535 Non-invasive ultrasound assessment of vascular reactivity in normal pregnancies using maternal brachial artery diameter

Abstract Aims Arterial hypertension (AH) is one of the main determinants of clinical disorders during pregnancy affecting 2% to 10% of pregnancies with a substantial public health impact. Both endothelial injury and increased vascular reactivity have been reported to be involved in the pathogenesis of pre-eclampsia syndrome. Abnormal patterns in brachial artery Doppler velocities have been shown to be predictive of pre-eclampsia in first trimester. The aim of this study is to investigate whether flow-mediated dilation (FMD) and Doppler flow derived-parameters can predict the occurrence of AH. Methods and results The study population consisted of pregnant women (mean age 32 years) who had been referred to the IRCCS Fondazione Ca’ Granda Policlinico of Milan. None of them had any medical issues and was taking any medications at the time of pregnancy. FMD was performed on left brachial artery according to expert recommendation. Measurements of brachial artery diameter and flow have been collected at rest, shortly before cuff release and then 5-, 15-, 30-, 60-, and 90-s during hyperaemia phase. Among Doppler measurements, systolic and diastolic velocity (Vs and Vd, respectively) as well as mean velocity (mean V) were considered. In addition, the pulsatility index (PI) and resistance index (RI) were calculated. A 3-months follow-up was planned in order to detect the presence of AH. All data were expressed as the median. U-test (Mann–Whitney analysis) was performed to test difference among hypertensives and non-hypertensives We recruited 48 women (median age 32 yeas) whose 4 (8.5%) developed AH during pregnancy. These latter had statistically significant higher systolic velocity measured at 5 s after the release of distal occlusion (126 cm/s vs. 173 cm/s; P < 0.05). No other velocity Doppler data [diastolic velocity (Vd), mean velocity (mean V), PI, RI, TAMAX, and TAMEAN] showed a statistical significant association with AH development. Conclusions The present study suggests that the vascular assessment through Doppler during FMD procedure may foresee the development of hypertensive disorder in pregnancy. Our result provides the first evidence that the peak systolic velocity of brachial artery may represent a marker of early endothelial activation or damage, that can be directly involved in the pathophysiological mechanisms of the hypertensive disorders in pregnancy.

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Brachial artery diameter measurement: A tool to simplify non-invasive vascular assessment

Nutrition Metabolism and Cardiovascular Diseases ◽

10.1016/j.numecd.2011.09.005 ◽

2012 ◽

Vol 22 (1) ◽

pp. 8-13 ◽

Cited By ~ 5

Author(s):

T. Montalcini ◽

G. Gorgone ◽

C. Gazzaruso ◽

S. Romeo ◽

D. Bosco ◽

...

Keyword(s):

Brachial Artery ◽

Diameter Measurement ◽

Brachial Artery Diameter ◽

Non Invasive ◽

Vascular Assessment

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The BB-Paraoxonase Genotype Is Associated with Impaired Brachial Reactivity after Acute Hypertriglyceridemia in Healthy Subjects

The Journal of Clinical Endocrinology & Metabolism ◽

10.1210/jcem.86.3.7286 ◽

2001 ◽

Vol 86 (3) ◽

pp. 1078-1082 ◽

Cited By ~ 10

Author(s):

Giuseppe Paolisso ◽

Daniela Manzella ◽

Maria Rosaria Tagliamonte ◽

Michelangela Barbieri ◽

Raffaele Marfella ◽

...

Keyword(s):

