Carotid blood flow changes with behavioral states in the late gestation llama fetus in utero.

PubMed

Blanco, C E; Giussani, D A; Riquelme, R A; Hanson, M A; Llanos, A J

1997-12-19

This study tested the hypothesis that in the llama fetus changes in cerebral blood flow are closely associated with changes in cerebral oxidative metabolism such as occur during transitions between electrocortical states. For the first time reported in any species, instantaneous changes in common carotid blood flow, employed as a continuous index of cerebrovascular perfusion, were related to instantaneous changes in electrocortical activity. Three late gestation fetal llamas were surgically prepared under general anesthesia with vascular catheters, a tracheal and amniotic catheter, and with electrodes implanted to monitor the fetal electrocorticogram (ECoG). In addition, Transonic flow probes were placed around a common carotid artery and a femoral artery. At least 4 days after surgery fetal arterial blood, amniotic and tracheal pressures, carotid and femoral blood flows and the fetal ECoG were recorded continuously. Our results suggest a close association between increases in common carotid blood flow and low voltage ECoG in the llama fetus. Close coupling between instantaneous changes in carotid blood flow and electrocortical states together with the lack of an increase in brain blood flow without increased cerebral oxygen extraction during hypoxemia in the llama fetus supports a fall in cerebral oxidative metabolism in this species during hypoxemic episodes.

Carotid Artery Stenting and Blood-Brain Barrier Permeability in Subjects with Chronic Carotid Artery Stenosis.

PubMed

Szarmach, Arkadiusz; Halena, Grzegorz; Kaszubowski, Mariusz; Piskunowicz, Maciej; Studniarek, Michal; Lass, Piotr; Szurowska, Edyta; Winklewski, Pawel J

2017-05-08

Failure of the blood-brain barrier (BBB) is a critical event in the development and progression of diseases such as acute ischemic stroke, chronic ischemia or small vessels disease that affect the central nervous system. It is not known whether BBB breakdown in subjects with chronic carotid artery stenosis can be restrained with postoperative recovery of cerebral perfusion. The aim of the study was to assess the short-term effect of internal carotid artery stenting on basic perfusion parameters and permeability surface area-product (PS) in such a population. Forty subjects (23 males) with stenosis of >70% within a single internal carotid artery and neurological symptoms who underwent a carotid artery stenting procedure were investigated. Differences in the following computed tomography perfusion (CTP) parameters were compared before and after surgery: global cerebral blood flow (CBF), cerebral blood volume (CBV), mean transit time (MTT), time to peak (TTP) and PS. PS acquired by CTP is used to measure the permeability of the BBB to contrast material. In all baseline cases, the CBF and CBV values were low, while MTT and TTP were high on both the ipsi- and contralateral sides compared to reference values. PS was approximately twice the normal value. CBF was higher (+6.14%), while MTT was lower (-9.34%) on the contralateral than on the ipsilateral side. All perfusion parameters improved after stenting on both the ipsilateral (CBF +22.66%; CBV +18.98%; MTT -16.09%, TTP -7.62%) and contralateral (CBF +22.27%, CBV +19.72%, MTT -14.65%, TTP -7.46%) sides. PS decreased by almost half: ipsilateral -48.11%, contralateral -45.19%. The decline in BBB permeability was symmetrical on the ipsi- and contralateral sides to the stenosis. Augmented BBB permeability can be controlled by surgical intervention in humans.

Chronic Lowering of Blood Pressure by Carotid Baroreflex Activation: Mechanisms and Potential for Hypertension Therapy

PubMed Central

Lohmeier, Thomas E.; Iliescu, Radu

2011-01-01

Recent technical advances have renewed interest in device-based therapy for the treatment of drug-resistant hypertension. Findings from recent clinical trials regarding the efficacy of electrical stimulation of the carotid sinus for the treatment of resistant hypertension are reviewed here. The main goal of this article, however, is to summarize the preclinical studies that have provided insight into the mechanisms that account for the chronic blood pressure lowering effects of carotid baroreflex activation. Some of the mechanisms identified were predictable and confirmed by experimentation. Others have been surprising and controversial and resolution will require further investigation. Although feasibility studies have been promising, firm conclusions regarding the value of this device-based therapy for the treatment of resistant hypertension awaits the results of current multicenter trials. PMID:21357283

Dynamic alteration of regional cerebral blood flow during carotid compression and proof of reversibility.

PubMed

Asahi, Kouichi; Hori, M; Hamasaki, N; Sato, S; Nakanishi, H; Kuwatsuru, R; Sasai, K; Aoki, S

2012-01-01

It is difficult to non-invasively visualize changes in regional cerebral blood flow caused by manual compression of the carotid artery. To visualize dynamic changes in regional cerebral blood flow during and after manual compression of the carotid artery. Two healthy volunteers were recruited. Anatomic features and flow directions in the circle of Willis were evaluated with time-of-flight magnetic resonance angiography (MRA) and two-dimensional phase-contrast (2DPC) MRA, respectively. Regional cerebral blood flow was visualized with territorial arterial spin-labeling magnetic resonance imaging (TASL-MRI). TASL-MRI and 2DPC-MRA were performed in three states: at rest, during manual compression of the right carotid artery, and after decompression. In one volunteer, time-space labeling inversion pulse (Time-SLIP) MRA was performed to confirm collateral flow. During manual carotid compression, in one volunteer, the right thalamus changed to be fed only by the vertebrobasilar system, and the right basal ganglia changed to be fed by the left internal carotid artery. In the other volunteer, the right basal ganglia changed to be fed by the vertebrobasilar system. 2DPC-MRA showed that the flow direction changed in the right A1 segment of the anterior cerebral artery and the right posterior communicating artery. Perfusion patterns and flow directions recovered after decompression. Time-SLIP MRA showed pial vessels and dural collateral circulation when the right carotid artery was manually compressed. Use of TASL-MRI and 2DPC-MRA was successful for non-invasive visualization of the dynamic changes in regional cerebral blood flow during and after manual carotid compression.

Ethnic differences in carotid intima-media thickness between UK children of black African-Caribbean and white European origin.

PubMed

Whincup, Peter H; Nightingale, Claire M; Owen, Christopher G; Rapala, Alicja; Bhowruth, Devina J; Prescott, Melanie H; Ellins, Elizabeth A; Donin, Angela S; Masi, Stefano; Rudnicka, Alicja R; Sattar, Naveed; Cook, Derek G; Deanfield, John E

2012-07-01

UK black African-Caribbean adults have higher risks of stroke than white Europeans and have been shown to have increased carotid intima-media thickness (cIMT). We examined whether corresponding ethnic differences in cIMT were apparent in childhood and, if so, whether these could be explained by ethnic differences in cardiovascular risk markers. We conducted a 2-stage survey of 939 children (208 white European, 240 black African-Caribbean, 258 South Asian, 63 other Asian, 170 other ethnicity), who had a cardiovascular risk assessment and measurements of cIMT at mean ages of 9.8 and 10.8 years, respectively. Black African-Caribbean children had a higher cIMT than white Europeans (mean difference, 0.014 mm; 95% CI, 0.008-0.021 mm; P<0.0001). cIMT levels in South Asian and other Asian children were however similar to those of white Europeans. Among all children, cIMT was positively associated with age, systolic and diastolic blood pressure and inversely with combined skinfold thickness and serum triglyceride. Mean triglyceride was lower among black African-Caribbeans than white Europeans; blood pressure and skinfold thickness did not differ appreciably. However, adjustment for these risk factors had little effect on the cIMT difference between black African-Caribbeans and white Europeans. UK black African-Caribbean children have higher cIMT levels in childhood; the difference is not explained by conventional cardiovascular risk markers. There may be important opportunities for early cardiovascular prevention, particularly in black African-Caribbean children.

Assessing the blood pressure waveform of the carotid artery using an ultrasound image processing method

PubMed Central

Fatouraee, Nasser; Saberi, Hazhir

2017-01-01

Purpose The aim of this study was to introduce and implement a noninvasive method to derive the carotid artery pressure waveform directly by processing diagnostic sonograms of the carotid artery. Methods Ultrasound image sequences of 20 healthy male subjects (age, 36±9 years) were recorded during three cardiac cycles. The internal diameter and blood velocity waveforms were extracted from consecutive sonograms over the cardiac cycles by using custom analysis programs written in MATLAB. Finally, the application of a mathematical equation resulted in time changes of the arterial pressure. The resulting pressures were calibrated using the mean and the diastolic pressure of the radial artery. Results A good correlation was found between the mean carotid blood pressure obtained from the ultrasound image processing and the mean radial blood pressure obtained using a standard digital sphygmomanometer (R=0.91). The mean absolute difference between the carotid calibrated pulse pressures and those measured clinically was -1.333±6.548 mm Hg. Conclusion The results of this study suggest that consecutive sonograms of the carotid artery can be used for estimating a blood pressure waveform. We believe that our results promote a noninvasive technique for clinical applications that overcomes the reproducibility problems of common carotid artery tonometry with technical and anatomical causes. PMID:27776401

[Carotid plaque assessment using inversion recovery T1 weighted-3 dimensions variable refocus flip angle turbo spin echo sampling perfection with application optimized contrast using different angle evolutions black blood imaging].

PubMed

Inoue, Yuji; Yoneyama, Masami; Nakamura, Masanobu; Ozaki, Satoshi; Ito, Kenjiro; Hiura, Mikio

2012-01-01

Vulnerable plaque can be attributed to induction of ischemic symptoms and magnetic resonance imaging of carotid artery is valuable to detect the plaque. Magnetization prepared rapid acquisition with gradient echo (MPRAGE) method could detect hemorrhagic vulnerable plaque as high intensity signal; however, blood flow is not sufficiently masked by this method. The contrast for plaque in T1 weighted image (T1WI) could not be obtained sufficiently with black blood image (BBI) by sampling perfection with application optimized contrast using different angle evolutions (SPACE) method as turbo spin echo (TSE). In addition, an appearance of artifact by slow flow is a problem. Considering these controversial situations in plaque imaging, we examined the modified BBI inversion recovery (IR)-SPACE in which IR was added for SPACE method so that the contrast for plaque in T1WI was optimized. We investigated the application of this method in plaque imaging. As a result of phantom imaging, the contrast for plaque in T1WI was definitely obtained by choosing an appropriate inversion time (TI) for the corresponding repetition time. In clinical cases, blood flow was sufficiently masked by IR-SPACE method and the plaque imaging was clearly obtained in clinical cases to the same extent as MPRAGE method. Since BBI with IR-SPACE method was derived from both IR pulse and flow void effect, this method could obtain the blood flow masking effect definitely. The present study suggested that SPACE method might be applicable to estimate properties of carotid artery plaque.

Atherosclerosis imaging using 3D black blood TSE SPACE vs 2D TSE

PubMed Central

Wong, Stephanie K; Mobolaji-Iawal, Motunrayo; Arama, Leron; Cambe, Joy; Biso, Sylvia; Alie, Nadia; Fayad, Zahi A; Mani, Venkatesh

2014-01-01

AIM: To compare 3D Black Blood turbo spin echo (TSE) sampling perfection with application-optimized contrast using different flip angle evolution (SPACE) vs 2D TSE in evaluating atherosclerotic plaques in multiple vascular territories. METHODS: The carotid, aortic, and femoral arterial walls of 16 patients at risk for cardiovascular or atherosclerotic disease were studied using both 3D black blood magnetic resonance imaging SPACE and conventional 2D multi-contrast TSE sequences using a consolidated imaging approach in the same imaging session. Qualitative and quantitative analyses were performed on the images. Agreement of morphometric measurements between the two imaging sequences was assessed using a two-sample t-test, calculation of the intra-class correlation coefficient and by the method of linear regression and Bland-Altman analyses. RESULTS: No statistically significant qualitative differences were found between the 3D SPACE and 2D TSE techniques for images of the carotids and aorta. For images of the femoral arteries, however, there were statistically significant differences in all four qualitative scores between the two techniques. Using the current approach, 3D SPACE is suboptimal for femoral imaging. However, this may be due to coils not being optimized for femoral imaging. Quantitatively, in our study, higher mean total vessel area measurements for the 3D SPACE technique across all three vascular beds were observed. No significant differences in lumen area for both the right and left carotids were observed between the two techniques. Overall, a significant-correlation existed between measures obtained between the two approaches. CONCLUSION: Qualitative and quantitative measurements between 3D SPACE and 2D TSE techniques are comparable. 3D-SPACE may be a feasible approach in the evaluation of cardiovascular patients. PMID:24876923

Optimal MR Plaque Imaging for Cervical Carotid Artery Stenosis in Predicting the Development of Microembolic Signals during Exposure of Carotid Arteries in Endarterectomy: Comparison of 4 T1-Weighted Imaging Techniques.

PubMed

Sato, Y; Ogasawara, K; Narumi, S; Sasaki, M; Saito, A; Tsushima, E; Namba, T; Kobayashi, M; Yoshida, K; Terayama, Y; Ogawa, A

2016-06-01

Preoperative identification of plaque vulnerability may allow improved risk stratification for patients considered for carotid endarterectomy. The present study aimed to determine which plaque imaging technique, cardiac-gated black-blood fast spin-echo, magnetization-prepared rapid acquisition of gradient echo, source image of 3D time-of-flight MR angiography, or noncardiac-gated spin-echo, most accurately predicts development of microembolic signals during exposure of carotid arteries in carotid endarterectomy. Eighty patients with ICA stenosis (≥70%) underwent the 4 sequences of preoperative MR plaque imaging of the affected carotid bifurcation and then carotid endarterectomy under transcranial Doppler monitoring of microembolic signals in the ipsilateral middle cerebral artery. The contrast ratio of the carotid plaque was calculated by dividing plaque signal intensity by sternocleidomastoid muscle signal intensity. Microembolic signals during exposure of carotid arteries were detected in 23 patients (29%), 3 of whom developed new neurologic deficits postoperatively. Those deficits remained at 24 hours after surgery in only 1 patient. The area under the receiver operating characteristic curve to discriminate between the presence and absence of microembolic signals during exposure of the carotid arteries was significantly greater with nongated spin-echo than with black-blood fast spin-echo (difference between areas, 0.258; P < .0001), MPRAGE (difference between areas, 0.106; P = .0023), or source image of 3D time-of-flight MR angiography (difference between areas, 0.128; P = .0010). Negative binomial regression showed that in the 23 patients with microembolic signals, the contrast ratio was associated with the number of microembolic signals only in nongated spin-echo (risk ratio, 1.36; 95% confidence interval, 1.01-1.97; P < .001). Nongated spin-echo may predict the development of microembolic signals during exposure of the carotid arteries in carotid

Carotid Artery Disease

MedlinePlus

... head with blood. If you have carotid artery disease, the arteries become narrow or blocked, usually because ... other substances found in the blood. Carotid artery disease is serious because it can block the blood ...

[Effect of Chinese drugs for activating blood circulation and removing blood stasis on carotid atherosclerosis and ischemic cerebrovascular events].

PubMed

Lu, Yan; Li, Tao

2014-03-01

To explore the effect of Chinese drugs for activating blood circulation and removing blood stasis (CDABCRBS) on carotid atherosclerotic plaque and long-term ischemic cerebrovascular events. By using open and control method, effect of 4 groups of platelet antagonists, platelet antagonists + CDABCRBS, platelet antagonists +atorvastatin, platelet antagonists +atorvastatin +CDABCRBS on carotid atherosclerotic plaque and long-term ischemic cerebrovascular events of 90 cerebral infarction patients were analyzed. Through survival analysis, there was no statistical difference in the effect of the 4 interventions on the variation of carotid stenosis rates or ischemic cerebrovascular events (P > 0.05). The occurrence of ischemic cerebrovascular events could be postponed by about 4 months in those treated with platelet antagonists + CDABCRBS and platelet antagonists + atorvastatin +CDABCRBS. By multivariate Logistic analysis, age, hypertension, and clopidogrel were associated with stenosis of extracranial carotid arteries (P <0.05). Age, diabetes, aspirin, clopidogrel, CDABCRBS were correlated with cerebrovascular accidents (P < 0.05). Whether or not accompanied with hypertension is an influential factor for carotid stenosis, but it does not affect the occurrence of ischemic cerebrovascular events. CDABCRBS could effectively prolong the occurrence time of ischemic cerebrovascular events.

Influence of blood flow velocity on arterial distensibility of carotid artery in healthy men.

PubMed

Tomoto, Tsubasa; Maeda, Seiji; Sugawara, Jun

2017-01-01

Decreased distensibility of carotid artery is independently associated with the incidence of cardiovascular and cerebrovascular events. Arterial distensibility is determined by vascular tone. Since shear stress is an important driving force of vasodilatory substances production form endothelial cells, we hypothesized that local basal (i.e., resting) arterial blood flow velocity is associated with regional arterial distensibility. To test this hypothesis, we determined the influence of local blood flow velocity on carotid arterial distensibility in cross-sectional study design. In a total of 73 apparent healthy men (18-64 years), carotid arterial properties, including measures of carotid arterial distensibility and BFV at rest, were evaluated via B-mode and Doppler ultrasound imaging and applanation tonometry system. Carotid arterial peak BFV and the absolute and normalized pulsatile BFV significantly correlated with age (r = -0.453 to -0.600, p < 0.0001), whereas mean and minimum BFV were not influenced by age. Distensibility coefficient of carotid artery correlated with peak BFV (r = 0.305, p < 0.01) and more strongly with pulsatile (i.e., systolic minus end-diastolic) BFV (r = 0.406, p < 0.0001) and the normalized pulsatile BFV by time-averaged velocity (r = 0.591, p < 0.0001). Multi-regression analysis revealed that age (β = -0.57, p < 0.0001) was the primary independent determinant for distensibility coefficient. In addition with this, carotid lumen diameter (β = -0.202, p < 0.01) and the normalized pulsatile BFV (β = 0.237, p < 0.05) were significant independent determinants of distensibility coefficient. Qualitatively similar results (although inverse in direction) were obtained by use of β-stiffness index. These results suggest that greater gradient of blood flow velocity during a cardiac cycle are favorably associated with distensibility of carotid artery.

Variability of carotid artery measurements on 3-Tesla MRI and its impact on sample size calculation for clinical research.

PubMed

Syed, Mushabbar A; Oshinski, John N; Kitchen, Charles; Ali, Arshad; Charnigo, Richard J; Quyyumi, Arshed A

2009-08-01

Carotid MRI measurements are increasingly being employed in research studies for atherosclerosis imaging. The majority of carotid imaging studies use 1.5 T MRI. Our objective was to investigate intra-observer and inter-observer variability in carotid measurements using high resolution 3 T MRI. We performed 3 T carotid MRI on 10 patients (age 56 +/- 8 years, 7 male) with atherosclerosis risk factors and ultrasound intima-media thickness > or =0.6 mm. A total of 20 transverse images of both right and left carotid arteries were acquired using T2 weighted black-blood sequence. The lumen and outer wall of the common carotid and internal carotid arteries were manually traced; vessel wall area, vessel wall volume, and average wall thickness measurements were then assessed for intra-observer and inter-observer variability. Pearson and intraclass correlations were used in these assessments, along with Bland-Altman plots. For inter-observer variability, Pearson correlations ranged from 0.936 to 0.996 and intraclass correlations from 0.927 to 0.991. For intra-observer variability, Pearson correlations ranged from 0.934 to 0.954 and intraclass correlations from 0.831 to 0.948. Calculations showed that inter-observer variability and other sources of error would inflate sample size requirements for a clinical trial by no more than 7.9%, indicating that 3 T MRI is nearly optimal in this respect. In patients with subclinical atherosclerosis, 3 T carotid MRI measurements are highly reproducible and have important implications for clinical trial design.

Normative values and correlates of carotid artery intima-media thickness and carotid atherosclerosis in Andean-Hispanics: The PREVENCION Study

PubMed Central

Pastorius, Catherine A.; Medina-Lezama, Josefina; Corrales-Medina, Fernando; Bernabé-Ortiz, Antonio; Paz-Manrique, Roberto; Salinas-Najarro, Belissa; Khan, Zubair A.; Takahashi, Junichiro; Toshima, Gen; Zea-Diaz, Humberto; Postigo-MacDowall, Mauricio; Chirinos-Pacheco, Julio; Ibañez, Francisco; Chirinos, Diana A.; Saif, Hassam; Chirinos, Julio A.

2010-01-01

Objectives Carotid intima-media thickness (cIMT) is an independent predictor of cardiovascular risk. Furthermore, ethnicity and gender-specific normative data are required to assess cIMT, which are not available for Andean-Hispanics. In addition, data regarding correlates of subclinical atherosclerosis in ethnic population are needed. Methods We studied 1448 adults enrolled in a population-based study in Peru. cIMT and carotid plaque were measured with high-resolution ultrasonography. A healthy reference sample (n=472) with no cardiovascular disease, normal weight and normal metabolic parameters was selected to establish normative cIMT values. Correlates of abnormal cIMT and carotid plaque were assessed in the entire population. Results In the reference sample, 95th-percentile cIMT values were both age and gender-dependent. In stepwise regression, selected predictors of increasing cIMT were: older age, impaired fasting glucose, diabetes mellitus, higher systolic blood pressure, higher LDL-cholesterol, smoking and male gender. Predictors of carotid plaque included older age, male gender, higher systolic blood pressure, lower diastolic blood pressure and higher LDL-cholesterol. HDL-cholesterol and C-reactive protein were not associated with cIMT or carotid plaque. The lack of association with HDL-cholesterol was confirmed using high performance liquid chromatography. Conclusions We present ethnic-specific cutoffs for abnormal cIMT applicable to Andean-Hispanics and correlates of subclinical atherosclerosis in this population. Pending longitudinal studies, our data supports several risk associations seen in other populations and can be used to identify Andean-Hispanics at increased risk for atherosclerotic cardiovascular disease. The lack of association between HDL-C and cIMT or carotid plaque in this population requires further investigation. PMID:20510418

Sustained acute voltage-dependent blood pressure decrease with prolonged carotid baroreflex activation in therapy-resistant hypertension.

PubMed

Alnima, Teba; Scheffers, Ingrid; De Leeuw, Peter W; Winkens, Bjorn; Jongen-Vancraybex, Heidi; Tordoir, Jan H M; Schmidli, Jürg; Mohaupt, Markus G; Allemann, Yves; Kroon, Abraham A

2012-08-01

Chronic carotid baroreflex stimulation (Rheos system) has been shown to effectively reduce blood pressure in patients with resistant hypertension. Upon acute stimulation blood pressure also falls as a function of voltage. the aim of this study is to evaluate whether this voltage-dependent blood pressure decrease is preserved after long-term carotid baroreflex stimulation. Forty-five patients implanted with Rheos underwent a voltage response test (VRT) before the start of carotid baroreflex activation (1m), as well as after 4 (4m) and 13 months (13 m) of device implantation. After switching off the device for 10 min (0 V), we started the VRT by increasing voltage from 1 to 6 V, by 1-V steps every 5 min. Blood pressure and heart rate were measured at the end of every step. At 1m, mean blood pressure was 178/101 mmHg at 0 V and fell to 142/83 mmHg at 6 V. Heart rate fell from 75 to 65 beats/min. At 4m and 13 m mean blood pressure was significantly lower compared to 1m when VRT started at 0 V (170/96 and 161/93 mmHg, respectively). However, pattern of blood pressure decrease during VRT was comparable with this at 1m. Maximum SBP reduction during VRT did not change with long-term therapy. Acute voltage-dependent blood pressure and heart rate decrease with electrical baroreflex stimulation is preserved after at least 1 year of continuous activation in patients with resistant hypertension. This indicates that response adaptation and nerve fatigue are very unlikely in long-term carotid baroreflex activation.

High-resolution magnetic resonance imaging of carotid atherosclerotic plaques - a correlation study with histopathology.

PubMed

Xia, Zhangyong; Yang, Hua; Yuan, Xiaochun; Wang, Jiyue; Zhang, Shigang; Zhang, Liyong; Qu, Yang; Chen, Jun; Jiao, Liqun; Wang, Le-Xin; Du, Yifeng

2017-07-01

This study aimed to utilize high-resolution magnetic resonance imaging (MRI) to investigate the characteristics of stable and vulnerable carotid arteriosclerotic plaques, with correlations to histopathological findings. High-resolution MRI was performed in 817 patients, using three-dimensional magnetic resonance angiography. Plaque composition was evaluated by measuring the areas occupied by calcification, a lipid-rich necrotic core, intra-plaque haemorrhage, and fibrous cap rupture. Plaque morphology was analysed by measuring vessel wall area, thickness, and luminal area at the bifurcation of the common carotid artery. Plaque tissues were sampled during carotid endarterectomy and examined using haematoxylin-eosin, Oil Red O, Masson trichrome staining, and immunohistochemical staining for CD68. Patients were divided into stable plaque group (n = 462) and vulnerable plaque group (n = 355), based on intraoperative observations and postoperative histopathological findings. Compared to the stable plaque group, the vulnerable plaque group exhibited increased vessel wall areas and thickness, and decreased mean luminal areas (P < 0.001). The vulnerable plaque group also had a lower collagen content, a higher lipid content, and higher CD68 expression in plaque tissues on histological examinations (P < 0.01). Incidences of lipid-rich necrotic core (38.1 % vs. 34.3 %), intra-plaque haemorrhage (26.9 % vs. 22.8 %), plaque calcification (45.2 % vs. 40.9 %), and fibrous cap rupture (36.0 % vs 39.8 %) in the plaques were concordant with MRI observations and histopathological findings (p > 0.05). Stable and vulnerable carotid plaques had different morphologies and compositions. High-resolution MRI can assess such differences qualitatively and quantitatively in vivo and provide guidance for risk stratification and management.

