scholarly journals Noninvasive Assessment of Endothelium-Dependent Flow-Mediated Dilation of the Brachial Artery

1997 ◽  
Vol 2 (2) ◽  
pp. 87-92 ◽  
Author(s):  
Akimi Uehata ◽  
Eric H Lieberman ◽  
Marie D Gerhard ◽  
Todd J Anderson ◽  
Peter Ganz ◽  
...  
Keyword(s):  
Blood Flow ◽  
Endothelial Function ◽  
Brachial Artery ◽  
Vascular Function ◽  
Reactive Hyperemia ◽  
Intraobserver Variability ◽  
Flow Mediated Dilation ◽  
Noninvasive Technique ◽  
Brachial Artery Diameter ◽  
Cuff Occlusion

Coronary atherosclerosis is characterized by an early loss of endothelium-dependent vasodilation. However, the methods of assessing coronary endothelial function are invasive and difficult to repeat over time. Recently, a noninvasive ultrasound method has been widely used to measure flow-mediated dilation in the brachial artery as a surrogate test for endothelial function. We seek to further validate this method of measuring vascular function. The brachial artery diameters and blood flow of 20 normal volunteers (10 males and 10 females) were measured using high resolution (7.5 MHz) ultrasound and strain gauge plethysmography. Flow-mediated endothelium-dependent vasodilation was measured in the brachial artery during reactive hyperemia after 5 minutes of cuff occlusion in the upper arm. The brachial artery diameter increased maximally by 9.7 ± 4.3% from baseline at 1 min after cuff release and blood flow increased by 1002 ± 376%. Five min of cuff occlusion was sufficient to achieve 97 ± 6% of maximal brachial artery dilation and degree of dilation was not different whether the cuff was inflated proximally or distally to the image site. The intraobserver variability in measuring brachial diameters was 2.9 % and the variability of the hyperemic response was 1.4%. In young, healthy men and women, the baseline brachial artery diameter was the only factor that was predictive of the flow-mediated vasodilation response. The brachial noninvasive technique has been further validated by the determination of flow-mediated dilation. This method of assessing endothelial function may help to determine the importance of vasodilator dysfunction as a risk factor in the development of atherosclerosis.

Technical aspects of evaluating brachial artery vasodilatation using high-frequency ultrasound

1995 ◽  
Vol 268 (4) ◽  
pp. H1397-H1404 ◽  
Author(s):  
M. C. Corretti ◽  
G. D. Plotnick ◽  
R. A. Vogel
Keyword(s):  
Blood Flow ◽  
Brachial Artery ◽  
Artery Occlusion ◽  
High Frequency Ultrasound ◽  
Noninvasive Technique ◽  
Brachial Artery Diameter ◽  
Pressure Cuff ◽  
Artery Disease ◽  
Cuff Occlusion ◽  
Frequency Ultrasound

Flow-mediated brachial artery vasoactivity has been recently proposed as a noninvasive means for assessing endothelial function. To better characterize this technique, we measured brachial artery diameter and flow using 7.5-MHz ultrasound following 1, 3, and 5 min of upper arm blood pressure cuff occlusion in 19 normal volunteers and 13 patients with coronary artery disease (CAD). Although similar flow increases were observed with each protocol, statistically significant vasodilatation (12.6 +/- 5.7%) was observed in the normals only after 5 min of occlusion. With the use of this protocol, postocclusion blood flow increased 528 +/- 271 and 481 +/- 247% in the normals and CAD patients, respectively (P = NS). More vasodilatation was observed in the normals compared with the CAD patients (11.3 +/- 5.4 vs. 1.6 +/- 5.2%, P < 0.001). Interestingly, vasodilatation persisted for 20 min despite return of blood flow to baseline in 2 min. With the use of lower arm occlusion, arterial diameter was found to decrease 4.4 +/- 3.9% in response to a 85 +/- 7% decrease in flow. We conclude that 1) longer brachial artery occlusion results in more vasodilatation despite similar hyperemic responses, 2) vasodilatation persists substantially beyond hyperemia, and 3) CAD patients have impaired flow-mediated vasodilatation using this noninvasive technique.