Brachial Artery ◽

Healthy Subjects ◽

Vascular Reactivity ◽

The Other ◽

Gender Ratio ◽

Brachial Artery Diameter ◽

Plasma Triglycerides ◽

Before And After ◽

Basal Plasma ◽

Baseline Values

The possible relationship between paraoxonase (PON) gene polymorphism and brachial reactivity in healthy adult subjects in the presence of acute hypertriglyceridemia (HT), as a prooxidant factor, was investigated. In 101 healthy subjects the response to flow- induced vasodilatation was measured before and after Intralipid infusion. In the same subjects the A/B PON polymorphism was detected. The frequency was 0.545 for AA genotype, 0.356 for the AB genotype, and 0.099 for the BB genotype. At baseline all genotype groups had a similar increase in brachial artery diameter and flow. After Intralipid infusion, subjects sharing the BB genotype had a significant decrease vs. baseline values in changes in brachial artery diameter (P for trend < 0.001 vs. the other genotypes), but not in flow. In a subgroup of 55 subjects distributed among the 3 PON genotypes the same study protocol was repeated by buccal nitroglycerine administration to study the endothelium-independent vasodilatation. Again, subjects with the BB genotype had the worse vasodilation (P for trend < 0.001). Furthermore, subjects sharing the BB genotype had the lowest endothelium-independent and -dependent changes in diameter (P for trend < 0.001 vs. the other genotypes) independently of gender ratio, basal plasma triglycerides concentrations, and changes in plasma triglycerides concentrations. In conclusion, our study demonstrates that transient HT decreases vascular reactivity more in subjects with the PON BB genotype than in those with the other PON genotypes.

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Increased response of brachial artery diameter to norepinephrine in hypertensive patients

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.1988.255.1.h36 ◽

1988 ◽

Vol 255 (1) ◽

pp. H36-H43 ◽

Cited By ~ 1

Author(s):

S. Laurent ◽

L. Juillerat ◽

G. M. London ◽

J. Nussberger ◽

H. Brunner ◽

...

Keyword(s):

Blood Flow ◽

Brachial Artery ◽

Vascular Reactivity ◽

Arterial Disease ◽

Plasma Norepinephrine ◽

Brachial Artery Diameter ◽

Hypertensive Patients ◽

Small Arteries ◽

Large Arteries ◽

Normotensive Subjects

The hyperresponsiveness of small arteries to norepinephrine is well documented in essential hypertensive patients. Our objective was to investigate in situ the reactivity to norepinephrine of the diameter of large arteries, which are involved in the arterial disease of hypertension as well as small arteries. Brachial artery diameter, blood flow velocity, local volumic blood flow, and local vascular resistances were determined noninvasively with a pulsed Doppler system in 19 patients with essential hypertension and 9 normotensive subjects, before and after the administration of placebo (glucose) or increasing doses of norepinephrine (10, 20, and 40 ng.kg-1.min-1 iv) given in a single-blind fashion. In hypertensive patients, norepinephrine (40 ng.kg-1.min-1) induced 1) a significant decrease in brachial artery diameter, local blood velocity, volumic flow, and conductance and 2) a small increase in mean arterial pressure. These hemodynamic changes did not occur in the placebo group and were significantly greater in hypertensive patients than in normotensive subjects, although plasma norepinephrine increased to the same extent in both groups. We conclude that in hypertensive patients the increase in vascular reactivity to norepinephrine involves not only the resistive vessels but also the large arteries thus decreasing their conducting and buffering function.

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The association between S1P and vascular disease markers in the general population

European Journal of Preventive Cardiology ◽

10.1093/eurjpc/zwab061.237 ◽

2021 ◽

Vol 28 (Supplement_1) ◽

Author(s):

L Rotheudt ◽

E Moritz ◽

M Markus ◽

H Voelzke ◽

N Friedrich ◽

...

Keyword(s):