Multi-contrast MRI registration of carotid arteries based on cross-sectional images and lumen boundaries

NASA Astrophysics Data System (ADS)

Wu, Yu-Xia; Zhang, Xi; Xu, Xiao-Pan; Liu, Yang; Zhang, Guo-Peng; Li, Bao-Juan; Chen, Hui-Jun; Lu, Hong-Bing

2017-02-01

Ischemic stroke has great correlation with carotid atherosclerosis and is mostly caused by vulnerable plaques. It's particularly important to analysis the components of plaques for the detection of vulnerable plaques. Recently plaque analysis based on multi-contrast magnetic resonance imaging has attracted great attention. Though multi-contrast MR imaging has potentials in enhanced demonstration of carotid wall, its performance is hampered by the misalignment of different imaging sequences. In this study, a coarse-to-fine registration strategy based on cross-sectional images and wall boundaries is proposed to solve the problem. It includes two steps: a rigid step using the iterative closest points to register the centerlines of carotid artery extracted from multi-contrast MR images, and a non-rigid step using the thin plate spline to register the lumen boundaries of carotid artery. In the rigid step, the centerline was extracted by tracking the crosssectional images along the vessel direction calculated by Hessian matrix. In the non-rigid step, a shape context descriptor is introduced to find corresponding points of two similar boundaries. In addition, the deterministic annealing technique is used to find a globally optimized solution. The proposed strategy was evaluated by newly developed three-dimensional, fast and high resolution multi-contrast black blood MR imaging. Quantitative validation indicated that after registration, the overlap of two boundaries from different sequences is 95%, and their mean surface distance is 0.12 mm. In conclusion, the proposed algorithm has improved the accuracy of registration effectively for further component analysis of carotid plaques.

Association of morning blood pressure surge with carotid intima-media thickness and cardiac dysfunction in patients with cardiac syndrome-X.

PubMed

Mahfouz, Ragab A; Goda, Mohammad; Galal, Islam; Ghareb, Mohamed S

2018-05-23

Background & hypothesis: We hypothesized that exaggerated morning blood pressure surge, may contribute in cardiac dysfunction and arterial stiffness in patients with cardiac syndrome X. Thus we investigated the impact of morning blood pressure surge on cardiac function and carotid intima-media thickness in subjects with cardiac syndrome X. We studied patients with cardiac syndrome X using ambulatory blood pressure monitoring and investigated the association of morning blood pressure surge with carotid intima thickness, left atrial volume index and left ventricular filling (E/e'). Seventy patients with cardiac syndrome X were enrolled for the study and compared with 70 age and sex matched controls. Patients with cardiac syndrome X were stratified based on the systolic morning blood pressure surge value of control subjects to patients with exaggerated blood pressure surge (n = 42) and those with normal morning blood pressure surge (n = 28). Basal heart rate (p < .05), high sensitive C-reactive protein (p < .01), left atrial volume index (p < .01), E/e' (p < .01); carotid intima-media thickness (p < .001) and percentage of detected plaque (p < .005) were significantly higher in patients with exaggerated morning blood pressure surge group than those with morning blood pressure surge group. Morning blood pressure surge was significantly correlated with carotid intima-media thickness, high sensitive C-reactive protein, left atrial volume index and E/e' ratio in patients with cardiac syndrome X. In multivariate analysis, exaggerated morning blood pressure surge was the only independent predictor of increased carotid intima-media thickness (OR = 2.379; p < .001), and diastolic dysfunction (OR = 2.464; p < .001) in patients with cardiac syndrome X. Our data suggest that excessive morning blood pressure surge is an independent predictor for arterial stiffness and diastolic dysfunction in patients with cardiac syndrome X.

Altered cerebral hemodyamics and cortical thinning in asymptomatic carotid artery stenosis.

PubMed

Marshall, Randolph S; Asllani, Iris; Pavol, Marykay A; Cheung, Ying-Kuen; Lazar, Ronald M

2017-01-01

Cortical thinning is a potentially important biomarker, but the pathophysiology in cerebrovascular disease is unknown. We investigated the association between regional cortical blood flow and regional cortical thickness in patients with asymptomatic unilateral high-grade internal carotid artery disease without stroke. Twenty-nine patients underwent high resolution anatomical and single-delay, pseudocontinuous arterial spin labeling magnetic resonance imaging with partial volume correction to assess gray matter baseline flow. Cortical thickness was estimated using Freesurfer software, followed by co-registration onto each patient's cerebral blood flow image space. Paired t-tests assessed regional cerebral blood flow in motor cortex (supplied by the carotid artery) and visual cortex (indirectly supplied by the carotid) on the occluded and unoccluded side. Pearson correlations were calculated between cortical thickness and regional cerebral blood flow, along with age, hypertension, diabetes and white matter hyperintensity volume. Multiple regression and generalized estimating equation were used to predict cortical thickness bilaterally and in each hemisphere separately. Cortical blood flow correlated with thickness in motor cortex bilaterally (p = 0.0002), and in the occluded and unoccluded sides individually; age (p = 0.002) was also a predictor of cortical thickness in the motor cortex. None of the variables predicted cortical thickness in visual cortex. Blood flow was significantly lower on the occluded versus unoccluded side in the motor cortex (p<0.0001) and in the visual cortex (p = 0.018). On average, cortex was thinner on the side of occlusion in motor but not in visual cortex. The association between cortical blood flow and cortical thickness in carotid arterial territory with greater thinning on the side of the carotid occlusion suggests that altered cerebral hemodynamics is a factor in cortical thinning.

Evaluation of the carotid artery stenosis based on minimization of mechanical energy loss of the blood flow.

PubMed

Sia, Sheau Fung; Zhao, Xihai; Li, Rui; Zhang, Yu; Chong, Winston; He, Le; Chen, Yu

2016-11-01

Internal carotid artery stenosis requires an accurate risk assessment for the prevention of stroke. Although the internal carotid artery area stenosis ratio at the common carotid artery bifurcation can be used as one of the diagnostic methods of internal carotid artery stenosis, the accuracy of results would still depend on the measurement techniques. The purpose of this study is to propose a novel method to estimate the effect of internal carotid artery stenosis on the blood flow based on the concept of minimization of energy loss. Eight internal carotid arteries from different medical centers were diagnosed as stenosed internal carotid arteries, as plaques were found at different locations on the vessel. A computational fluid dynamics solver was developed based on an open-source code (OpenFOAM) to test the flow ratio and energy loss of those stenosed internal carotid arteries. For comparison, a healthy internal carotid artery and an idealized internal carotid artery model have also been tested and compared with stenosed internal carotid artery in terms of flow ratio and energy loss. We found that at a given common carotid artery bifurcation, there must be a certain flow distribution in the internal carotid artery and external carotid artery, for which the total energy loss at the bifurcation is at a minimum; for a given common carotid artery flow rate, an irregular shaped plaque at the bifurcation constantly resulted in a large value of minimization of energy loss. Thus, minimization of energy loss can be used as an indicator for the estimation of internal carotid artery stenosis.

Measurement of carotid blood pressure and local pulse wave velocity changes during cuff induced hyperemia.

PubMed

Nabeel, P M; Karthik, Srinivasa; Joseph, Jayaraj; Sivaprakasam, Mohanasankar

2017-07-01

We present a prototype design of dual element photoplethysmograph (PPG) probe along with associated measurement system for carotid local pulse wave velocity (PWV) evaluation in a non-invasive and continuous manner. The PPG probe consists of two identical sensing modules placed 23 mm apart. Simultaneously measured blood pulse waveforms from these arterial sites were processed and the pulse transit time delay was resolved using the developed application-specific software. The ability of developed PPG probe and associated measurement system to detect acute changes in carotid local PWV due to blood pressure (BP) variations was experimentally validated by an in-vivo study. Intra-subject carotid BP elevation was achieved by an upper arm cuff based occlusion, which offered a controlled way of local PWV escalation. The elevated carotid BP values were also recorded by a calibrated pressure tonometer prior to the study, and was used as a reference. A significant increment (1.0 - 2.6 m/s) in local PWV was observed and was proportional to the BP increment induced by the occlusive reactive hyperemia. Study results demonstrated the feasibility of real-time signal acquisition and reliable local PWV evaluation under normal and elevated BP conditions using the developed measurement system.

Magnetic Resonance Imaging-Based Assessment of Carotid Atheroma: a Comparative Study of Patients with and without Coronary Artery Disease.

PubMed

Usman, Ammara; Sadat, Umar; Teng, Zhongzhao; Graves, Martin J; Boyle, Jonathan R; Varty, Kevin; Hayes, Paul D; Gillard, Jonathan H

2017-02-01

Functional magnetic resonance (MR) imaging of atheroma using contrast media enables assessment of the systemic severity of atherosclerosis in different arterial beds. Whether black-blood imaging has similar ability remains widely unexplored. In this study, we evaluate whether black-blood imaging can differentiate carotid plaques of patients with and without coronary artery disease (CAD) in terms of morphological and biomechanical features of plaque vulnerability, thereby allowing assessment of the systemic severity nature of atherosclerosis in different arterial beds. Forty-one patients with CAD and 59 patients without CAD underwent carotid black-blood MR imaging. Plaque components were segmented to identify large lipid core (LC), ruptured fibrous cap (FC), and plaque hemorrhage (PH). These segmented contours of plaque components were used to quantify maximum structural biomechanical stress. Patients with CAD and without CAD had comparable demographics and comorbidities. Both groups had comparable prevalence of morphological features of plaque vulnerability (FC rupture, 44% versus 41%, P = .90; PH, 58% versus 47%, P = .78; large LC, 32% versus 47%, P = .17), respectively. The maximum biomechanical stress was not significantly different for both groups (241versus 278 kPa, P = .14) respectively. Black-blood imaging does not appear to have the ability to differentiate between the morphological and biomechanical features of plaque vulnerability when comparing patients with and without symptomatic atherosclerotic disease in a distant arterial territory such as coronary artery. Copyright © 2017 National Stroke Association. Published by Elsevier Inc. All rights reserved.

Relationship between haemodynamic impairment and collateral blood flow in carotid artery disease.

PubMed

Hartkamp, Nolan S; Petersen, Esben T; Chappell, Michael A; Okell, Thomas W; Uyttenboogaart, Maarten; Zeebregts, Clark J; Bokkers, Reinoud Ph

2017-01-01

Collateral blood flow plays a pivotal role in steno-occlusive internal carotid artery (ICA) disease to prevent irreversible ischaemic damage. Our aim was to investigate the effect of carotid artery disease upon cerebral perfusion and cerebrovascular reactivity and whether haemodynamic impairment is influenced at brain tissue level by the existence of primary and/or secondary collateral. Eighty-eight patients with steno-occlusive ICA disease and 29 healthy controls underwent MR examination. The presence of collaterals was determined with time-of-flight, two-dimensional phase contrast MRA and territorial arterial spin labeling (ASL) imaging. Cerebral blood flow and cerebrovascular reactivity were assessed with ASL before and after acetazolamide. Cerebral haemodynamics were normal in asymptomatic ICA stenosis patients, as opposed to patients with ICA occlusion, in whom the haemodynamics in both hemispheres were compromised. Haemodynamic impairment in the affected brain region was always present in symptomatic patients. The degree of collateral blood flow was inversely correlated with haemodynamic impairment. Recruitment of secondary collaterals only occurred in symptomatic ICA occlusion patients. In conclusion, both CBF and cerebrovascular reactivity were found to be reduced in symptomatic patients with steno-occlusive ICA disease. The presence of collateral flow is associated with further haemodynamic impairment. Recruitment of secondary collaterals is associated with severe haemodynamic impairment.

Blood Flow in the Stenotic Carotid Bifurcation

NASA Astrophysics Data System (ADS)

Rayz, Vitaliy

2005-11-01

The carotid artery is prone to atherosclerotic disease and the growth of plaque in the vessel, leading often to severe occlusion or plaque rupture, resulting in emboli and thrombus, and, possibly, stroke. Modeling the flow in stenotic blood vessels can elucidate the influence of the flow on plaque growth and stability. Numerical simulations are carried out to model the complex flows in anatomically realistic, patient-specific geometries constructed from magnetic resonance images. The 3-D unsteady Navier-Stokes equations are solved in a finite-volume formulation, using an iterative pressure-correction algorithm. The flow field computed is highly three-dimensional, with high-speed jets and strong recirculating secondary flows. Sharp spatial and temporal variations of the velocities and shear stresses are observed. The results are in a good agreement with the available experimental and clinical data. The influence of non-Newtonian blood behavior and arterial wall compliance are considered. Transitional and turbulent regimes have been looked at using LES. This work supports the conjecture that numerical simulations can provide a diagnostic tool for assessing plaque stability.

Impaired carotid baroreflex control of arterial blood pressure in multiple sclerosis.

PubMed

Huang, Mu; Allen, Dustin R; Keller, David M; Fadel, Paul J; Frohman, Elliot M; Davis, Scott L

2016-07-01

Multiple sclerosis (MS), a progressive neurological disease, can lead to impairments in the autonomic control of cardiovascular function. We tested the hypothesis that individuals with relapsing-remitting MS (n = 10; 7 females, 3 males; 13 ± 4 yr from diagnosis) exhibit impaired carotid baroreflex control of blood pressure and heart rate compared with sex, age, and body weight-matched healthy individuals (CON: n = 10; 7 females, 3 males). At rest, 5-s trials of neck pressure (NP; +40 Torr) and neck suction (NS; -60 Torr) were applied to simulate carotid hypotension and hypertension, respectively, while mean arterial pressure (MAP; finger photoplethysmography), heart rate (HR), cardiac output (CO; Modelflow), and total vascular conductance (TVC) were continuously measured. In response to NP, there was a blunted increase in peak MAP responses (MS: 5 ± 2 mmHg) in individuals with MS compared with healthy controls (CON: 9 ± 3 mmHg; P = 0.005), whereas peak HR responses were not different between groups. At the peak MAP response to NP, individuals with MS demonstrated an attenuated decrease in TVC (MS, -10 ± 4% baseline vs. CON, -15 ± 4% baseline, P = 0.012), whereas changes in CO were similar between groups. Following NS, all cardiovascular responses (i.e., nadir MAP and HR and percent changes in CO and TVC) were not different between MS and CON groups. These data suggest that individuals with MS have impaired carotid baroreflex control of blood pressure via a blunted vascular conductance response resulting in a diminished ability to increase MAP in response to a hypotensive challenge. Copyright © 2016 the American Physiological Society.

Impaired carotid baroreflex control of arterial blood pressure in multiple sclerosis

PubMed Central

Huang, Mu; Allen, Dustin R.; Keller, David M.; Fadel, Paul J.; Frohman, Elliot M.

2016-01-01

Multiple sclerosis (MS), a progressive neurological disease, can lead to impairments in the autonomic control of cardiovascular function. We tested the hypothesis that individuals with relapsing-remitting MS (n = 10; 7 females, 3 males; 13 ± 4 yr from diagnosis) exhibit impaired carotid baroreflex control of blood pressure and heart rate compared with sex, age, and body weight-matched healthy individuals (CON: n = 10; 7 females, 3 males). At rest, 5-s trials of neck pressure (NP; +40 Torr) and neck suction (NS; −60 Torr) were applied to simulate carotid hypotension and hypertension, respectively, while mean arterial pressure (MAP; finger photoplethysmography), heart rate (HR), cardiac output (CO; Modelflow), and total vascular conductance (TVC) were continuously measured. In response to NP, there was a blunted increase in peak MAP responses (MS: 5 ± 2 mmHg) in individuals with MS compared with healthy controls (CON: 9 ± 3 mmHg; P = 0.005), whereas peak HR responses were not different between groups. At the peak MAP response to NP, individuals with MS demonstrated an attenuated decrease in TVC (MS, −10 ± 4% baseline vs. CON, −15 ± 4% baseline, P = 0.012), whereas changes in CO were similar between groups. Following NS, all cardiovascular responses (i.e., nadir MAP and HR and percent changes in CO and TVC) were not different between MS and CON groups. These data suggest that individuals with MS have impaired carotid baroreflex control of blood pressure via a blunted vascular conductance response resulting in a diminished ability to increase MAP in response to a hypotensive challenge. PMID:27075533

Screening for Carotid Artery Stenosis

MedlinePlus

... build up and harden the arteries, limiting the flow of blood to the brain. Facts About Carotid Artery Stenosis Carotid artery stenosis is one of many risk factors for stroke, a leading cause of death and disability in the United States. However, carotid artery stenosis is uncommon—about ½ ...

Effects of raloxifene on carotid blood flow resistance and endothelium-dependent vasodilation in postmenopausal women.

PubMed

Ceresini, Graziano; Marchini, Lorenzo; Rebecchi, Isabella; Morganti, Simonetta; Bertone, Luca; Montanari, Ilaria; Bacchi-Modena, Alberto; Sgarabotto, Maria; Baldini, Monica; Denti, Licia; Ablondi, Fabrizio; Ceda, Gian Paolo; Valenti, Giorgio

2003-03-01

Raloxifene is one of the most important selective estrogen receptor modulators currently employed for the treatment of postmenopausal osteoporosis. However, it has also been suggested that this compound affects the vascular system. We evaluated both carotid blood flow resistance and endothelium-dependent vasodilation in 50 healthy postmenopausal women randomly assigned to receive, in a double blind design, either raloxifene (60 mg per day; N=25 subjects) or placebo (N=25 subjects) for 4 months. Indices of carotid blood flow resistance, such as the pulsatility index (PI) and resistance index (RI), as well as the flow-mediated brachial artery dilation were measured both at baseline and at the end of treatment. Changes in PI were -1.86+/-2.24 and -2.15+/-2.22% after placebo and raloxifene treatment, respectively, with no significant differences between groups. Changes in RI were -0.77+/-1.72 and -1.81+/-1.54% after placebo and raloxifene treatment, respectively, with no significant differences between groups. At the end of the treatment period, the increments in artery diameter measured after the flow stimulus were 10.79+/-2.39 and 6.70+/-1.23% for placebo and raloxifene, respectively, with no significant differences between groups. These results demonstrate no significant effects of raloxifene on either carotid blood flow resistance or brachial artery flow-mediated dilation in postmenopausal women.

MRI-based biomechanical parameters for carotid artery plaque vulnerability assessment.

PubMed

Speelman, Lambert; Teng, Zhongzhao; Nederveen, Aart J; van der Lugt, Aad; Gillard, Jonathan H

2016-03-01

Carotid atherosclerotic plaques are a major cause of ischaemic stroke. The biomechanical environment to which the arterial wall and plaque is subjected to plays an important role in the initiation, progression and rupture of carotid plaques. MRI is frequently used to characterize the morphology of a carotid plaque, but new developments in MRI enable more functional assessment of carotid plaques. In this review, MRI based biomechanical parameters are evaluated on their current status, clinical applicability, and future developments. Blood flow related biomechanical parameters, including endothelial wall shear stress and oscillatory shear index, have been shown to be related to plaque formation. Deriving these parameters directly from MRI flow measurements is feasible and has great potential for future carotid plaque development prediction. Blood pressure induced stresses in a plaque may exceed the tissue strength, potentially leading to plaque rupture. Multi-contrast MRI based stress calculations in combination with tissue strength assessment based on MRI inflammation imaging may provide a plaque stress-strength balance that can be used to assess the plaque rupture risk potential. Direct plaque strain analysis based on dynamic MRI is already able to identify local plaque displacement during the cardiac cycle. However, clinical evidence linking MRI strain to plaque vulnerability is still lacking. MRI based biomechanical parameters may lead to improved assessment of carotid plaque development and rupture risk. However, better MRI systems and faster sequences are required to improve the spatial and temporal resolution, as well as increase the image contrast and signal-to-noise ratio.

Mathematical model of carotid artery for stent placement

NASA Astrophysics Data System (ADS)

Rahman, Tengku Husna Tengku Abdul; Din, Ummul Khair Salma; Ahmad, Rokiah @ Rozita

2016-11-01

The carotid artery stenting is one of the methods used to reduce the effect of artherosclerosis which caused by the thickening of the artery wall. In most of the studies, the measure of wall elasticity, shear stress and the blood pressure through the blood flow were considered. The aim of this study is to determine the position to place the stent inside the carotid artery. A mathematical model is reconstructed to determine the suitable location of the stent in the carotid artery. Throughout the study, differences in fluid flow between a normal carotid artery wall and stenosed carotid artery wall are investigated. Since the existence of the stenosis provides a resistance in the flow, it is important to identify the right position to place the stent. The stent will be placed in the position where stenosis exists to ease the blood to flow normally. Later after the stent placement, the blood flow normally through the blood vessel.

Role of the carotid body chemoreceptors in baroreflex control of blood pressure during hypoglycaemia in humans

PubMed Central

Limberg, Jacqueline K; Taylor, Jennifer L; Dube, Simmi; Basu, Rita; Basu, Ananda; Joyner, Michael J; Wehrwein, Erica A

2014-01-01

Activation of the carotid body chemoreceptors with hypoxia alters baroreceptor mediated responses. We aimed to examine whether this relationship can be translated to other chemoreceptor stimuli (i.e. hypoglycaemia) and hypothesized: 1) activation of the carotid body chemoreceptors with hypoglycaemia would reduce spontaneous cardiac baroreflex sensitivity (sCBRS) in healthy humans and, 2) desensitization of the carotid chemoreceptors with hyperoxia would restore sCBRS to baseline levels during hypoglycaemia. Ten young healthy adults completed two 180-min hyperinsulinaemic (2 mU.kg FFM−1.min−1), hypoglycaemic (~3.2 µmol.mL−1) clamps, separated by at least one week and randomized to normoxia (PaO2 122±10 mmHg) or hyperoxia (PaO2 424±123 mmHg; to blunt activation of the carotid body glomus cells). Changes in heart rate, blood pressure, plasma catecholamines, heart rate variability (HRV), and sCBRS were assessed. During hypoglycaemia, HRV and sCBRS were reduced (p<0.05) and the baroreflex working range was shifted to higher heart rates. When hyperoxia was superimposed on hypoglycaemia, there was a greater reduction in blood pressure and a blunted rise in heart rate when compared to normoxic conditions (p<0.05); however, there was no detectable effect of hyperoxia on sCBRS or HRV during hypoglycaemia (p>0.05). In summary, hypoglycaemia-mediated changes in HRV and sCBRS cannot be exclusively attributed to the carotid chemoreceptors; however, the chemoreceptors appear to play a role in resetting the baroreflex working range during hypoglycaemia. PMID:24414173

Investigation of blood flow rheology using second-grade viscoelastic model (Phan-Thien-Tanner) within carotid artery.

PubMed

Ramiar, Abas; Larimi, Morsal Momenti; Ranjbar, Ali Akbar

2017-01-01

Hemodynamic factors, such as Wall Shear Stress (WSS), play a substantial role in arterial diseases. In the larger arteries, such as the carotid artery, interaction between the vessel wall and blood flow affects the distribution of hemodynamic factors. The fluid is considered to be non-Newtonian, whose flow is governed by the equation of a second-grade viscoelastic fluid and the effects of viscoelastic on blood flow in carotid artery is investigated. Pulsatile flow studies were carried out in a 3D model of carotid artery. The governing equations were solved using finite volume C++ based on open source code, OpenFOAM. To describe blood flow, conservation of mass and momentum, a constitutive relation of simplified Phan-Thien-Tanner (sPTT), and appropriate relations were used to explain shear thinning behavior. The first recirculation was observed at t = 0.2 s, in deceleration phase. In the acceleration phase from t = 0.3 s to t = 0.5 s, vortex and recirculation sizes in bulb regions in both ECA and ICA gradually increased. As is observed in the line graphs based on extracted data from ICA, at t = 0.2 s, τyy is the maximum amount of wall shear stress and τxy the minimum one. The maximum shear stress occurred in the inner side of the main branch (inner side of ICA and ECA) because the velocity of blood flow in the inner side of the bulb region was maximum due to the created recirculation zone in the opposite side in this area. The rheology of blood flow and shear stress in various important parts (the area that are in higher rates of WSS such as bifurcation region and the regions after bulb areas in both branches, Line1-4 in Fig. 7) were also analyzed. The investigation of velocity stream line, velocity profile and shear stress in various sections of carotid artery showed that the maximum shear stress occurred in acceleration phase and in the bifurcation region between ECA and ICA which is due to velocity gradients and changes in thinning behavior of blood and

Advice on lifestyle changes (diet, red wine and physical activity) does not affect internal carotid and middle cerebral artery blood flow velocity in patients with carotid arteriosclerosis in a randomized controlled trial.

