Haemodynamks of Recovery after Strenuous Exercise in Physically Trained Hypertensive and Normotensive Subjects

1994 ◽  
Vol 86 (1) ◽  
pp. 27-34 ◽  
Author(s):  
Edoardo Casiglia ◽  
Paolo Palatini ◽  
Stefano Bongiovi ◽  
Luca Mario ◽  
Giovanna Colangeli ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Cardiac Output ◽  
Anaerobic Threshold ◽  
Recovery Period ◽  
Peripheral Resistance ◽  
Left Ventricular ◽  
Mean Blood Pressure ◽  
Left Ventricular Ejection ◽  
Arterial Blood ◽  
Normotensive Subjects

1. Central and peripheral post-exercise haemo-dynamics were studied in 18 physically trained male subjects (10 hypertensive and eight normotensive) engaging in sports activities for 3–5 h/week. After a preliminary multistage bicycle ergometric test to evaluate their maximal oxygen consumption and anaerobic threshold, they underwent prolonged exercise at anaerobic threshold in the semi-supine position at 30% grade until exhaustion (mean duration 60.0 + 16.7 min in the normotensive subjects and 61.0 + 5.7 min in the hypertensive subjects, not significant). During the recovery time, intra-arterial blood pressure, echocardiographic cardiac output and indium-gallium strain-gauge plethysmographc peripheral flow were measured, and total, forearm and leg peripheral resistances were calculated respectively from mean blood pressure/cardiac output and mean blood pressure/peripheral resistance. 2. Systolic blood pressure was decreased during the entire recovery period in comparison with the baseline values (−8.4 mmHg, −43.8 mmHg and −39.7 mmHg at the 1st, 5th and 10th min in the hypertensive subjects, P = 0.001, P = 0.0001 and P = 0.0001 respectively; −18.8, −25.5 and −24.1 mmHg in the normotensive subjects, not significant, P = 0.01 and P = 0.01, respectively) without any significant difference between the two groups, whereas the reduction in diastolic blood pressure was not statistically significant. Peripheral flow increased and peripheral resistance decreased in parallel in the forearm and the leg and showed similar trends in the hypertensive subjects and the normotensive subjects. The increase in cardiac output and left ventricular ejection fraction and the decrease in total resistance were also similar in the two groups. 3. In conclusion, after long-lasting strenuous leg exercise central and peripheral haemodynamics vary to the same degree in hypertensive and normotensive trained subjects. Peripheral haemodynamics (similar in the leg and the arm in both groups) closely reflect systemic haemodynamics. The blood pressure reduction observed in the recovery period is totally due to the fall in systemic vascular resistance, while cardiac output is increased.

Comparison of cardiovascular response to passive tilt in young and elderly men

1988 ◽  
Vol 66 (11) ◽  
pp. 1425-1432 ◽  
Author(s):  
D. A. Cunningham ◽  
R. J. Petrella ◽  
D. H. Paterson ◽  
P. M. Nichol
Keyword(s):  
Blood Pressure ◽  
Cardiac Output ◽  
Cardiovascular Response ◽  
Peripheral Resistance ◽  
Cardiovascular Responses ◽  
Left Ventricular ◽  
Age Effects ◽  
Hemodynamic Responses ◽  
Arterial Blood ◽  
Postural Changes

To test the hypothesis that altered hemodynamic responses to postural changes are associated with aging, cardiovascular responses to head-up tilt (HUT) and head-down tilt (HDT) were examined in 12 healthy young (average age, 24.6 ± 1.7 years) and 12 healthy elderly (average age, 68.6 ± 2.2 years) men. Subjects were passively tilted from supine to 30°, 60°, and 90° HUT and HDT. Responses to these perturbations were determined 5 min after tilting with measures of heart rate (HR), blood pressure (SBP, DBP), and echocardiographically determined left ventricular diameter in systole and diastole (LVIDs, LVIDd). In HUT there were no significant age effects. In both young and elderly, SBP decreased significantly (p < 0.05), and DBP and HR increased significantly. Ejection fraction (EF), mean arterial blood pressure (MABP), and rate-pressure product (RPP) were unchanged in both groups. In HDT, the hemodynamic responses of the young and elderly were in opposite directions and significant age effects were found for SBP, DBP, HR, LVIDs, EF, MABP, and RPP. In HDT, the young appear to increase cardiac output primarily due to an increase in EF and end-diastolic volume (LVIDd), while HR is unchanged and SBP is decreased. MABP is unchanged, suggesting a small decrease in total peripheral resistance. The elderly may increase cardiac output slightly, owing to an increase in LVIDd with no change in EF, and a large increase in HR. Afterload increased markedly, therefore attenuating any increase in cardiac output. These results suggest that in healthy men, the cardiovascular response to HUT is not age related, while conversely there appear to be significant differences between young and elderly in response to HDT.