Abstract 12000: Altered Vascular Elasticity Reflected Vascular Endothelial Dysfunction and Elevated Galectin-3 Using Novel Brachial Artery Vascular Volume Elastic Modulus With Automated Oscillometric Approach

Circulation ◽  
2015 ◽  
Vol 132 (suppl_3) ◽  
Author(s):  
Keiichiro Yoshinaga ◽  
Yuuki Tomiyama ◽  
Satoshi Fujii ◽  
Saori Nishio ◽  
Noriki Ochi ◽  
...  
Keyword(s):  
Elastic Modulus ◽  
Brachial Artery ◽  
Vascular Function ◽  
Inflammatory Marker ◽  
Reactive Hyperemia ◽  
Vascular Stiffness ◽  
Brachial Artery Diameter ◽  
Novel Approach ◽  
Galectin 3 ◽  
Vascular Elasticity

Introduction: Simple vascular function measurements are desirable for atherosclerosis risk assessments. Recently, we developed a novel modality of automated oscillometric method to measure a brachial artery’s vascular elastic modulus (V E ) and reported that V E is uninfluenced by blood pressure. Galectin-3 (Gal-3) expressed in endothelial cells regulates vascular fibrosis and is a molecular determinant of vascular stiffness. Hypothesis: We aimed to clarify whether V E selectively correlates with marker of vascular stiffness in chronic kidney disease (CKD). Methods: 12 moderate-to-severe CKD pts (mean eGFR 25.9±23.5 mL/min/1.73m 2 ) and 15 controls were studied. Rest V E in brachial artery was measured by new automated oscillometric detector. V E was defined as follows [VE =ΔPressure/ (100XΔarea/Area) mmHg/%]. Using ultrasound, the brachial artery diameter at rest and during reactive hyperemia [flow mediated dilatation (FMD) with endothelial-dependent dilatation] was measured. Gal-3 and interleukin-6 (IL-6), a representative inflammatory marker, were measured by enzyme-linked immune assay. Results: CKD had lower FMD (4.86±3.37 vs 9.05±2.98 %, P=0.003) and had attenuated V E than control (1.08±0.26 vs 0.83±0.17 mmHg/%, P=0.002). CKD had higher IL-6 (0.67±0.29 vs 0.29±0.33 pg/mL, P=0.003) and higher Gal-3 (20.0±12.4 vs. 5.84±2.83 pg/mL, P<0.001). V E was negatively correlated with %FMD (r=-0.46, P=0.015) and correlated with Gal-3 (r=0.40, P=0.036) but not in IL-6 (r=0.21, P=0.28). Conclusions: Attenuated vascular elasticity detected by this novel approach closely correlated with increase in Gal-3 and reduced FMD in CKD. This may indicate that the attenuated vascular elasticity selectively reflects vascular fibrosis as evidenced by Gal-3 and subsequent endothelial responses to vascular stiffness. Thus, this oscillometric measurement may be useful for detecting vascular fibrosis information and dysfunction in endothelium level.

Abstract 16530: Post-exercise Flow-mediated Dilation is augmented in Highly Trained Female Athletes

Circulation ◽  
2015 ◽  
Vol 132 (suppl_3) ◽  
Author(s):  
Daniela K Andaku ◽  
Bruno Archiza ◽  
Flavia C Caruso ◽  
Katiany T Zangrando ◽  
Humberto Lanzotti ◽  
...  
Keyword(s):  
Flow Velocity ◽  
Brachial Artery ◽  
Vascular Function ◽  
Female Athletes ◽  
Maximal Exercise ◽  
High Volume ◽  
Flow Mediated Dilation ◽  
Brachial Artery Diameter ◽  
Arterial Function ◽  
Training History

