scholarly journals Role of Blood Pressure in Mediating Carotid Artery Dilation in Response to Sympathetic Stimulation in Healthy, Middle-Aged Individuals

2019 ◽  
Author(s):  
Arron Peace ◽  
Virginia Pinna ◽  
Friso Timmen ◽  
Guillherme Speretta ◽  
Helen Jones ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Carotid Artery ◽  
Cold Pressor Test ◽  
Cold Pressor ◽  
Sympathetic Stimulation ◽  
Middle Aged ◽  
Cvd Risk ◽  
Significant Difference ◽  
History Of ◽  
Relative Change

Abstract Objectives Carotid artery diameter responses to sympathetic stimulation, i.e., carotid artery reactivity (CAR), represent a novel test of vascular health and relates to cardiovascular disease (CVD)/risk. This study aims to understand the relationship between the increase in blood pressure and carotid artery diameter response during the CAR-test in healthy, middle-aged men. Methods Sample consisted of 40 normotensive men (aged 31–59 years) with no history of CVD of currently taking medication. Noninvasive ultrasound was used to measure carotid artery diameter during the cold pressor test (CPT), with CAR% being calculated as the relative change from baseline (%). Mean arterial pressure (MAP) was measured with beat-to-beat blood pressure recording. Results CAR% was 4.4 ± 5.4%, peaking at 92 ± 43 seconds. MAP increased from 88 ± 9 mmHg to 110 ± 15 mmHg, peaked at 112 ± 38 seconds, which was significantly later than the diameter peak (P = 0.04). The correlation between resting MAP and CAR% was weak (r = 0.209 P = 0.197). Tertiles based on resting MAP or MAP-increase revealed no significant differences between groups in subject characteristics including age, body mass index, or CAR% (all P > 0.05). Subgroup analysis of individuals with carotid constriction (n = 6) vs. dilation (n = 34), revealed no significant difference in resting MAP or increase in MAP (P = 0.209 and 0.272, respectively). Conclusion Our data suggest that the characteristic increase in MAP during the CPT does not mediate carotid artery vasomotion.

Abstract 081: Obesity-related Reductions in Cardiac Baroreflex Sensitivity and Higher 24-hour Blood Pressure Variability Are Not Related to Carotid Artery and Aortic Stiffness in Young And Middle-aged Adults

Hypertension ◽  
2016 ◽  
Vol 68 (suppl_1) ◽  
Author(s):  
Seth Holwerda ◽  
Jess Fiedorowicz ◽  
Lyndsey DuBose ◽  
Amy Stroud ◽  
Tiwa Ajibewa ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Carotid Artery ◽  
Blood Pressure Variability ◽  
Aortic Stiffness ◽  
Baroreflex Sensitivity ◽  
Normal Weight ◽  
Middle Aged ◽  
Cvd Risk ◽  
Cross Sectional ◽  
Artery Stiffness

Alterations in cardiac baroreflex sensitivity (BRS) and 24-hr blood pressure variability (24-hr BPV) are independent predictors of increased cardiovascular disease (CVD) risk, and occur in individuals with obesity. Obese humans are also likely to have a higher large elastic artery stiffness compared with normal-weight individuals. While an increase in stiffness of carotid and aortic arteries, the anatomical sites where baroreceptors reside, may likely be responsible in part for the decline in cardiac BRS with advancing age in adults, it remains unclear whether 1) elevated carotid and aortic stiffness are also directly associated with obesity-associated reductions in cardiac BRS in young/middle-aged individuals, and 2) if reduced BRS with obesity is associated with elevated 24hr BPV. We tested the hypothesis that lower BRS would be associated with higher carotid and aortic stiffness and 24hr BPV in young and middle-aged individuals with obesity. In a cross-sectional design, 22 normal-weight (body mass index, BMI 24.5 ± 0.6 kg/m 2 ; age 35±2 yrs; 8M/14F) and 22 obese (BMI 34.2 ± 1.1 kg/m 2 ; age 39 ± 2 yrs; 8M/14F) individuals underwent measures of spontaneous cardiac BRS (sequence technique), carotid artery β-stiffness (carotid tonometry and B-mode ultrasound of common carotid artery), aortic stiffness (carotid-femoral pulse wave velocity, CFPWV), and 24-hr-systolic BPV (24 hr ambulatory BP monitoring). A significant relation between cardiac BRS and 24-hr systolic BPV (r=-0.42, P<0.01) was corroborated by lower cardiac BRS (11.7±1.2 vs. 16.8±1.7 ms/mmHg, P<0.05) and higher 24-hr BPV (12.4±0.6 vs. 10.1±0.4 mmHg SD, P<0.05) among obese compared with normal-weight subjects. In contrast, carotid β-stiffness (7.8±0.6 vs. 6.9±0.4 U, P>0.05) and CFPWV (745±71 vs. 611±19 cm/s, P=0.07) were not significantly different between groups despite greater average 24-hr systolic BP in the obese vs. normal weight subjects (127±2 vs. 118±1 mmHg, P<0.05). These preliminary data suggest that an increase in carotid artery and aortic stiffness may not precede the decline in cardiac BRS and increase in 24hr BPV in young and middle-aged obese individuals, suggesting non-arterial stiffness related mechanisms for obesity-related reductions in cardiac BRS.

