients, suffering initial eukinetic hemodynamical variant of arterial hypertension, the cardiac index have fluctuated from 2.88 to 4.67 l × min-1 × m-2, general peripheral vascular resistance have rested in the norm borders, the oxygen saturation level of arterial blood did not demand the oxygen therapy, index of the oxygen delivery have exceeded the appropriate values and fluctuated in borders from 541 to 903 l × min-1 × m-2. In complex of differentiated antihypertensive therapy there was applied a constant intravenous injection of magnesium sulfate in a daily dose 2500 - 5000 mg. For patients with initial hypokinetic hemodynamic variant of arterial hypertension following signs are characteristic: low cardiac index - from 1.65 to 2.08 l × min-1 × m-2, the enhanced general peripheral vascular resistance - 2813 (from 2393 to 3403) dyne × s-1 × cm-5 and the lowered index of the oxygen delivery - from 306 to 412 l × min-1 × m-2. Differentiated antihypertensive therapy was conducted, using urapidyl: intravenous boluses 1.25 – 2.5 mg with further infusion 5 - 40 mg × h-1. For hyperkinetic hemodynamic variant of arterial hypertension the raised cardiac index is characteristic – 3.75 l × min-1 × m-2 (fluctuated in borders from 3.62 to 4.10 l × min-1 × m-2), as well as normal general peripheral vascular resistance - 1189 (from 1055 to 1449) dyne × s-1 × cm-5 and raised index of the oxygen delivery - 762 (from 725 to 828) l × min-1 × m-2. Differentiated antihypertensive therapy was conducted, using labetalol: intravenous infusion with velocity 2 - 8 mg × min-1. Conclusion. In the patients with ischemic cerebral stroke of the middle grade of severity the conduction of differentiated antihypertensive therapy, taking into account hemodynamic type of arterial hypertension and the oxygen-hemodynamic stabilization of the blood circulation system, improved the results of treatment and accelerated the rehabilitation duration.


2020 ◽  
Vol 128 (5) ◽  
pp. 1310-1320
Author(s):  
J. Krohova ◽  
L. Faes ◽  
B. Czippelova ◽  
R. Pernice ◽  
Z. Turianikova ◽  
...  

Baroreflex response consists of several arms, but the cardiac chronotropic arm (blood pressure changes evoking heart rate response) is usually analyzed. This study introduces a method to assess the vascular baroreflex arm with the continuous noninvasive measurement of peripheral vascular resistance as an output considering causality in the interaction between oscillations and slower dynamics of vascular tone changes. We conclude that although vascular baroreflex arm involvement becomes dominant during orthostasis, gain of this interaction is relatively stable.


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