Background: Recent evidence has indicated a ceiling to the benefits of exercise training that, if chronically surpassed, may have a negative effect on cardiac function. Conversely, improvements in peripheral arterial function may respond positively to chronic high volume training. Recent studies have shown that flow-mediated dilation (FMD) is decreased immediately after maximal exercise in sedentary subjects and is unaltered in subjects who participate in moderate volume exercise. We investigated the acute effects of maximal exercise on vascular function of elite female athletes with a high-volume training history. Methods: Fifteen elite female soccer players (mean age: 22.1 ± 4.4 years; BMI: 20.76 ± 1.75 kg/m2), with a high volume/intensity training history (4-6 hours per day) were evaluated. Subjects underwent maximal cardiopulmonary exercise testing (CPX) on a treadmill (VO2max 41.1 ± 3.9 mLO2•kg-1•min-1). Brachial artery FMD was determined using high-resolution ultrasound before and immediately after CPX. Flow velocity were measured at baseline (BSL) and during reactive hyperemia (RH) both prior to and following exercise. Results: Brachial artery diameter increased during RH before (3.42 ± 0.38mm vs. 3.03 ± 0.28mm, p<0.001) and after CPX (3.61 ± 0.44mm vs. 3.10 ± 0.37mm, p<0.001). Importantly, FMD was increased following CPX compared to BSL (16.86 ± 9.04% vs. 12.95 ± 7.03%, p=0.027). There was significant increase in peak flow velocity during RH before (135.28 ± 42.19cm/s vs. 79.19 ± 28.14cm/s, p=0.001) and after CPX (139.15 ± 41.07cm/s vs. 87.64 ± 21.23cm/s, p<0.001) (Table). Conclusion: The results of the current study indicate that arterial function is improved following acute aerobic exercise in elite female athletes with a chronic high volume training history. These findings deviate from the emerging literature suggesting chronic high volume training may be detrimental to cardiovascular function in the long term.

scholarly journals Study of endothelial function in pregnant women with gestational diabetes mellitus by flow mediated dilation of brachial artery

2020 ◽  
Vol 9 (6) ◽  
pp. 2377
Author(s):  
Nidhi Pandey ◽  
Poonam Goel ◽  
Anita Malhotra ◽  
Reeti Mehra ◽  
Navjot Kaur
Keyword(s):  
Gestational Diabetes ◽  
Endothelial Function ◽  
Pregnant Women ◽  
Brachial Artery ◽  
Vascular Function ◽  
Post Partum ◽  
Control Group ◽  
Flow Mediated Dilation ◽  
The Mean ◽  
The Difference

Background: The objective of the study was to assess vascular function in normal pregnant women and women with gestational diabetes and to study its temporal relationship with gestational age at 24-28-week POG and at 36-38-week POG and changes in FMD in postpartum period.Methods: Assessment of vascular function was done at 24-28-week POG, 36-38-week POG and at 6-12-week postpartum by flow mediated dilation of brachial artery in 37 healthy pregnant women and 37 pregnant women with GDM.Results: In GDM group mean FMD at 24-28 weeks of POG, at 36-38 weeks POG was lower as compared to the control group (11.225±6.20,8.464±6.09 versus 14.49±5.21, 10.898±4.12) although the difference in mean FMD in two groups was not statistically significant. It was found that the decrease in FMD at 36-38-week POG as compared to 24-28 weeks POG was statistically significant in both the groups (p<0.001).Conclusions: This study revealed that when endothelial function as assessed by FMD was compared at different period of gestation, the mean decrease in FMD at 36-38-week POG as compared to 24-28-week POG and 6-week post-partum was statistically significant in patients with GDM and as well as the control group, however this trend of change was same in both the groups and was not statistically significant when compared between the two group (GDM versus control). A negative correlation of FMD was found with BMI, and HBA1c, that was stronger in GDM group.