Confidence Interval ◽

Vascular Disease ◽

Brachial Artery ◽

Extreme Values ◽

Ankle Brachial Index ◽

Lipid Mediator ◽

Vascular Health ◽

Linear Regression Models ◽

Brachial Artery Diameter ◽

Carotid Plaques

Abstract Funding Acknowledgements Type of funding sources: None. Introduction Sphingosine-1-phosphate (S1P) is a lipid mediator of the immune system and vascular bed. However, cross-sectional analyses of S1P and parameters of vascular health in the population are sparse. Purpose We explored the relation between S1P concentrations and several parameters of vascular health, i.e. ankle-brachial index (ABI), carotid intima-media thickness (cIMT), presence of carotid atherosclerotic plaques/stenosis, brachial artery flow-mediated dilation (FMD) as well as aortic wall thickness (AWT). Methods S1P was measured by liquid chromatography-tandem mass spectrometry in the population-based Study of Health in Pomerania (SHIP-TREND-0). ABI was calculated as the ratio of systolic blood pressure in arms and ankles. For cIMT, the distance between the lumen-intima and media-adventitia interfaces in longitudinal scans were measured. Carotid plaques were defined as a focal protrusion of the carotid vessel wall. Carotid stenosis was assessed with Doppler ultrasonography. FMD was evaluated by measuring the increase in brachial artery diameter after transient forearm ischemia. AWT was assessed by Magnetic Resonance Imaging. Subjects with cancer, severe renal insufficiency, previous myocardial infarction and extreme values for S1P (< 1st and > 99th percentile) were excluded. Sex stratified linear regression models adjusted for age, smoking, waist-to-hip ratio and platelets were used to assess the relation between S1P and vascular disease parameters. Results A total of n = 3,643 participants (48% male, median age 51, 25th and 75th percentile 39 and 63 years) could be included in the analyses. The median S1P concentration was 0.788 µM (25th and 75th percentile 0.679 and 0.906, respectively). In men a 1 standard deviation higher S1P was associated with a significantly greater cIMT (β: 0.0057 95% confidence interval [CI]: 0.00027 to 0.0112 mm; p = 0.0396) and a lower ABI (β: -0.0090 (95% confidence interval [CI]: -0.0153 to -0.0029; p = 0.0038. In women S1P was significantly associated with cIMT (β: 0.0044 95% confidence interval [CI]: 0.0001 to 0.0086 mm; p = 0.0445) while no significant association was found for the relation of S1P with ABI. For both men and women S1P was not associated with FMD, the presence of carotid plaques/stenosis and AWT. Conclusions We found that S1P concentrations were positively related to a thicker cIMT in both sexes and lower ABI values in men. There was no association of S1P with any of the other vascular markers of interest. Future studies need to validate our results in other populations.

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Determinants of short-term variation in arterial flow-mediated dilatation in healthy young men

Clinical Science ◽

10.1042/cs20050333 ◽

2006 ◽

Vol 110 (4) ◽

pp. 475-482 ◽

Cited By ~ 28

Author(s):

Mikko J. Järvisalo ◽

Laura Jartti ◽

Jukka Marniemi ◽

Tapani Rönnemaa ◽

Jorma S. A. Viikari ◽

...

Keyword(s):

Endothelial Function ◽

Brachial Artery ◽

Serum Insulin ◽

Circadian Variation ◽

Low Fat ◽

Ultrasound Technique ◽

Brachial Artery Diameter ◽

Flow Mediated Dilatation ◽

Hourly Variation ◽

Fat Meal

Brachial artery FMD (flow-mediated dilatation) is widely used as a marker of systemic arterial endothelial function. FMD, however, shows considerable 25% day-to-day variation that hinders its clinical use. The reasons for this variability are poorly characterized. Therefore the present study was designed to clarify factors responsible for the hourly variation in endothelial function, including consuming a low-fat meal and circadian rhythms in endogenous hormonal levels. Brachial artery FMD, along with serum glucose, triacylglycerols (triglycerides) and levels of several hormones were measured six times per day on two separate days 1 week apart. On one day, the subjects (healthy males: n=12, mean age, 24 years) ate a light breakfast and a standardized lunch (23.5% fat, 48.7% carbohydrate and 27.8% protein). On the other day, they had a similar breakfast after which they fasted. Postprandial FMD values (both after breakfast and after lunch) were similar to baseline FMD. FMD showed a 28% hourly variation and 27% weekly variation. Variation in plasma levels of insulin (P=0.02) associated negatively and DHPG (3,4-dihydroxyphenylglycol) (P=0.001), a marker of sympathetic nervous activation, associated positively with variation in FMD. The effects of DHPG and insulin on FMD were independent of changes in baseline brachial artery diameter, although DHPG was also inversely associated with baseline diameter. Eating a regular low-fat meal does not have any measurable effects on brachial artery endothelial function. These data suggest that strict requirements for fasting conditions may be unnecessary when measuring peripheral endothelial function using the ultrasound technique. Circadian variation in serum insulin and sympathetic tone are physiological determinants of endothelial function.

