Arterial distensibility: acute changes following dynamic  exercise in normal subjects

The time course of acute changes in large artery distensibility immediately and for 60 min following maximum treadmill exercise in normal subjects was characterized by simultaneously measuring upper and lower limb pulse wave velocity (PWV). A new oscillometric technique was used, which has proven to be sensitive to changes in distensibility induced by acute changes in vascular tone independently of blood pressure. The observed changes in PWV are attributable to changes in vascular tone corresponding to recovery from a systemic net constrictor response and a local net dilator response to exercise with persisting postexercise vasodilatation. They are inadequately explained by associated changes in blood pressure and cannot be attributed to changes in heart rate or viscosity. Modeled as a system of n coupled linear differential equations, the minimum (and adequate) order required to reproduce these patterns was n = 1 for the upper and n = 2 for the exercising lower limb. The economy of the solution suggests entrainment among the multiple interactive mechanisms governing vasomotor control.

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Arterial Distensibility in Normal and Hypertensive Man

Clinical Science ◽

10.1042/cs0560413 ◽

1979 ◽

Vol 56 (5) ◽

pp. 413-417 ◽

Cited By ~ 93

Author(s):

B. Gribbin ◽

T. G. Pickering ◽

P. Sleight

Keyword(s):

Blood Pressure ◽

Pulse Wave Velocity ◽

Wave Velocity ◽

Radial Artery ◽

Structural Changes ◽

Arterial Wall ◽

Pulse Wave ◽

Normal Subjects ◽

Arterial Distensibility ◽

Resting Blood Pressure

1. The pulse-wave velocity along the brachial radial artery was measured in 38 subjects and volume distensibility values were calculated. 2. Measurements made at each subject's resting blood pressure showed that those with high blood pressure had higher pulse-wave velocity values and hence less distensible arteries. 3. An acute rise in arterial distending pressure was accompanied by a rise in pulse-wave velocity. 4. When pulse-wave velocity was remeasured in all subjects at identical arterial distending pressures, no difference was found between hypertensive and normal subjects. 5. It appears that poor distensibility of large arteries in hypertensive subjects is a consequence of the elevated distending pressures and not due to irreversible structural changes in the arterial wall.

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A Comparison of the Bronchodilator and Vasopressor Effects of Exercise Levels of Adrenaline in Man

Clinical Science ◽

10.1042/cs0640475 ◽

1983 ◽

Vol 64 (5) ◽

pp. 475-479 ◽

Cited By ~ 40

Author(s):

J. B. Warren ◽

N. Dalton

Keyword(s):

Blood Pressure ◽

Heart Rate ◽

Plasma Glucose ◽

Exercise Test ◽

Cardiovascular Response ◽

Normal Subjects ◽

Significant Rise ◽

Cardiovascular Physiology ◽

Plasma Adrenaline ◽

Response To Exercise

1. Plasma adrenaline was measured at rest and on exercise in six normal, non-atopic subjects. The exercise test produced a minimum tachycardia of 158 beats/min and a mean plasma adrenaline level of 1.89 nmol/l. 2. On a separate occasion, two doses of l-adrenaline (0.025 μg min−1 kg−1 and 0.05 μg min−1 kg−1) were infused in the same subjects at rest to produce two mean plasma levels similar to those found on exercise. 3. Significant bronchodilation and elevation of plasma glucose occurred with both infusion doses when compared with placebo. 4. Neither infusion caused a significant change in heart rate and only the higher dose caused a small but significant rise in systolic and fall in diastolic blood pressure. 5. Our results suggest that adrenaline as a hormone, at the levels found on exercise, is capable of causing bronchodilation and glycogenolysis in normal subjects. Its contribution to the cardiovascular response to exercise appears to be slight and suggests that its role in cardiovascular physiology may also be marginal.

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Haemodynamic characteristics and blood pressure evolution of hypertension subtypes in young to middle age adults

European Heart Journal ◽

10.1093/ehjci/ehaa946.2734 ◽

2020 ◽

Vol 41 (Supplement_2) ◽

Author(s):

F Saladini ◽

C Fania ◽

L Mos ◽

A Mazzer ◽

O Vriz ◽

...