Role of vasopressin in acutely altered baroreflex sensitivity during hemorrhage in rats

1991 ◽  
Vol 261 (3) ◽  
pp. R677-R685 ◽  
Author(s):  
B. L. Brizzee ◽  
R. D. Russ ◽  
B. R. Walker
Keyword(s):  
Blood Pressure ◽  
Cardiac Output ◽  
Blood Loss ◽  
Baroreflex Sensitivity ◽  
Peripheral Resistance ◽  
Conscious Rat ◽  
Arterial Blood ◽  
Arterial Hemorrhage ◽  
Moderate Elevation

Experiments were performed to examine the potential role of circulating arginine vasopressin (AVP) on baroreflex sensitivity during hypotensive and nonhypotensive hemorrhage in the conscious rat. Animals were chronically instrumented for measurement of cardiac output, blood pressure, and heart rate (HR). Three potential stimuli for release of AVP were utilized: 1) rapid 20% arterial hemorrhage that resulted in hypotension, 2) nonhypovolemic hypotension induced by intravenous infusion of nitroprusside, and 3) nonhypotensive hemorrhage (rapid 10% arterial blood withdrawal). Hypotensive hemorrhage was associated with significant reductions in blood pressure, cardiac output, HR, and calculated total peripheral resistance, an increase in baroreflex (BRR) bradycardia in response to pressor infusions of phenylephrine, and a moderate elevation in circulating AVP. Prior intravenous administration of a specific V1-vasopressinergic antagonist augmented the hypotensive response to hemorrhage; however, neither V1- nor V2-blockade affected hemorrhage-induced augmentation of the BRR. Inducement of hypotension by infusion of nitroprusside did not alter subsequent BRR sensitivity. Finally, nonhypotensive hemorrhage was associated with an increase in resting HR and augmented BRR sensitivity. However, in contrast to hypotensive hemorrhage, either V1- or V2-antagonism attenuated the increase in BRR sensitivity seen with 10% hemorrhage. These data suggest that, although AVP may play a role in blood pressure maintenance via its direct vasoconstrictor actions during hypotensive hemorrhage, the observed augmentation of BRR sensitivity associated with severe blood loss is not attributable to a vasopressinergic mechanism activated by circulating AVP. However, blood-borne AVP may contribute to BRR sensitivity alterations in response to mild blood loss.

L-propionylcarnitine increases postischemic blood flow but does not affect recovery of energy charge

1991 ◽  
Vol 261 (1) ◽  
pp. H172-H180 ◽  
Author(s):  
L. M. Sassen ◽  
K. Bezstarosti ◽  
W. J. Van der Giessen ◽  
J. M. Lamers ◽  
P. D. Verdouw
Keyword(s):  
Blood Pressure ◽  
Blood Flow ◽  
Cardiac Output ◽  
Systemic Vascular Resistance ◽  
Arterial Blood Pressure ◽  
Vascular Resistance ◽  
Contractile Function ◽  
Energy Charge ◽  
Left Ventricular ◽  
Arterial Blood

Effects of pretreatment with L-propionylcarnitine (50 mg/kg, n = 9) or saline (n = 10) were studied in open-chest anesthetized pigs, in which ischemia was induced by decreasing left anterior descending coronary artery blood flow to 20% of baseline. After 60 min of ischemia, myocardium was reperfused for 2 h. In both groups, flow reduction abolished contractile function of the affected myocardium and caused similar decreases in ATP (by 55%) and energy charge [(ATP + 0.5ADP)/(ATP + ADP + AMP); decrease from 0.91 to 0.60], mean arterial blood pressure (by 10-24%), the maximum rate of rise in left ventricular pressure (by 26-32%), and cardiac output (by 20-30%). During reperfusion, “no-reflow” was attenuated by L-propionylcarnitine, because myocardial blood flow returned to 61 and 82% of baseline in the saline- and L-propionylcarnitine-treated animals, respectively. Cardiac output of the saline-treated animals further decreased (to 52% of baseline), and systemic vascular resistance increased from 46 +/- 3 to 61 +/- 9 mmHg.min.l-1, thereby maintaining arterial blood pressure. In L-propionylcarnitine-treated pigs, cardiac output remained at 75% of baseline, and systemic vascular resistance decreased from 42 +/- 3 to 38 +/- 4 mmHg.min.l-1. In both groups, energy charge but not the ATP level of the ischemic-reperfused myocardium tended to recover, whereas the creatine phosphate level showed significantly more recovery in saline-treated animals. We conclude that L-propionylcarnitine partially preserved vascular patency in ischemic-reperfused porcine myocardium but had no immediate effect on “myocardial stunning.” Potential markers for long-term recovery were not affected by L-propionylcarnitine.