PubMed

Droste, Dirk W; Iliescu, Catalina; Vaillant, Michel; Gantenbein, Manon; De Bremaeker, Nancy; Lieunard, Charlotte; Velez, Telma; Meyer, Michèle; Guth, Tessy; Kuemmerle, Andrea; Chioti, Anna

2014-01-01

A Mediterranean diet, with and without small daily amounts of red wine, and physical activity reduce the risk of cerebrovascular disease and improve cognition. An increase in cerebral blood flow may be the underlying mechanism. Under normal conditions, cerebral blood flow velocity changes in the internal carotid arteries and in large basal cerebral arteries correlate closely with cerebral blood flow changes, as the diameter of these vessels hardly changes and only the smaller vessels downstream change their diameter. A prospective randomized controlled trial was performed in 108 patients with carotid atherosclerosis (mean age 64 years, 67% men, 66% on statin therapy). Half of them were advised to follow a polyphenol-rich modified Mediterranean diet including 1-2 tomatoes, 3-5 walnuts and a bar of dark chocolate (25 g) a day and to perform moderate physical exercise for 30 min/day (lifestyle changes). Within these two groups, half of the patients were randomized either to avoid any alcohol or to drink 100 ml of red wine (women) or 200 ml of red wine (men) daily. Bilateral middle cerebral and internal carotid blood flow velocity (peak systolic, peak end-diastolic and mean) was measured at baseline and after 4 and 20 weeks using colour-coded duplex ultrasound. Insonation depth and insonation angle were used to identically place the sample volume during follow-up investigations. A general linear model with Tukey-Kramer adjustment for multiple comparisons was used to assess the primary end points. For the analysis we used the mean values of the right and left artery. Neither lifestyle changes nor red wine had an effect on peak systolic, peak end-diastolic or mean cerebral blood flow velocity. Advice on lifestyle changes, including a modified polyphenol-rich Mediterranean diet, a glass of red wine daily and physical exercise, did not affect middle cerebral and internal carotid blood flow velocity in our patient group with carotid atherosclerosis. An increase in cerebral

Black-blood native T1 mapping: Blood signal suppression for reduced partial voluming in the myocardium.

PubMed

Weingärtner, Sebastian; Meßner, Nadja M; Zöllner, Frank G; Akçakaya, Mehmet; Schad, Lothar R

2017-08-01

To study the feasibility of black-blood contrast in native T 1 mapping for reduction of partial voluming at the blood-myocardium interface. A saturation pulse prepared heart-rate-independent inversion recovery (SAPPHIRE) T 1 mapping sequence was combined with motion-sensitized driven-equilibrium (MSDE) blood suppression for black-blood T 1 mapping at 3 Tesla. Phantom scans were performed to assess the T 1 time accuracy. In vivo black-blood and conventional SAPPHIRE T 1 mapping was performed in eight healthy subjects and analyzed for T 1 times, precision, and inter- and intraobserver variability. Furthermore, manually drawn regions of interest (ROIs) in all T 1 maps were dilated and eroded to analyze the dependence of septal T 1 times on the ROI thickness. Phantom results and in vivo myocardial T 1 times show comparable accuracy with black-blood compared to conventional SAPPHIRE (in vivo: black-blood: 1562 ± 56 ms vs. conventional: 1583 ± 58 ms, P = 0.20); Using black-blood SAPPHIRE precision was significantly lower (standard deviation: 133.9 ± 24.6 ms vs. 63.1 ± 6.4 ms, P < .0001), and blood T 1 time measurement was not possible. Significantly increased interobserver interclass correlation coefficient (ICC) (0.996 vs. 0.967, P = 0.011) and similar intraobserver ICC (0.979 vs. 0.939, P = 0.11) was obtained with the black-blood sequence. Conventional SAPPHIRE showed strong dependence on the ROI thickness (R 2 = 0.99). No such trend was observed using the black-blood approach (R 2 = 0.29). Black-blood SAPPHIRE successfully eliminates partial voluming at the blood pool in native myocardial T 1 mapping while providing accurate T 1 times, albeit at a reduced precision. Magn Reson Med 78:484-493, 2017. © 2016 International Society for Magnetic Resonance in Medicine. © 2016 International Society for Magnetic Resonance in Medicine.

Effects of the Right Carotid Sinus Compression Technique on Blood Pressure and Heart Rate in Medicated Patients with Hypertension.

PubMed

Campón-Checkroun, Angélica María; Luceño-Mardones, Agustín; Riquelme, Inmaculada; Oliva-Pascual-Vaca, Jesús; Ricard, François; Oliva-Pascual-Vaca, Ángel

2018-05-07

To identify the immediate and middle-term effects of the right carotid sinus compression technique on blood pressure and heart rate in hypertensive patients. Randomized blinded experimental study. Primary health centers of Cáceres (Spain). Sixty-four medicated patients with hypertension were randomly assigned to an intervention group (n = 33) or to a control group (n = 31). In the intervention group a compression of the right carotid sinus was applied for 20 sec. In the control group, a placebo technique of placing hands on the radial styloid processes was performed. Blood pressure and heart rate were measured in both groups before the intervention (preintervention), immediately after the intervention, 5 min after the intervention, and 60 min after the intervention. The intervention group significantly decreased systolic and diastolic blood pressure and heart rate immediately after the intervention, with a large clinical effect; systolic blood pressure remained reduced 5 min after the intervention, and heart rate remained reduced 60 min after the intervention. No significant changes were observed in the control group. Right carotid sinus compression could be clinically useful for regulating acute hypertension.

Evaluation of cerebral function after carotid endarterectomy.

PubMed

Uclés, P; Almárcegui, C; Lorente, S; Romero, F; Marco, M

1997-05-01

Neuroimaging methods have failed to disclose correlation between degree of cerebral atrophy and blood flow in carotid artery stenosis patients. Moreover, intellectual improvement after carotid endarterectomy does not correlate fully with neuroimaging data in such patients. We performed brain electrical activity mapping and psychological testing before and 4 weeks after operation in 28 patients with symptomatic, high-grade, carotid stenosis. Postoperatively, electroencephalographic (EEG) mean frequency and absolute theta power improved significantly (p < 0.01). Mean frequency increased >1 Hz in most areas while power decreased dramatically, mainly because of resolution of high-voltage foci in 8 patients. Differences were conspicuous in both frontal lobes irrespective of the operated side, which suggests changes in perfusion affecting the whole brain. This is a positive effect of endarterectomy. Mini-Mental test and Set Test for verbal fluency had a positive correlation with the qEEG changes. Quantitative EEG as a measure of cerebral function has disclosed discriminative improvement in the early postoperative period. Our results support the thesis of improvement subsequent to endarterectomy.

Abrupt increase in rat carotid blood flow induces rapid alteration of artery mechanical properties

PubMed Central

Monson, Kenneth L.; Matsumoto, Melissa M.; Young, William L.; Manley, Geoffrey T.; Hashimoto, Tomoki

2010-01-01

Vascular remodeling is essential to proper vessel function. Dramatic changes in mechanical environment, however, may initiate pathophysiological vascular remodeling processes that lead to vascular disease. Previous work by some of our group has demonstrated a dramatic rise in matrix metalloproteinase (MMP) expression shortly following an abrupt increase in carotid blood flow. We hypothesized that there would be a corresponding change in carotid mechanical properties. Unilateral carotid ligation surgery was performed to produce an abrupt, sustained increase in blood flow through the contralateral carotid artery of rats. The flow-augmented artery was harvested after sham surgery or 1, 2, or 6 days after flow augmentation. Vessel mechanical response in the circumferential direction was then evaluated through a series of pressure-diameter tests. Results show that the extent of circumferential stretch (normalized change in diameter) at in vivo pressure levels was significantly different (p<0.05) from normo-flow controls at 1 and 2 days following flow augmentation. Measurements at 1, 2, and 6 days were not significantly different from one another, but a trend in the data suggested that circumferential stretch was largest 1 day following surgery and subsequently decreased toward baseline values. Because previous work with this model indicated a similar temporal pattern for MMP-9 expression, an exploratory set of experiments was conducted where vessels were tested 1 day following surgery in animals treated with broad spectrum MMP inhibitors (either doxycycline or GM6001). Results showed a trend for the inhibitors to minimize changes in mechanical properties. Observations demonstrate that vessel mechanical properties change rapidly following flow augmentation and that alterations may be linked to expression of MMPs. PMID:21094476

Assessing carotid atherosclerosis by fiber-optic multispectral photoacoustic tomography

NASA Astrophysics Data System (ADS)

Hui, Jie; Li, Rui; Wang, Pu; Phillips, Evan; Bruning, Rebecca; Liao, Chien-Sheng; Sturek, Michael; Goergen, Craig J.; Cheng, Ji-Xin

2015-03-01

Atherosclerotic plaque at the carotid bifurcation is the underlying cause of the majority of ischemic strokes. Noninvasive imaging and quantification of the compositional changes preceding gross anatomic changes within the arterial wall is essential for diagnosis of disease. Current imaging modalities such as duplex ultrasound, computed tomography, positron emission tomography are limited by the lack of compositional contrast and the detection of flow-limiting lesions. Although high-resolution magnetic resonance imaging has been developed to characterize atherosclerotic plaque composition, its accessibility for wide clinical use is limited. Here, we demonstrate a fiber-based multispectral photoacoustic tomography system for excitation of lipids and external acoustic detection of the generated ultrasound. Using sequential ultrasound imaging of ex vivo preparations we achieved ~2 cm imaging depth and chemical selectivity for assessment of human arterial plaques. A multivariate curve resolution alternating least squares analysis method was applied to resolve the major chemical components, including intravascular lipid, intramuscular fat, and blood. These results show the promise of detecting carotid plaque in vivo through esophageal fiber-optic excitation of lipids and external acoustic detection of the generated ultrasound. This imaging system has great potential for serving as a point-ofcare device for early diagnosis of carotid artery disease in the clinic.

[Studies on the role of high pressure baroreceptors in vasopressin (ADH) secretion. Effect of occlusion of common carotid and vertebral arteries on blood ADH level (author's transl)].

PubMed

Matsuzaki, M

1977-08-20

The role of baroreceptors in common carotid and vertebral arteries and arteries in the thoracic cavity in vasopressin secretion was investigated in this study. Effects of bilateral occlusion of common carotid and vertebral arteries on blood ADH level as well as mean arterial pressure were studied in common carotid arterial plexus-denervated dogs, cervically vagotomized dogs and intact dogs. Blood ADH titers were determined by bioassay technic before and 5 minutes after the occlusion of the arteries and were compared with the changes of mean arterial pressure (MAP). The following results were obtained. (1) Blood ADH titers and MAP were elevated by the occlusion of the common carotid arteries in both intact and vagotomized dogs, while they were not significantly affected in denervated dogs. Elevation of blood ADH titers was more pronounced in vagotomized dogs than in intact dogs. (2) Blood ADH titers and MAP were elevated by the occlusion of vertebral arteries in all groups of dogs. However, the elevation of blood ADH titers in denervated dogs was more pronounced than in intact dogs, but less than in vagotomized dogs. (3) The effects of the occlusion of common carotid arteries on blood ADH titers and MPA were more pronounced than those of the occlusion of vertebral arteries. These results may suggest that: a. baroreceptors involved in vasopressin secretion are present in vertebral arteries as well, and that b. the intrathoracic baroreceptors are dominant in controlling vasopressin secretion, while those in common carotid arteries are secondly and those in vertebral arteries thirdly dominant.

Blood Flow in Stenotic Carotid Bifurcation

NASA Astrophysics Data System (ADS)

Rayz, Vitaliy L.; Williamson, Shobha Devi; Berger, Stanley A.; Saloner, David

2004-11-01

Mechanical forces induced by blood flow on an arterial wall play an important role in the development and growth of atherosclerotic plaque. To assess vulnerability of a plaque it is important to model the flow in a realistic, patient-specific geometry. Three-dimensional models of stenotic carotid bifurcations were obtained from MR images and grids were generated for the flow domains. The unsteady, incompressible Navier-Stokes equations were solved numerically using physiological boundary conditions. The results obtained by computations were compared with in-vivo ultrasound measurements and flow visualization experiments carried out for the same geometry. The simulations show a high velocity jet forming at the stenotic throat and a strong recirculation zone downstream of the stenosis. The jet grows rapidly during the systolic part of the pulse. During diastole the flow is more stagnant. The flow is highly three-dimensional and unsteady which is clearly demonstrated by the flow streamlines. These unsteady flows cause rapid temporal and spatial changes of the forces acting on the atherosclerotic plaque, which has important effects on its growth and stability.

Carotid arterial wall MRI at 3T using 3D variable-flip-angle turbo spin-echo (TSE) with flow-sensitive dephasing (FSD).

PubMed

Fan, Zhaoyang; Zhang, Zhuoli; Chung, Yiu-Cho; Weale, Peter; Zuehlsdorff, Sven; Carr, James; Li, Debiao

2010-03-01

To evaluate the effectiveness of flow-sensitive dephasing (FSD) magnetization preparation in improving blood signal suppression of three-dimensional (3D) turbo spin-echo (TSE) sequence (SPACE) for isotropic high-spatial-resolution carotid arterial wall imaging at 3T. The FSD-prepared SPACE sequence (FSD-SPACE) was implemented by adding two identical FSD gradient pulses right before and after the first refocusing 180 degrees -pulse of the SPACE sequence in all three orthogonal directions. Nine healthy volunteers were imaged at 3T with SPACE, FSD-SPACE, and multislice T2-weighted 2D TSE coupled with saturation band (SB-TSE). Apparent carotid wall-lumen contrast-to-noise ratio (aCNR(w-l)) and apparent lumen area (aLA) at the locations with residual-blood (rb) signal shown on SPACE images were compared between SPACE and FSD-SPACE. Carotid aCNR(w-l) and lumen (LA) and wall area (WA) measured from FSD-SPACE were compared to those measured from SB-TSE. Plaque-mimicking flow artifacts identified in seven carotids on SPACE images were eliminated on FSD-SPACE images. The FSD preparation resulted in slightly reduced aCNR(w-l) (P = 0.025), but significantly improved aCNR between the wall and rb regions (P < 0.001) and larger aLA (P < 0.001). Compared to SB-TSE, FSD-SPACE offered comparable aCNR(w-l) with much higher spatial resolution, shorter imaging time, and larger artery coverage. The LA and WA measurements from the two techniques were in good agreement based on intraclasss correlation coefficient (0.988 and 0.949, respectively; P < 0.001) and Bland-Altman analyses. FSD-SPACE is a time-efficient 3D imaging technique for carotid arterial wall with superior spatial resolution and blood signal suppression.

Symptomatic Post Endarterectomy Common Carotid Artery Pseudoaneurysm Treated with Combination of Flow Diverter Implantation and Carotid Stenting

PubMed Central

Imbarrato, Greg; Gordhan, Ajeet

2018-01-01

A 74-year-old male developed cervical carotid artery psuedoaneurysm 8 months after carotid endarterectomy. The patient was successfully managed with dual implantation of flow-diverter and conventional carotid stent. Flow-diverter was placed across the neck of pseudoaneurysm to provide flow diversion while carotid stent was implanted within the lumen of the expanded flow-diverter to approximate and hold the flow diverter proximal and distal to the pseudoaneurysm. Follow-up ultrasonography revealed complete resolution of the pseudoaneurysm. PMID:29535899

Effect of modest salt reduction on blood pressure, urinary albumin, and pulse wave velocity in white, black, and Asian mild hypertensives.

PubMed

He, Feng J; Marciniak, Maciej; Visagie, Elisabeth; Markandu, Nirmala D; Anand, Vidya; Dalton, R Neil; MacGregor, Graham A

2009-09-01

A reduction in salt intake lowers blood pressure. However, most previous trials were in whites with few in blacks and Asians. Salt reduction may also reduce other cardiovascular risk factors (eg, urinary albumin excretion, arterial stiffness). However, few well-controlled trials have studied these effects. We carried out a randomized double-blind crossover trial of salt restriction with slow sodium or placebo, each for 6 weeks, in 71 whites, 69 blacks, and 29 Asians with untreated mildly raised blood pressure. From slow sodium to placebo, urinary sodium was reduced from 165+/-58 (+/-SD) to 110+/-49 mmol/24 hours (9.7 to 6.5 g/d salt). With this reduction in salt intake, there was a significant decrease in blood pressure from 146+/-13/91+/-8 to 141+/-12/88+/-9 mm Hg (P<0.001), urinary albumin from 10.2 (IQR: 6.8 to 18.9) to 9.1 (6.6 to 14.0) mg/24 hours (P<0.001), albumin/creatinine ratio from 0.81 (0.47 to 1.43) to 0.66 (0.44 to 1.22) mg/mmol (P<0.001), and carotid-femoral pulse wave velocity from 11.5+/-2.3 to 11.1+/-1.9 m/s (P<0.01). Subgroup analysis showed that the reductions in blood pressure and urinary albumin/creatinine ratio were significant in all groups, and the decrease in pulse wave velocity was significant in blacks only. These results demonstrate that a modest reduction in salt intake, approximately the amount of the current public health recommendations, causes significant falls in blood pressure in all 3 ethnic groups. Furthermore, it reduces urinary albumin and improves large artery compliance. Although both could be attributable to the falls in blood pressure, they may carry additional benefits on reducing cardiovascular disease above that obtained from the blood pressure falls alone.

Lean body mass may explain apparent racial differences in carotid intima-media thickness in obese children.

PubMed

Chowdhury, Shahryar M; Henshaw, Melissa H; Friedman, Brad; Saul, J Philip; Shirali, Girish S; Carter, Janet; Levitan, Bryana M; Hulsey, Tom

2014-05-01

Racial differences in carotid intima-media thickness (cIMT) have been suggested to be associated with the disproportionally high prevalence of cardiovascular disease in black adults. The objective of this study was to evaluate the effects of cardiovascular risk factors on the racial differences seen in cIMT in obese children. Obese subjects aged 4 to 21 years were recruited prospectively. Height, weight, blood pressure, fasting insulin, glucose, lipid panel, high-sensitivity C-reactive protein, and body composition by dual-energy x-ray absorptiometry were obtained. B-mode carotid imaging was analyzed by a single blinded physician. A total of 120 subjects (46 white, 74 black) were enrolled. Black subjects exhibited greater cIMT (0.45 ± 0.03 vs 0.43 ± 0.02 cm, P < .01) and higher lean body mass index (19.3 ± 3.4 vs 17.3 ± 3.2 kg/m², P = .02) than white subjects. Simple linear regression revealed modest associations between mean cIMT and race (R = 0.52, P < .01), systolic blood pressure (R = 0.47, P < .01), and lean body mass (R = 0.51, P < .01). On multivariate regression analysis, lean body mass remained the only measure to maintain a statistically significant relationship with mean cIMT (P < .01). Black subjects demonstrated greater cIMT than white subjects. The relationship between race and cIMT disappeared when lean body mass was accounted for. Future studies assessing the association of cardiovascular disease risk factors to cIMT in obese children should include lean body mass in the analysis. Published by Mosby, Inc.

Study of the intima-media thickening in carotid arteries of healthy elderly with high blood pressure and elderly with high blood pressure and dyslipidemia

PubMed Central

de Freitas, Elizabete Viana; Brandão, Andréa Araújo; Pozzan, Roberto; Magalhães, Maria Eliane; Castier, Márcia; Brandão, Airton Pires

2008-01-01

Objective The objective of this study was to assess the mean intima-media thickening of carotid arteries of elderly subjects, and its relationship with age, anthropometric measurements, high systolic blood pressure and dyslipidemia. Methods In this investigation, 129 subjects were enrolled between 1995 and 1998, age ranging from 29 to 94 years. They were assigned to one of 4 groups, including 2 control groups (group I, of healthy younger subjects; group II of healthy elderly subjects). Groups III and IV included those who presented with isolated systolic hypertension (ISH), and ISH and dyslipidemia, respectively. All subjects were submitted to a medical interview, lab tests with measurement of cholesterol levels, electrocardiogram, and carotid ultrasound. The ultrasound included measurement of the intima-media thickening (IMT) of the carotid arteries, the right carotid artery (RCA) and left carotid artery (LCA), and assessment of the presence of plaques. Blood fat and glucose were measured by a standard method. The results were compared among the groups through statistical tests. The tests employed were: Chi-Square, Pearson’s and Likelihood Ratio, Student’s t, Mann-Whitney; ANOVA followed by Tukey’s test, Kruskal-Wallis nonparametric test, and test for multiple comparisons and Odds Ratio determination (OR). Results In this investigation, a positive association was observed between aging and IMT. In relation to systolic hypertension, a significant association was observed with IMT (IMT-RCA p = 0.0034; IMT-LCA p = 0.0196; IMT-RLCA p = 0.0299), and with the presence of plaques (PlaqueR p = 0.0110; PlaqueL p = 0.0294; PlaqueRL p = 0.0040). Conclusion This investigation evidenced the important role of aging in IMT, and of systolic hypertension in the IMT and presence of plaque. However, further studies are needed for a better understanding of the actual role of risk factors in aging. PMID:18982922

Usefulness of dual protection combined with blood aspiration for distal embolic protection during carotid artery stenting.

PubMed

Sakamoto, Shigeyuki; Kiura, Yoshihiro; Okazaki, Takahito; Shinagawa, Katsuhiro; Ichinose, Nobuhiko; Shibukawa, Masaaki; Orita, Yoji; Shimonaga, Koji; Kajihara, Yosuke; Kurisu, Kaoru

2015-03-01

We describe dual protection (simultaneous flow reversal and distal filter) combined with blood aspiration as a novel technique to provide distal embolic protection during carotid artery stenting (CAS). Between July 2011 and August 2014, 190 patients with internal carotid artery (ICA) stenosis underwent 190 CAS procedures as follows. After post-dilation of the stent using dual protection, the aspiration catheter was placed between the distal filter and the proximal end of the stent, and the blood was aspirated several times from the ICA. We assessed hyper-intensity spots in diffusion-weighted images (DWI), and major adverse events (MAE) defined as major stroke, myocardial infarction and death after CAS. We then assessed visible debris captured in aspirated blood, the distal filter and a blood filter during flow reversal. The overall technical success rate was 100 %, and all stenoses were dilated. Hyper-intense spots were found in 33 (17.3 %) of 190 DWI. The rate of MAE within 30 days was 1.05 % (2/190). Visible debris in 175 of 190 CAS procedures was captured in 92 (52.5 %) of these 175. In 25 (27.2 %) of these 92, visible debris was captured in all of aspirated blood, the distal filter and the blood filter during flow reversal, only the blood filter during flow reversal (n = 19; 20.7 %), only the distal filter (n = 14; 15.2 %), only aspirated blood (n = 11; 12 %), aspirated blood and the blood filter during flow reversal (n = 10; 10.8 %), aspirated blood and the distal filter (n = 7; 7.6 %) and the distal filter and blood filter during flow reversal (n = 6; 6.5 %). Adding a distal filter and blood aspiration to flow reversal during CAS could provide effective distal embolic protection.

Carotid Artery Disease

MedlinePlus

... brain (cerebrovascular disease). Like the heart, the brain’s cells need a constant supply of oxygen-rich blood. This blood supply is delivered to the brain by the 2 large carotid arteries in the front of your neck and by 2 smaller vertebral arteries at the back of your ...

Estimation of arterial baroreflex sensitivity in relation to carotid artery stiffness.

PubMed

Lipponen, Jukka A; Tarvainen, Mika P; Laitinen, Tomi; Karjalainen, Pasi A; Vanninen, Joonas; Koponen, Timo; Lyyra-Laitinen, Tiina

2012-01-01

Arterial baroreflex has a significant role in regulating blood pressure. It is known that increased stiffness of the carotid sinus affects mecanotransduction of baroreceptors and therefore limits baroreceptors capability to detect changes in blood pressure. By using high resolution ultrasound video signal and continuous measurement of electrocardiogram (ECG) and blood pressure, it is possible to define elastic properties of artery simultaneously with baroreflex sensitivity parameters. In this paper dataset which consist 38 subjects, 11 diabetics and 27 healthy controls was analyzed. Use of diabetic and healthy test subjects gives wide scale of arteries with different elasticity properties, which provide opportunity to validate baroreflex and artery stiffness estimation methods.

Management of high blood pressure in Blacks: an update of the International Society on Hypertension in Blacks consensus statement.

PubMed

Flack, John M; Sica, Domenic A; Bakris, George; Brown, Angela L; Ferdinand, Keith C; Grimm, Richard H; Hall, W Dallas; Jones, Wendell E; Kountz, David S; Lea, Janice P; Nasser, Samar; Nesbitt, Shawna D; Saunders, Elijah; Scisney-Matlock, Margaret; Jamerson, Kenneth A

2010-11-01

Since the first International Society on Hypertension in Blacks consensus statement on the "Management of High Blood Pressure in African American" in 2003, data from additional clinical trials have become available. We reviewed hypertension and cardiovascular disease prevention and treatment guidelines, pharmacological hypertension clinical end point trials, and blood pressure-lowering trials in blacks. Selected trials without significant black representation were considered. In this update, blacks with hypertension are divided into 2 risk strata, primary prevention, where elevated blood pressure without target organ damage, preclinical cardiovascular disease, or overt cardiovascular disease for whom blood pressure consistently <135/85 mm Hg is recommended, and secondary prevention, where elevated blood pressure with target organ damage, preclinical cardiovascular disease, and/or a history of cardiovascular disease, for whom blood pressure consistently <130/80 mm Hg is recommended. If blood pressure is ≤10 mm Hg above target levels, monotherapy with a diuretic or calcium channel blocker is preferred. When blood pressure is >15/10 mm Hg above target, 2-drug therapy is recommended, with either a calcium channel blocker plus a renin-angiotensin system blocker or, alternatively, in edematous and/or volume-overload states, with a thiazide diuretic plus a renin-angiotensin system blocker. Effective multidrug therapeutic combinations through 4 drugs are described. Comprehensive lifestyle modifications should be initiated in blacks when blood pressure is ≥115/75 mm Hg. The updated International Society on Hypertension in Blacks consensus statement on hypertension management in blacks lowers the minimum target blood pressure level for the lowest-risk blacks, emphasizes effective multidrug regimens, and de-emphasizes monotherapy.

