Comparison of baroreflex sensitivity with a fall and rise in blood pressure induced by the Valsalva manoeuvre

The baroreflexes are essential in maintaining standing blood pressure. In the present study, we describe and validate an accurate and relatively simple method of evaluating baroreflexes in the clinical laboratory using heart period responses to both a rise and fall in blood pressure.

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Evaluation of Adrenergic Function

Clinical Neurophysiology ◽

10.1093/med/9780190259631.003.0037 ◽

2016 ◽

pp. 635-642

Author(s):

Phillip A. Low

Keyword(s):

Blood Pressure ◽

Recovery Time ◽

Baroreflex Sensitivity ◽

Autonomic Function ◽

Pressure Change ◽

Pressure Recovery ◽

Blood Pressure Change ◽

Noninvasive Evaluation ◽

Peripheral Neuropathies ◽

Heart Period

Peripheral adrenergic function is important in the maintenance of postural normotension. It may be impaired in peripheral neuropathies, and this may be manifested as alterations in acral temperature, color, or sweating. Simple, accurate, and reproducible tests of peripheral adrenergic function are now routinely used in clinical autonomic laboratories. For noninvasive evaluation of autonomic function, tests of peripheral adrenergic function can be used to separately evaluate the vagal and adrenergic components of baroreflex sensitivity. The vagal component is derived from the heart period response to blood pressure change and the adrenergic component by the blood pressure recovery time in response to the preceding fall in blood pressure, induced by the Valsalva maneuver.This chapter describes methods used to determine peripheral adrenergic function and their value and shortcomings.

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Baroreflex sensitivity and susceptibility to systolic hypertension induced by DOCA-salt in the Sabra rat

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.1984.246.3.h448 ◽

1984 ◽

Vol 246 (3) ◽

pp. H448-H452

Author(s):

M. Weinstock ◽

D. Schorer-Apelbaum ◽

D. Ben-Ishay

Keyword(s):

Blood Pressure ◽

Systolic Hypertension ◽

Baroreflex Sensitivity ◽

Normal Serum ◽

Heart Period ◽

Salt Treatment ◽

Baroreflex Control ◽

Tail Artery ◽

The Mean ◽

Drinking Fluid

Rats of the salt-resistant Sabra strain (SBN) have a more sensitive baroreflex control of heart rate than do normotensive hypertension-prone salt-sensitive (SBH) rats. To test the hypothesis that increased baroreflex sensitivity confers resistance to hypertension, aortic baroreceptor deafferentation (ABD) was performed in 7- to 10-wk-old SBN rats. This treatment reduced the slope of the mean arterial pressure-heart period (MAP-HP) relationship in response to infusions of increasing doses of phenylephrine in conscious rats, from 1.92 +/- 0.21 to 0.66 +/- 0.11 ms X mmHg-1 (P less than 0.01). The latter value did not differ significantly from that of untreated SBH rats (0.56 +/- 0.07 ms X mmHg-1). Treatment of uniphrectomized SBH, SBN-ABD, and sham-operated SBN rats for 3 wk with deoxycorticosterone acetate (DOCA; 25-mg pellet) and 0.9% NaCl + 0.4% KCl (to maintain normal serum K+ values) as drinking fluid caused increases in systolic blood pressure from 126 +/- 3 to 147 +/- 5 mmHg and 104 +/- 6 to 130 +/- 8 mmHg in the former two groups, respectively, but no significant change (105 +/- 3 to 110 +/- 4 mmHg) in SBN rats when measured by an indwelling arterial catheter in the tail artery. The slopes of the MAP-HP relationships of each of the above three groups of rats were not significantly altered by DOCA-salt treatment. It is concluded that a decrease in baroreflex control of the heart by ABD can render SBN rats sensitive to DOCA-salt-induced systolic hypertension.

