Read by QxMD icon Read

carotid wall stress

Michel E Safar
Mid-life elevated BP is classically associated with a raised systemic vascular resistance. A classical interpretation of the association between aortic stiffness and blood pressure (BP) invokes hypertension as a simple form of premature aging that increases stress on the arterial wall and accelerates age-related stiffening of the aorta. Recent clinical and experimental data have called into question the directionality of this sequence of events associating stiffness and hypertension.Therefore an initial abnormality in stiffness may antedate and contribute initially to the pathogenesis of hypertension, namely isolated systolic hypertension...
September 2016: Journal of Hypertension
Giorgio Spatola, Laura Frosio, Marco Losa, Antonella Del Vecchio, Martina Piloni, Pietro Mortini
BACKGROUND: Gamma knife radiosurgery is an effective and safe treatment modality in the management of pituitary adenomas. Internal carotid occlusion is a rare but possible complication of Gamma Knife Radiosurgery for lesions within the cavernous sinus. AIM: To stress the importance of considering the Internal carotid artery as an organ at risk in cavernous sinus invading adenomas and reduce the dose delivered to this structure whenever possible. CASE DESCRIPTION: We report two cases of asymptomatic occlusion of the intracavernous segment of the internal carotid artery seven years after treatment in acromegalic patients...
November 2016: Reports of Practical Oncology and Radiotherapy
Sophia F Shakur, Victor A Aletich, Sepideh Amin-Hanjani, Ahmed E Hussein, Fady T Charbel, Ali Alaraj
BACKGROUND: Pipeline embolization devices (PEDs) are commonly used for endovascular treatment of cerebral aneurysms but can be associated with delayed ipsilateral intraparenchymal hemorrhage. Although intra-aneurysmal hemodynamic changes have been studied, parent vessel and intracranial hemodynamics after PED use are unknown. We examine the impact of flow diversion on parent artery and distal intracranial hemodynamics. METHOD: Patients with internal carotid cerebral aneurysms treated with PED who had flow volume rate, flow velocities, pulsatility index, resistance index, Lindegaard ratio, and wall shear stress (WSS) obtained after treatment using quantitative magnetic resonance angiography were reviewed...
October 4, 2016: Interventional Neuroradiology
Merih Cibis, Wouter V Potters, Frank J Gijsen, Henk Marquering, Pim van Ooij, Ed vanBavel, Jolanda J Wentzel, Aart J Nederveen
INTRODUCTION: Wall shear stress (WSS) and oscillatory shear index (OSI) are associated with atherosclerotic disease. Both parameters are derived from blood velocities, which can be measured with phase-contrast MRI (PC-MRI). Limitations in spatiotemporal resolution of PC-MRI are known to affect these measurements. Our aim was to investigate the effect of spatiotemporal resolution using a carotid artery phantom. METHODS: A carotid artery phantom was connected to a flow set-up supplying pulsatile flow...
2016: PloS One
Michel E Safar
Mid-life elevated BP is classically associated with a raised systemic vascular resistance. A classical interpretation of the association between aortic stiffness and blood pressure (BP) invokes hypertension as a simple form of premature aging that increases stress on the arterial wall and accelerates age-related stiffening of the aorta. Recent clinical and experimental data have called into question the directionality of this sequence of events associating stiffness and hypertension.Therefore an initial abnormality in stiffness may antedate and contribute initially to the pathogenesis of hypertension, namely isolated systolic hypertension...
September 2016: Journal of Hypertension
Jane M Black, Eric J Stöhr, Keeron Stone, Christopher J A Pugh, Mike Stembridge, Rob Shave, Joseph I Esformes
Arterial wall mechanics likely play an integral role in arterial responses to acute physiological stress. Therefore, this study aimed to determine the impact of low and moderate intensity double-leg press exercise on common carotid artery (CCA) wall mechanics using 2D vascular strain imaging. Short-axis CCA ultrasound images were collected in 15 healthy men (age: 21 ± 3 years; stature: 176.5 ± 6.2 cm; body mass; 80.6 ± 15.3 kg) before, during, and immediately after short-duration isometric double-leg press exercise at 30% and 60% of participants' one-repetition maximum (1RM: 317 ± 72 kg)...
September 2016: Physiological Reports
Rasmus F W Olander, Johnny K M Sundholm, Tiina H Ojala, Sture Andersson, Taisto Sarkola
BACKGROUND: Restriction in fetal growth is associated with cardiovascular disease in adulthood. It is unclear whether abnormal intrauterine growth influences arterial morphology during the fetal or neonatal stage. The objective was to study the regional arterial morphology with respect to gestational age and abnormal fetal body size. METHODS AND RESULTS: We studied body anthropometrics and arterial morphology and physiology in 174 neonates born between 31 and 42 weeks of gestation, including neonates with birth weights appropriate, small, and large for age, with very high resolution vascular ultrasound (35-55 MHz)...
