scholarly journals Recent Insights into Carotid Baroreflex Function in Humans Using the Variable Pressure Neck Chamber

2003 ◽  
Vol 88 (6) ◽  
pp. 671-680 ◽  
Author(s):  
Paul J. Fadel ◽  
Shigehiko Ogoh ◽  
David M. Keller ◽  
Peter B. Raven
Keyword(s):  
Variable Pressure ◽  
Baroreflex Function ◽  
Carotid Baroreflex ◽  
Neck Chamber

Modulation of the carotid baroreflex function during volume expansion

1979 ◽  
Vol 237 (2) ◽  
pp. H153-H158 ◽  
Author(s):  
H. I. Chen ◽  
C. Y. Chai ◽  
C. S. Tung ◽  
H. C. Chen
Keyword(s):  
Volume Expansion ◽  
Baroreflex Function ◽  
Carotid Baroreflex

Carotid baroreflex control of heart rate during acute exposure to simulated altitudes of 3,800 m and 4,300 m

1997 ◽  
Vol 273 (4) ◽  
pp. R1219-R1223 ◽  
Author(s):  
S. Sagawa ◽  
R. Torii ◽  
K. Nagaya ◽  
F. Wada ◽  
Y. Endo ◽  
...  
Keyword(s):  
High Altitude ◽  
Sea Level ◽  
Logistic Function ◽  
Cardiac Response ◽  
Baroreflex Control ◽  
Carotid Baroreflex ◽  
Maximal Gain ◽  
Neck Chamber ◽  
Male Subjects ◽  
Made In

To examine the baroreflex response in humans during acute high-altitude exposure, the carotid baroreflex cardiac responsiveness was studied using a neck chamber in seven unacclimatized male subjects. Measurements were made in a high-altitude chamber on separate days at sea level and during 1-h exposure at two different altitudes of 3,800 m [partial pressure of oxygen in inspired air (Pi O2 ) = 90 mmHg] and 4,300 m (Pi O2  = 82 mmHg). R-R intervals were plotted against neck chamber pressures, and the baroreceptor response was analyzed by applying a four-parameter sigmoidal logistic function. The baroreceptor response curve shifted downward in either altitude, reflecting a tachycardic response at high altitude, and the magnitude of the shift was greater at 4,300 m than at 3,800 m. There was no change in the sigmoidal parameters at 3,800 m compared with sea level except for a reduction ( P < 0.05) of the minimum R-R interval. At 4,300 m the maximal R-R range, slope coefficient, minimum R-R interval, and maximal gain of the curve decreased significantly ( P < 0.05) compared with sea level values, whereas the centering point of the curve remained unchanged. These results suggest that hypoxia (Pi O2  = 82 mmHg) reduces the sensitivity of carotid baroreflex cardiac response.

EFFECTS OF CENTRAL COMMAND ON CAROTID BAROREFLEX FUNCTION DURING STATIC EXERCISE IN HUMANS

2002 ◽  
Vol 34 (5) ◽  
pp. S112
Author(s):  
S Ogoh ◽  
D Keller ◽  
R Vinson ◽  
W Wasmund ◽  
A H. Olivencia-Yurvati ◽  
...  
Keyword(s):  
Central Command ◽  
Static Exercise ◽  
Baroreflex Function ◽  
Carotid Baroreflex ◽  
Exercise In Humans

Plasma Catecholamines and Blood Pressure Responses to the Carotid Baroreceptor Reflex in Essential Hypertension

1979 ◽  
Vol 57 (s5) ◽  
pp. 165s-167s ◽  
Author(s):  
G. Mancia ◽  
G. Leonetti ◽  
G. B. Picotti ◽  
A. Ferrari ◽  
M. D. Galva ◽  
...  
Keyword(s):  
Essential Hypertension ◽  
Arterial Pressure ◽  
Sympathetic Activity ◽  
Plasma Catecholamines ◽  
Variable Pressure ◽  
Carotid Baroreceptor ◽  
Pressure Variable ◽  
Blood Pressure Responses ◽  
Neck Chamber ◽  
Noradrenaline And Adrenaline