scholarly journals Similarity between carotid and coronary artery responses to sympathetic stimulation and the role of α1-receptors in humans

2018 ◽  
Vol 125 (2) ◽  
pp. 409-418 ◽  
Author(s):  
Anke C.C.M. van Mil ◽  
Michael M. Tymko ◽  
Thijs P. Kerstens ◽  
Mike Stembridge ◽  
Daniel J. Green ◽  
...  
Keyword(s):  
Coronary Artery ◽  
Carotid Artery ◽  
Lower Body Negative Pressure ◽  
Cold Pressor Test ◽  
Cold Pressor ◽  
Receptor Blockade ◽  
Maximal Velocity ◽  
Sympathetic Stimulation ◽  
Time Integral

Carotid artery (CCA) dilation occurs in healthy subjects during cold pressor test (CPT), while the magnitude of dilation relates to cardiovascular risk. To further explore this phenomenon and mechanism, we examined carotid artery responses to different sympathetic tests, with and without α1-receptor blockade and assessed similarity to these responses between carotid and coronary arteries. In randomized order, 10 healthy participants (25 ± 3 yr) underwent sympathetic stimulation using the CPT (3-min left-hand immersion in ice-slush) and lower-body negative pressure (LBNP). Before and during sympathetic tests, CCA diameter and velocity (Doppler ultrasound) and left anterior descending (LAD) coronary artery velocity (echocardiography) were recorded across 3 min. Measures were repeated 90 min following selective α1-receptor blockade via oral prazosin (0.05 mg/kg body wt). CPT significantly increased CCA diameter, LAD maximal velocity, and velocity-time integral area-under-the-curve (all P < 0.05). In contrast, LBNP resulted in a decrease in CCA diameter, LAD maximal velocity, and velocity time integral (VTI; all P < 0.05). Following α1-receptor blockade, CCA and LAD velocity responses to CPT were diminished. In contrast, during LBNP (−30 mmHg), α1-receptor blockade did not alter CCA or LAD responses. Finally, changes in CCA diameter and LAD VTI responses to sympathetic stimulation were positively correlated ( r = 0.66, P < 0.01). We found distinct carotid artery responses to different tests of sympathetic stimulation, where α1 receptors partly contribute to CPT-induced responses. Finally, we found agreement between carotid and coronary artery responses. These data indicate similarity between carotid and coronary responses to sympathetic tests and the role of α1 receptors that is dependent on the nature of the sympathetic challenge. NEW & NOTEWORTHY We showed distinct carotid artery responses to cold pressor test (CPT; i.e., dilation) and lower-body negative pressure (LBNP; i.e., constriction). Blockade of α1-receptors significantly attenuated dilator responses in carotid and coronary arteries during CPT, while no changes were found during LBNP. Our findings indicate strong similarity between carotid and coronary artery responses to distinct sympathetic stimuli, and for the role of α-receptors.

scholarly journals The study of cardiovascular sympathetic reactivity in prehypertensives with normal and higher BMI

2017 ◽  
Vol 5 (3) ◽  
pp. 1033
Author(s):  
Mangala Bhongade ◽  
Amit Navare
Keyword(s):  
Blood Pressure ◽  
Cardiovascular Disease ◽  
Diastolic Blood Pressure ◽  
Cold Pressor Test ◽  
Cold Pressor ◽  
Exclusion Criterion ◽  
National Commission ◽  
Cross Sectional ◽  
Hand Grip ◽  
Significant Difference

Background: Hypertension is one of major causes responsible for cardiovascular disease. Prehypertension, as defined by joint national commission-2003 as condition with SBP 120-139 or DBP as 80-89mmH, was identified as a precursor for hypertension and also associated with 1.5 to 2 fold increase in cardiovascular disease. The aim of the study was to determine the sympathetic reactivity in pre-hypertensives with normal and higher body mass index (BMI).Methods: A cross-sectional study was conducted at Seth G.S Medical College, Mumbai, India. A total of 129 study participants were recruited based on the inclusion and exclusion criterion of the study. Changes in diastolic blood pressure were measured in isometric hand grip and cold pressor tests.Results: The prevalence of prehypertension was observed to be 66.66% in age group of 28-40 years. There was a statistically significant difference in change of diastolic blood pressure in isometric hand grip (IHG) and cold pressor test (CPT), in prehypertensives with higher BMI as compared to prehypertensives with normal BMI.Conclusions: The finding of the study reveals that there is an increased sympathetic reactivity in prehypertensives with normal BMI as compared to normotensives. There is lesser sympathetic reactivity in prehypertensives with higher BMI compared to prehypertensives with prehypertensives with normal BMI.