Periodontal Microbiota and Carotid Intima-Media Thickness

PubMed Central

Desvarieux, Moïse; Demmer, Ryan T.; Rundek, Tatjana; Boden-Albala, Bernadette; Jacobs, David R.; Sacco, Ralph L.; Papapanou, Panos N.

2009-01-01

Background Chronic infections, including periodontal infections, may predispose to cardiovascular disease. We investigated the relationship between periodontal microbiota and subclinical atherosclerosis. Methods and Results Of 1056 persons (age 69±9 years) with no history of stroke or myocardial infarction enrolled in the Oral Infections and Vascular Disease Epidemiology Study (INVEST), we analyzed 657 dentate subjects. Among these subjects, 4561 subgingival plaque samples were collected (average of 7 samples/subject) and quantitatively assessed for 11 known periodontal bacteria by DNA-DNA checkerboard hybridization. Extensive in-person cardiovascular risk factor measurements, a carotid scan with high-resolution B-mode ultrasound, white blood cell count, and C-reactive protein values were obtained. In 3 separate analyses, mean carotid artery intima-media thickness (IMT) was regressed on tertiles of (1) burden of all bacteria assessed, (2) burden of bacteria causative of periodontal disease (etiologic bacterial burden), and (3) the relative predominance of causative/over other bacteria in the subgingival plaque. All analyses were adjusted for age, race/ethnicity, gender, education, body mass index, smoking, diabetes, systolic blood pressure, and LDL and HDL cholesterol. Overall periodontal bacterial burden was related to carotid IMT. This relationship was specific to causative bacterial burden and the dominance of etiologic bacteria in the observed microbiological niche. Adjusted mean IMT values across tertiles of etiologic bacterial dominance were 0.84, 0.85, and 0.88 (P=0.002). Similarly, white blood cell values increased across tertiles of etiologic bacterial burden from 5.57 to 6.09 and 6.03 cells × 109/L (P=0.01). C-reactive protein values were unrelated to periodontal microbial status (P=0.82). Conclusions Our data provide evidence of a direct relationship between periodontal microbiology and subclinical atherosclerosis. This relationship exists independent

High Central Aortic Rather than Brachial Blood Pressure is Associated with Carotid Wall Remodeling and Increased Arterial Stiffness in Childhood.

PubMed

Peluso, Gonzalo; García-Espinosa, Victoria; Curcio, Santiago; Marota, Marco; Castro, Juan; Chiesa, Pedro; Giachetto, Gustavo; Bia, Daniel; Zócalo, Yanina

2017-03-01

In adults, central blood pressure (cBP) is reported to associate target organ damages (TODs) rather than peripheral blood pressure (pBP). However, data regarding the association of pre-clinical TODs with cBP and pBP in pediatric populations are scarce. To evaluate in children and adolescents the importance of cBP and pBP levels, in terms of their association with hemodynamic and vascular changes. 315 subjects [age (mean/range) 12/8-18 years] were included. pBP (oscillometry, Omron-HEM433INT and Mobil-O-Graph), cBP levels and waveforms (oscillometry, Mobil-O-Graph; applanation tonometry, SphygmoCor), aortic wave reflection-related parameters, carotid intima-media thickness (CIMT) and carotid (elastic modulus, stiffness-index) and aortic stiffness (carotid-femoral pulse wave velocity, PWV). Four groups were defined considering pBP and cBP percentiles (th): cBP ≥90th, cBP <90th, pBP ≥90th, pBP <90th. In each group, haemodynamic and vascular parameters were compared for subgroups defined considering the level of the remaining blood pressure (cBP or pBP). Subgroups were matched for anthropometric and cardiovascular risk factors (propensity matching-score). Subjects with high cBP showed a worse cardiovascular risk profile in addition to worse peripheral hemodynamic conditions. The CIMT, carotid and aortic stiffness levels were also higher in those subjects. CIMT and carotid stiffness remained statistically higher when subjects were matched for pBP and other cardiovascular risk factors. There were no differences in arterial properties when subjects were analyzed (compared) considering similar pBP levels, during normal and high cBP conditions. Compared with pBP, the cBP levels show a greater association with vascular alterations (high CIMT and arterial stiffness), in children and adolescents.

Artificial embolization of carotid-cavernous fistula with post-operative patency of internal carotid artery

PubMed Central

Isamat, Fabian; Salleras, V.; Miranda, A. M.

1970-01-01

This report deals with a patient of 86 who developed a carotid-cavernous fistula. Artificial embolization alone was considered the safest treatment for this patient and proved to be adequate. Post-operative preservation of the patency of the internal carotid artery was demonstrated by angiography. We believe this method is particularly appropriate for carotid-cavernous fistulas if it is demonstrated by angiography that the major blood flow of the carotid artery pours into the fistula. A soft-iron clip attached to the muscle can be used for external and forceful guidance of the embolus into the fistula with the help of an electromagnet, hence the patency of the internal carotid artery can be preserved. The embolus should be introduced through the external carotid artery. This is the only case known to us in which patency of the internal carotid artery was post-operatively maintained. We have reviewed 545 reported cases of surgically treated carotid-cavernous fistulas and analysed the results from simple cervical carotid ligation to the more sophisticated methods of artificial embolizations. The results obtained by artificial embolization have been consistently good, while the other techniques have failed in large percentages. Artificial embolization should be used as the primary treatment for carotid-cavernous fistula, since ligation of the internal carotid artery precludes its embolization at a later date. Images PMID:5478949

Carotid baroreflex responsiveness in heat-stressed humans

NASA Technical Reports Server (NTRS)

Crandall, C. G.

2000-01-01

The effects of whole body heating on human baroreflex function are relatively unknown. The purpose of this project was to identify whether whole body heating reduces the maximal slope of the carotid baroreflex. In 12 subjects, carotid-vasomotor and carotid-cardiac baroreflex responsiveness were assessed in normothermia and during whole body heating. Whole body heating increased sublingual temperature (from 36.4 +/- 0.1 to 37.4 +/- 0.1 degrees C, P < 0.01) and increased heart rate (from 59 +/- 3 to 83 +/- 3 beats/min, P < 0. 01), whereas mean arterial blood pressure (MAP) was slightly decreased (from 88 +/- 2 to 83 +/- 2 mmHg, P < 0.01). Carotid-vasomotor and carotid-cardiac responsiveness were assessed by identifying the maximal gain of MAP and heart rate to R wave-triggered changes in carotid sinus transmural pressure. Whole body heating significantly decreased the responsiveness of the carotid-vasomotor baroreflex (from -0.20 +/- 0.02 to -0.13 +/- 0.02 mmHg/mmHg, P < 0.01) without altering the responsiveness of the carotid-cardiac baroreflex (from -0.40 +/- 0.05 to -0.36 +/- 0.02 beats x min(-1) x mmHg(-1), P = 0.21). Carotid-vasomotor and carotid-cardiac baroreflex curves were shifted downward and upward, respectively, to accommodate the decrease in blood pressure and increase in heart rate that accompanied the heat stress. Moreover, the operating point of the carotid-cardiac baroreflex was shifted closer to threshold (P = 0.02) by the heat stress. Reduced carotid-vasomotor baroreflex responsiveness, coupled with a reduction in the functional reserve for the carotid baroreflex to increase heart rate during a hypotensive challenge, may contribute to increased susceptibility to orthostatic intolerance during a heat stress.

Fast simultaneous noncontrast angiography and intraplaque hemorrhage (fSNAP) sequence for carotid artery imaging.

PubMed

Chen, Shuo; Ning, Jia; Zhao, Xihai; Wang, Jinnan; Zhou, Zechen; Yuan, Chun; Chen, Huijun

2017-02-01

To propose a fast simultaneous noncontrast angiography and intraplaque hemorrhage (fSNAP) sequence for carotid artery imaging. The proposed fSNAP sequence uses a low-resolution reference acquisition for phase-sensitive reconstruction to speed up the scan, and an inversion recovery acquisition with arbitrary k-space filling order to generate similar contrast to conventional SNAP. Four healthy volunteers and eight patients were recruited to test the performance of fSNAP in vivo. The lumen area quantification, muscle-blood CNR, IPH-blood CNR, lumen SNR, and standard deviation and intraplaque hemorrhage (IPH) detection accuracy were compared between fSNAP and SNAP. By using a low-resolution reference acquisition with 1/4 matrix size of the full-resolution reference scan, the scan time of fSNAP was 37.5% less than that of SNAP. A high agreement of lumen area measurement (ICC = 0.97, 95% CI: 0.96-0.99) and IPH detection (Kappa = 1) were found between fSNAP and SNAP. Also, no significant difference was found for muscle-blood CNR (P = 0.25), IPH-blood CNR (P = 0.35), lumen SNR (P = 0.60), and standard deviation (P = 0.46) between the two techniques. The feasibility of fSNAP was validated. fSNAP can improve the imaging efficiency with similar performance to SNAP on carotid artery imaging. Magn Reson Med 77:753-758, 2017. © 2016 International Society for Magnetic Resonance in Medicine. © 2016 International Society for Magnetic Resonance in Medicine.

Relationship between the Direction of Ophthalmic Artery Blood Flow and Ocular Microcirculation before and after Carotid Artery Stenting.

PubMed

Ishii, Masashi; Hayashi, Morito; Yagi, Fumihiko; Sato, Kenichiro; Tomita, Goji; Iwabuchi, Satoshi

2016-01-01

When internal carotid artery stenosis is accompanied by ocular ischemic syndrome, intervention is recommended to prevent irreversible visual loss. In this study, we used laser speckle flowgraphy to measure the ocular microcirculation in the optic nerve head before and after carotid artery stenting (CAS) of 40 advanced internal carotid stenosis lesions from 37 patients. The aim was to investigate the relationship between ocular microcirculation and the direction of ophthalmic artery blood flow obtained by angiography. We found that there was a significant increase in blood flow after CAS ( P = 0.003). Peak systolic velocity as an indicator of the rate of stenosis was also significantly higher in the group with retrograde/undetected flow of the ophthalmic artery than in the group with antegrade flow ( P = 0.002). In all cases where retrograde flow of the ophthalmic artery was observed before stenting, the flow changed to antegrade after stenting. Through the use of laser speckle flowgraphy, this study found that CAS can improve ocular microcirculation. Furthermore, while patients displaying retrograde flow of the ophthalmic artery before stenting have a poor prognosis, CAS corrected the flow to antegrade, suggesting that visual loss can be prevented by improving the ocular microcirculation.

Sex differences in predictors of longitudinal changes in carotid artery stiffness: the Multi-Ethnic Study of Atherosclerosis.

PubMed

Stern, Rebecca; Tattersall, Matthew C; Gepner, Adam D; Korcarz, Claudia E; Kaufman, Joel; Colangelo, Laura A; Liu, Kiang; Stein, James H

2015-02-01

To identify sex differences in predictors of longitudinal changes in carotid arterial stiffness in a multiethnic cohort. Carotid artery distensibility coefficient (DC) and Young's elastic modulus (YEM) were measured in 2650 Multi-Ethnic Study of Atherosclerosis participants (45-84 years old and free of cardiovascular disease) at baseline and after a mean of 9.4 years. Predictors of changes in DC and YEM for each sex were evaluated using multivariable linear regression models. The 1236 men (46.6%) were 60.0 (SD, 9.3) years: 40% were white, 22% black, 16% Chinese, and 22% Hispanic. The 1414 (53.4%) women were 59.8 (9.4) years old with a similar race distribution. Despite similar rates of change in DC and YEM, predictors of changes in distensibility markers differed by sex. In men, Chinese (P=0.002) and black (P=0.003) race/ethnicity, systolic blood pressure (P=0.012), and diabetes mellitus (P=0.05) were associated with more rapidly decreasing DC (accelerated stiffening). Starting antihypertensive medication was associated with improved DC (P=0.03); stopping antihypertensives was associated with more rapid stiffening (increased YEM, P=0.05). In women, higher education was associated with slower stiffening (DC, P=0.041; YEM, P<0.001) as was use of lipid-lowering medication (P=0.03), whereas baseline use of antihypertensive medications (YEM, P=0.01) and systolic blood pressure (DC, P=0.02; P=0.04) predicted increasing stiffening in women. Longitudinal changes in carotid artery stiffness are associated with systolic blood pressure and antihypertensive therapy in both sexes; however, race/ethnicity (in men) and level of education (in women) may have different contributions between the sexes. © 2014 American Heart Association, Inc.

Rapid dark-blood carotid vessel-wall imaging with random bipolar gradients in a radial SSFP acquisition.

PubMed

Lin, Hung-Yu; Flask, Chris A; Dale, Brian M; Duerk, Jeffrey L

2007-06-01

To investigate and evaluate a new rapid dark-blood vessel-wall imaging method using random bipolar gradients with a radial steady-state free precession (SSFP) acquisition in carotid applications. The carotid artery bifurcations of four asymptomatic volunteers (28-37 years old, mean age = 31 years) were included in this study. Dark-blood contrast was achieved through the use of random bipolar gradients applied prior to the signal acquisition of each radial projection in a balanced SSFP acquisition. The resulting phase variation for moving spins established significant destructive interference in the low-frequency region of k-space. This phase variation resulted in a net nulling of the signal from flowing spins, while the bipolar gradients had a minimal effect on the static spins. The net effect was that the regular SSFP signal amplitude (SA) in stationary tissues was preserved while dark-blood contrast was achieved for moving spins. In this implementation, application of the random bipolar gradient pulses along all three spatial directions nulled the signal from both in-plane and through-plane flow in phantom and in vivo studies. In vivo imaging trials confirmed that dark-blood contrast can be achieved with the radial random bipolar SSFP method, thereby substantially reversing the vessel-to-lumen contrast-to-noise ratio (CNR) of a conventional rectilinear SSFP "bright-blood" acquisition from bright blood to dark blood with only a modest increase in TR (approximately 4 msec) to accommodate the additional bipolar gradients. Overall, this sequence offers a simple and effective dark-blood contrast mechanism for high-SNR SSFP acquisitions in vessel wall imaging within a short acquisition time.

Differential blood flow responses to CO2 in human internal and external carotid and vertebral arteries

PubMed Central

Sato, Kohei; Sadamoto, Tomoko; Hirasawa, Ai; Oue, Anna; Subudhi, Andrew W; Miyazawa, Taiki; Ogoh, Shigehiko

2012-01-01

Arterial CO2 serves as a mediator of cerebral blood flow (CBF), and its relative influence on the regulation of CBF is defined as cerebral CO2 reactivity. Our previous studies have demonstrated that there are differences in CBF responses to physiological stimuli (i.e. dynamic exercise and orthostatic stress) between arteries in humans. These findings suggest that dynamic CBF regulation and cerebral CO2 reactivity may be different in the anterior and posterior cerebral circulation. The aim of this study was to identify cerebral CO2 reactivity by measuring blood flow and examine potential differences in CO2 reactivity between the internal carotid artery (ICA), external carotid artery (ECA) and vertebral artery (VA). In 10 healthy young subjects, we evaluated the ICA, ECA, and VA blood flow responses by duplex ultrasonography (Vivid-e, GE Healthcare), and mean blood flow velocity in middle cerebral artery (MCA) and basilar artery (BA) by transcranial Doppler (Vivid-7, GE healthcare) during two levels of hypercapnia (3% and 6% CO2), normocapnia and hypocapnia to estimate CO2 reactivity. To characterize cerebrovascular reactivity to CO2, we used both exponential and linear regression analysis between CBF and estimated partial pressure of arterial CO2, calculated by end-tidal partial pressure of CO2. CO2 reactivity in VA was significantly lower than in ICA (coefficient of exponential regression 0.021 ± 0.008 vs. 0.030 ± 0.008; slope of linear regression 2.11 ± 0.84 vs. 3.18 ± 1.09% mmHg−1: VA vs. ICA, P < 0.01). Lower CO2 reactivity in the posterior cerebral circulation was persistent in distal intracranial arteries (exponent 0.023 ± 0.006 vs. 0.037 ± 0.009; linear 2.29 ± 0.56 vs. 3.31 ± 0.87% mmHg−1: BA vs. MCA). In contrast, CO2 reactivity in ECA was markedly lower than in the intra-cerebral circulation (exponent 0.006 ± 0.007; linear 0.63 ± 0.64% mmHg−1, P < 0.01). These findings indicate that vertebro-basilar circulation has lower CO2 reactivity than

Hispanic ethnicity is associated with increased costs after carotid endarterectomy and carotid stenting in the United States.

PubMed

Propper, Brandon; Black, James H; Schneider, Eric B; Lum, Ying Wei; Malas, Mahmoud B; Arnold, Margaret W; Abularrage, Christopher J

2013-09-01

We have previously demonstrated an adverse impact of black race and Hispanic ethnicity on the outcomes of carotid endarterectomy (CEA) and carotid artery stenting (CAS). The current study was undertaken to examine the influence of race and ethnicity on the cost of CEA and CAS. The Nationwide Inpatient Sample (2005-2009) was queried using ICD-9 codes for CEA and CAS in patients with carotid artery stenosis. The primary outcome was total hospital charges. Multivariate analysis was performed using a generalized linear model adjusting for age, sex, race, comorbidities (Charlson index), high-risk status, procedure type, symptomatic status, year, insurance type, and surgeon and hospital operative volumes and characteristics. Hispanic and black patients were more likely to have a symptomatic presentation, and were more likely to undergo either CEA or CAS by low-volume surgeons at low-volume hospitals (P < 0.05, all). They were also less likely to have private insurance or Medicare (P < 0.001). Overall, CEA was less expensive than CAS over the 4-y study period ($29,502 ± $104 versus $46,713 ± $409, P < 0.001). Total hospital charges after CEA were increased in both blacks ($39,562 ± $843) and Hispanics ($45,325 ± $735) compared with whites on univariate analysis ($28,403 ± $101, P < 0.001). After CAS, total hospital charges were similarly increased in both blacks ($51,770 ± $2085) and Hispanics ($63,637 ± $2766) compared with whites on univariate analysis ($45,550 ± $412, P < 0.001). On multivariable analysis, however, only Hispanic ethnicity remained independently associated with increased charges after both CEA (exponentiated coefficient 1.18; 95% CI [1.15-1.20]; P < 0.001) and CAS (exponentiated coefficient 1.17; 95% CI [1.09-1.24]; P < 0.001). Hispanic ethnicity was independently associated with increased hospital charges after both CEA and CAS. The increased charges seen in black patients were explained, in part, by decreased surgeon operative volume

Arrested blood flow during false aneurysm formation in the carotid arteries of cattle slaughtered with and without stunning.

PubMed

Gregory, N G; Schuster, P; Mirabito, L; Kolesar, R; McManus, T

2012-02-01

The time to onset of arrested blood flow and the size of false aneurysms in the severed carotid arteries were assessed in 126 cattle during halal slaughter without stunning. Thirty six cattle (29%) showed early arrest of blood flow. In 6%, both the left and right carotid arteries in the same animal stopped bleeding before 60s had elapsed following the neck cut. The time to early arrested blood flow was on average 21s, and this was accompanied by enlargement with false aneurysms which occluded the arteries. In the arteries which were still bleeding at 60s after the neck was cut the artery size was normal. Based on comparative data from different slaughter premises it appeared that making the cut in the neck at the first cervical vertebra instead of the second to fourth cervical vertebrae reduced the frequency of false aneurysm formation and early arrested blood flow. This was confirmed in a separate controlled trial where 100 cattle were stunned with a captive bolt and the arteries were examined following neck cutting at either the C1 or C3 positions. Copyright © 2011 Elsevier Ltd. All rights reserved.

High-flow bypass and wrap-clipping for ruptured blood blister-like aneurysm of the internal carotid artery using intraoperative monitoring of cerebral hemodynamics

PubMed Central

Kubo, Yoshitaka; Koji, Takahiro; Yoshida, Kenji; Saito, Hideo; Ogawa, Akira; Ogasawara, Kuniaki

2015-01-01

Aneurysms at non-branching sites in the supraclinoid internal carotid artery (ICA) can be classified as “blood blister-like aneurysms” (BBAs), which have blood blister-like configurations and fragile walls. While surgical treatment for the BBA in the acute stage is recommended, the optimal surgical procedure remains controversial. In the study reported here, we describe the case of a 37-year-old woman with a ruptured BBA in the ophthalmic segment of the right ICA who underwent wrap-clipping with external carotid artery–internal carotid artery bypass by intraoperative estimation of the measurement of cortical cerebral blood flow (CoBF) using a thermal diffusion flow probe. Trapping of the ICA in the acute stage of subarachnoid hemorrhage may result in ischemic complications secondary to hemodynamic hypoperfusion or occlusion of the perforating artery, and/or delayed vasospasm, even with concomitant bypass surgery. We believe that it is important to perform scheduled external carotid artery–internal carotid artery bypass before trapping of the ICA in patients with a ruptured BBA in the acute stage of subarachnoid hemorrhage and to perform wrap-clipping rather than trapping. This would provide much more CoBF if a reduction of CoBF occurs after trapping occlusion of the ICA including a ruptured BBA according to intraoperative CoBF monitoring. As far as we are aware, the case reported here is the first report on high-flow bypass and wrap-clipping for a ruptured BBA of the ICA using intraoperative monitoring of cerebral hemodynamics. PMID:26082641

The distribution of cholinesterases in the cat carotid body

PubMed Central

Biscoe, T. J.; Silver, Ann

1966-01-01

1. The distribution of acetyl- and butyrylcholinesterase in the carotid body of the cat has been examined histochemically. Studies were made on normal carotid bodies and on carotid bodies from cats in which certain nerves had been cut some time previously. The nerves sectioned were the sinus nerve, the post-ganglionic sympathetic branch of the superior cervical ganglion or the preganglionic cervical sympathetic trunk. 2. It was confirmed that more butyrylcholinesterase than acetylcholinesterase is present. Both enzymes are found in three sites: (i) as strands, (ii) as plexuses, (iii) inside a few cells. 3. The distribution is unaffected by cutting the sinus nerve or preganglionic cervical sympathetic nerves. Disorganization and depletion of the cholinesterases in the strands and plexuses occurs when the post-ganglionic branch of the superior cervical ganglion is cut. The cholinesterase in cells is unaffected. 4. In carotid bodies in which vessels were filled with red blood cells or in which the vascular bed was injected with carmine-gelatine, it was seen that strands and plexuses are associated with blood vessels, and with blood vessels and cells respectively. 5. It is suggested that a cholinergic pathway controlling carotid body blood vessels runs in the post-ganglionic cervical sympathetic. ImagesabcdefPlate 2abcdef PMID:5942823

The distribution of cholinesterases in the cat carotid body.

PubMed

Biscoe, T J; Silver, A

1966-03-01

1. The distribution of acetyl- and butyrylcholinesterase in the carotid body of the cat has been examined histochemically. Studies were made on normal carotid bodies and on carotid bodies from cats in which certain nerves had been cut some time previously. The nerves sectioned were the sinus nerve, the post-ganglionic sympathetic branch of the superior cervical ganglion or the preganglionic cervical sympathetic trunk.2. It was confirmed that more butyrylcholinesterase than acetylcholinesterase is present. Both enzymes are found in three sites: (i) as strands, (ii) as plexuses, (iii) inside a few cells.3. The distribution is unaffected by cutting the sinus nerve or preganglionic cervical sympathetic nerves. Disorganization and depletion of the cholinesterases in the strands and plexuses occurs when the post-ganglionic branch of the superior cervical ganglion is cut. The cholinesterase in cells is unaffected.4. In carotid bodies in which vessels were filled with red blood cells or in which the vascular bed was injected with carmine-gelatine, it was seen that strands and plexuses are associated with blood vessels, and with blood vessels and cells respectively.5. It is suggested that a cholinergic pathway controlling carotid body blood vessels runs in the post-ganglionic cervical sympathetic.

Carotid Artery Screening

MedlinePlus

... the artery walls may signal the development of cardiovascular disease. top of page Who should consider carotid artery ... high blood pressure diabetes smoking high cholesterol known cardiovascular disease The American Heart Association guidelines also state that ...

Carotid duplex ultrasound and transcranial Doppler findings in commercial divers and pilots.

PubMed

Dormanesh, Banafshe; Vosoughi, Kia; Akhoundi, Fahimeh H; Mehrpour, Masoud; Fereshtehnejad, Seyed-Mohammad; Esmaeili, Setareh; Sabet, Azin Shafiee

2016-12-01

The risky working environments of divers and pilots, and the possible role of extreme ambient pressure in carotid stenosis, make ischemic stroke an important occupational concern among these professionals. In this study, we aimed to evaluate the association of being exposed to hyperbaric or hypobaric conditions with carotid artery stenosis by comparing common carotid intima-media thickness (CCIMT) and blood flow velocities of cerebral arteries in divers and pilots using carotid duplex ultrasound (CDUS) and transcranial Doppler (TCD). CDUS and transtemporal TCD were performed in 29 divers, 36 pilots and 30 control participants. Medical history, blood pressure, lipid profile and blood sugar were recorded to control the previously well-known risk factors of atherosclerosis. Findings of the CDUS and TCD [including: CCIMT and blood flow velocities of internal carotid artery (ICA), common carotid artery (CCA), and middle cerebral artery (MCA)] of divers and pilots were compared with those of the control group using regression analysis models. Both right and left side CCIMT were significantly higher in divers (P < 0.05) and pilots (P < 0.05) in comparison with the control group. Carotid index [peak systolic velocity (PSV) of ICA/PSV of CCA) of divers and pilots were also higher than the control group. TCD findings were not significantly different between divers, pilots, and the control group. Increased CCIMT and carotid index in diver and pilot groups appear to be suggestive of accelerated atherosclerosis of carotid artery in these occupational groups.