Keyword(s):

Blood Pressure ◽

Heart Rate ◽

Cardiac Output ◽

Time Course ◽

Prognostic Significance ◽

White Coat ◽

Large Artery ◽

Metabolic Characteristics ◽

White Coat Effect

Abstract Aim The prognostic significance of different hypertension subtypes in young hypertensives, in particular of isolated systolic hypertensives (ISHs) is still debated. The aim of the present study was to investigate clinical and haemodynamic characteristics and blood pressure (BP) evolution of different hypertension subtypes in young stage I hypertensives. Methods We investigated 1206 young subjects from the HARVEST study: 81 normotensives (NTs), 146 ISHs, 281 isolated diastolic hypertensives (IDHs) and 698 systolic-diastolic hypertensives (SDHs) according to office BP values at baseline. Data on baseline haemodynamic and metabolic characteristics, BP and heart rate changes during follow-up (mean 7 years) were collected. ANCOVA analysis was used for all comparisons adjusting for age and sex. Results Males were more frequent among ISHs (90.4%) compared to other categories (70.4, 67.3, 71.5% among NTs, IDHs, SHDs). Moreover, ISHs were younger compared to the others (25.6±6.6 years, p<0.001) and thinner compared to SDHs (24.6±.2.6 vs 25.8±3.6 kg/m2, p=0.028). Heart rate was higher among ISHs (75.7±9.4 bpm) and SDHs (75.8±9.7) compared to other categories (p<0.001). Metabolic characteristics were not significantly different among groups. ISHs were more active in sports (55.5%) and drank less alcohol compared to others (p<0.001, p=0.05 respectively). Systolic white coat effect was higher among ISH (17.6±12.4 mmHg) compared to others (p<0.001), as was cardiac output ISH (6.3±1.2 ml/min) compared to NTs and IDHs (p<0.001); Peripheral resistances were similar in ISHs and NTs and were lower than in IDHs and SDHs (p<0.001). Small and large artery compliance was higher, central systolic BP and augmentation index were lower among NTs and ISHs compared to IDHs and SDHs, even if these differences were not statistically significant. During follow-up systolic BP decreased (−7.6±14.4 mmHg) among ISHs, while it increased among NTs and IDHs (p<0.001). Heart rate decreased in all categories but to a higher extent among ISHs (−3.8±10.9 bpm) and SDHs (−3.4±10.8 bpm) (p=0.002 vs others). Changes in diastolic BP were similar among ISHs and NTs and higher than those observed among IDHs and SDHs (p<0.001). The percent of patients who started pharmacological treatment during follow-up was 70.6% among SDHs, 54.1% among IDHs, 41.1% among ISHs, and 39.5% among NTs (p<0.001). Conclusions ISHs had increased cardiac output and white coat effect and lower peripheral resistances compared to other hypertension subtypes while distensibility parameters did not differ significantly among groups. The percent of patients who developed hypertension needing treatment was lower among ISHs than other hypertensives. This was due to a favourable time course of BP during follow-up. Longer follow-ups are needed to confirm the lower risk profile of ISH of the young Funding Acknowledgement Type of funding source: None

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Patterns of Cerebral Blood Flow and Systemic Hemodynamics During Arithmetic Processing

Journal of Psychophysiology ◽

10.1027/0269-8803.22.2.81 ◽

2008 ◽

Vol 22 (2) ◽

pp. 81-90 ◽

Cited By ~ 21

Author(s):

Natalie Werner ◽

Neval Kapan ◽

Gustavo A. Reyes del Paso

Keyword(s):

Blood Pressure ◽

Blood Flow ◽

Cerebral Blood Flow ◽

Time Course ◽

Doppler Sonography ◽

Transcranial Doppler Sonography ◽

Systemic Hemodynamics ◽

Heart Period ◽

Blood Flow Velocities ◽

Flow Velocities

The present study explored modulations in cerebral blood flow and systemic hemodynamics during the execution of a mental calculation task in 41 healthy subjects. Time course and lateralization of blood flow velocities in the medial cerebral arteries of both hemispheres were assessed using functional transcranial Doppler sonography. Indices of systemic hemodynamics were obtained using continuous blood pressure recordings. Doppler sonography revealed a biphasic left dominant rise in cerebral blood flow velocities during task execution. Systemic blood pressure increased, whereas heart period, heart period variability, and baroreflex sensitivity declined. Blood pressure and heart period proved predictive of the magnitude of the cerebral blood flow response, particularly of its initial component. Various physiological mechanisms may be assumed to be involved in cardiovascular adjustment to cognitive demands. While specific contributions of the sympathetic and parasympathetic systems may account for the observed pattern of systemic hemodynamics, flow metabolism coupling, fast neurogenic vasodilation, and cerebral autoregulation may be involved in mediating cerebral blood flow modulations. Furthermore, during conditions of high cardiovascular reactivity, systemic hemodynamic changes exert a marked influence on cerebral blood perfusion.