Exploring the effects of oily fish consumption on measures of acute and long-term stress in healthy 8-9-year-old children: The FiSK Junior randomized trial

2020 ◽  
pp. 1-26
Author(s):  
Marie N Teisen ◽  
Stine Vuholm ◽  
Jesper M Rantanen ◽  
Jeppe H Christensen ◽  
Camilla T Damsgaard ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Fish Consumption ◽  
Cold Pressor Test ◽  
Cold Pressor ◽  
Heart Beat ◽  
Autonomic Response ◽  
Hair Cortisol ◽  
Oily Fish ◽  
Fish Group

Abstract Long-chain n-3 PUFA (n-3 LCPUFA) have been shown to reduce blood pressure, heart rate and vagal tone, but potential stress-mitigating effects of n-3 LCPUFA are not well investigated. We aim to explore the effects of oily fish consumption on long-term stress and the stress response in schoolchildren. Healthy 8-9-year-old children were randomized to receive ~300 g/week of oily fish or poultry for 12 ± 2 weeks. At baseline and endpoint, we measured erythrocyte n-3 LCPUFA, hair cortisol and the response to a 1-min cold pressor test (CPT) on saliva cortisol, blood pressure, and continuous electrocardiogram recordings. Of the 199 randomized children, 197 completed the trial. Hair cortisol did not differ between the groups, but a sex-interaction was indicated (Psex*group = 0.074, difference between means -0.9 (95% CI: -2.9,1.0) ng/g and 0.7 (-0.2,1.6) ng/g in boys and girls, respectively). The children in the fish group tended to be less prone to terminate CPT prematurely (OR 0.20 [0.02,1.04]). The mean heart beat interval during CPT was 18.2 (0.3,36.6) ms longer and the high frequency power increased (159 (29,289) ms2) in the fish versus the poultry group. The cardiac autonomic response in the 10 min following CPT was characterized by a sympathetic peak followed by a parasympathetic peak, which was most pronounced in the fish group. This exploratory study does not support a strong effect of oily fish consumption on stress, but indicates that oily fish consumption may increase vagal cardiac tone during the physiological response to CPT. These results warrant further investigation.

Variability of the haemodynamic responses to laboratory tests employed in assessment of neural cardiovascular regulation in man

1985 ◽  
Vol 69 (5) ◽  
pp. 533-540 ◽  
Author(s):  
Gianfranco Parati ◽  
Guido Pomidossi ◽  
Agustin Ramirez ◽  
Bruno Cesana ◽  
Giuseppe Mancia
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Test Performance ◽  
Blood Pressure Response ◽  
Cold Pressor Test ◽  
Cold Pressor ◽  
Cardiovascular Regulation ◽  
Pressor Test ◽  
Carotid Baroreceptor ◽  
Baroreceptor Stimulation

1. In man evaluation of neural cardiovascular regulation makes use of a variety of tests which address the excitatory and reflex inhibitory neural influences that control circulation. Because interpretation of these tests is largely based on the magnitude of the elicited haemodynamic responses, their reproducibility in any given subject is critical. 2. In 39 subjects with continuous blood pressure (intra-arterial catheter) and heart rate monitoring we measured (i) the blood pressure and heart rate rises during hand-grip and cold-pressor test, (ii) the heart rate changes occurring during baroreceptor stimulation and deactivation by injection of phenylephrine and trinitroglycerine, and (iii) the heart rate and blood pressure changes occurring with alteration in carotid baroreceptor activity by a neck chamber. Each test was carefully standardized and performed at 30 min intervals for a total of six times in each subject. 3. The results showed that the responses to any test were clearly different from one another and that this occurred in all subjects studied. For the group as a whole the average response variability (coefficient of variation) ranged from 10.2% for the blood pressure response to carotid baroreceptor stimulation to 44.2% for the heart rate response to cold-pressor test. The variability of the responses was not related to basal blood pressure or heart rate, nor to the temporal sequence of the test performance. 4. Thus tests employed for studying neural cardiovascular control in man produce responses whose reproducibility is limited. This phenomenon may make it more difficult to define the response magnitude typical of each subject, as well as its comparison in different conditions and diseases.

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