Effective Intraluminal Shunt in Carotid Endarterectomy for Carotid Artery Near Occlusion: Technical Report.

PubMed

Kawamura, Yoichiro; Maruyama, Daisuke; Akagi, Yojiro; Iihara, Koji

2017-10-01

Carotid artery near occlusion is a critical degree of stenosis whereby blood flow is decreased and the distal cervical and intracranial internal carotid arteries (ICAs) are prone to collapse. Considering the diminished perfusion and risk of progression to total occlusion and periocclusive embolism, we performed carotid endarterectomy for carotid artery near occlusion. Accurate evaluation of tandem stenosis or patency of the poststenotic ICA in carotid artery near occlusion is often difficult preoperatively. Thus we performed carotid endarterectomy in a hybrid operating room where intraoperative digital subtraction angiography (DSA) and endovascular angioplasty or stenting for distal lesions can be performed if necessary. In addition, to evaluate the distal ICA intraoperatively, we used an intraluminal shunt for shunt angiography, with injection of contrast material through the shunt tube, as a replacement for conventional DSA. Furthermore, an intraluminal shunt held the collapsed lumen open and provided a scaffold for suturing, which prevented postoperative stenosis of the distal ICA. The present report is intended to underline the merits of intraluminal shunt as a replacement for conventional DSA and as a scaffold for suturing. Copyright © 2017 Elsevier Inc. All rights reserved.

Influence of arterial wave reflection on carotid blood pressure and intima-media thickness in older endurance trained men and women with pre-hypertension.

PubMed

Heffernan, Kevin S; Jae, Sae Young; Tomayko, Emily; Ishaque, Muhammad R; Fernhall, Bo; Wilund, Kenneth R

2009-05-01

Increased carotid intima-media thickness (IMT) with aging is a significant predictor of mortality. Older endurance trained (ET) individuals have lower carotid artery stiffness but similar carotid IMT when compared to sedentary (SED) age-matched peers. The purpose of this study was to examine the contribution of arterial wave reflections to carotid hemodynamics and IMT in older ET and SED with pre-hypertension. Subjects consisted of endurance-trained master athletes and age-matched sedentary controls (mean age 67 years). Carotid artery Beta-stiffness index and IMT was assessed with ultrasonography. Carotid pressure and augmented pressure from wave reflections (obtained from pulse contour analysis) was measured with applanation tonometry. Carotid systolic blood pressure (SBP) and IMT were not different between groups (P>0.05). Carotid stiffness was significantly lower in ET versus SED (7.3 +/- 0.8 versus 9.9 +/- 0.6, P<0.05). Augmented pressure was significantly greater in ET versus SED (17.7 +/- 1.6 versus 13.3 +/- 1.5 mmHg, P<0.05). When adjusting for differences in resting heart rate, there were no group differences in augmented pressure. In conclusion, older ET persons with pre-hypertension have reduced carotid artery stiffness, but similar carotid SBP and carotid IMT when compared to SED. The lack of change in carotid SBP and IMT in older ET may be related to the inability of chronic exercise training to reduce bradycardia-related augmented pressure from wave reflections with aging.

Assessment of carotid stenosis using three-dimensional T2-weighted dark blood imaging: Initial experience.

PubMed

Mihai, Georgeta; Winner, Marshall W; Raman, Subha V; Rajagopalan, Sanjay; Simonetti, Orlando P; Chung, Yiu-Cho

2012-02-01

To evaluate the use of a T2-weighted SPACE sequence (T2w-SPACE) to assess carotid stenosis via several methods and compare its performance with contrast-enhanced magnetic resonance angiography (ceMRA). Fifteen patients with carotid atherosclerosis underwent dark blood (DB)-MRI using a 3D turbo spin echo with variable flip angles sequence (T2w-SPACE) and ceMRA. Images were coregistered and evaluated by two observers. Comparisons were made for luminal diameter, luminal area, degree of luminal stenosis (NASCET: North American Symptomatic Endarterectomy Trial; ECST: European Carotid Surgery Trial, and area stenosis), and vessel wall area. Degree of NASCET stenosis was clinically classified as mild (<50%), moderate (50%-69%), or severe (>69%). Excellent agreement was seen between ceMRA and T2w-SPACE and between observers for assessment of lumen diameter, lumen area, vessel wall area, and degree of NASCET stenosis (r > 0.80, P < 0.001). ECST stenosis was consistently higher than NASCET stenosis (48 ± 14% vs. 24 ± 22%, P < 0.001). Area stenosis (72 ± 2%) was significantly higher (P < 0.001) than both ESCT and NASCET stenosis. DB-MRI of carotid arteries using T2w-SPACE is clinically feasible. It provides accurate measurements of lumen size and degree of stenosis in comparison with ceMRA and offers a more reproducible measure of ECST stenosis than ceMRA. Copyright © 2011 Wiley Periodicals, Inc.

Carotid artery stenting for vulnerable plaques on MR angiography and ultrasonography: utility of dual protection and blood aspiration method.

PubMed

Sakamoto, Shigeyuki; Kiura, Yoshihiro; Okazaki, Takahito; Shinagawa, Katsuhiro; Ishii, Daizo; Ichinose, Nobuhiko; Kurisu, Kaoru

2016-10-01

Carotid artery stenting (CAS) for internal carotid artery (ICA) stenosis with vulnerable plaques is controversial. We analyzed the effect of a dual protection and blood aspiration method during CAS in patients with vulnerable plaques. A total of 111 patients with ICA stenosis underwent CAS using the dual protection (simultaneous flow reversal and distal filter) and blood aspiration method. In 103 of 111 patients, preoperative carotid plaque was estimated by both 3 T MRI and ultrasonography (US). ICA plaques with a high intensity signal on time-of-flight-MR angiography (TOF-MRA) and/or mobile component on US were defined as vulnerable plaques. We assessed major adverse events (MAE) (ie, major stroke, myocardial infarction, and death) and hyperintense spots on diffusion-weighted images (DWI) after CAS. We then evaluated the visible debris captured by dual protection and blood aspiration during CAS. The preoperative ICA plaque on TOF-MRA and US was judged to be vulnerable in 48.5% (50/103 patients). The success rate of the CAS procedure was 100% with no MAE within 30 days. DWI showed small hyperintense spots in 18% (9/50 patients) and 18.9% (10/53 patients) in the vulnerable and non-vulnerable plaque groups, respectively. Visible debris was captured in 68% (34/50 patients) and 45.3% (24/53 patients) in the vulnerable and non-vulnerable plaque groups, respectively (p=0.0286). The combination of dual protection and blood aspiration could provide effective distal embolic protection although vulnerable plaques on TOF-MRA and US had a high incidence of debris during CAS. Thus, CAS using dual protection and blood aspiration is safe in patients with vulnerable plaques. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

High Pulse Wave Velocity Has a Strong Impact on Early Carotid Atherosclerosis in a Japanese General Male Population.

PubMed

Kubozono, Takuro; Miyata, Masaaki; Kawasoe, Shin; Ojima, Satoko; Yoshifuku, Shiro; Miyahara, Hironori; Maenohara, Shigeho; Ohishi, Mitsuru

2017-02-24

Although there have been several reports on the risk factors associated with intima-media thickness (IMT), many questions remain. The purpose of this study was to investigate the association between IMT and cardiovascular risk factors in a Japanese general population.Methods and Results:The study group consisted of 1,583 male subjects undergoing routine health checkups. IMT of the common carotid artery was measured by high-resolution ultrasonography. Brachial-ankle pulse wave velocity (baPWV) was measured using an automated device. Univariate analysis demonstrated that carotid IMT significantly associated with age, body mass index (BMI), systolic blood pressure (SBP), diastolic blood pressure (DBP), baPWV, fasting glucose, low-density lipoprotein cholesterol (LDL-C), triglycerides (TG), and high-density lipoprotein cholesterol (HDL-C). Multiple logistic regression analysis for carotid atherosclerosis (carotid IMT ≥1.0 mm) was performed using obesity (BMI ≥25.0 kg/m 2 ), high BP (SBP ≥130 mmHg or DBP ≥85 mmHg), dyslipidemia (LDL-C ≥140 mg/dL, TG ≥150 mg/dL, or HDL-C <40 mg/dL), impaired fasting glucose (IFG) (fasting glucose ≥110 g/dL), and high baPWV (≥1,400 cm/s). Carotid atherosclerosis was significantly associated with only high baPWV (OR: 2.22, 95% CI: 1.24-4.17, P<0.01). High baPWV was a stronger predictor of early carotid atherosclerosis than high BP, dyslipidemia, or IFG in a Japanese general male population.

Hematocrit is associated with carotid atherosclerosis in men but not in women.

PubMed

Irace, Concetta; Ciamei, Monica; Crivaro, Andrea; Fiaschi, Elio; Madia, Angela; Cortese, Claudio; Gnasso, Agostino

2003-06-01

It is known that blood and plasma viscosities are associated with clinical manifestations of atherosclerosis, though evidence is not conclusive particularly in women. To verify whether hematocrit and blood and plasma viscosities are independently associated with carotid atherosclerosis and whether their measurement can improve the definition of the global coronary heart disease (CHD) risk. Eight hundred and ninety-two participants in a cardiovascular disease prevention campaign were examined with regard to conventional CHD risk factors (age, blood pressure, lipids, glucose, body mass index, waist/hip ratio, cigarette smoking and diabetes), hematocrit and blood and plasma viscosities. According to the degree of carotid atherosclerosis, investigated by echo-Doppler, participants were divided in three groups: those without atherosclerosis, those with a low degree of atherosclerosis and those with a high degree of atherosclerosis. In men, age, blood pressure, intima-media thickness (IMT), hematocrit (47.4+/-3.7%, 47.8+/-3.7%, 48.4+/-3.7%, P<0.05) and blood viscosity (4.69+/-0.51 cP, 4.77+/-0.55 cP, 4.82+/-0.51 cP, P=0.05) increased with increasing degree of carotid atherosclerosis. In women, age, blood pressure, total cholesterol and low-density lipoprotein-cholesterol, IMT and plasma viscosity (1.42+/-0.12 cP, 1.44+/-0.11 cP, 1.46+/-0.13 cP, P<0.05) increased with increasing carotid score. Analysis of covariance (ANCOVA) showed that after adjusting for hematocrit, blood viscosity was no longer different in the three groups. In discriminant analysis, hematocrit, among the hemorheological variables investigated, was independently associated with carotid score in men (F=3.66, P<0.05). Neither hematocrit nor blood and plasma viscosities were significantly associated with carotid score in women. These findings suggest that in men, both hematocrit and blood viscosity are related to carotid atherosclerosis but hematocrit would appear to have an independent effect over and

Physical and computational fluid dynamics models for the hemodynamics of the artiodactyl carotid rete.

PubMed

O'Brien, Haley D; Bourke, Jason

2015-12-07

In the mammalian order Artiodactyla, the majority of arterial blood entering the intracranial cavity is supplied by a large arterial meshwork called the carotid rete. This vascular structure functionally replaces the internal carotid artery. Extensive experimentation has demonstrated that the artiodactyl carotid rete drives one of the most effective selective brain cooling mechanisms among terrestrial vertebrates. Less well understood is the impact that the unique morphology of the carotid rete may have on the hemodynamics of blood flow to the cerebrum. It has been hypothesized that, relative to the tubular internal carotid arteries of most other vertebrates, the highly convoluted morphology of the carotid rete may increase resistance to flow during extreme changes in cerebral blood pressure, essentially protecting the brain by acting as a resistor. We test this hypothesis by employing simple and complex physical models to a 3D surface rendering of the carotid rete of the domestic goat, Capra hircus. First, we modeled the potential for increased resistance across the carotid rete using an electrical circuit analog. The extensive branching of the rete equates to a parallel circuit that is bound in series by single tubular arteries, both upstream and downstream. This method calculated a near-zero increase in resistance across the rete. Because basic equations do not incorporate drag, shear-stress, and turbulence, we used computational fluid dynamics to simulate the impact of these computationally intensive factors on resistance. Ultimately, both simple and complex models demonstrated negligible changes in resistance and blood pressure across the arterial meshwork. We further tested the resistive potential of the carotid rete by simulating blood pressures known to occur in giraffes. Based on these models, we found resistance (and blood pressure mitigation as a whole) to be an unlikely function for the artiodactyl carotid rete. Copyright © 2015 Elsevier Ltd. All

Carotid artery intimal medial thickness and carotid artery plaques in hypertensive patients with non-arteritic anterior ischaemic optic neuropathy.

PubMed

Zhu, Wenhui; Chen, Tingting; Jin, Ling; Wang, Haoyu; Yao, Fengjuan; Wang, Congyao; Wang, Qi; Congdon, Nathan

2017-10-01

To assess the correlation of carotid artery intimal medial thickness (C-IMT) and carotid artery plaque score (CPS) of the common carotid artery with non-arteritic anterior ischemic optic neuropathy (NAION) in hypertensive patients. This case-control study recruited 192 subjects. Forty-eight patients had NAION with systemic hypertension, 46 had hypertension without visual complaints, and 98 were normal controls. C-IMT and common carotid arterial plaque were measured by high-resolution vascular ultrasonography. High-density lipoprotein (HDL) in patients with NAION (1.24 ± 0.31) was significantly lower than that of the Hypertensive group (1.39 ± 0.30, P = 0.034). The C-IMT in the affected side of patients with NAION (1.00 ± 0.23) was significantly increased compared to the unaffected side (0.83 ± 0.19, P < 0.001), the Hypertensive group (0.83 ± 0.17, P < 0.001), and the Normal group (0.69 ± 0.16, P < 0.001). The presence of carotid artery plaque was more frequent in the patients with NAION, compared to either the Hypertensive group (P = 0.001) or the Normal group (P < 0.001). By multiple regression analysis, lower high-density lipoprotein (HDL) (P = 0.009), thicker C-IMT (P = 0.002), CPS Grade = 1 (P = 0.028), and Grade = 2 (P = 0.005) were associated with increased NAION risk, when the NAION group compared with the Hypertensive group (OR > 1.0). Systolic blood pressure (P = 0.001), thicker C-IMT (P < 0.001), CPS Grade = 1 (P = 0.006), Grade = 2 (P = 0.002), and Grade = 3 (P = 0.015) were associated with increased NAION risk, when the NAION group compared with the Normal group (OR > 1.0). C-IMT and CPS were associated with NAION in hypertensive patients, suggesting that NAION might be associated with carotid artery atherosclerosis. This association may be due to similar pathological changes of the inner vascular walls in the carotid artery and the arteries supplying the optic nerve head.

Retrograde suction decompression of a large internal carotid aneurysm using a balloon guide catheter combined with a blood-returning circuit and STA-MCA bypass: a technical note.

PubMed

Matano, Fumihiro; Mizunari, Takayuki; Kominami, Shushi; Suzuki, Masanori; Fujiki, Yu; Kubota, Asami; Kobayashi, Shiro; Murai, Yasuo; Morita, Akio

2017-04-01

It is difficult to treat large internal carotid aneurysms with simple surgical clipping. Here, we present a retrograde suction decompression (RSD) procedure for large internal carotid aneurysms using a balloon guide catheter combined with a blood-returning circuit and a superficial temporal artery to middle cerebral artery (STA-MCA) bypass.All patients underwent an STA-MCA bypass before the temporary occlusion of the internal carotid artery (ICA). A 6-French sheath was inserted into the common carotid artery (CCA), and a 6-French Patrive balloon catheter was placed into the ICA 5 cm past the bifurcation. Aneurysm exposure was obtained; temporary clips were placed on the proximal M1, A1, and posterior communicating (Pcom) segments; and an extension tube was then connected to the balloon catheter. A three-way stopcock was placed, and aspiration was performed through the device to collapse the aneurysm. The aspirated blood was returned to a venous line with an added heparin to prevent anemia after aspiration. During the decompression, the blood flow to the cortical area was supplied through the STA-MCA bypass. After the aneurysm collapse, the surgeon carefully dissected the perforating artery from the aneurysm dome or neck, and permanent clips were then placed on the aneurysm neck. Our procedure has several advantages, such as STA-MCA bypass without external carotid artery occlusion for preventing ischemic complications of the cortical area, anemia may be avoided because of the return of the aspirated blood, and a hybrid operation room is not required to perform this method.

Tissue Vibration Induces Carotid Artery Endothelial Dysfunction: A Mechanism Linking Snoring and Carotid Atherosclerosis?

PubMed Central

Cho, Jin-Gun; Witting, Paul K.; Verma, Manisha; Wu, Ben J.; Shanu, Anu; Kairaitis, Kristina; Amis, Terence C.; Wheatley, John R.

2011-01-01

Study Objectives: We have previously identified heavy snoring as an independent risk factor for carotid atherosclerosis. In order to explore the hypothesis that snoring-associated vibration of the carotid artery induces endothelial dysfunction (an established atherogenic precursor), we utilized an animal model to examine direct effects of peri-carotid tissue vibration on carotid artery endothelial function and structure. Design: In supine anesthetized, ventilated rabbits, the right carotid artery (RCA) was directly exposed to vibrations for 6 h (peak frequency 60 Hz, energy matched to that of induced snoring in rabbits). Similarly instrumented unvibrated rabbits served as controls. Features of OSA such as hypoxemia, large intra-pleural swings and blood pressure volatility were prevented. Carotid endothelial function was then examined: (1) biochemically by measurement of tissue cyclic guanosine monophosphate (cGMP) to acetylcholine (ACh) and sodium nitroprusside (SNP); and (2) functionally by monitoring vessel relaxation with acetylcholine in a myobath. Measurement and Results: Vessel cGMP after stimulation with ACh was reduced in vibrated RCA compared with unvibrated (control) arteries in a vibration energy dose-dependent manner. Vibrated RCA also showed decreased vasorelaxation to ACh compared with control arteries. Notably, after addition of SNP (nitric oxide donor), cGMP levels did not differ between vibrated and control arteries, thereby isolating vibration-induced dysfunction to the endothelium alone. This dysfunction occurred in the presence of a morphologically intact endothelium without increased apoptosis. Conclusions: Carotid arteries subjected to 6 h of continuous peri-carotid tissue vibration displayed endothelial dysfunction, suggesting a direct plausible mechanism linking heavy snoring to the development of carotid atherosclerosis. Citation: Cho JG; Witting PK; Verma M; Wu BJ; Shanu A; Kairaitis K; Amis TC; Wheatley JR. Tissue vibration induces

Childhood family psychosocial environment and carotid intima media thickness: the CARDIA study.

PubMed

Loucks, Eric B; Taylor, Shelley E; Polak, Joseph F; Wilhelm, Aude; Kalra, Preety; Matthews, Karen A

2014-03-01

Little is known about whether the childhood family psychosocial environment (characterized by cold, unaffectionate interactions, conflict, aggression, neglect and/or low nurturance) affects coronary heart disease (CHD) risk. Objectives were to evaluate associations of childhood family psychosocial environment with carotid intima media thickness (IMT), a subclinical measure of atherosclerosis. The study population included 2659 CARDIA study participants, aged 37-52 years. Childhood family psychosocial environment was measured using a risky family questionnaire via self-report. Carotid IMT was calculated using the average of 20 measurements of mean common carotid, bulb and internal carotid IMT, assessed using high-resolution B-mode ultrasound images. Utilizing linear regression analyses adjusted for age, a 1-unit (range 0-21) increase in risky family score was associated with 0.0036 (95% CI: 0.0006,0.0066 mm) and 0.0020 (95% CI: 0.0002,0.0038) mm increase in mean IMT in white males and females, respectively. Formal mediation analyses and covariate adjustments suggested childhood socioeconomic position and smoking may be important mechanisms in white males and females, as well as education and depressive symptomatology in white males. No associations were found in black participants. Formal statistical tests for interaction between risky family score and sex, and between risky family score and race/ethnicity, demonstrated borderline evidence of interactions for both sex (p = 0.12) and race/ethnicity (p = 0.14) with risky family score for associations with mean IMT. In conclusion, childhood family psychosocial environment was positively associated with IMT in white participants, with little evidence of association in black participants. Mechanisms in white participants may include potential negative impacts of socioeconomic constraints on parenting quality, potentially influencing offspring's cardiovascular risk factors (e.g. smoking), socioeconomic position (e

Triglyceride glucose index and common carotid wall shear stress.

PubMed

Tripolino, Cesare; Irace, Concetta; Scavelli, Faustina B; de Franceschi, Maria S; Esposito, Teresa; Carallo, Claudio; Gnasso, Agostino

2014-02-01

Alterations in wall shear stress contribute to both clinical and subclinical atherosclerosis. Several conditions such as hypertension, diabetes, and obesity can impair shear stress, but the role of insulin resistance has never been investigated. The present study was designed to investigate whether insulin resistance assessed by TyG Index associates with wall shear stress in the common carotid artery. One hundred six individuals were enrolled. Blood pressure, lipids, glucose, and cigarette smoking were evaluated. TyG Index was calculated as log[fasting triglycerides × fasting glucose / 2]. Subjects underwent blood viscosity measurement and echo-Doppler evaluation of carotid arteries to calculate wall shear stress. The association between TyG Index and carotid wall shear stress was assessed by simple and multiple regression analyses. TyG Index was significantly and inversely associated with carotid wall shear stress both in simple (r = -0.44, P < 0.001) and multiple regression analyses accounting for age, sex, and major cardiovascular risk factors. The association was further confirmed after exclusion of subjects with diabetes, dyslipidemia, fasting blood glucose greater than 100 mg/dL, and triglycerides greater than 150 mg/dL. The present findings suggest that increasing insulin resistance, as assessed by TyG Index, associates with atherosclerosis-prone shear stress reduction in the common carotid artery.

The relationship between heart-carotid pulse transit time and carotid intima-media thickness in hypertensive patients.

PubMed

Li, C; Xiong, H; Wu, W; Tian, X; Wang, Y; Wu, D; Lin, W-H; Miao, F; Zhang, H; Huang, W; Zhang, Y-T

2015-11-01

The study aimed to investigate the relationship between heart-carotid pulse transit time and carotid intima-media thickness (CIMT) in hypertensive patients, and whether including the pre-ejection period (PEP) in heart-carotid pulse transit time would affect this correlation. A total of 62 hypertensive patients were included in this study. They were divided into the normal CIMT group (n=33, CIMT⩽0.8 mm) and the thickened CIMT group (n=29, CIMT>0.8 mm). The noninvasive ultrasound method was used to measure CIMT, electrocardiogram R-wave-based heart-carotid pulse transit time (rcPTT) and PEP. Aortic valve-carotid artery pulse transit time (acPTT) was calculated by subtracting PEP from rcPTT. Simple linear analysis showed that CIMT was negatively associated with rcPTT and acPTT (r=-0.57, P<0.0001; r=-0.41, P=0.016) in the normal CIMT group as well as in the thickened CIMT group (r=-0.50, P=0.0053; r=-0.59, P=0.001). These relationships were eliminated in the normal CIMT group after adjusting for age, gender, smoking behaviour, systolic blood pressure, diastolic blood pressure and cholesterol levels. However, rcPTT and acPTT still showed significant correlations with CIMT in the thickened CIMT group. In conclusion, rcPTT and acPTT were associated with CIMT, independent of well-known clinical confounders in thickened CIMT hypertensive patients. Therefore, rcPTT and acPTT might be useful markers for atherosclerosis evaluation.

Habitual fish intake and clinically silent carotid atherosclerosis

PubMed Central

2014-01-01

Background Fish consumption is recommended as part of a healthy diet. However, there is a paucity of data concerning the relation between fish consumption and carotid atherosclerosis. We investigated the association between habitual fish consumption and asymptomatic carotid atherosclerosis, defined as the presence of plaques and/or increased intima-media thickness (≥ 0.90 mm), in non-diabetic participants. Methods Nine hundred-sixty-one (range of age: 18–89 yrs; 37.1% males) adult participants without clinically known atherosclerotic disease were randomly recruited among the customers of a shopping mall in Palermo, Italy, and cross-sectionally investigated. Each participant answered a food frequency questionnaire and underwent high-resolution ultrasonographic evaluation of both carotid arteries. Routine laboratory blood measurements were obtained in a subsample of 507 participants. Results Based on habitual fish consumption, participants were divided into three groups: non-consumers or consumers of less than 1 serving a week (24.0%), consumers of 1 serving a week (38.8%), and consumers of ≥ 2 servings a week (37.2%). Age-adjusted prevalence of carotid atherosclerosis (presence of plaques or intima media thickness ≥ 0.9 mm) was higher in the low fish consumption group (13.3%, 12.1% and 6.6%, respectively; P = 0.003). Multivariate analysis evidenced that carotid atherosclerosis was significantly associated with age (OR = 1.12; 95% CI = 1.09-1.14), hypertension on pharmacologic treatment (OR = 1.81; 95% CI = 1.16-2.82), and pulse pressure (OR = 1.03; 95% CI = 1.01-1.04), while consuming ≥2 servings of fish weekly was protective compared with the condition of consumption of <1 serving of fish weekly (OR = 0.46; 95% CI = 0.26-0.80). Conclusions High habitual fish consumption seems to be associated with less carotid atherosclerosis, though adequate interventional trials are necessary to confirm the role of fish

Habitual fish intake and clinically silent carotid atherosclerosis.