1. Slight decreases and increases in carotid baroreceptor activity were induced in subjects with essential hypertension by slight alterations in carotid transmural pressure (variable pressure neck-chamber technique) in order to obtain limited increases and reductions in sympathetic adrenergic activity. 2. When sympathetic activity was reflexly increased there was a rise in arterial pressure but no significant increase in plasma catecholamines. Likewise when sympathetic activity was reflexly reduced there was a fall in arterial pressure but no significant reduction in plasma catecholamines. 3. Plasma noradrenaline and adrenaline significantly and markedly increased in the same subjects when sympathetic activity was increased by activation of both arterial and low pressure baroreceptor reflexes with tilting. 4. It is suggested that measurements of catecholamines in systemic plasma may reveal marked degrees of sympathetic activation but may not be a sensitive index of more moderate changes in sympathetic tone.

EPIDURAL ANESTHESIA AND CAROTID BAROREFLEX FUNCTION DURING DYNAMIC EXERCISE IN MAN

1999 ◽  
Vol 31 (Supplement) ◽  
pp. S224
Author(s):  
S. A. Smith ◽  
R. G. Querry ◽  
K. M. Gallagher ◽  
M. Stromstad ◽  
K. Ide ◽  
...  
Keyword(s):  
Epidural Anesthesia ◽  
Dynamic Exercise ◽  
Baroreflex Function ◽  
Carotid Baroreflex

scholarly journals Intermittent hypoxia and arterial blood pressure control in humans: role of the peripheral vasculature and carotid baroreflex

2016 ◽  
Vol 311 (3) ◽  
pp. H699-H706 ◽  
Author(s):  
Joshua C. Tremblay ◽  
Lindsey M. Boulet ◽  
Michael M. Tymko ◽  
Glen E. Foster
Keyword(s):  
Blood Pressure ◽  
Endothelial Function ◽  
Femoral Artery ◽  
Brachial Artery ◽  
Intermittent Hypoxia ◽  
Variable Pressure ◽  
Peripheral Vasculature ◽  
Arterial Blood ◽  
Carotid Baroreflex ◽  
Obstructive Sleep

Intermittent hypoxia (IH) occurs in association with obstructive sleep apnea and likely contributes to the pathogenesis of hypertension. The purpose of this study was to examine the putative early adaptations at the level of the peripheral vasculature and carotid baroreflex (CBR) that may promote the development of hypertension. Ten healthy male participants (26 ± 1 yr, BMI = 24 ± 1 kg/m2) were exposed to 6 h of IH (1-min cycles of normoxia and hypoxia) and SHAM in a single-blinded, counterbalanced crossover study design. Ambulatory blood pressure was measured during each condition and the following night. Vascular strain of the carotid and femoral artery, a measure of localized arterial stiffness, and hemodynamic shear patterns in the brachial and femoral arteries were measured during each condition. Brachial artery reactive hyperemia flow-mediated vasodilation was assessed before and after each condition as a measure of endothelial function. CBR function and its control over leg vascular conductance (LVC) were measured after each condition with a variable-pressure neck chamber. Intermittent hypoxia 1) increased nighttime pulse pressure by 3.2 ± 1.3 mmHg, 2) altered femoral but not brachial artery hemodynamics, 3) did not affect brachial artery endothelial function, 4) reduced vascular strain in the carotid and possibly femoral artery, and 5) shifted CBR mean arterial pressure (MAP) to higher MAP while blunting LVC responses to CBR loading. These results suggest limb-specific vascular impairments, reduced vascular strain, and CBR resetting combined with blunted LVC responses are factors in the early pathogenesis of IH-induced development of hypertension.

scholarly journals Interaction between graviception and carotid baroreflex function in humans during parabolic flight-induced microgravity

2018 ◽  
Vol 125 (2) ◽  
pp. 634-641 ◽  
Author(s):  
Shigehiko Ogoh ◽  
Michaël Marais ◽  
Romain Lericollais ◽  
Pierre Denise ◽  
Peter B. Raven ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Mean Arterial Pressure ◽  
Arterial Pressure ◽  
Parabolic Flight ◽  
Central Blood Volume ◽  
Pressure Regulation ◽  
Baroreflex Function ◽  
Carotid Baroreflex ◽  
Acute Changes