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Heart Rate Signal Decomposition

Methods of Information in Medicine ◽

10.1055/s-0038-1634264 ◽

2000 ◽

Vol 39 (02) ◽

pp. 200-203

Author(s):

H. Mizuta ◽

K. Yana

Keyword(s):

Blood Pressure ◽

Heart Rate ◽

Pressure Change ◽

Normal Subjects ◽

Signal Decomposition ◽

Large Individual ◽

Heart Rate Fluctuations ◽

Type Pattern ◽

Signal Cancellation ◽

Pressure Changes

Abstract:This paper proposes a method for decomposing heart rate fluctuations into background, respiratory and blood pressure oriented fluctuations. A signal cancellation scheme using the adaptive RLS algorithm has been introduced for canceling respiration and blood pressure oriented changes in the heart rate fluctuations. The computer simulation confirmed the validity of the proposed method. Then, heart rate fluctuations, instantaneous lung volume and blood pressure changes are simultaneously recorded from eight normal subjects aged 20-24 years. It was shown that after signal decomposition, the power spectrum of the heart rate showed a consistent monotonic 1/fa type pattern. The proposed method enables a clear interpretation of heart rate spectrum removing uncertain large individual variations due to the respiration and blood pressure change.

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Desmopressin Stimulates Parallel Norepinephrine and Tissue Plasminogen Activator Release in Normal Subjects and Patients with Diabetes Mellitus

Thrombosis and Haemostasis ◽

10.1055/s-0038-1642768 ◽

1988 ◽

Vol 59 (02) ◽

pp. 269-272 ◽

Cited By ~ 13

Author(s):

M B Grant ◽

C Guay ◽

R Lottenberg

Keyword(s):

Diabetes Mellitus ◽

Plasminogen Activator ◽

Tissue Plasminogen Activator ◽

Time Course ◽

Vascular Endothelial Cells ◽

Normal Subjects ◽

Plasma Norepinephrine ◽

Endogenous Catecholamine ◽

Tissue Plasminogen ◽

Patients With Diabetes

SummaryDesmopressin acetate administration markedly stimulates release of tissue plasminogen activator (t-PA) from vascular endothelial cells. The mechanism for this effect is unknown. Because infusion of epinephrine has been shown to increase t-PA levels, we examined the role of endogenous catecholamine mediation of t-PA release by desmopressin. Intravenous desmopressin acetate (0.3 μg/kg) was infused over 30 min in 9 controls and 11 subjects with diabetes mellitus, a condition associated with abnormalities of the fibrinolytic system. Plasma was collected in the supine, overnight fasted state at 15 min intervals (0-60 min) for measurement of t-PA activity, t-PA antigen and fractionated catecholamines. t-PA activity peaked at 30-45 min and subsequently decreased. The norepinephrine levels paralleled the t-PA activity. t-PA activity increased 10-fold from 0.14 ± .12 to 1.49 ± 0.79 IU/ml (Mean ± SD) and plasma norepinephrine increased 2- fold from 426 ± 90 to 780 ± 292 pg/ml. However, epinephrine and dopamine levels did not change significantly. The response to desmopressin of control and diabetic subjects was not shown to differ and their data were combined. We conclude that desmopressin increases plasma norepinephrine in addition to t-PA and that the parallel time course of change suggests a possible role for norepinephrine in mediating endothelial cell t-PA release.

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EARLY VARIATIONS OF PLASMA CORTISOL AFTER PULSE INTRAVENOUS INJECTION OF DIBUTYRYL CYCLIC ADENOSINE 3′,5′-MONOPHOSPHATE IN NORMAL SUBJECTS

Acta Endocrinologica ◽

10.1530/acta.0.0720753 ◽

1973 ◽

Vol 72 (4) ◽

pp. 753-761 ◽

Cited By ~ 3

Author(s):

Alberto Angeli ◽

Giuseppe Boccuzzi ◽

Roberto Frajria ◽

Daniela Bisbocci ◽

Franco Ceresa

Keyword(s):

Intravenous Injection ◽

Plasma Cortisol ◽

Time Course ◽

Healthy Adult ◽

Normal Subjects ◽

Adult Women ◽

Healthy Women ◽

Adrenal Steroidogenesis ◽

The Mean ◽

Zero Time

ABSTRACT 10 mg/kg of dibutyryl cyclic adenosine 3′,5′-monophosphate (Db-cAMP) was iv pulse injected into twelve healthy adult women. The plasma cortisol levels were determined as 11-OHCS at zero time and then at 2.5, 5, 7.5, 10, 15, 30, 60 and 180 min after the injection. The data were compared with those obtained at the corresponding times in two groups of eleven and seventeen healthy women after the injection of 250 ng and 250 μg of synthetic β-1-24 corticotrophin performed in the same manner as the injection of the nucleotide. The mean increments in plasma cortisol were significantly lower after Db-cAMP than after ACTH. Differences were noted by analyzing the time course of the responses. In the case of stimulation with Db-cAMP the 11-OHCS levels rose progressively to a maximum at 15–30 min. By contrast, a peak of plasma cortisol was evident in most cases within a few min after the injection of ACTH; after a fall, a later rise was then observed starting from 15 min. The differences in the plasma 11-OHCS responses after the two stimuli may also be of interest clinically for the investigation of some aspects of adrenal steroidogenesis.

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