Effect of sympathetic blockade on diurnal variation of hemodynamic patterns

1989 ◽  
Vol 256 (3) ◽  
pp. R778-R785 ◽  
Author(s):  
M. I. Talan ◽  
B. T. Engel
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Cardiac Output ◽  
Stroke Volume ◽  
Total Peripheral Resistance ◽  
Peripheral Resistance ◽  
Base Line ◽  
Sympathetic Blockade ◽  
Selective Blockade ◽  
Arterial Blood

Heart rate, stroke volume, and intra-arterial blood pressure were monitored continuously in each of four monkeys, 18 consecutive h/day for several weeks. The mean heart rate, stroke volume, cardiac output, systolic and diastolic blood pressure, and total peripheral resistance were calculated for each minute and reduced to hourly means. After base-line data were collected for approximately 20 days, observation was continued for equal periods of time under conditions of alpha-sympathetic blockade, beta-sympathetic blockade, and double sympathetic blockade. This was achieved by intra-arterial infusion of prazosin, atenolol, or a combination of both in concentration sufficient for at least 75% reduction of response to injection of agonists. The results confirmed previous findings of a diurnal pattern characterized by a fall in cardiac output and a rise in total peripheral resistance throughout the night. This pattern was not eliminated by selective blockade, of alpha- or beta-sympathetic receptors or by double sympathetic blockade; in fact, it was exacerbated by sympathetic blockade, indicating that the sympathetic nervous system attenuates these events. Because these findings indicate that blood volume redistribution is probably not the mechanism mediating the observed effects, we have hypothesized that a diurnal loss in plasma volume may mediate the fall in cardiac output and that the rise in total peripheral resistance reflects a homeostatic regulation of arterial pressure.

Effects of isoproterenol on the cardiovascular system of fetal sheep exposed to long-term high-altitude hypoxemia

1995 ◽  
Vol 78 (5) ◽  
pp. 1793-1799 ◽  
Author(s):  
M. Kamitomo ◽  
T. Ohtsuka ◽  
R. D. Gilbert
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Cardiac Output ◽  
Right Ventricular ◽  
High Altitude ◽  
Arterial Blood Pressure ◽  
Left Ventricular ◽  
Arterial Blood ◽  
Isoproterenol Infusion

We exposed fetuses to high-altitude (3,820 m) hypoxemia from 30 to 130 days gestation, when we measured fetal heart rate, right and left ventricular outputs with electromagnetic flow probes, and arterial blood pressure during an isoproterenol dose-response infusion. We also measured the distribution of cardiac output with radiolabeled microspheres during the maximal isoproterenol dose. Baseline fetal arterial blood pressure was higher in long-term hypoxemic fetuses (50.1 +/- 1.3 vs. 43.4 +/- 1.0 mmHg) but fell during the isoproterenol infusion to 41.3 +/- 1.4 and 37.5 +/- 1.4 mmHg, respectively, at the highest dose. Heart rate was the same in both groups and did not differ during isoproterenol infusion. Baseline fetal cardiac output was lower in the hypoxemic group (339 +/- 18 vs. 436 +/- 19 ml.min-1.kg-1) due mainly to a reduction in right ventricular output. During the isoproterenol infusion, right ventricular output increased to the same extent in both hypoxemic and normoxic fetuses (approximately 35%); however, left ventricular output increased only approximately 15% in the hypoxemic group compared with approximately 40% in the normoxic group. The percent change in individual organ blood flows during isoproterenol infusion in the hypoxemic groups was not significantly different from the normoxic group. All of the mechanisms that might be responsible for the differential response of the fetal left and right ventricles to long-term hypoxia are not understood and need further exploration.

Carotid baroreceptor control of liver and spleen volume in cats

1991 ◽  
Vol 260 (1) ◽  
pp. H254-H259
Author(s):  
R. Maass-Moreno ◽  
C. F. Rothe
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Cardiac Output ◽  
Arterial Blood Pressure ◽  
Total Peripheral Resistance ◽  
Venous Pressure ◽  
Peripheral Resistance ◽  
Normal Brain ◽  
Spleen Volume ◽  
Arterial Blood