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Differences in age-independent effects of blood pressure on baroreflex sensitivity between normal and hypertensive subjects

Clinical Science ◽

10.1042/cs0700489 ◽

1986 ◽

Vol 70 (5) ◽

pp. 489-494 ◽

Cited By ~ 29

Author(s):

Kazuyuki Shimada ◽

Tadao Kitazumi ◽

Hisakazu Ogura ◽

Noriko Sadakane ◽

Toshio Ozawa

Keyword(s):

Blood Pressure ◽

Systolic Blood Pressure ◽

Baroreflex Sensitivity ◽

Blood Pressure Level ◽

Normal Subjects ◽

Inhibitory Effect ◽

Valsalva Manoeuvre ◽

Sensitivity Index ◽

Baroreflex Function ◽

Age Related

1. Inter-relationship between age, systolic blood pressure and baroreflex sensitivity index derived from the Valsalva manoeuvre was investigated in either combined or separated groups of normal and hypertensive subjects. 2. Both in the total population as a whole and in each blood pressure subgroup, the baroreflex sensitivity index was significantly inversely related to age and to systolic blood pressure. Furthermore, age was significantly related to systolic blood pressure except in the hypertensive group. 3. Partial correlation analysis showed that, in the total and hypertensive population, the baroreflex sensitivity index was significantly related to age and systolic blood pressure independently of each other variable. In the normal group, however, the baroreflex sensitivity index was not related to systolic blood pressure after adjusting for the effect of age, but remained significantly related to age independently of systolic blood pressure. The estimates of relative effects of the two variables on baroreflex sensitivity by multiple regression analysis were consistent with these results. 4. Thus a prevailing concept of the inhibitory effect of blood pressure on baroreflex function may be accurate exclusively in hypertensive patients, and baroreflex function appears to be more sensitive to age-related changes in this system than to those related to blood pressure level, particularly in non-hypertensive normal subjects.

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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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Effects of Fear Induction on Heart Period Variability

Journal of Psychophysiology ◽

10.1027//0269-8803.13.1.18 ◽

1999 ◽

Vol 13 (1) ◽

pp. 18-26 ◽

Cited By ~ 3

Author(s):

Rudolf Stark ◽

Alfons Hamm ◽

Anne Schienle ◽

Bertram Walter ◽

Dieter Vaitl

Keyword(s):

Blood Pressure ◽

Trait Anxiety ◽

State Anxiety ◽

Self Report ◽

Emotional States ◽

Heart Period ◽

Experimental Conditions ◽

Heart Period Variability ◽

Physiological Variables ◽

Period Variability

Abstract The present study investigated the influence of contextual fear in comparison to relaxation on heart period variability (HPV), and analyzed differences in HPV between low and high anxious, nonclinical subjects. Fifty-three women participated in the study. Each subject underwent four experimental conditions (control, fear, relaxation, and a combined fear-relaxation condition), lasting 10 min each. Fear was provoked by an unpredictable aversive human scream. Relaxation should be induced with the aid of verbal instructions. To control for respiratory effects on HPV, breathing was paced at 0.2 Hz using an indirect light source. Besides physiological measures (HPV measures, ECG, respiration, forearm EMG, blood pressure), emotional states (pleasure, arousal, dominance, state anxiety) were assessed by subjects' self-reports. Since relaxation instructions did not have any effect neither on the subjective nor on the physiological variables, the present paper focuses on the comparison of the control and the fear condition. The scream reliably induced changes in both physiological and self-report measures. During the fear condition, subjects reported more arousal and state anxiety as well as less pleasure and dominance. Heart period decreased, while EMG and diastolic blood pressure showed a tendency to increase. HPV remained largely unaltered with the exception of the LF component, which slightly decreased under fear induction. Replicating previous findings, trait anxiety was negatively associated with HPV, but there were no treatment-specific differences between subjects with low and high trait anxiety.

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Faculty Opinions recommendation of Blood pressure and heart period variability ratios derived from 24-h ambulatory measurements are predictors of all-cause mortality.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.725370808.793504604 ◽

2015 ◽

Author(s):

Andrea Semplicini

Keyword(s):

Blood Pressure ◽

Heart Period ◽

Heart Period Variability ◽

Period Variability ◽

All Cause Mortality

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Exercise and pyridostigmine prevents gastric emptying delay and increase blood pressure and cisplatin-induced baroreflex sensitivity in rats

Life Sciences ◽

10.1016/j.lfs.2020.118972 ◽

2021 ◽

Vol 267 ◽

pp. 118972

Author(s):

Mariana Sousa Silva ◽

Yasmim de Andrade Gomes ◽

Mickael Laudrup de Sousa Cavalcante ◽

Pedro Victor Nogueira Telles ◽

Alda Cássia Alves da Silva ◽

...