Effects of polycythemia on systemic endothelial function in chronic hypoxic lung disease

2011 ◽  
Vol 110 (5) ◽  
pp. 1196-1203 ◽  
Author(s):  
Laurent Boyer ◽  
Vicky Chaar ◽  
Gabriel Pelle ◽  
Bernard Maitre ◽  
Christos Chouaid ◽  
...  
Keyword(s):  
Endothelial Function ◽  
Brachial Artery ◽  
Blood Viscosity ◽  
Vascular Function ◽  
Venous Occlusion ◽  
Chronic Obstructive ◽  
Brachial Artery Diameter ◽  
Obstructive Pulmonary Disease ◽  
Vasoconstrictor Response ◽  
No Release

Chronic obstructive pulmonary disease (COPD) is a major risk factor for cardiovascular disease. Polycythemia, a common complication of hypoxic COPD, may affect systemic vascular function by altering blood viscosity, vessel wall shear stress (WSS), and endothelium-derived nitric oxide (NO) release. Here, we evaluated the effects of hypoxia-related polycythemia on systemic endothelial function in patients with COPD. We investigated blood viscosity, WSS, and endothelial function in 15 polycythemic and 13 normocythemic patients with COPD of equal severity, by recording brachial artery diameter variations in response to hyperemia and by using venous occlusion plethysmography (VOP) to measure forearm blood flow (FBF) responses to a brachial artery infusion of acetylcholine (ACh), bradykinin (BK), sodium nitroprusside (SNP), substance P (SP), isoptin, and N-monomethyl-l-arginine (l-NMMA). At baseline, polycythemic patients had higher blood viscosity and larger brachial artery diameter than normocythemic patients but similar calculated WSS. Flow-mediated brachial artery vasodilation was increased in the polycythemic patients, in proportion to the hemoglobin levels. ACh-induced vasodilation was markedly impaired in the polycythemic patients and negatively correlated with hemoglobin levels. FBF responses to endothelium- (BK, SP) and non-endothelium-dependent (SNP, isoptin) vasodilators were not significantly different between the two groups. l-NMMA infusion induced a similar vasoconstrictor response in both groups, in accordance with their similar baseline WSS. In conclusion, systemic arteries in polycythemic patients adjust appropriately to chronic or acute WSS elevations by appropriate basal and stimulated NO release. Overall, our results suggest that moderate polycythemia has no adverse effect on vascular function in COPD.

Combined aerobic and resistance training and vascular function: effect of aerobic exercise before and after resistance training

2007 ◽  
Vol 103 (5) ◽  
pp. 1655-1661 ◽  
Author(s):  
Takanobu Okamoto ◽  
Mitsuhiko Masuhara ◽  
Komei Ikuta
Keyword(s):  
Resistance Training ◽  
Aerobic Exercise ◽  
Brachial Artery ◽  
Vascular Function ◽  
Pulse Wave ◽  
Aerobic Exercise Training ◽  
Flow Mediated Dilation ◽  
Brachial Artery Diameter ◽  
Combined Training ◽  
Before And After

Aerobic exercise training combined with resistance training (RT) might prevent the deterioration of vascular function. However, how aerobic exercise performed before or after a bout of RT affects vascular function is unknown. The present study investigates the effect of aerobic exercise before and after RT on vascular function. Thirty-three young, healthy subjects were randomly assigned to groups that ran before RT (BRT: 4 male, 7 female), ran after RT (ART: 4 male, 7 female), or remained sedentary (SED: 3 male, 8 female). The BRT and ART groups performed RT at 80% of one repetition maximum and ran at 60% of the targeted heart rate twice each week for 8 wk. Both brachial-ankle pulse wave velocity (baPWV) and flow-mediated dilation (FMD) after combined training in the BRT group did not change from baseline. In contrast, baPWV after combined training in the ART group reduced from baseline (from 1,025 ± 43 to 910 ± 33 cm/s, P < 0.01). Moreover, brachial artery FMD after combined training in the ART group increased from baseline (from 7.3 ± 0.8 to 9.6 ± 0.8%, P < 0.01). Brachial artery diameter, mean blood velocity, and blood flow in the BRT and ART groups after combined training increased from baseline ( P < 0.05, P < 0.01, and P < 0.001, respectively). These values returned to the baseline during the detraining period. These values did not change in the SED group. These results suggest that although vascular function is not improved by aerobic exercise before RT, performing aerobic exercise thereafter can prevent the deteriorating of vascular function.