We tested the hypothesis that the blood volumes of the spleen and liver of cats are reflexly controlled by the carotid sinus (CS) baroreceptors. In pentobarbital-anesthetized cats the CS area was isolated and perfused so that intracarotid pressure (Pcs) could be controlled while maintaining a normal brain blood perfusion. The volume changes of the liver and spleen were estimated by measuring their thickness using ultrasonic techniques. Cardiac output, systemic arterial blood pressure (Psa), central venous pressure, central blood volume, total peripheral resistance, and heart rate were also measured. In vagotomized cats, increasing Pcs by 100 mmHg caused a significant reduction in Psa (-67.8%), cardiac output (-26.6%), total peripheral resistance (-49.5%), and heart rate (-15%) and significantly increased spleen volume (9.7%, corresponding to a 2.1 +/- 0.5 mm increase in thickness). The liver volume decreased, but only by 1.6% (0.6 +/- 0.2 mm decrease in thickness), a change opposite that observed in the spleen. The changes in cardiovascular variables and in spleen volume suggest that the animals had functioning reflexes. These results indicate that in pentobarbital-anesthetized cats the carotid baroreceptors affect the volume of the spleen but not the liver and suggest that, although the spleen has an active role in the control of arterial blood pressure in the cat, the liver does not.

Circulatory effects of acute or chronic endotoxemia in rats

1981 ◽  
Vol 59 (2) ◽  
pp. 204-208 ◽  
Author(s):  
R. Keeler ◽  
Anamaria Barrientos ◽  
K. Lee
Keyword(s):  
Escherichia Coli ◽  
Blood Pressure ◽  
Blood Flow ◽  
Cardiac Output ◽  
Gastrointestinal Tract ◽  
Peripheral Resistance ◽  
Circulatory Effects ◽  
Arterial Blood ◽  
Flow Changes ◽  
Fractional Distribution

A study was made of the effects of acute (4 h) or chronic (4 days) infusion of Escherichia coli endotoxin on cardiovascular function in rats. Rats with acute endotoxemia had a reduced cardiac output but maintained their arterial blood pressure. Fractional distribution of the cardiac output was increased to the liver and reduced to the gastrointestinal tract and skin. No changes in fractional distribution to the kidneys, lungs, or heart were observed although absolute blood flow to these areas was reduced.Rats with chronic endotoxemia had a reduced cardiac output and hypotension with no change in peripheral resistance. Other changes resembled those seen in acute endotoxemia apart from a low renal fraction of the cardiac output. Calculation and interpretation of blood flow changes in these animals was difficult because of a large fall in hematocrit and changes in organ weight.

Cardiac Output by the Dye Dilution Technique Under Thiopental Sodium-Oxygen and Ether Anesthesia

1956 ◽  
Vol 186 (1) ◽  
pp. 101-104 ◽  
Author(s):  
Esther M. Greisheimer ◽  
Dorothy W. Ellis ◽  
George Stewart ◽  
Lydia Makarenko ◽  
Nadia Oleksyshyn ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Cardiac Output ◽  
Arterial Blood Pressure ◽  
Total Peripheral Resistance ◽  
Peripheral Resistance ◽  
Stroke Index ◽  
Ether Anesthesia ◽  
Dye Dilution ◽  
Arterial Blood ◽  
Thiopental Sodium

One hundred-twenty determinations of cardiac output by the dye dilution technic utilizing the cuvette oximeter were made on 20 dogs. Of these, 60 were done under thiopental sodium-oxygen analgesia and 60 were done after supplementing with ether. Arterial blood pressure was recorded by strain gauge. Electrocardiograms were taken periodically. Concentrations of thiopental and ether in arterial blood were determined. Cardiac output began to increase under thiopental analgesia and continued to increase when ether was administered. Arterial blood pressure and heart rate decreased slightly when ether was administered. Stroke index increased when ether was administered. Total peripheral resistance decreased markedly under thiopental analgesia, and continued to decrease when ether was administered. When compared with an earlier study in which cyclopropane was used as the supplementing agent, it was found that cyclopropane and ether exert opposite effects on cardiac output and peripheral resistance despite the fact that the effect on arterial blood pressure is similar under the two agents. Increase in cardiac output was found to be parallel with decrease in total peripheral resistance in this study. Amount of dye injected did not influence cardiac output. Under the conditions of this study, cardiac output was in no way dependent on the concentration of thiopental in the blood nor on the amount injected. Level of ether in the blood did not show much effect, if any, on cardiac output. It is probable that the changes observed in this study are comparable with those which obtain clinically when thiopental-oxygen analgesia is supplemented with ether. Systolic blood pressure is not an infallible guide to other cardiovascular functions since it may remain fairly steady while cardiac output and peripheral resistance undergo marked changes under anesthesia.

scholarly journals Continuous cardiac output monitoring in humans by invasive and noninvasive peripheral blood pressure waveform analysis