PubMed

Buscemi, Silvio; Nicolucci, Antonio; Lucisano, Giuseppe; Galvano, Fabio; Grosso, Giuseppe; Belmonte, Serena; Sprini, Delia; Migliaccio, Silvia; Cianferotti, Luisella; Brandi, Maria Luisa; Rini, Giovam Battista

2014-01-09

Fish consumption is recommended as part of a healthy diet. However, there is a paucity of data concerning the relation between fish consumption and carotid atherosclerosis. We investigated the association between habitual fish consumption and asymptomatic carotid atherosclerosis, defined as the presence of plaques and/or increased intima-media thickness (≥ 0.90 mm), in non-diabetic participants. Nine hundred-sixty-one (range of age: 18-89 yrs; 37.1% males) adult participants without clinically known atherosclerotic disease were randomly recruited among the customers of a shopping mall in Palermo, Italy, and cross-sectionally investigated. Each participant answered a food frequency questionnaire and underwent high-resolution ultrasonographic evaluation of both carotid arteries. Routine laboratory blood measurements were obtained in a subsample of 507 participants. Based on habitual fish consumption, participants were divided into three groups: non-consumers or consumers of less than 1 serving a week (24.0%), consumers of 1 serving a week (38.8%), and consumers of ≥ 2 servings a week (37.2%). Age-adjusted prevalence of carotid atherosclerosis (presence of plaques or intima media thickness ≥ 0.9 mm) was higher in the low fish consumption group (13.3%, 12.1% and 6.6%, respectively; P = 0.003). Multivariate analysis evidenced that carotid atherosclerosis was significantly associated with age (OR = 1.12; 95% CI = 1.09-1.14), hypertension on pharmacologic treatment (OR = 1.81; 95% CI = 1.16-2.82), and pulse pressure (OR = 1.03; 95% CI = 1.01-1.04), while consuming ≥2 servings of fish weekly was protective compared with the condition of consumption of <1 serving of fish weekly (OR = 0.46; 95% CI = 0.26-0.80). High habitual fish consumption seems to be associated with less carotid atherosclerosis, though adequate interventional trials are necessary to confirm the role of fish consumption in prevention of cardiovascular

[Arterial sequelae of pregnancy hypertension. Detection by carotid piezogram].

PubMed

Meyer-Heine, A; Asquer, J C; Lagrue, G

1989-01-01

High blood pressure (HTA) is characterized by elevation of pression, but also by modifications of arterial pulse wave. Carotid piezograms were used to evaluate arterial pulse wave. Diastolic blood pressure is significantly correlated with dicrotic notch pressure. The duration of dicrotic notch is negatively correlated with arterial wall elasticity. Thus by carotid piezogram analysis one can determine the respective participation of arterial wall elasticity, peripheral resistance and cardiac factors in blood pressure elevation. Carotid piezograms were measured in 97 women (mean age 27, 8 y), with previous hypertensive pregnancy and apparently cured (mean blood pressure 122-74 mmHg at time of examination). 25 women only had normal piezogram drawing. Abnormalities similar to that of permanent hypertensive disease were observed in most cases. Dicrotic notch duration was significantly reduced and dicrotic notch pressure enhanced; in 34 women both of these abnormalities were present. In conclusion, among women previously hypertensive during pregnancy, even when blood pressure is returned to normal, abnormalities of arterial pulse wave may be present, suggesting that these women are prone to subsequent permanent hypertension.

Posttraumatic carotid cavernous fistula that presented as seizure and focal neurological deficits with symptom resolution after therapeutic coil embolization.

PubMed

Klevtsova, Ekaterina; Nguyen-Min, Caroline; Lalani, Tania; Carlan, Stephen James; Madruga, Mario

2015-02-01

A posttraumatic carotid cavernous fistula can remain unrecognized and ultimately present with symptoms characteristic for a middle cerebral artery stroke. Progressive neurologic deterioration can occur until the condition is diagnosed and treated. If unrecognized and untreated, permanent damage may result. A 46-year-old white man with the history of a motor vehicle crash 6 months prior presented with complaints of acute onset of expressive aphasia and seizure-like activity for 3 days. On presentation, the patient was noted to have moderate proptosis and chemosis of the left eye. Magnetic resonance imaging of the brain showed an arteriovenous fistula arising from the anterolateral precavernous left internal carotid artery. This was directly communicating with the adjacent cortical veins along the medial aspect of the left temporal lobe, resulting in venous congestion in the left frontal opercular region, the left insula, and subinsular tracks. The patient underwent an intracranial coil embolization of a left carotid cavernous fistula. No complications were encountered, and the patient had near-complete resolution of neurologic deficits and left eye proptosis. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Although posttraumatic carotid cavernous fistula is a rare condition, it is important to be aware of this entity because immediate diagnosis and treatment may improve outcome. Copyright © 2015 Elsevier Inc. All rights reserved.

Non-rigid registration for fusion of carotid vascular ultrasound and MRI volumetric datasets

NASA Astrophysics Data System (ADS)

Chan, R. C.; Sokka, S.; Hinton, D.; Houser, S.; Manzke, R.; Hanekamp, A.; Reddy, V. Y.; Kaazempur-Mofrad, M. R.; Rasche, V.

2006-03-01

In carotid plaque imaging, MRI provides exquisite soft-tissue characterization, but lacks the temporal resolution for tissue strain imaging that real-time 3D ultrasound (3DUS) can provide. On the other hand, real-time 3DUS currently lacks the spatial resolution of carotid MRI. Non-rigid alignment of ultrasound and MRI data is essential for integrating complementary morphology and biomechanical information for carotid vascular assessment. We assessed non-rigid registration for fusion of 3DUS and MRI carotid data based on deformable models which are warped to maximize voxel similarity. We performed validation in vitro using isolated carotid artery imaging. These samples were subjected to soft-tissue deformations during 3DUS and were imaged in a static configuration with standard MR carotid pulse sequences. Registration of the source ultrasound sequences to the target MR volume was performed and the mean absolute distance between fiducials within the ultrasound and MR datasets was measured to determine inter-modality alignment quality. Our results indicate that registration errors on the order of 1mm are possible in vitro despite the low-resolution of current generation 3DUS transducers. Registration performance should be further improved with the use of higher frequency 3DUS prototypes and efforts are underway to test those probes for in vivo 3DUS carotid imaging.

21 CFR 882.5175 - Carotid artery clamp.

Code of Federal Regulations, 2014 CFR

2014-04-01

... carotid artery to treat intracranial aneurysms (balloonlike sacs formed on blood vessels) or other intracranial vascular malformations that are difficult to attach directly by reducing the blood pressure and... (the principal artery in the neck that supplies blood to the brain) and has a removable adjusting...

21 CFR 882.5175 - Carotid artery clamp.

Code of Federal Regulations, 2013 CFR

2013-04-01

... carotid artery to treat intracranial aneurysms (balloonlike sacs formed on blood vessels) or other intracranial vascular malformations that are difficult to attach directly by reducing the blood pressure and... (the principal artery in the neck that supplies blood to the brain) and has a removable adjusting...

21 CFR 882.5175 - Carotid artery clamp.

Code of Federal Regulations, 2010 CFR

2010-04-01

... carotid artery to treat intracranial aneurysms (balloonlike sacs formed on blood vessels) or other intracranial vascular malformations that are difficult to attach directly by reducing the blood pressure and... (the principal artery in the neck that supplies blood to the brain) and has a removable adjusting...

21 CFR 882.5175 - Carotid artery clamp.

Code of Federal Regulations, 2012 CFR

2012-04-01

... carotid artery to treat intracranial aneurysms (balloonlike sacs formed on blood vessels) or other intracranial vascular malformations that are difficult to attach directly by reducing the blood pressure and... (the principal artery in the neck that supplies blood to the brain) and has a removable adjusting...

21 CFR 882.5175 - Carotid artery clamp.

Code of Federal Regulations, 2011 CFR

2011-04-01

... carotid artery to treat intracranial aneurysms (balloonlike sacs formed on blood vessels) or other intracranial vascular malformations that are difficult to attach directly by reducing the blood pressure and... (the principal artery in the neck that supplies blood to the brain) and has a removable adjusting...

Aortic Baroreceptors Display Higher Mechanosensitivity than Carotid Baroreceptors.

PubMed

Lau, Eva On-Chai; Lo, Chun-Yin; Yao, Yifei; Mak, Arthur Fuk-Tat; Jiang, Liwen; Huang, Yu; Yao, Xiaoqiang

2016-01-01

Arterial baroreceptors are mechanical sensors that detect blood pressure changes. It has long been suggested that the two arterial baroreceptors, aortic and carotid baroreceptors, have different pressure sensitivities. However, there is no consensus as to which of the arterial baroreceptors are more sensitive to changes in blood pressure. In the present study, we employed independent methods to compare the pressure sensitivity of the two arterial baroreceptors. Firstly, pressure-activated action potential firing was measured by whole-cell current clamp with a high-speed pressure clamp system in primary cultured baroreceptor neurons. The results show that aortic depressor neurons possessed a higher percentage of mechano-sensitive neurons. Furthermore, aortic baroreceptor neurons show a lower pressure threshold than that of carotid baroreceptor neurons. Secondly, uniaxial stretching of baroreceptor neurons, that mimics the forces exerted on blood vessels, elicited a larger increase in intracellular Ca(2+) rise in aortic baroreceptor neurons than in carotid baroreceptor neurons. Thirdly, the pressure-induced action potential firing in the aortic depressor nerve recorded in vivo was also higher. The present study therefore provides for a basic physiological understanding on the pressure sensitivity of the two baroreceptor neurons and suggests that aortic baroreceptors have a higher pressure sensitivity than carotid baroreceptors.

Blood flow of the right and left submandibular gland during unilateral carotid artery occlusion in rat: role of nitric oxide.

PubMed

Vág, J; Hably, C; Fazekas, A; Bartha, J

1999-01-01

The aim of the present study was to investigate the effect of unilateral carotid artery occlusion on the blood flow of submandibular gland in anesthetized rats and identify the role of nitric oxide (NO) in blood flow changes after the artery occlusion. L-NAME (N omega-nitro-L-arginine-methyl-ester; 10 mg/kg/day, per os) dissolved in tap water was used to block nitric oxide synthase. Glandular blood flow was measured using Sapirstein's indicator (86Rb) distribution technique. In the control animals the blood flow of left (ligated side) submandibular gland was lower than in the right (unligated side) one (right: 76.4+/-15.4 ml/min/100 g, 64.1+/-13.4 ml/min/100 g, p<0.01). The blood flow of submandibular glands decreased in NOS blocked group versus control. The vascular resistance after L-NAME treatment was elevated (control: 11+/-2.3 R/kg, L-NAME: 17.5+/-4.1 R/kg, p<0.001). In L-NAME group the difference between blood flow value of the left and right submandibular gland was significantly lower than in the control group (control: -16%, NAME: -8%, p<0.01). The maintenance of the blood flow in the left submandibular gland during ligation of the left common carotid artery could be due to the good vascular anastomotic system at these regions and adaptation of the submandibular vessels to the decreased perfusion pressure. Nitric oxide may have a role in the regulation of blood flow tinder this condition.

The contribution of carotid rete variability to brain temperature variability in sheep in a thermoneutral environment.

PubMed

Maloney, Shane K; Mitchell, Duncan; Blache, Dominique

2007-03-01

The degree of variability in the temperature difference between the brain and carotid arterial blood is greater than expected from the presumed tight coupling between brain heat production and brain blood flow. In animals with a carotid rete, some of that variability arises in the rete. Using thermometric data loggers in five sheep, we have measured the temperature of arterial blood before it enters the carotid rete and after it has perfused the carotid rete, as well as hypothalamic temperature, every 2 min for between 6 and 12 days. The sheep were conscious, unrestrained, and maintained at an ambient temperature of 20-22 degrees C. On average, carotid arterial blood and brain temperatures were the same, with a decrease in blood temperature of 0.35 degrees C across the rete and then an increase in temperature of the same magnitude between blood leaving the rete and the brain. Rete cooling of arterial blood took place at temperatures below the threshold for selective brain cooling. All of the variability in the temperature difference between carotid artery and brain was attributable statistically to variability in the temperature difference across the rete. The temperature difference between arterial blood leaving the rete and the brain varied from -0.1 to 0.9 degrees C. Some of this variability was related to a thermal inertia of the brain, but the majority we attribute to instability in the relationship between brain blood flow and brain heat production.

DIRECT NUMERICAL SIMULATION OF TRANSITIONAL FLOW IN A STENOSED CAROTID BIFURCATION

PubMed Central

Lee, Seung E.; Lee, Sang-Wook; Fischer, Paul F.; Bassiouny, Hisham S.; Loth, Francis

2008-01-01

The blood flow dynamics of a stenosed, subject-specific, carotid bifurcation were numerically simulated using the spectral element method. Pulsatile inlet conditions were based on in vivo color Doppler ultrasound measurements of blood velocity. The results demonstrated the transitional or weakly turbulent state of the blood flow, which featured rapid velocity and pressure fluctuations in the post-stenotic region of the internal carotid artery during systole and laminar flow during diastole. High-frequency vortex shedding was greatest downstream of the stenosis during the deceleration phase of systole. Velocity fluctuations had a frequency within the audible range of 100–300 Hz. Instantaneous wall shear stress within the stenosis was relatively high during systole (~25-45 Pa) compared to that in a healthy carotid. In addition, high spatial gradients of wall shear stress were present due to flow separation on the inner wall. Oscillatory flow reversal and low pressure were observed distal to the stenosis in the internal carotid artery. This study predicts the complex flow field, the turbulence levels and the distribution of the biomechanical stresses present in vivo within a stenosed carotid artery. PMID:18656199

Impaired baroreflex sensitivity, carotid stiffness, and exaggerated exercise blood pressure: a community-based analysis from the Paris Prospective Study III.

PubMed

Sharman, James E; Boutouyrie, Pierre; Perier, Marie-Cécile; Thomas, Frédérique; Guibout, Catherine; Khettab, Hakim; Pannier, Bruno; Laurent, Stéphane; Jouven, Xavier; Empana, Jean-Philippe

2018-02-14

People with exaggerated exercise blood pressure (BP) have adverse cardiovascular outcomes. Mechanisms are unknown but could be explained through impaired neural baroreflex sensitivity (BRS) and/or large artery stiffness. This study aimed to determine the associations of carotid BRS and carotid stiffness with exaggerated exercise BP. Blood pressure was recorded at rest and following an exercise step-test among 8976 adults aged 50 to 75 years from the Paris Prospective Study III. Resting carotid BRS (low frequency gain, from carotid distension rate, and heart rate) and stiffness were measured by high-precision echotracking. A systolic BP threshold of ≥ 150 mmHg defined exaggerated exercise BP and ≥140/90 mmHg defined resting hypertension (±antihypertensive treatment). Participants with exaggerated exercise BP had significantly lower BRS [median (Q1; Q3) 0.10 (0.06; 0.16) vs. 0.12 (0.08; 0.19) (ms2/mm) 2×108; P < 0.001] but higher stiffness [mean ± standard deviation (SD); 7.34 ± 1.37 vs. 6.76 ± 1.25 m/s; P < 0.001) compared to those with non-exaggerated exercise BP. However, only lower BRS (per 1SD decrement) was associated with exaggerated exercise BP among people without hypertension at rest {specifically among those with optimal BP; odds ratio (OR) 1.16 [95% confidence intervals (95% CI) 1.01; 1.33], P = 0.04 and high-normal BP; OR, 1.19 (95% CI 1.07; 1.32), P = 0.001} after adjustment for age, sex, body mass index, smoking, alcohol, total cholesterol, high-density lipoprotein cholesterol, resting heart rate, and antihypertensive medications. Impaired BRS, but not carotid stiffness, is independently associated with exaggerated exercise BP even among those with well controlled resting BP. This indicates a potential pathway from depressed neural baroreflex function to abnormal exercise BP and clinical outcomes. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2017. For

Monitoring black-tailed prairie dog colonies with high-resolution satellite imagery

USGS Publications Warehouse

Sidle, John G.; Johnson, D.H.; Euliss, B.R.; Tooze, M.

2002-01-01

The United States Fish and Wildlife Service has determined that the black-tailed prairie dog (Cynomys ludovicianus) warrants listing as a threatened species under the Endangered Species Act. Central to any conservation planning for the black-tailed prairie dog is an appropriate detection and monitoring technique. Because coarse-resolution satellite imagery is not adequate to detect black-tailed prairie dog colonies, we examined the usefulness of recently available high-resolution (1-m) satellite imagery. In 6 purchased scenes of national grasslands, we were easily able to visually detect small and large colonies without using image-processing algorithms. The Ikonos (Space Imaging(tm)) satellite imagery was as adequate as large-scale aerial photography to delineate colonies. Based on the high quality of imagery, we discuss a possible monitoring program for black-tailed prairie dog colonies throughout the Great Plains, using the species' distribution in North Dakota as an example. Monitoring plots could be established and imagery acquired periodically to track the expansion and contraction of colonies.

APOL1 genetic variants are not associated with longitudinal blood pressure in young black adults.

PubMed

Chen, Teresa K; Estrella, Michelle M; Vittinghoff, Eric; Lin, Feng; Gutierrez, Orlando M; Kramer, Holly; Lewis, Cora E; Kopp, Jeffrey B; Allen, Norrina B; Winkler, Cheryl A; Bibbins-Domingo, Kirsten B; Peralta, Carmen A

2017-10-01

Whether APOL1 polymorphisms contribute to the excess risk of hypertension among blacks is unknown. To assess this we evaluated whether self-reported race and, in blacks, APOL1 risk variants (high-risk [2 risk alleles] versus low-risk [0-1 risk allele]) were associated with longitudinal blood pressure. Blood pressure trajectories were determined using linear mixed-effects (slope) and latent class models (5 distinct groups) during 25 years of follow-up in the Coronary Artery Risk Development in Young Adults Study. Associations of race and APOL1 genotypes with blood pressure change, separately, using linear mixed-effects and multinomial logistic regression models, adjusting for demographic, socioeconomic, and traditional hypertension risk factors, anti-hypertensive medication use, and kidney function were evaluated. Among 1700 whites and 1330 blacks (13% APOL1 high-risk, mean age 25 years; 46% male) mean mid-, ([systolic + diastolic blood pressure]/2), systolic, and diastolic blood pressures were 89, 110, and 69 mm Hg, respectively. One percent of participants used anti-hypertensive medications at baseline. Compared to whites, blacks, regardless of APOL1 genotype, had significantly greater increases in mid-blood pressure and were more likely to experience significantly increasing mid-blood pressure trajectories with adjusted relative risk ratios of 5.21 and 7.27 for moderate-increasing and elevated-increasing versus low-stable blood pressure, respectively. Among blacks, longitudinal mid-blood pressure changes and mid-blood pressure trajectory classification were similar by APOL1 risk status. Modeling systolic and diastolic blood pressure as outcomes yielded similar findings. From young adulthood to mid-life, blacks have greater blood pressure increases versus whites that are not fully explained by traditional risk factors. Thus APOL1 variants are not associated with longitudinal blood pressure in blacks. Copyright © 2017 International Society of Nephrology. All

Carotid artery bypass in acute postendarterectomy thrombosis.

PubMed

Paty, P S; Darling, R C; Cordero, J A; Shah, D M; Chang, B B; Leather, R P

1996-08-01

Carotid endarterectomy has demonstrated excellent results over the past 2 decades with combined stroke mortality of < 4% in most active centers. However, the optimal technique for surgical reconstruction for patients with acute postoperative deficits is more controversial. In the last 10 years (1985 to 1995), we performed 1,267 carotid endarterectomies, with 17 strokes (1.3%) and 16 deaths (1.2%). Twenty-four patients developed acute (within 72 hours) postoperative neurologic deficits. In 10 patients, the carotid artery was confirmed patent by duplex scan or angiography, and the neurologic deficit resolved without further therapy. Early reexploration was performed in 14 cases for suspected thrombosis associated with a new neurologic deficit. In each case, resection of the endarterectomy site and an interposition bypass was performed with greater saphenous vein (11), jugular vein (2), or polytetrafluoroethylene (2) grafts. (One patient required a new bypass for acute occlusion of the initial vein bypass.) Postoperatively, 8 patients had complete resolution of their deficit, 3 had minimal residual deficits, and 3 suffered permanent stroke. However, 2 of these patients died. Carotid artery bypass with exclusion of the endarterectomy site resulted in improvement in symptoms in 79% (11 of 14) of the patients and complete resolution in 57% (8 of 14). In long-term follow up (1 to 41 months), there have been no occlusions and one restenosis requiring revision at 11 months. Carotid artery bypass can be performed safely with acceptable results. The use of autogenous venous conduits allows reconstruction with an endothelial lined conduit that may improve results in patients with acute postoperative neurologic deficit secondary to thrombosis of the endarterectomized carotid artery.

Compensatory patterns of collateral flow in stroke patients with unilateral and bilateral carotid stenosis.

PubMed

Fang, Hui; Song, Bo; Cheng, Bo; Wong, Ka Sing; Xu, Yu Ming; Ho, Stella Sin Yee; Chen, Xiang Yan

2016-03-18

Collateral pathways are important in maintaining adequate cerebral blood flow in patients with carotid stenosis. We aimed to evaluate the hemodynamic patterns in relation to carotid stenosis in acute stroke patients. Consecutive 586 stroke patients in a hospital based cohort were included in the present study. Carotid duplex was performed to identify patients with absolute minimal diameter reductions of 50% or greater in their internal carotid arteries (ICAs). Color velocity imaging quantification ultrasound (CVIQ) was used to measure extracranial arterial blood flow volume (BFV) in bilateral common carotid arteries (CCAs) and bilateral vertebral arteries (VAs). The absolute values of BFV and the ratios were compared between patients with and without ICA stenosis. Among 586 acute ischemic stroke patients (mean age: 67.5 ± 12.4y), ICA stenosis was detected in 112 patients (19.1%), including unilateral ICA stenosis in 81 patients (13.8%) and bilateral ICA stenosis in 31 patients (5.3%). Among patients with unilateral ICA stenosis, the BFV in contralateral CCA was significantly higher than that in ipsilateral CCA (325.5 ± 99.8 mL/min vs. 242.2 ± 112.2 mL/min, P < 0.001). Among patients with bilateral ICA stenosis, the sum of BFV in bilateral VAs accounted for 22% of the whole cerebral blood flow, which was significantly higher than that in those without ICA stenosis (14.8%, P < 0.001) or with unilateral ICA stenosis (16.9%, P = 0.007). In patients with unilateral carotid stenosis, contralateral carotid blood flow increases to compensate decreased blood flow, while posterior circulation may compensate for the decreased brain perfusion in those with bilateral carotid stenosis.

[Risk factors of rupture of internal carotid artery during surgical resection of carotid body tumor].

PubMed

Li, Y H; Wang, J S; Yao, C; Chang, G Q; Yin, H H; Li, S Q; Lü, W M; Hu, Z J; Wang, S M

2017-06-13

Objective: To investigate risk factors of rupture of internal carotid artery resection during carotid body tumor resection and to summarize our treatment experience. Methods: During the period from 1991 to 2016, rupture of internal carotid artery occurred in 27 patients (28 tumors) during surgical resection of carotid body tumor in the First Affiliated Hospital of Sun Yat-sen University. Their clinical and follow-up data were retrospectively collected and analyzed. For all patients underwent surgical resection during this period, Logistic regression analysis was used to investigate the risk factors of intraoperative rupture of internal carotid artery. Results: Of these 28 tumors, there were 15 (53.6%) tumors with diameter≥5 cm and 20 (71.4%) Shamblin Ⅲ tumors. Intraoperatively, shunt was applied for 8 (28.6%) cases. Thirteen (46.4%) patients underwent ligation of external carotid artery, while 2 (7.1%) patients accepted resection of cranial nerves. Direct closure/patchplasty, autologous vessels or graft reconstruction was used in 16, 10 and 2 cases, respectively. Postoperatively, stroke occurred in 4(14.3%) cases and cranial nerve deficit in 15 (53.6%) cases. During a median length of 36 (14-125) months, cranial nerve deficit persisted in 5 cases. Follow-up radiologic examination indicated 3 (10.7%) cases of targeted vessel occlusion. However, no new-onset stroke was identified. Among all patients underwent surgical resection of carotid body tumor, female ( OR =3.650, P =0.012), age≤25 years old ( OR =3.710, P =0.013) and Shamblin Ⅲ tumor ( OR =4.631, P =0.008) increase the risks of intraoperative carotid artery rupture. Conclusions: Shamblin Ⅲ tumor is the predictor of rupture of internal carotid artery. Intraoperative, properly increased blood pressure, intraoperative heparinization and use of shunt for those cases without well-compensated cranial collateral arteries are likely to decreasing the incidence of stroke.

Improvement in Cerebral and Ocular Hemodynamics Early after Carotid Endarterectomy in Patients of Severe Carotid Artery Stenosis with or without Contralateral Carotid Occlusion.