Keyword(s):

Blood Pressure ◽

Gastric Emptying ◽

Baroreflex Sensitivity ◽

Increase Blood Pressure

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Heart rate and blood pressure variability and baroreflex sensitivity in patients with acute brain injury

Journal of Critical Care ◽

10.1016/j.jcrc.2005.09.048 ◽

2005 ◽

Vol 20 (4) ◽

pp. 394 ◽

Cited By ~ 1

Author(s):

V. Papaioannou ◽

M. Giannakou ◽

N. Maglaveras ◽

E. Sofianos ◽

M. Giala

Keyword(s):

Blood Pressure ◽

Heart Rate ◽

Brain Injury ◽

Blood Pressure Variability ◽

Baroreflex Sensitivity ◽

Acute Brain Injury

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Blood pressure reduction after gastric bypass surgery is explained by a decrease in cardiac output

Journal of Applied Physiology ◽

10.1152/japplphysiol.00362.2016 ◽

2017 ◽

Vol 122 (2) ◽

pp. 223-229 ◽

Cited By ~ 4

Author(s):

Peter M. van Brussel ◽

Bas van den Bogaard ◽

Barbara A. de Weijer ◽

Jasper Truijen ◽

C.T. Paul Krediet ◽

...

Keyword(s):

Blood Pressure ◽

Gastric Bypass ◽

Body Weight ◽

Cardiac Output ◽

Baroreflex Sensitivity ◽

Bypass Surgery ◽

Gastric Bypass Surgery ◽

Left Ventricular ◽

Ventricular Contractility ◽

Left Ventricular Contractility

Blood pressure (BP) decreases in the first weeks after Roux-and-Y gastric bypass surgery. Yet the pathophysiology of the BP-lowering effects observed after gastric bypass surgery is incompletely understood. We evaluated BP, systemic hemodynamics, and baroreflex sensitivity in 15 obese women[mean age 42 ± 7 standard deviation (SD) yr, body mass index 45 ± 6 kg/m2] 2 wk before and 6 wk following Roux-and-Y gastric bypass surgery. Six weeks after gastric bypass surgery, mean body weight decreased by 13 ± 5 kg (10%, P < 0.001). Office BP decreased from 137 ± 10/86 ± 6 to 128 ± 12/81 ± 9 mmHg ( P < 0.001, P < 0.01), while daytime ambulatory BP decreased from 128 ± 14/80 ± 9 to 114 ± 10/73 ± 6 mmHg ( P = 0.01, P = 0.05), whereas nighttime BP decreased from 111 ± 13/66 ± 7 to 102 ± 9/62 ± 7 mmHg ( P = 0.04, P < 0.01). The decrease in BP was associated with a 1.6 ± 1.2 l/min (20%, P < 0.01) decrease in cardiac output (CO), while systemic vascular resistance increased (153 ± 189 dyn·s·cm−5, 15%, P < 0.01). The maximal ascending slope in systolic blood pressure decreased (192 mmHg/s, 19%, P = 0.01), suggesting a reduction in left ventricular contractility. Baroreflex sensitivity increased from 9.0 [6.4–14.3] to 13.8 [8.5–19.0] ms/mmHg (median [interquartile range]; P < 0.01) and was inversely correlated with the reductions in heart rate ( R = −0.64, P = 0.02) and CO ( R = −0.61, P = 0.03). In contrast, changes in body weight were not correlated with changes in either BP or CO. The BP reduction following Roux-and-Y gastric bypass surgery is correlated with a decrease in CO independent of changes in body weight. The contribution of heart rate to the reduction in CO together with enhanced baroreflex sensitivity suggests a shift toward increased parasympathetic cardiovascular control. NEW & NOTEWORTHY The reason for the decrease in blood pressure (BP) in the first weeks after gastric bypass surgery remains to be elucidated. We show that the reduction in BP following surgery is caused by a decrease in cardiac output. In addition, the maximal ascending slope in systolic blood pressure decreased suggesting a reduction in left ventricular contractility and cardiac workload. These findings help to understand the physiological changes following gastric bypass surgery and are relevant in light of the increased risk of heart failure in these patients.

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