2006 ◽  
Vol 101 (2) ◽  
pp. 598-608 ◽  
Author(s):  
Zhenwei Lu ◽  
Ramakrishna Mukkamala
Keyword(s):  
Blood Pressure ◽  
Cardiac Output ◽  
Peripheral Resistance ◽  
Waveform Analysis ◽  
Cardiac Output Monitoring ◽  
Time Interval ◽  
Data Sets ◽  
Data Set ◽  
Arterial Blood ◽  
Output Monitoring

We present an evaluation of a novel technique for continuous (i.e., automatic) monitoring of relative cardiac output (CO) changes by long time interval analysis of a peripheral arterial blood pressure (ABP) waveform in humans. We specifically tested the mathematical analysis technique based on existing invasive and noninvasive hemodynamic data sets. With the former data set, we compared the application of the technique to peripheral ABP waveforms obtained via radial artery catheterization with simultaneous thermodilution CO measurements in 15 intensive care unit patients in which CO was changing because of disease progression and therapy. With the latter data set, we compared the application of the technique to noninvasive peripheral ABP waveforms obtained via a finger-cuff photoplethysmography system with simultaneous Doppler ultrasound CO measurements made by an expert in 10 healthy subjects during pharmacological and postural interventions. We report an overall CO root-mean-squared normalized error of 15.3% with respect to the invasive hemodynamic data set and 15.1% with respect to the noninvasive hemodynamic data set. Moreover, the CO errors from the invasive and noninvasive hemodynamic data sets were only mildly correlated with mean ABP (ρ = 0.41, 0.37) and even less correlated with CO (ρ = −0.14, −0.17), heart rate (ρ = 0.04, 0.19), total peripheral resistance (ρ = 0.38, 0.10), CO changes (ρ = −0.26, −0.20), and absolute CO changes (ρ = 0.03, 0.38). With further development and successful prospective testing, the technique may potentially be employed for continuous hemodynamic monitoring in the acute setting such as critical care and emergency care.

scholarly journals Heritability of Hemodynamic Reactivity to Laboratory Stressors in a Homogenous Arab Population: ‘Oman Family Study’

2009 ◽  
Vol 12 (6) ◽  
pp. 541-548 ◽  
Author(s):  
Mohammed O. Hassan ◽  
Riad A. Bayoumi ◽  
Juan C. Lopez-Alvarenga ◽  
Harold Snieder ◽  
Deepali Jaju ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Cardiovascular Reactivity ◽  
Acute Stress ◽  
Univariate Analysis ◽  
Peripheral Resistance ◽  
Left Ventricular ◽  
Left Ventricular Ejection ◽  
Arab Population ◽  
Heritability Estimates ◽  
Ventricular Ejection Time

AbstractBackground:Exaggerated cardiovascular reactivity to stressful stimuli may be a risk factor for the development of hypertension. The genetic influence on blood pressure (BP) reactivity to stress and its control mechanisms has been receiving considerable support. This study aims at examining the heritability of BP and its intermediate hemodynamic phenotypes to acute stress in a homogeneous Arab population.Methods:Parameters were computed from continuous BP, electrocardiography and impedance cardiography measurements, during rest, word conflict (WCT) and cold pressor (CPT) tests. Heritability estimates (h2) were obtained using the variance components-based approach implemented in the SOLAR software package.Results:Reactivity scores for WCT and CPT increased significantly (P< .05) for systolic (SBP), diastolic (DBP), heart rate (HR), cardiac output (CO), and total peripheral resistance (TPR). They decreased significantly (P< .05) for stroke volume (SV), left ventricular ejection time (LVET), end diastolic (EDI) and cardiac contractility (IC) indices. Univariate analysis detected heritability estimates that ranged from 0.19–0.35 for rest, 0.002–0.40 for WCT and 0.08–0.35 for CPT.Conclusion:In this unique cohort, resting as well as challenged cardiovascular phenotypes are significantly influenced by additive genetic effects. Heritability estimates for resting phenotypes are in a relatively narrow range, while h2for their reactivity is somewhat broader with lower estimates. Further analyses of this study may offer important opportunities for gene finding in hypertension.What is Known About the Topic:(1) cardiovascular reactivity to stress predicts cardiovascular disease; (2) genetic susceptibility plays an important role in stress reactivity. Family studies using the cold pressure test reported significant heritability for blood pressure.What this Study Adds:(1) this cohort is from five highly consanguineous isolated Arab pedigrees with genetically verified genealogical records and environmental homogeneity; (2) This is the first study to estimate heritability of detailed intermediate hemodynamic phenotypes that make up normal blood pressure.

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