PubMed

Wang, Jian; Wang, Weici; Jin, Bi; Zhang, Yanrong; Xu, Ping; Xiang, Feixiang; Zheng, Yi; Chen, Juan; Sheng, Shi; Ouyang, Chenxi; Li, Yiqing

2016-01-01

Purpose. To investigate the alternation in cerebral and ocular blood flow velocity (BFV) in patients of carotid stenosis (CS) with or without contralateral carotid occlusion (CO) early after carotid endarterectomy (CEA). Patients and Methods. Nineteen patients underwent CEA for ≥50% CS. Fourteen patients had the unilateral CS, and five patients had the ipsilateral CS and the contralateral CO. Transcranial Doppler (TCD) and Color Doppler Imaging (CDI) were performed before and early after CEA. Results. In patients with unilateral CS, significant improvements in BFV were observed in anterior cerebral artery (ACA) and middle cerebral artery (MCA) on the ipsilateral side after CEA. In patients of ipsilateral CS and contralateral CO, significant improvements in BFV were observed in the ACA and MCA not only on the ipsilateral side but also on the contralateral side postoperatively. The ipsilateral ophthalmic artery (OA) retrograde flows in two patients were recovered to anterograde direction following CEA. The BFV in short posterior ciliary artery (SPCA) of the ipsilateral side significantly increased postoperatively irrespective of the presence of contralateral CO. Conclusions. CEA improved cerebral anterior circulation hemodynamics especially in patients of unilateral CS and contralateral CO, normalized the OA reverse flow, and increased the blood perfusion of SPCA.

Effect of black tea consumption on radial blood pulse spectrum and cognitive health.

PubMed

Chang, Chi-Wei; Wang, Sheng-Hung; Jan, Ming-Yie; Wang, Wei-Kung

2017-04-01

Black tea consumption has been proven to improve endothelial function and to lower the risk of stroke and cognitive impairment. Several effects of black tea on cardiovascular system had been surveyed. However, the black tea effect on pressure pulse spectrum remains unknown. The study was aimed to investigate the influence of black tea on radial blood pressure and Pulse Spectrum. Fourteen healthy subjects received water and single doses of black tea (0.05g/Kg) in separate weeks. The radial blood pressure and pulse wave were measured and the pressure pulses were evaluated using harmonic analysis. This report confirmed that black tea consumption (dose=0.05g/Kg) significantly increased third, fifth, (P<0.1), sixth, seventh, and eighth harmonics (p<0.05) of radial pressure wave comparing to water control. We proposed that black tea may increase cerebral blood flow (CBF), which was deduced from the results and from the conclusions of previous studies. The results also showed that the harmonic components of pressure pulse could be the vascular kinetic index that assessed the hemodynamic status in each time frame before and after consumption of black tea. Copyright © 2017 Elsevier Ltd. All rights reserved.

Metabolic syndrome and subclinical carotid atherosclerosis among Chinese elderly people living in a rural community.

PubMed

Yan, Zhongrui; Liang, Yajun; Jiang, Hui; Cai, Chuanzhu; Sun, Binglun; Qiu, Chengxuan

2014-06-01

The relationship between the metabolic syndrome and subclinical atherosclerosis among elderly people remains controversial. We seek to investigate the associations of metabolic syndrome and its components with subclinical carotid atherosclerosis in older people living in rural China. This cross-sectional study included 911 participants (age ≥60 years, 59.4% women) of the community-based Confucius Hometown Aging Project in Shandong, China, who were free of clinical cardiovascular disease. In 2010-2011, data were collected through interviews, clinical examinations, and laboratory tests. Carotid intima media thickness (cIMT) and carotid artery plaque were assessed using ultrasonography. Metabolic syndrome was defined by four sets of criteria. Data were analyzed with multiple general linear and logistic regression models. Carotid plaque was detected in 514 (56.4%) persons. Depending on the defining criteria, prevalence of metabolic syndrome ranged from 30.6% to 56.9%. Hypertension, elevated blood pressure (≥130/85 mmHg), diabetes/prediabetes, and high fasting plasma glucose (≥5.6 mmol/L) were significantly associated with an increased likelihood of carotid plaque, whereas an increased cIMT was associated with elevated blood pressure and hypertension (P<0.05). Obesity, high triglycerides, and dyslipidemia were not associated with carotid artery plaque or cIMT. The significant association of metabolic syndrome with an increased likelihood of carotid plaque disappeared when elevated blood pressure and high plasma glucose were added to the models. Metabolic syndrome was not associated with cIMT. Metabolic syndrome is associated with subclinical carotid plaque among Chinese elderly people, driven primarily by elevated blood pressure and hyperglycemia. Older adults with metabolic syndrome, especially those with high blood pressure and hyperglycemia, may benefit from evaluation for subclinical atherosclerosis.

3D reconstruction of a carotid bifurcation from 2D transversal ultrasound images.

PubMed

Yeom, Eunseop; Nam, Kweon-Ho; Jin, Changzhu; Paeng, Dong-Guk; Lee, Sang-Joon

2014-12-01

Visualizing and analyzing the morphological structure of carotid bifurcations are important for understanding the etiology of carotid atherosclerosis, which is a major cause of stroke and transient ischemic attack. For delineation of vasculatures in the carotid artery, ultrasound examinations have been widely employed because of a noninvasive procedure without ionizing radiation. However, conventional 2D ultrasound imaging has technical limitations in observing the complicated 3D shapes and asymmetric vasodilation of bifurcations. This study aims to propose image-processing techniques for better 3D reconstruction of a carotid bifurcation in a rat by using 2D cross-sectional ultrasound images. A high-resolution ultrasound imaging system with a probe centered at 40MHz was employed to obtain 2D transversal images. The lumen boundaries in each transverse ultrasound image were detected by using three different techniques; an ellipse-fitting, a correlation mapping to visualize the decorrelation of blood flow, and the ellipse-fitting on the correlation map. When the results are compared, the third technique provides relatively good boundary extraction. The incomplete boundaries of arterial lumen caused by acoustic artifacts are somewhat resolved by adopting the correlation mapping and the distortion in the boundary detection near the bifurcation apex was largely reduced by using the ellipse-fitting technique. The 3D lumen geometry of a carotid artery was obtained by volumetric rendering of several 2D slices. For the 3D vasodilatation of the carotid bifurcation, lumen geometries at the contraction and expansion states were simultaneously depicted at various view angles. The present 3D reconstruction methods would be useful for efficient extraction and construction of the 3D lumen geometries of carotid bifurcations from 2D ultrasound images. Copyright © 2014 Elsevier B.V. All rights reserved.

24-hour aortic blood pressure variability showed a stronger association with carotid damage than 24-hour brachial blood pressure variability: The SAFAR study.

PubMed

Yu, Shikai; Chi, Chen; Protogerou, Athanase D; Safar, Michel E; Blacher, Jacques; Argyris, Antonis A; Nasothimiou, Efthimia G; Sfikakis, Petros P; Papaioannou, Theodore G; Xu, Henry; Zhang, Yi; Xu, Yawei

2018-03-01

We aim to compare 24-hour aortic blood pressure variability (BPV) with brachial BPV in relation to carotid damage as estimated by carotid intima-media thickness (CIMT) and cross-sectional area (CCSA). Four hundred and forty five individuals received brachial and aortic 24-hour ambulatory BP monitoring with a validated device (Mobil-O-Graph). Systolic BPV was estimated by average real variability (ARV) and time-weighted standard deviation (wSD). In multiple logistic regression analysis, CIMT > 900 μm was significantly and independently associated with aortic ARV (OR = 1.38; 95% CI: 1.04-1.84), aortic wSD (OR = 1.65; 95% CI: 1.19-2.29) and brachial ARV (OR = 1.53; 95% CI: 1.07-2.18), but not with brachial wSD. CCSA > 90th percentile was significantly and independently associated with aortic ARV (OR = 1.50; 95% CI: 1.07-2.10) and wSD (OR = 1.70; 95% CI: 1.12-2.56), but not with brachial BPVs. In receiver operator characteristics curve analysis, aortic wSD identified CCSA > 90th percentile better than brachial wSD (AUC: 0.73 vs 0.68, P < .01). In conclusion, aortic 24-hour systolic BPV showed a slightly stronger association with carotid damage than brachial BPV. ©2018 Wiley Periodicals, Inc.

Association of selenium status and blood glutathione concentrations in blacks and whites

PubMed Central

Richie, John P.; Muscat, Joshua E.; Ellison, Irina; Calcagnotto, Ana; Kleinman, Wayne; El-Bayoumy, Karam

2011-01-01

Selenium deficiency has been linked with increased cancer risk and, in some studies, selenium supplementation was protective against certain cancers. Previous studies suggest that selenium chemoprevention may involve reduced oxidative stress through enhanced glutathione (GSH). Our objectives were to examine the relationships between selenium and GSH in blood and modifying effects of race and sex in free living adults and individuals supplemented with selenium. Plasma selenium concentrations and free and bound GSH concentrations and γ-glutamyl cysteine ligase (GCL) activity in blood were measured in 336 healthy adults, (161 blacks, 175 whites). Plasma selenium and blood GSH were also measured in 36 healthy men from our previously conducted placebo-controlled trial of selenium-enriched yeast (247 μg/day for 9 months). In free-living adults, selenium concentrations were associated with increased blood GSH concentration and GCL activity (P<0.05). Further, selenium was significantly higher in whites than in blacks (P<0.01). After 9 months of supplementation, plasma selenium was increased 114% in whites and 50% in blacks (P<0.05) and blood GSH was increased 35% in whites (P<0.05) but was unchanged in blacks. These results indicate a direct association between selenium and GSH in blood of both free-living and selenium-supplemented individuals, with race being an important modifying factor. PMID:21462082

Flow pattern analysis in a highly stenotic patient-specific carotid bifurcation model using a turbulence model.

PubMed

Li, Zhi-Yong; Tan, Felicia P P; Soloperto, Giulia; Wood, Nigel B; Xu, Xiao Y; Gillard, Jonathan H

2015-08-01

The aim of this study is to investigate the blood flow pattern in carotid bifurcation with a high degree of luminal stenosis, combining in vivo magnetic resonance imaging (MRI) and computational fluid dynamics (CFD). A newly developed two-equation transitional model was employed to evaluate wall shear stress (WSS) distribution and pressure drop across the stenosis, which are closely related to plaque vulnerability. A patient with an 80% left carotid stenosis was imaged using high resolution MRI, from which a patient-specific geometry was reconstructed and flow boundary conditions were acquired for CFD simulation. A transitional model was implemented to investigate the flow velocity and WSS distribution in the patient-specific model. The peak time-averaged WSS value of approximately 73 Pa was predicted by the transitional flow model, and the regions of high WSS occurred at the throat of the stenosis. High oscillatory shear index values up to 0.50 were present in a helical flow pattern from the outer wall of the internal carotid artery immediately after the throat. This study shows the potential suitability of a transitional turbulent flow model in capturing the flow phenomena in severely stenosed carotid arteries using patient-specific MRI data and provides the basis for further investigation of the links between haemodynamic variables and plaque vulnerability. It may be useful in the future for risk assessment of patients with carotid disease.

Social support, stress, and blood pressure in black adults.

PubMed

Strogatz, D S; Croft, J B; James, S A; Keenan, N L; Browning, S R; Garrett, J M; Curtis, A B

1997-09-01

Psychosocial factors arising from socioeconomic disadvantage and discrimination may contribute to the excess risk of elevated blood pressure in African-Americans. The purpose of this study was to assess the association of social support and stress with blood pressure in a community-based sample of 25-to 50-year-old black adults in Pitt County, NC. A stratified random sample of dwellings was selected in 1988, and 1,784 black adults (80% of those eligible) were interviewed. Analyses were sex specific and adjusted for age, obesity, and waist/hip ratio. In separate analyses of emotional support, instrumental support, and stress with blood pressure, all associations were in the predicted direction (inverse for support, direct for stress) but were stronger for systolic than for diastolic blood pressure. Differences in systolic blood pressure associated with low support or high stress ranged from 5.2 to 3.6 mmHg in women and 3.5 to 2.5 mmHg in men. In simultaneous regression analyses of support and stress, each of the separate effects was reduced for women, but a sizable aggregate effect of low support and high stress remained [+7.2 mmHg (95% confidence limits = +1.3, +13.1) for systolic blood pressure and +4.0 mmHg (95% confidence limits = +0.1, +7.9) for diastolic blood pressure.

Risk Factors For Stroke, Myocardial Infarction, or Death Following Carotid Endarterectomy: Results From the International Carotid Stenting Study.

PubMed

Doig, D; Turner, E L; Dobson, J; Featherstone, R L; de Borst, G J; Stansby, G; Beard, J D; Engelter, S T; Richards, T; Brown, M M

2015-12-01

Carotid endarterectomy (CEA) is standard treatment for symptomatic carotid artery stenosis but carries a risk of stroke, myocardial infarction (MI), or death. This study investigated risk factors for these procedural complications occurring within 30 days of endarterectomy in the International Carotid Stenting Study (ICSS). Patients with recently symptomatic carotid stenosis >50% were randomly allocated to endarterectomy or stenting. Analysis is reported of patients in ICSS assigned to endarterectomy and limited to those in whom CEA was initiated. The occurrence of stroke, MI, or death within 30 days of the procedure was reported by investigators and adjudicated. Demographic and technical risk factors for these complications were analysed sequentially in a binomial regression analysis and subsequently in a multivariable model. Eight-hundred and twenty-one patients were included in the analysis. The risk of stroke, MI, or death within 30 days of CEA was 4.0%. The risk was higher in female patients (risk ratio [RR] 1.98, 95% CI 1.02-3.87, p = .05) and with increasing baseline diastolic blood pressure (dBP) (RR 1.30 per +10 mmHg, 95% CI 1.02-1.66, p = .04). Mean baseline dBP, obtained at the time of randomization in the trial, was 78 mmHg (SD 13 mmHg). In a multivariable model, only dBP remained a significant predictor. The risk was not related to the type of surgical reconstruction, anaesthetic technique, or perioperative medication regimen. Patients undergoing CEA stayed a median of 4 days before discharge, and 21.2% of events occurred on or after the day of discharge. Increasing diastolic blood pressure was the only independent risk factor for stroke, MI, or death following CEA. Cautious attention to blood pressure control following symptoms attributable to carotid stenosis could reduce the risks associated with subsequent CEA. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

The 5-HT1-like receptor mediating the increase in canine external carotid blood flow: close resemblance to the 5-HT1D subtype.

PubMed Central

Villalón, C M; Terrón, J A

1994-01-01

1. It has recently been shown that the increase in external carotid blood flow induced by 5-hydroxy-tryptamine (5-HT) in the anaesthetized dog, being mimicked by 5-carboxamidotryptamine (5-CT), inhibited by methiothepin, vagosympathectomy and sympatho-inhibitory drugs, and resistant to blockade by ritanserin and MDL 72222, is mediated by stimulation of prejunctional 5-HT1-like receptors leading to an inhibitory action on carotid sympathetic nerves; these 5-HT1-like receptors are unrelated to either the 5-HT1A, 5-HT1B or 5-HT1C (now 5-HT2C) receptor subtypes. Inasmuch as 5-CT, 5-methoxytryptamine, sumatriptan and metergoline display high affinity, amongst other 5-HT binding sites, for the 5-HT1D subtype, in the present study we have used these drugs in an attempt to determine whether the above inhibitory prejunctional 5-HT1-like receptors correlate with the 5-HT1D subtype. 2. One-minute intracarotid (i.c.) infusions of 5-HT (0.3, 1, 3 and 10 micrograms), 5-CT (0.01, 0.03, 0.1 and 0.3 micrograms), 5-methoxytryptamine (1, 3, 10 and 30 micrograms) and sumatriptan (1, 3, 10, 30 and 100 micrograms) resulted in dose-dependent increases in external carotid blood flow (without changes in mean arterial blood pressure or heart rate) with the following rank order of agonist potency: 5-CT >> 5-HT > 5-methoxytryptamine > or = sumatriptan. Interestingly, sumatriptan-induced vasodilatation was followed by a more pronounced vasoconstriction. 3. The external carotid vasodilator effects of 5-HT, 5-CT, 5-methoxytryptamine and sumatriptan were dose-dependently and specifically antagonized by metergoline (10, 30 and/or 100 micrograms kg-1, i.v.).(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7812603

Effect of Angiotensin II Type I Receptor Blockade with Valsartan on Carotid Artery Atherosclerosis: A Double Blind Randomized Clinical Trial Comparing Valsartan and Placebo (EFFERVESCENT).

PubMed

Ramadan, Ronnie; Dhawan, Saurabh S; Binongo, José Nilo G; Alkhoder, Ayman; Jones, Dean P; Oshinski, John N; Quyyumi, Arshed A

2016-04-01

Progression of atherosclerosis is associated with a greater risk for adverse outcomes. Angiotensin II plays a key role in the pathogenesis and progression of atherosclerosis. We aimed to investigate the effects of angiotensin II type-1 receptor blockade with Valsartan on carotid wall atherosclerosis, with the hypothesis that Valsartan will reduce progression of atherosclerosis. Subjects (n = 120) with carotid intima-media thickness >0.65 mm by ultrasound were randomized (2:1) in a double-blind manner to receive either Valsartan or placebo for 2 years. Bilateral T2-weighted black-blood carotid magnetic resonance imaging was performed at baseline, 12 and 24 months. Changes in the carotid bulb vessel wall area and wall thickness were primary endpoints. Secondary endpoints included changes in carotid plaque thickness, plasma levels of aminothiols, C-reactive protein, fibrinogen, and endothelium-dependent and -independent vascular function. Over 2 years, the carotid bulb vessel wall area decreased with Valsartan (-6.7, 95% CI [-11.6, -1.9] mm(2)) but not with placebo (3.4, 95% CI [-2.8, 9.6] mm(2)), P = .01 between groups. Similarly, mean wall thickness decreased with Valsartan (-0.18, 95% CI [-0.30, -0.06] mm), but not with placebo (0.08, 95% CI [-0.07, 0.23] mm), P = .009 between groups. Furthermore, plaque thickness decreased with Valsartan (-0.35, 95% CI [-0.63, -0.08] mm) but was unchanged with placebo (+0.28, 95% CI [-0.11, 0.69] mm), P = .01 between groups. These findings were unaffected by statin therapy or changes in blood pressure. Notably, there were significant improvements in the aminothiol cysteineglutathione disulfide, and trends to improvements in fibrinogen levels and endothelium-independent vascular function. In subjects with carotid wall thickening, angiotensin II type-1 receptor blockade was associated with regression in carotid atherosclerosis. Whether these effects translate into improved outcomes in subjects with subclinical atherosclerosis

Effect of Angiotensin II Type I Receptor Blockade with Valsartan on Carotid Artery Atherosclerosis: A Double Blind Randomized Clinical Trial Comparing Valsartan and Placebo (EFFERVESCENT)

PubMed Central

Ramadan, Ronnie; Dhawan, Saurabh S.; Binongo, José Nilo G.; Alkhoder, Ayman; Jones, Dean P.; Oshinski, John N.; Quyyumi, Arshed A.

2016-01-01

Background Progression of atherosclerosis is associated with a greater risk for adverse outcomes. Angiotensin II plays a key role in the pathogenesis and progression of atherosclerosis. We aimed to investigate the effects of Angiotensin II type-1 receptor (AT1R) blockade with Valsartan on carotid wall atherosclerosis, with the hypothesis that Valsartan will reduce progression of atherosclerosis. Methods Subjects (n= 120) with carotid intima-media thickness >0.65mm by ultrasound were randomized (2:1) in a double-blind manner to receive either Valsartan or placebo for 2 years. Bilateral T2-weighted black-blood carotid magnetic resonance imaging was performed at baseline, 12 and 24 months. Changes in the carotid bulb vessel wall area (VWA) and wall thickness (WT) were primary endpoints. Secondary endpoints included changes in carotid plaque thickness, plasma levels of aminothiols, C-reactive protein, fibrinogen, and endothelium-dependent and -independent vascular function. Results Over 2 years, the carotid bulb VWA decreased with Valsartan (−6.7, 95% CI: (−11.6,−1.9) mm2) but not with placebo (3.4, 95% CI: (−2.8,9.6) mm2)), p=0.01 between groups. Similarly, mean WT decreased with Valsartan (−0.18, 95% CI: (−0.30,−0.06) mm), but not with placebo (0.08, 95% CI: (−0.07,0.23) mm),), p=0.009 between groups. Furthermore, plaque thickness decreased with Valsartan (−0.35, 95% CI: (−0.63,−0.08) mm) but was unchanged with placebo (+0.28, 95% CI: (−0.11,0.69) mm), p=0.01 between groups. These findings were unaffected by statin therapy or changes in blood pressure. Notably, there were significant improvements in the aminothiol cysteineglutathione disulfide, and trends to improvements in fibrinogen levels and endothelium–independent vascular function. Conclusions In subjects with carotid wall thickening, AT1R blockade was associated with regression in carotid atherosclerosis. Whether these effects translate into improved outcomes in subjects with

Effects of long-term vasodilator therapy in patients with carotid sinus hypersensitivity.

PubMed

Brignole, M; Menozzi, C; Gaggioli, G; Musso, G; Foglia-Manzillo, G; Mascioli, G; Fradella, G; Bottoni, N; Mureddu, R

1998-08-01

In patients affected by carotid sinus hypersensitivity, long-term vasodilator therapy might increase the risk of syncopal episodes by reducing systolic blood pressure and venous return to the heart. Thirty-two patients (mean age 73 +/- 9 years; 20 men) who met all the following criteria were included: (1) one or more episodes of syncope occurring during long-term (>6 months) treatment with angiotensin-converting enzyme inhibitors, long-acting nitrates, calcium antagonists, or a combination of these; (2) a positive response to carotid sinus massage, defined as the reproduction of spontaneous syncope in the presence of ventricular asystole > or =3 seconds or a fall in systolic blood pressure > or =50 mm Hg; (3) negative workup for other causes of syncope. The patients were randomly assigned to continue or to discontinue use of vasodilators; carotid sinus massage was repeated 2 weeks after randomization. By the end of the study period, the baseline values of systolic blood pressure were significantly different between the 2 groups of patients both in supine (P=.01) and upright (P=.03) positions. Syncope had been induced by carotid sinus massage in 81% of patients in the "on-vasodilator" group and in 62% of patients in the "off-vasodilator" group (P=.21). The cardioinhibitory reflex was of similar magnitude in the 2 groups, being found in 50% of the patients in each group, with a maximum ventricular pause of 7.1 +/- 2.7 and 6.7 +/- 1.8 seconds, respectively. The percentage decrease of blood pressure did not differ between the 2 groups, even if, in absolute values, the baseline difference of blood pressure roughly persisted for the duration of the test. In consequence of that, the rise of blood pressure to similar values was delayed approximately 30 seconds in the "on-vasodilator" group and took more than 2 minutes to return to baseline values. In patients affected by carotid sinus hypersensitivity, chronic vasodilator therapy does not have a direct effect on carotid

On the Shape of the Common Carotid Artery, with Implications for Blood Velocity Profiles

PubMed Central

Manbachi, Amir; Hoi, Yiemeng; Wasserman, Bruce A.; Lakatta, Edward G.; Steinman, David A

2012-01-01

Clinical and engineering studies typically assume that the common carotid artery (CCA) is straight enough to assume fully developed flow, yet recent studies have demonstrated the presence of skewed velocity profiles. Towards elucidating the influence of mild vascular curvatures on blood flow patterns and atherosclerosis, the present study aimed to characterize the three-dimensional shape of the human CCA. The left and right carotid arteries of 28 participants (62±13 years) in the VALIDATE (Vascular Aging – The Link that Bridges Age to Atherosclerosis) study were digitally segmented from 3D contrast-enhanced magnetic resonance angiograms, from the aortic arch to the carotid bifurcation. Each CCA was divided into nominal cervical and thoracic segments, for which curvatures were estimated by least squares fitting of the respective centerlines to planar arcs. The cervical CCA had mean radius of curvature of 127 mm, corresponding to a mean lumen:curvature radius ratio of 1:50. The thoracic CCA was significantly more curved at 1:16, with the plane of curvature tilted by a mean angle of 25 degrees and rotated close to 90 degrees with respect to that of the cervical CCA. The left CCA was significantly longer and slightly more curved than the right CCA, and there was a weak but significant increase in CCA curvature with age. Computational fluid dynamic (CFD) simulations carried out for idealized CCA geometries derived from these and other measured geometric parameters demonstrated that mild cervical curvature is sufficient to prevent flow from fully developing, independent of the degree of thoracic curvature. These findings reinforce the idea that fully-developed flow may be the exception rather than the rule for the CCA, and perhaps other nominally long and straight vessels. PMID:22031538

Baroreflex activation therapy lowers arterial pressure without apparent stimulation of the carotid bodies.

PubMed

Alnima, Teba; Goedhart, Emilie J B M; Seelen, Randy; van der Grinten, Chris P M; de Leeuw, Peter W; Kroon, Abraham A

2015-06-01

Carotid baroreflex activation therapy produces a sustained fall in blood pressure in patients with resistant hypertension. Because the activation electrodes are implanted at the level of the carotid sinus, it is conceivable that the nearby located carotid body chemoreceptors are stimulated as well. Physiological stimulation of the carotid chemoreceptors not only stimulates respiration but also increases sympathetic activity, which may counteract the effects of baroreflex activation. The aim of this exploratory study is to investigate whether there is concomitant carotid chemoreflex activation during baroreflex activation therapy. Fifteen participants with the Rheos system were included in this single-center study. At arrival at the clinic, the device was switched off for 2 hours while patients were at rest. Subsequently, the device was switched on at 6 electric settings of high and low frequencies and amplitudes. Respiration and blood pressure measurements were performed during all device activation settings. Multilevel statistical models were adjusted for age, sex, body mass index, antihypertensive therapeutic index, sleep apnea, coronary artery disease, systolic blood pressure, and heart rate. There was no change in end-tidal carbon dioxide, partial pressure of carbon dioxide, breath duration, and breathing frequency during any of the electric settings with the device. Nevertheless, mean arterial pressure showed a highly significant decrease during electric activation (P<0.001). Carotid baroreflex activation therapy using the Rheos system did not stimulate respiration at several electric device activation energies, which suggests that there is no appreciable coactivation of carotid body chemoreceptors during device therapy. © 2015 American Heart Association, Inc.