scholarly journals Brachial artery diameter, blood flow and flow-mediated dilation in sleep-disordered breathing

2009 ◽  
Vol 14 (4) ◽  
pp. 351-360 ◽  
Author(s):  
Hassan A Chami ◽  
Michelle J Keyes ◽  
Joseph A Vita ◽  
Gary F Mitchell ◽  
Martin G Larson ◽  
...  
Keyword(s):  
Blood Flow ◽  
Brachial Artery ◽  
Sleep Disordered Breathing ◽  
Flow Mediated Dilation ◽  
Brachial Artery Diameter ◽  
Disordered Breathing

Occlusion cuff position is an important determinant of the time course and magnitude of human brachial artery flow-mediated dilation

2000 ◽  
Vol 99 (4) ◽  
pp. 261-267 ◽  
Author(s):  
Karen L. BERRY ◽  
R. Andrew P. SKYRME-JONES ◽  
Ian T. MEREDITH
Keyword(s):  
Blood Flow ◽  
Brachial Artery ◽  
Time Course ◽  
Arterial Occlusion ◽  
Flow Mediated Dilation ◽  
Reactive Hyperaemia ◽  
Upper Arm ◽  
Brachial Artery Diameter ◽  
Occlusion Cuff ◽  
Forearm Occlusion

Non-invasive ultrasound techniques to assess flow-mediated vasodilation (FMD) are frequently used to assess arterial endothelial vasodilator function. However, the range of normal values varies considerably, possibly due to differences in methodological factors. We sought to determine the effect of occlusion cuff position on the time course and magnitude of brachial artery blood flow and flow-mediated dilation. Twelve healthy subjects underwent measurements of forearm blood flow using venous occlusion plethysmography (VOP) before and after 5 min of susprasystolic cuff inflation, using two randomly assigned occlusion cuff positions (upper arm and forearm). An additional 16 subjects underwent two brachial ultrasound studies, using the two cuff positions, to assess the extent and time course of changes in brachial artery diameter and blood flow. Maximum increase in blood flow (peak reactive hyperaemia), measured by VOP, occurred immediately upon each cuff deflation, but was greater after upper arm compared with forearm arterial occlusion (33.1±3.1 versus 22.8±2.2 ml/min per forearm tissue, P = 0.001). Maximal brachial artery FMD was significantly greater following upper arm occlusion (9.0±1.2%, mean±S.E.M.) compared with forearm occlusion (5.9±0.7%, P = 0.01). The time course of the change in brachial artery diameter was affected differently in response to each protocol. The time to peak dilation following upper arm occlusion was delayed by 22 s compared with forearm occlusion. Occlusion cuff position is thus a powerful determinant of peak reactive hyperaemia, volume repaid and the extent and time course of brachial artery FMD. Positioning the cuff on the upper arm produces a greater FMD. These results highlight the need for comparisons between FMD studies to be made with care.