The aim of the present study was to assess carotid baroreflex (CBR) function during acute changes in otolithic activity in humans. To address this question, we designed a set of experiments to identify the modulatory effects of microgravity on CBR function at a tilt angle of −2°, which was identified to minimize changes in central blood volume during parabolic flight. During parabolic flight at 0 and 1 g, CBR function curves were modeled from the heart rate (HR) and mean arterial pressure (MAP) responses to rapid pulse trains of neck pressure and neck suction ranging from +40 to −80 Torr; CBR control of HR (carotid-HR) and MAP (carotid-MAP) function curves, respectively. The maximal gain of both carotid-HR and carotid-MAP baroreflex function curves were augmented during microgravity compared with 1 g (carotid-HR, −0.53 to −0.80 beats·min−1·mmHg−1, P < 0.05; carotid-MAP, −0.24 to −0.30 mmHg/mmHg, P < 0.05). These findings suggest that parabolic flight-induced acute change of otolithic activity may modify CBR function and identifies that the vestibular system contributes to blood pressure regulation under fluctuations in gravitational forces. NEW & NOTEWORTHY The effect of acute changes in vestibular activity on arterial baroreflex function remains unclear. In the present study, we assessed carotid baroreflex function without changes in central blood volume during parabolic flight, which causes acute changes in otolithic activity. The sensitivity of both carotid heart rate and carotid mean arterial pressure baroreflex function was augmented in microgravity compared with 1 g, suggesting that the vestibular system contributes to blood pressure regulation in humans on Earth.

scholarly journals Neck Chamber Technique Revisited: Low-Noise Device Delivering Negative and Positive Pressure and Enabling Concomitant Carotid Artery Imaging With Ultrasonography

2021 ◽  
Vol 12 ◽  
Author(s):  
Rafał Seredyński ◽  
Tymoteusz Okupnik ◽  
Przemysław Musz ◽  
Stanisław Tubek ◽  
Beata Ponikowska ◽  
...  
Keyword(s):  
Carotid Artery ◽  
Response Curve ◽  
Applied Pressure ◽  
Low Noise ◽  
Variable Pressure ◽  
Positive Pressure ◽  
Carotid Baroreceptors ◽  
Dependent Relation ◽  
3D Printed ◽  
Neck Chamber

Background and Objectives: Recently, novel noiseless device for the assessment of baroreceptor function with the neck suction (NS) has been presented. In this study, we present another in-house approach to the variable-pressure neck chamber method. Our device offers further critical improvements. First, it enables delivery of negative (NS) as well as positive pressure (neck pressurizing, NP) in a noiseless manner. Second, we used small, 3D-printed cups positioned over the carotid sinuses instead of cumbersome neck collar to improve subject comfort and to test feasibility of tracking the pressure-induced changes in carotid artery with ultrasonography.Methods: Five healthy, non-smoking, normal-weight subjects aged 29 ± 3 years (mean ± SD) volunteered for the study. Heart rate (HR, bpm) and mean arterial pressure (MAP, mmHg) responses to short, 7-s long episodes of NS and NP were recorded. Each trial consisted of 12 episodes of variable-pressure: six episodes of NS (suction ranging between -10 and -80 mmHg) and six episodes of NP (pressure ranging between + 10 and + 80 mmHg). Carotid artery sonography was performed during the NS and NP in four subjects, on another occasion.Results: The variable-pressure episodes resulted consistently in the expected pattern of hemodynamic alterations: HR and MAP increases or decreases following the NP and NS, respectively, as evidenced by the coefficient of determination (R2) of ≥0.78 for the carotid-HR response curve (for all five participants) and the carotid-MAP response curve (for four out of five participants; the curve cannot be calculated for one subject). We found a linear, dose-dependent relation between the applied pressure and the systolic-diastolic difference in carotid artery diameter.Conclusion: The novel device enables noiseless stimulation and unloading of the carotid baroreceptors with the negative and positive pressure, respectively, applied on the subject’s neck via small, asymmetric and one-side flattened, 3D-printed cups. The unique design of the cups enables concomitant visualizing of the carotid artery during the NS or NP administration, and thereby direct monitoring of the intensity of mechanical stimulus targeting the carotid baroreceptors.

Sign in / Sign up

Export Citation Format

Share Document