Biaxial Mechanical Properties of Carotid Arteries From Normotensive and Hypertensive Rats

Lichtenstein, Oscar; Safar, Michel E.; Poitevin, Pierre; Lévy, Bernard

doi:10.1161/01.hyp.26.1.15

Cited by 22 publications

(15 citation statements)

References 21 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The identical values we observed for carotid wall elasticity and MS in the circumferential direction illustrates the anisotropy of the wall. 17,18 Thus our study demonstrates that the global mechanical behavior of the SHR CA is well adapted to the increase in circumferential wall stress. This finding is consistent with previous in vivo observations of an adaptation of arterial elasticity in genetic hypertension in rats and human beings.…”

Section: Cohuet Et Al Arterial Mechanical Strength In Shrsupporting

confidence: 54%

Mechanical Strength of the Isolated Carotid Artery in SHR

et al. 2001

View full text Add to dashboard Cite

Abstract-We have previously reported an adaptation of arterial wall elasticity in spontaneously hypertensive rats (SHR) that involves an increase in both fibronectin/␣5␤1-integrin complexes and smooth-muscle elastic lamellae connections. We examined the mechanical strength (MS) of the carotid artery in relation to its elastic properties, its elastin/collagen content, and the structure of the internal elastic lamina. MS was defined as the in vitro intraluminal pressure and wall stress that produces rupture of the vascular wall. Intact carotid arteries from 3-month-old normotensive rats (Wistar-Kyoto, WKY) and SHR were cannulated on a specially designed device and adjusted to their in situ length. A slowly increasing static pressure was applied until wall rupture occurred to determine the static mechanical behavior and MS. Static elasticity was similar in SHR and WKY, as were the rupture pressure (2740Ϯ90 versus 2740Ϯ40 mm Hg) and wall stress at rupture (11.5Ϯ1.0 versus 12.8Ϯ0.4 MPa), indicating equivalent MS in both groups. Histological examination showed several wall ruptures and dissociation of lamellar units that did not differ significantly between the 2 groups. Confocal microscopy showed that the size of fenestrations of the internal elastic lamina and the fraction of area occupied by them were reduced 3-fold in SHR. We have demonstrated that static elasticity of the arterial wall and mechanical strength are similar in carotid arteries from SHR and WKY. (Hypertension. 2001;38:1167-1171.)

show abstract

Section: Cohuet Et Al Arterial Mechanical Strength In Shrsupporting

confidence: 54%

Mechanical Strength of the Isolated Carotid Artery in SHR

et al. 2001

View full text Add to dashboard Cite

show abstract

“…In this study, the investigated arterial segment showed a lengthening in systole, which is in concordance with previous results from video microscopy in rats [14] but contradictive to a previous study using sonomicrometry in a porcine model [15]. In the latter, a shortening of the carotid artery in systole was demonstrated.…”

Section: Discussionsupporting

confidence: 75%

Assessment of longitudinal strain in the carotid artery wall using ultrasound-based Speckle tracking - Validation in a sheep model

Larsson

Verbrugghe

Smoljkic

et al. 2013

2013 IEEE International Ultrasonics Symposium (IUS)

View full text Add to dashboard Cite

Abstract-Assessment of strain in the longitudinal direction of the arterial wall has been suggested to improve the evaluation of arterial stiffness and atherosclerosis. Recently, we showed the feasibility of ultrasound speckle tracking to assess carotid longitudinal strain in-silico and in-vitro. However, validation in the more challenging in-vivo setting is still lacking. The aim of this study was to validate longitudinal strain assessment in the common carotid artery (CCA) in an animal setup. The left CCAs of five sheep were exposed during Isoflurane anesthesia and sonomicrometry crystals were sutured onto the artery wall to obtain reference longitudinal strain. Ultrasound long-axis images were recorded at baseline and hypertension (Phenylephrine) and an in-house speckle tracking algorithm was applied to estimate longitudinal strain. The estimated strain curves varied cyclically throughout the cardiac cycles, showing a lengthening of the arterial segment in systole. A significant correlation between peak systolic estimated and reference strain was found (r=0.95, p < 0.001). The results indicate the feasibility of arterial longitudinal strain assessment in-vivo using ultrasound speckle tracking.

show abstract

“…Finally, for measurement of carotid E inc , the classic assumption of equal stiffness in all directions may be highly questionable, a major point that we and others have previously and extensively discussed. 28,35,36 Taken together, these findings indicate that E inc should be considered to be only an "effective" measurement for clinical applications.…”

Section: Basic Concepts In Arterial Structure and Functionmentioning

confidence: 90%

“…31 However, these findings are limited to the circumferential direction (due to cross-sectional measurements) and might differ in the longitudinal axis. 35,36 Levels of compliance and distensibility differed in accordance with the topography of the vessels; for the radial artery, normal (operational conditions) or increased (isobaric conditions) values have been reported, whereas for the carotid artery, reduced (operational conditions) or normal (isobaric conditions) values were observed. 16,17,31,32,45 In middle-aged hypertensive patients, the mechanisms responsible for such minor changes in E inc remain difficult to elucidate, given that increased wall thickness might modify vascular stiffness.…”

Section: Carotid and Radial Arterial Wall Hypertrophy With Normal Walmentioning

confidence: 99%

Stiffness of Carotid Artery Wall Material and Blood Pressure in Humans

Safar

Blacher

Mourad

et al. 2000

Stroke

115

View full text Add to dashboard Cite

Background and Purpose-Because epidemiological studies show that increased pulse pressure and carotid wall-material stiffness are predictors of cardiovascular mortality independent of age, atherosclerosis, and conventional risk factors, the relationships between carotid wall stiffness and blood pressure are important to the optimization of cardiovascular prevention. Summary of Review-In middle-aged hypertensive patients, mean and pulse pressures are increased, and systolic and diastolic pressures are increased to the same degree as mean pressure. Carotid hypertrophy is associated with normal wall stress, but no increased stiffness of wall material has been reported. With age, the normal wall stress is associated with a larger diameter and a stiffer material of carotid but not peripheral arteries. The stiffer wall involves calcifications, large amounts of collagen, and fragmentation and rupture of elastic tissue, which results in increased pulse-wave velocity and alterations of amplitude and timing of wave reflections and thus causes a disproportionate increase in systolic and pulse pressure. During this period, acutely administered nitrates in elderly subjects are able to reduce selectively systolic and pulse pressures without altering diastolic and mean blood pressure and composition of the carotid wall. Conclusions-New therapeutic approaches acting mainly on the wall of large arteries are needed to treat hypertension in elderly patients and prevent stroke and myocardial infarction. These drugs could either selectively lower pulse pressure through changes in wave reflections (as nitrates do) or decrease arterial wall stiffness through modification of the composition of material (such as compounds that act on collagen cross-linking). (Stroke. 2000;31:782-790.)

show abstract

Biaxial Mechanical Properties of Carotid Arteries From Normotensive and Hypertensive Rats

Cited by 22 publications

References 21 publications

Mechanical Strength of the Isolated Carotid Artery in SHR

Mechanical Strength of the Isolated Carotid Artery in SHR

Assessment of longitudinal strain in the carotid artery wall using ultrasound-based Speckle tracking - Validation in a sheep model

Stiffness of Carotid Artery Wall Material and Blood Pressure in Humans

Contact Info

Product

Resources

About