September 2016: Circulation. Cardiovascular Imaging
Hamidreza Gharahi, Byron A Zambrano, David C Zhu, J Kevin DeMarco, Seungik Baek
Blood flow patterns and local hemodynamic parameters have been widely associated with the onset and progression of atherosclerosis in the carotid artery. Assessment of these parameters can be performed noninvasively using cine phase-contrast (PC) magnetic resonance imaging (MRI). In addition, in the last two decades, computational fluid dynamics (CFD) simulation in three dimensional models derived from anatomic medical images has been employed to investigate the blood flow in the carotid artery. This study developed a workflow of a subject-specific CFD analysis using MRI to enhance estimating hemodynamics of the carotid artery...
March 2016: International Journal of Advances in Engineering Sciences and Applied Mathematics
L Marais, P Boutouyrie, H Khettab, C Boulanger, A Lorthiroir, M Frank, R Niarra, J Renard, Y Chambon, X Jeunemaitre, M Zidi, P-F Plouin, S Laurent, M Azizi
OBJECTIVE: Fibromuscular dysplasia (FMD) is a non-atherosclerotic non-inflammatory arterial disease, which occurs mostly in middle-aged women and affects medium-sized arteries. We previously showed abnormalities within common carotid artery (CCA) wall, with the presence of triple signal (TS) at ultrasound suggesting the presence of supplementary layers. We aimed at coupling TS presence with microconstituents of the vessel wall, derived from fitting of the pressure-diameter curve. DESIGN AND METHOD: We included 50 non-smoking patients with multifocal FMD, 50 essential hypertensive (EH) patients and 50 healthy subjects (HS) matched for age, sex, ethnicity and BP (EH and FD)...
September 2016: Journal of Hypertension
Kartik V Bulusu, Michael W Plesniak
The arterial network in the human vasculature comprises of ubiquitously present blood vessels with complex geometries (branches, curvatures and tortuosity). Secondary flow structures are vortical flow patterns that occur in curved arteries due to the combined action of centrifugal forces, adverse pressure gradients and inflow characteristics. Such flow morphologies are greatly affected by pulsatility and multiple harmonics of physiological inflow conditions and vary greatly in size-strength-shape characteristics compared to non-physiological (steady and oscillatory) flows (1 - 7)...
2016: Journal of Visualized Experiments: JoVE
Konstantinos M Lampropoulos, Dimitrios P Sokolis
BACKGROUND: Limited attention has been paid to the role of beta-adrenergic blocking agents on large artery function/structure, despite being clinically useful for treating many forms of cardiovascular disease. OBJECTIVE: To assess long-term consequences of beta-blocker administration on the biomechanical properties, geometry, and histological structure of two major elastic arteries. METHODS: Healthy male rats received water with their food, while beta-blockade was produced in rats by adding propranolol in their drinking water...
July 29, 2016: Biorheology
Shusaku Sone, Toshiyuki Hayase, Kenichi Funamoto, Atsushi Shirai
Understanding the spatiotemporal change in hemodynamics is essential for the basic research of atherosclerosis. The objective of this study was to establish a methodology to clarify the relation between a two-dimensional (2D) unsteady blood flow field and forward and backward propagating waves in a carotid artery. This study utilized photoplethysmography (PPG) for blood pressure measurement and two-dimensional ultrasonic-measurement-integrated (2D-UMI) simulation for flow field analysis. The validity of the methodology was confirmed in an experiment for a carotid artery of a healthy volunteer...
July 27, 2016: Medical & Biological Engineering & Computing
Morsal Momeni Larimi, Abas Ramiar, Ali A Ranjbar
Nanoparticles play an important role in the molecular diagnosis, treatment, and monitoring therapeutic outcomes in various diseases. Magnetic nanoparticles are being of great interest due to their unique purposes, especially medicine, in which the application of magnetic nanoparticles is much promising. Magnetic nanoparticles have been actively investigated as the next generation of targeted drug delivery for more than three decades. This article is devoted to study on the magnetic drug targeting technique by particle tracking in the presence of a magnetic field in the carotid artery...
July 14, 2016: Proceedings of the Institution of Mechanical Engineers. Part H, Journal of Engineering in Medicine
Laura Ellwein, Margaret M Samyn, Michael Danduran, Sheila Schindler-Ivens, Stacy Liebham, John F LaDisa
Image-based computational fluid dynamics (CFD) studies conducted at rest have shown that atherosclerotic plaque in the thoracic aorta (TA) correlates with adverse wall shear stress (WSS), but there is a paucity of such data under elevated flow conditions. We developed a pedaling exercise protocol to obtain phase contrast magnetic resonance imaging (PC-MRI) blood flow measurements in the TA and brachiocephalic arteries during three-tiered supine pedaling at 130, 150, and 170 % of resting heart rate (HR), and relate these measurements to non-invasive tissue oxygen saturation [Formula: see text] acquired by near-infrared spectroscopy (NIRS) while conducting the same protocol...