Flow-mediated dilation in human brachial artery after different circulatory occlusion conditions

2004 ◽  
Vol 286 (1) ◽  
pp. H442-H448 ◽  
Author(s):  
Andrew C. Betik ◽  
Victoria B. Luckham ◽  
Richard L. Hughson
Keyword(s):  
Blood Flow ◽  
Brachial Artery ◽  
Reactive Hyperemia ◽  
Flow Mediated Dilation ◽  
High Frequency Ultrasound ◽  
Upper Arm ◽  
Random Measurement Error ◽  
Occlusion Cuff ◽  
Proximal Occlusion ◽  
Forearm Occlusion

Different magnitudes and durations of postocclusion reactive hyperemia were achieved by occluding different volumes of tissue with and without ischemic exercise to test the hypotheses that flow-mediated dilation (FMD) of the brachial artery would depend on the increase in peak flow rate or shear stress and that the position of the occlusion cuff would affect the response. The brachial artery FMD response was observed by high-frequency ultrasound imaging with curve fitting to minimize the effects of random measurement error in eight healthy, young, nonsmoking men. Reactive hyperemia was graded by 5-min occlusion distal to the measurement site at the wrist and the forearm and proximal to the site in the upper arm. Flow was further increased by exercise during occlusion at the wrist and forearm positions. For the two wrist occlusion conditions, flow increased eightfold and FMD was only 1 to 2% ( P > 0.05). After the forearm and upper arm occlusions, blood flow was almost identical but FMD after forearm occlusions was 3.4% ( P < 0.05), whereas it was significantly greater (6.6%, P < 0.05) and more prolonged after proximal occlusion. Forearm occlusion plus exercise caused a greater and more prolonged increase in blood flow, yet FMD (7.0%) was qualitatively and quantitatively similar to that after proximal occlusion. Overall, the magnitude of FMD was significantly correlated with peak forearm blood flow ( r = 0.59, P < 0.001), peak shear rate ( r = 0.49, P < 0.002), and total 5-min reactive hyperemia ( r = 0.52, P < 0.001). The prolonged FMD after upper arm occlusion suggests that the mechanism for FMD differs with occlusion cuff position.

Endothelial function of young healthy males following whole body resistance training

2005 ◽  
Vol 98 (6) ◽  
pp. 2185-2190 ◽  
Author(s):  
M. Rakobowchuk ◽  
C. L. McGowan ◽  
P. C. de Groot ◽  
J. W. Hartman ◽  
S. M. Phillips ◽  
...  
Keyword(s):  
Blood Flow ◽  
Shear Rate ◽  
Resistance Training ◽  
Endothelial Function ◽  
Resistance Exercise ◽  
Brachial Artery ◽  
Whole Body ◽  
Flow Mediated Dilation ◽  
Body Resistance ◽  
Time Point

Given the increasing emphasis on performance of resistance exercise as an essential component of health, we evaluated, using a prospective longitudinal design, the potential for resistance training to affect arterial endothelial function. Twenty-eight men (23 ± 3.9 yr old; mean ± SE) engaged in 12 wk of whole body resistance training five times per week using a repeating split-body 3-day cycle. Brachial endothelial function was measured using occlusion cuff-induced flow-mediated dilation. After occlusion of the forearm for 4.5 min, brachial artery dilation and postocclusion blood flow was measured continuously for 15 and 70 s, respectively. Peak and 10-s postocclusion blood flow, shear rate, and brachial artery flow-mediated dilation (relative and normalized to shear rate) were measured pretraining (Pre), at 6 wk of training (Mid), and at 13 wk of training (Post). Results indicated an increase of mean brachial artery diameter by Mid and Post vs. Pre. Peak and 10-s postocclusion blood flow increased by Mid and remained elevated at Post; however, shear rates were not different at any time point. Relative and normalized flow-mediated dilation was also not different at any time point. This study is the first to show that peripheral arterial remodeling does occur with resistance training in healthy young men. In addition, the increase in postocclusion blood flow may indicate improved resistance vessel function. However, unlike studies involving endurance training, flow-mediated dilation did not increase with resistance training. Thus arterial adaptations with high-pressure loads, such as those experienced during resistance exercise, may be quite different compared with endurance training.

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