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Effect of acute sympathetic nervous system activation on flow-mediated dilation of brachial artery

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.00771.2005 ◽

2006 ◽

Vol 290 (4) ◽

pp. H1446-H1453 ◽

Cited By ~ 81

Author(s):

Kenneth S. Dyson ◽

J. Kevin Shoemaker ◽

Richard L. Hughson

Keyword(s):

Nervous System ◽

Sympathetic Nervous System ◽

Brachial Artery ◽

Cold Pressor Test ◽

Plasma Norepinephrine ◽

Flow Mediated Dilation ◽

Brachial Artery Diameter ◽

Peak Shear Stress ◽

Sympathetic Nervous ◽

General Response

We tested the hypothesis that flow-mediated dilation (FMD) of the brachial artery would be impaired by acute increases in sympathetic nervous system activity (SNA) in models where similar peak shear stress stimulus was achieved by varying the duration of forearm muscle ischemia. Eleven healthy young men were studied under four different conditions, each with its own control: lower body suction (LBS), cold pressor test (CPT), mental arithmetic task (MAT), and activation of muscle chemoreflex (MCR). The duration of ischemia before observation of FMD by ultrasound imaging was 5 min each for control, LBS, and CPT; 3 min for MAT; and 2-min for MCR. Peak shear rate was not different between control and any of the SNA conditions, although total shear in the first minute was reduced in MAT. MCR was the only condition in which brachial artery vasoconstriction was observed before forearm occlusion [4.38 (SD 0.53) vs. control 4.60 (SD 0.53) mm, P < 0.05]; however, diameter increased to the same absolute value as that of the control, so the percent FMD was greater for MCR [9.85 (SD 2.33) vs. control 5.29 (SD 1.50)%]. Blunting of the FMD response occurred only in the CPT model [1.51 (SD 1.20)%]. During SNA, the increase in plasma cortisol from baseline was significant only for MCR; the increase in plasma norepinephrine was significant for MCR, LBS, and CPT; and the increase in epinephrine was significant only for MCR. These results showed that the four models employed to achieve increases in SNA had different effects on baseline brachial artery diameter and that blunted FMD is not a general response to increased SNA.

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Are the dynamic response characteristics of brachial artery flow-mediated dilation sensitive to the magnitude of increase in shear stimulus?

Journal of Applied Physiology ◽

10.1152/japplphysiol.01190.2007 ◽

2008 ◽

Vol 105 (1) ◽

pp. 282-292 ◽

Cited By ~ 50

Author(s):

K. E. Pyke ◽

J. A. Hartnett ◽

M. E. Tschakovsky

Keyword(s):

Shear Stress ◽

Shear Rate ◽

Dynamic Response ◽

Phase I ◽

Brachial Artery ◽

Flow Mediated Dilation ◽

Final Phase ◽

Stimulus Magnitude ◽

Brachial Artery Diameter ◽

Response Characteristics

The purpose of this study was to determine the dynamic characteristics of brachial artery dilation in response to step increases in shear stress [flow-mediated dilation (FMD)]. Brachial artery diameter (BAD) and mean blood velocity (MBV) (Doppler ultrasound) were obtained in 15 healthy subjects. Step increases in MBV at two shear stimulus magnitudes were investigated: large (L; maximal MBV attainable), and small (S; MBV at 50% of the large step). Increase in shear rate (estimate of shear stress: MBV/BAD) was 76.8 ± 15.6 s−1 for L and 41.4 ± 8.7 s−1 for S. The peak %FMD was 14.5 ± 3.8% for L and 5.7 ± 2.1% for S ( P < 0.001). Both the L (all subjects) and the S step trials (12 of 15 subjects) elicited a biphasic diameter response with a fast initial phase (phase I) followed by a slower final phase. Relative contribution of phase I to total FMD when two phases occurred was not sensitive to shear rate magnitude ( r2 = 0.003, slope P = 0.775). Parameters quantifying the dynamics of the FMD response [time delay (TD), time constant (τ)] were also not sensitive to shear rate magnitude for both phases (phase I: TD r2 = 0.03, slope P = 0.376, τ r2 = 0.04, slope P = 0.261; final phase: TD r2 = 0.07, slope P = 0.169, τ r2 = 0.07, slope P = 0.996). These data support the existence of two distinct mechanisms, or sets of mechanisms, in the human conduit artery FMD response that are proportionally sensitive to shear stimulus magnitude and whose dynamic response is not sensitive to shear stimulus magnitude.

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