July 4, 2016: Biomechanics and Modeling in Mechanobiology
David De Wilde, Bram Trachet, Guido De Meyer, Patrick Segers
BACKGROUND: Low and oscillatory wall shear stresses (WSS) near aortic bifurcations have been linked to the onset of atherosclerosis. In previous work, we calculated detailed WSS patterns in the carotid bifurcation of mice using a Fluid-structure interaction (FSI) approach. We subsequently fed the animals a high-fat diet and linked the results of the FSI simulations to those of atherosclerotic plaque location on a within-subject basis. However, these simulations were based on boundary conditions measured under anesthesia, while active mice might experience different hemodynamics...
June 15, 2016: Journal of Biomechanics
Claudio Carallo, Cesare Tripolino, Maria Serena De Franceschi, Concetta Irace, Xiao Yun Xu, Agostino Gnasso
BACKGROUND AND AIMS: Atherosclerosis is associated with clinical, biochemical and haemodynamic risk factors. In a group of subjects studied twelve years apart, we evaluated carotid plaque development in relation to baseline and to changes at follow-up in common carotid haemodynamic profile. METHODS: Forty-eight participants were recruited to a cardiovascular disease prevention programme. Atherosclerotic plaques were evaluated and scored by echography. Endothelial shear stress, circumferential wall tension, and Peterson's elastic modulus as an index of arterial stiffness, were computed by echo-Doppler, along with blood viscosity data...
August 2016: Atherosclerosis
A Tuenter, M Selwaness, A Arias Lorza, J C H Schuurbiers, L Speelman, M Cibis, A van der Lugt, M de Bruijne, A F W van der Steen, O H Franco, M W Vernooij, J J Wentzel
BACKGROUND AND AIMS: Carotid artery plaques with vulnerable plaque components are related to a higher risk of cerebrovascular accidents. It is unknown which factors drive vulnerable plaque development. Shear stress, the frictional force of blood at the vessel wall, is known to influence plaque formation. We evaluated the association between shear stress and plaque components (intraplaque haemorrhage (IPH), lipid rich necrotic core (LRNC) and/or calcifications) in relatively small carotid artery plaques in asymptomatic persons...
August 2016: Atherosclerosis
Jimmy Tat, Ioannis N Psaromiligkos, Stella S Daskalopoulou
Longitudinal motion of the artery, a cyclical, bidirectional movement of the wall in the long axis of the artery, has recently gained interest in the characterization of artery function. The aim of this study was to evaluate longitudinal motion in patients with internal carotid atherosclerotic plaques. Speckle tracking ultrasound was used to assess common carotid artery wall motion in 12 patients with carotid plaque causing either moderate (50%-79%) or severe (80%-99%) stenosis based on the North American Carotid Endarterectomy Trial, and 23 healthy participants...
September 2016: Ultrasound in Medicine & Biology
Tatsunori Saho, Hideo Onishi
In this study, we evaluated the hemodynamics of carotid artery bifurcation with various geometries using simulated and volunteer models based on magnetic resonance imaging (MRI). Computational fluid dynamics (CFD) was analyzed by use of OpenFOAM. The velocity distribution, streamline, and wall shear stress (WSS) were evaluated in a simulated model with known bifurcation angles (30°, 40°, 50°, 60°, derived from patients' data) and in three-dimensional (3D) healthy volunteer models. Separated flow was observed at the outer side of the bifurcation, and large bifurcation models represented upstream transfer of the point...
July 2016: Radiological Physics and Technology
Muhammad Jamil, Germaine Xin Yi Tan, Mehnaz Huq, Heidi Kang, Zhi Rui Lee, Phua Hwee Tang, Xi Hong Hu, Choon Hwai Yap
BACKGROUND: The Moyamoya disease is a cerebrovascular disease that causes occlusion of the distal end of the internal carotid artery, leading to the formation of multiple tiny collateral arteries. To date, the pathogenesis of Moyamoya is unknown. Improved understanding of the changes to vascular geometry and fluid mechanics of the carotid siphon during disease may improve understanding of the pathogenesis, prognosis techniques and disease management. METHODS: A retrospective analysis of Magnetic Resonance Angiography (MRA) images was performed for Moyamoya pediatric patients (MMD) (n = 23) and control (Ctrl) pediatric patients (n = 20)...
May 11, 2016: Computer Methods in Biomechanics and Biomedical Engineering
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"