Three-dimensional quantitative T1 and T2 mapping of the carotid artery: Sequence design and in vivo feasibility.

PubMed

Coolen, Bram F; Poot, Dirk H J; Liem, Madieke I; Smits, Loek P; Gao, Shan; Kotek, Gyula; Klein, Stefan; Nederveen, Aart J

2016-03-01

A novel three-dimensional (3D) T1 and T2 mapping protocol for the carotid artery is presented. A 3D black-blood imaging sequence was adapted allowing carotid T1 and T2 mapping using multiple flip angles and echo time (TE) preparation times. B1 mapping was performed to correct for spatially varying deviations from the nominal flip angle. The protocol was optimized using simulations and phantom experiments. In vivo scans were performed on six healthy volunteers in two sessions, and in a patient with advanced atherosclerosis. Compensation for patient motion was achieved by 3D registration of the inter/intrasession scans. Subsequently, T1 and T2 maps were obtained by maximum likelihood estimation. Simulations and phantom experiments showed that the bias in T1 and T2 estimation was < 10% within the range of physiological values. In vivo T1 and T2 values for carotid vessel wall were 844 ± 96 and 39 ± 5 ms, with good repeatability across scans. Patient data revealed altered T1 and T2 values in regions of atherosclerotic plaque. The 3D T1 and T2 mapping of the carotid artery is feasible using variable flip angle and variable TE preparation acquisitions. We foresee application of this technique for plaque characterization and monitoring plaque progression in atherosclerotic patients. © 2015 Wiley Periodicals, Inc.

Carotid-cardiac baroreflex influence on forearm vascular resistance during low level LBNP

NASA Technical Reports Server (NTRS)

Ludwig, David

1990-01-01

Twelve healthy males were tested at low levels of lower body negative pressure (LBNP) with and without artificial stimulation of the carotid-cardiac baroreceptors. The carotid-cardiac baroreceptors were stimulated by applying a pressure of 10 mmHg to the carotid artery via a pressurized neck chamber. During the procedure, forearm blood flow (FBF) and forearm vascular resistance (FVR) were measured using a Whitney mercury silastic strain gauge technique. FBF decreased while FVR increased with increased intensity of LBNP. Both FBF and FVR were unaffected by carotid-cardiac baroreceptor stimulation.

Treatment of symptomatic carotid stenosis: carotid stent placement versus endarterectomy.

PubMed

Alqadri, Syeda L; Qureshi, Adnan I

2013-08-01

The mainstay of treatment options for symptomatic carotid stenosis is focused around medical management, carotid endarterectomy, and carotid angioplasty and stent placement. The International Carotid Stenting Study (ICSS), also called Carotid and Vertebral Artery Transluminal Angioplasty Study 2 (CAVATAS 2), the Stent-Supported Percutaneous Angioplasty of the Carotid Artery Versus Endarterectomy (SPACE) trial, the Endarterectomy Versus Angioplasty in Patients with Symptomatic Severe Carotid Stenosis (EVA-3S) trial, the Stenting and Angioplasty with Protection in Patients at High Risk for Endarterectomy (SAPPHIRE) trial, and the Carotid Revascularization Endarterectomy Versus Stenting Trial (CREST) were five major trials which compared carotid endarterectomy and carotid angioplasty and stent placement. We review the results of the trials and incorporation of the results into clinical decision making.

Dietary and urinary metabonomic factors possibly accounting for higher blood pressure of black compared with white Americans: results of International Collaborative Study on macro-/micronutrients and blood pressure.

PubMed

Stamler, Jeremiah; Brown, Ian J; Yap, Ivan K S; Chan, Queenie; Wijeyesekera, Anisha; Garcia-Perez, Isabel; Chadeau-Hyam, Marc; Ebbels, Timothy M D; De Iorio, Maria; Posma, Joram; Daviglus, Martha L; Carnethon, Mercedes; Holmes, Elaine; Nicholson, Jeremy K; Elliott, Paul

2013-12-01

Black compared with non-Hispanic white Americans have higher systolic and diastolic blood pressure and rates of prehypertension/hypertension. Reasons for these adverse findings remain obscure. Analyses here focused on relations of foods/nutrients/urinary metabolites and higher black blood pressure for 369 black compared with 1190 non-Hispanic white Americans aged 40 to 59 years from 8 population samples. Multiple linear regression, standardized data from four 24-hour dietary recalls per person, two 24-hour urine collections, and 8 blood pressure measurements were used to quantitate the role of foods, nutrients, and metabolites in higher black blood pressure. Compared with non-Hispanic white Americans, blacks' average systolic/diastolic pressure was higher by 4.7/3.4 mm Hg (men) and 9.0/4.8 mm Hg (women). Control for higher body mass index of black women reduced excess black systolic/diastolic pressure to 6.8/3.8 mm Hg. Lesser intake of vegetables, fruits, grains, vegetable protein, glutamic acid, starch, fiber, minerals, and potassium, and higher intake of processed meats, pork, eggs, and sugar-sweetened beverages, along with higher cholesterol and higher Na/K ratio, related to in higher black blood pressure. Control for 11 nutrient and 10 non-nutrient correlates reduced higher black systolic/diastolic pressure to 2.3/2.3 mm Hg (52% and 33% reduction in men) and to 5.3/2.8 mm Hg (21% and 27% reduction in women). Control for foods/urinary metabolites had little further influence on higher black blood pressure. Less favorable multiple nutrient intake by blacks than non-Hispanic white Americans accounted, at least in part, for higher black blood pressure. Improved dietary patterns can contribute to prevention/control of more adverse black blood pressure levels.

Spatial mapping of dynamic cerebral autoregulation by multichannel near-infrared spectroscopy in high-grade carotid artery disease

NASA Astrophysics Data System (ADS)

Reinhard, Matthias; Schumacher, F. Konrad; Rutsch, Sebastian; Oeinck, Maximilian; Timmer, Jens; Mader, Irina; Schelter, Björn; Weiller, Cornelius; Kaller, Christoph P.

2014-09-01

The exact spatial distribution of impaired cerebral autoregulation in carotid artery disease is unknown. In this pilot study, we present a new approach of multichannel near-infrared spectroscopy (mcNIRS) for noninvasive spatial mapping of dynamic autoregulation in carotid artery disease. In 15 patients with unilateral severe carotid artery stenosis or occlusion, cortical hemodynamics in the bilateral frontal cortex were assessed from changes in oxyhemoglobin concentration using 52-channel NIRS (spatial resolution ˜2 cm). Dynamic autoregulation was graded by the phase shift between respiratory-induced 0.1 Hz oscillations of blood pressure and oxyhemoglobin. Ten of 15 patients showed regular phase values in the expected (patho) physiological range. Five patients had clearly outlying irregular phase values mostly due to artifacts. In patients with a regular phase pattern, a significant side-to-side difference of dynamic autoregulation was observed for the cortical border zone area between the middle and anterior cerebral artery (p<0.05). In conclusion, dynamic cerebral autoregulation can be spatially assessed from slow hemodynamic oscillations with mcNIRS. In high-grade carotid artery disease, cortical dynamic autoregulation is affected mostly in the vascular border zone. Spatial mapping of dynamic autoregulation may serve as a powerful tool for identifying brain regions at specific risks for hemodynamic infarction.

Heritability of carotid intima-media thickness: a twin study.

PubMed

Zhao, Jinying; Cheema, Faiz A; Bremner, J Douglas; Goldberg, Jack; Su, Shaoyong; Snieder, Harold; Maisano, Carisa; Jones, Linda; Javed, Farhan; Murrah, Nancy; Le, Ngoc-Anh; Vaccarino, Viola

2008-04-01

To estimate the heritability of carotid intima-media thickness (IMT), a surrogate marker for atherosclerosis, independent of traditional coronary risk factors. We performed a classical twin study of carotid IMT using 98 middle-aged male twin pairs, 58 monozygotic (MZ) and 40 dizygotic (DZ) pairs, from the Vietnam Era Twin Registry. All twins were free of overt cardiovascular disease. Carotid IMT was measured by ultrasound. Bivariate and multivariate analyses were used to determine the association between traditional cardiovascular risk factors and carotid IMT. Intraclass correlation coefficients and genetic modeling techniques were used to determine the relative contributions of genes and environment to the variation in carotid IMT. In our sample, the mean of the maximum carotid IMT was 0.75+/-0.11. Age, systolic blood pressure and HDL were significantly associated with carotid IMT. The intraclass correlation coefficient for carotid IMT was larger in MZ (0.66; 95% confidence interval [CI], 0.62-0.69) than in DZ twins (0.37; 95% CI, 0.29-0.44), and the unadjusted heritability was 0.69 (95% CI, 0.54-0.79). After adjusting for traditional coronary risk factors, the heritability of carotid IMT was slightly reduced but still of considerable magnitude (0.59; 95% CI, 0.39-0.73). Genetic factors have a substantial influence on the variation of carotid IMT. Most of this genetic effect occurs through pathways independent of traditional coronary risk factors.

Heritability of Carotid Intima-Media Thickness: A Twin Study

PubMed Central

Zhao, Jinying; Cheema, Faiz A.; Bremner, J. Douglas; Goldberg, Jack; Su, Shaoyong; Snieder, Harold; Maisano, Carisa; Jones, Linda; Javed, Farhan; Murrah, Nancy; Le, Ngoc-Anh; Vaccarino, Viola

2008-01-01

Objective To estimate the heritability of carotid intima-media thickness (IMT), a surrogate marker for atherosclerosis, independent of traditional coronary risk factors. Methods and Results We performed a classical twin study of carotid IMT using 98 middle-aged male twin pairs, 58 monozygotic (MZ) and 40 dizygotic (DZ) pairs, from the Vietnam Era Twin Registry. All twins were free of overt cardiovascular disease. Carotid IMT was measured by ultrasound. Bivariate and multivariate analyses were used to determine the association between traditional cardiovascular risk factors and carotid IMT. Intraclass correlation coefficients and genetic modeling techniques were used to determine the relative contributions of genes and environment to the variation in carotid IMT. In our sample, the mean of the maximum carotid IMT was 0.75 ± 0.11. Age, systolic blood pressure and HDL were significantly associated with carotid IMT. The intraclass correlation coefficient for carotid IMT was larger in MZ (0.66; 95% confidence interval [CI], 0.62–0.69) than in DZ twins (0.37; 95% CI, 0.29–0.44), and the unadjusted heritability was 0.69 (95% CI, 0.54–0.79). After adjusting for traditional coronary risk factors, the heritability of carotid IMT was slightly reduced but still of considerable magnitude (0.59; 95% CI, 0.39–0.73). Conclusion Genetic factors have a substantial influence on the variation of carotid IMT. Most of this genetic effect occurs through pathways independent of traditional coronary risk factors. PMID:17825306

Phase-sensitive dual-inversion recovery for accelerated carotid vessel wall imaging.

PubMed

Bonanno, Gabriele; Brotman, David; Stuber, Matthias

2015-03-01

Dual-inversion recovery (DIR) is widely used for magnetic resonance vessel wall imaging. However, optimal contrast may be difficult to obtain and is subject to RR variability. Furthermore, DIR imaging is time-inefficient and multislice acquisitions may lead to prolonged scanning times. Therefore, an extension of phase-sensitive (PS) DIR is proposed for carotid vessel wall imaging. The statistical distribution of the phase signal after DIR is probed to segment carotid lumens and suppress their residual blood signal. The proposed PS-DIR technique was characterized over a broad range of inversion times. Multislice imaging was then implemented by interleaving the acquisition of 3 slices after DIR. Quantitative evaluation was then performed in healthy adult subjects and compared with conventional DIR imaging. Single-slice PS-DIR provided effective blood-signal suppression over a wide range of inversion times, enhancing wall-lumen contrast and vessel wall conspicuity for carotid arteries. Multislice PS-DIR imaging with effective blood-signal suppression is enabled. A variant of the PS-DIR method has successfully been implemented and tested for carotid vessel wall imaging. This technique removes timing constraints related to inversion recovery, enhances wall-lumen contrast, and enables a 3-fold increase in volumetric coverage at no extra cost in scanning time.

Carotid artery stiffness in patients with symptomatic carotid artery disease with contralateral asymptomatic carotid artery disease and in patients with bilateral asymptomatic carotid artery disease: a cine phase-contrast carotid MR study.

PubMed

Sadat, Umar; Usman, Ammara; Howarth, Simon P S; Tang, Tjun Y; Alam, Fahreyar; Graves, Martin J; Gillard, Jonathan H

2014-04-01

Atherosclerosis is a systemic inflammatory disease that may affect multiple arterial beds simultaneously. Vascular distensibility is increasingly used in the clinical assessment of patients with atherosclerotic disease. In this study, we assess distensibility of symptomatic atherosclerotic carotid artery and of contralateral asymptomatic side. We also investigate the distensibility of bilaterally asymptomatic atherosclerotic carotid arteries using cine phase-contrast carotid magnetic resonance (MR) imaging. Nineteen patients with bilateral carotid artery disease underwent cine phase-contrast carotid imaging on a 1.5 T MR system. Ten patients had ipsilateral symptomatic carotid artery disease and contralateral asymptomatic stenosis. Nine additional patients with bilateral asymptomatic carotid artery disease constituted historical control group. Cine phase-contrast MR imaging acquired at the common carotid artery, maximum luminal stenosis, and internal carotid artery was used to determine carotid distensibility bilaterally for carotid arteries in both patient groups. Symptomatic carotid arteries were found to be significantly less distensible (mean distensibility coefficient [DC] 35.4 ± 6.12 × 10(-3)/kPa) than the contralateral asymptomatic vessels (mean DC 54.4 ± 7.88 × 10(-3)/kPa, P = .03) at the level of the common carotid artery. A similar trend of high distensibility for asymptomatic side in the area of maximum stenosis and the internal carotid artery was seen, but it was not found to be statistically significant. Plaque burden was comparable between the 2 groups at all locations. DC was comparable for patients with bilateral asymptomatic carotid artery stenoses. Distensibility of bilaterally asymptomatic carotid arteries was greater than that of asymptomatic carotid artery contralateral to the symptomatic side. Symptomatic carotid artery is stiffer than the contralateral asymptomatic side, despite comparable plaque burden. Patients with bilateral

Advances in MRI for the evaluation of carotid atherosclerosis

PubMed Central

Teng, Z; Patterson, A J; Lin, J-M; Young, V; Graves, M J; Gillard, J H

2015-01-01

Carotid artery atherosclerosis is an important source of mortality and morbidity in the Western world with significant socioeconomic implications. The quest for the early identification of the vulnerable carotid plaque is already in its third decade and traditional measures, such as the sonographic degree of stenosis, are not selective enough to distinguish those who would really benefit from a carotid endarterectomy. MRI of the carotid plaque enables the visualization of plaque composition and specific plaque components that have been linked to a higher risk of subsequent embolic events. Blood suppressed T1 and T2 weighted and proton density-weighted fast spin echo, gradient echo and time-of-flight sequences are typically used to quantify plaque components such as lipid-rich necrotic core, intraplaque haemorrhage, calcification and surface defects including erosion, disruption and ulceration. The purpose of this article is to review the most important recent advances in MRI technology to enable better diagnostic carotid imaging. PMID:25826233

Long-term exposure to traffic-related air pollution and progression of carotid artery atherosclerosis: a prospective cohort study

PubMed Central

Gan, Wen Qi; Allen, Ryan W; Brauer, Michael; Davies, Hugh W; Mancini, G B John; Lear, Scott A

2014-01-01

Objectives Epidemiological studies have demonstrated associations between long-term exposure to traffic-related air pollution and coronary heart disease (CHD). Atherosclerosis is the principal pathological process responsible for CHD events, but effects of traffic-related air pollution on progression of atherosclerosis are not clear. This study aimed to investigate associations between long-term exposure to traffic-related air pollution and progression of carotid artery atherosclerosis. Setting Healthy volunteers in metropolitan Vancouver, Canada. Participants and outcome measures 509 participants aged 30–65 years were recruited and followed for approximately 5 years. At baseline and end of follow-up, participants underwent carotid artery ultrasound examinations to assess atherosclerosis severity, including carotid intima-media thickness, plaque area, plaque number and total area. Annual change of each atherosclerosis marker during the follow-up period was calculated as the difference between these two measurements divided by years of follow-up. Living close to major roads was defined as ≤150 m from a highway or ≤50 m from a major road. Residential exposures to traffic-related air pollutants including black carbon, fine particles, nitrogen dioxide and nitric oxide were estimated using high-resolution land-use regression models. The data were analysed using general linear models adjusting for various covariates. Results At baseline, there were no significant differences in any atherosclerosis markers between participants living close to and those living away from major roads. After follow-up, the differences in annual changes of these markers between these two groups were small and not statistically significant. Also, no significant associations were observed with concentrations of traffic-related air pollutants including black carbon, fine particles, nitrogen dioxide and nitric oxide. Conclusions This study did not find significant associations

Intra-individual comparison of carotid and femoral atherosclerotic plaque features with in vivo MR plaque imaging.

PubMed

Helck, Andreas; Bianda, Nicola; Canton, Gador; Yuan, Chun; Hippe, Daniel S; Reiser, Maximilian F; Gallino, Augusto; Wyttenbach, Rolf; Saam, Tobias

2015-12-01

The purpose of this study was to evaluate differences of plaque composition and morphology within the same patient in different vascular beds using non-invasive MR-plaque imaging. 28 patients (67.8 ± 7.4 years, 8 females) with high Framingham general cardiovascular disease 10-year risk score and mild-to-moderate atherosclerosis were consecutively included in the study. All subjects underwent a dedicated MRI-plaque imaging protocol using TOF and T1w and T2w black-blood-sequences with fat suppression at 1.5 T. The scan was centered on the carotid bulb of the carotid arteries and on the most stenotic lesion of the ipsilateral femoral artery, respectively. Plaques were classified according to the American Heart Association (AHA) lesion type classification and area measurements of lumen, wall and the major plaque components, such as calcification, necrotic core and hemorrhage were determined in consensus by two blinded reviewers using dedicated software (Cascade, Seattle, USA). Plaque components were recorded as maximum percentages of the wall area. Carotid arteries had larger maximum wall and smaller minimum lumen areas (p < 0.001) than femoral arteries, whereas no significant difference was find with respect to the max. NWI (p = 0.87). Prevalence of lipid-rich AHA lesion type IV/V and complicated AHA lesion type VI with hemorrhage/thrombus/fibrous cap rupture was significantly higher in the carotid arteries compared to the femoral arteries. Plaque composition as percentage of the vessel wall differed significantly between carotid and femoral arteries: Max. %necrotic core and max. %hemorrhage were significantly higher in the carotid arteries compared to the femoral arteries (p = 0.001 and p = 0.02, respectively). Max. %calcification did not differ significantly. Average stenotic degree of carotid arteries at duplex was 49.7 ± 12.5 (%). Non-invasive MR plaque-imaging is able to visualize differences in plaque composition across the vascular tree. We observed

Investigation of blood flow in the external carotid artery and its branches with a new 0D peripheral model.

PubMed

Ohhara, Yoshihito; Oshima, Marie; Iwai, Toshinori; Kitajima, Hiroaki; Yajima, Yasuharu; Mitsudo, Kenji; Krdy, Absy; Tohnai, Iwai

2016-02-04

Patient-specific modelling in clinical studies requires a realistic simulation to be performed within a reasonable computational time. The aim of this study was to develop simple but realistic outflow boundary conditions for patient-specific blood flow simulation which can be used to clarify the distribution of the anticancer agent in intra-arterial chemotherapy for oral cancer. In this study, the boundary conditions are expressed as a zero dimension (0D) resistance model of the peripheral vessel network based on the fractal characteristics of branching arteries combined with knowledge of the circulatory system and the energy minimization principle. This resistance model was applied to four patient-specific blood flow simulations at the region where the common carotid artery bifurcates into the internal and external carotid arteries. Results of these simulations with the proposed boundary conditions were compared with the results of ultrasound measurements for the same patients. The pressure was found to be within the physiological range. The difference in velocity in the superficial temporal artery results in an error of 5.21 ± 0.78 % between the numerical results and the measurement data. The proposed outflow boundary conditions, therefore, constitute a simple resistance-based model and can be used for performing accurate simulations with commercial fluid dynamics software.

Cardiac Iodine-123-Meta-Iodo-Benzylguanidine Uptake in Carotid Sinus Hypersensitivity

PubMed Central

Tan, Maw Pin; Murray, Alan; Hawkins, Terry; Chadwick, Thomas J.; Kerr, Simon R. J.; Parry, Steve W.

2015-01-01

Background Carotid sinus syndrome is the association of carotid sinus hypersensitivity with syncope, unexplained falls and drop attacks in generally older people. We evaluated cardiac sympathetic innervation in this disorder in individuals with carotid sinus syndrome, asymptomatic carotid sinus hypersensitivity and controls without carotid sinus hypersensitivity. Methods Consecutive patients diagnosed with carotid sinus syndrome at a specialist falls and syncope unit were recruited. Asymptomatic carotid sinus hypersensitivity and non-carotid sinus hypersensitivity control participants recruited from a community-dwelling cohort. Cardiac sympathetic innervation was determined using Iodine-123-metaiodobenzylguanidine (123-I-MIBG) scanning. Heart to mediastinal uptake ratio (H:M) were determined for early and late uptake on planar scintigraphy at 20 minutes and 3 hours following intravenous injection of 123-I-MIBG. Results Forty-two subjects: carotid sinus syndrome (n = 21), asymptomatic carotid sinus hypersensitivity (n = 12) and no carotid sinus hypersensitivity (n = 9) were included. Compared to the non- carotid sinus hypersensitivity control group, the carotid sinus syndrome group had significantly higher early H:M (estimated mean difference, B = 0.40; 95% confidence interval, CI = 0.13 to 0.67, p = 0.005) and late H:M (B = 0.32; 95%CI = 0.03 to 0.62, p = 0.032). There was, however, no significant difference in early H:M (p = 0.326) or late H:M (p = 0.351) between the asymptomatic carotid sinus hypersensitivity group and non- carotid sinus hypersensitivity controls. Conclusions Cardiac sympathetic neuronal activity is increased relative to age-matched controls in individuals with carotid sinus syndrome but not those with asymptomatic carotid sinus hypersensitivity. Blood pressure and heart rate measurements alone may therefore represent an over simplification in the assessment for carotid sinus syndrome and the relative increase in cardiac sympathetic innervation

Cardiac Iodine-123-Meta-Iodo-Benzylguanidine Uptake in Carotid Sinus Hypersensitivity.

PubMed

Tan, Maw Pin; Murray, Alan; Hawkins, Terry; Chadwick, Thomas J; Kerr, Simon R J; Parry, Steve W

2015-01-01

Carotid sinus syndrome is the association of carotid sinus hypersensitivity with syncope, unexplained falls and drop attacks in generally older people. We evaluated cardiac sympathetic innervation in this disorder in individuals with carotid sinus syndrome, asymptomatic carotid sinus hypersensitivity and controls without carotid sinus hypersensitivity. Consecutive patients diagnosed with carotid sinus syndrome at a specialist falls and syncope unit were recruited. Asymptomatic carotid sinus hypersensitivity and non-carotid sinus hypersensitivity control participants recruited from a community-dwelling cohort. Cardiac sympathetic innervation was determined using Iodine-123-metaiodobenzylguanidine (123-I-MIBG) scanning. Heart to mediastinal uptake ratio (H:M) were determined for early and late uptake on planar scintigraphy at 20 minutes and 3 hours following intravenous injection of 123-I-MIBG. Forty-two subjects: carotid sinus syndrome (n = 21), asymptomatic carotid sinus hypersensitivity (n = 12) and no carotid sinus hypersensitivity (n = 9) were included. Compared to the non- carotid sinus hypersensitivity control group, the carotid sinus syndrome group had significantly higher early H:M (estimated mean difference, B = 0.40; 95% confidence interval, CI = 0.13 to 0.67, p = 0.005) and late H:M (B = 0.32; 95%CI = 0.03 to 0.62, p = 0.032). There was, however, no significant difference in early H:M (p = 0.326) or late H:M (p = 0.351) between the asymptomatic carotid sinus hypersensitivity group and non- carotid sinus hypersensitivity controls. Cardiac sympathetic neuronal activity is increased relative to age-matched controls in individuals with carotid sinus syndrome but not those with asymptomatic carotid sinus hypersensitivity. Blood pressure and heart rate measurements alone may therefore represent an over simplification in the assessment for carotid sinus syndrome and the relative increase in cardiac sympathetic innervation provides additional clues to

Interaction between graviception and carotid baroreflex function in humans during parabolic flight-induced microgravity.

PubMed

Ogoh, Shigehiko; Marais, Michaël; Lericollais, Romain; Denise, Pierre; Raven, Peter B; Normand, Hervé

2018-05-10

The aim of the present study was to assess carotid baroreflex (CBR) during acute changes in otolithic activity in humans. To address this question, we designed a set of experiments to identify the modulatory effects of microgravity on CBR function at a tilt angle of -2{degree sign}, which was identified to minimize changes in central blood volume during parabolic flight. During parabolic flight at 0g and 1g, CBR function curves were modelled from the heart rate (HR) and mean arterial pressure (MAP) responses to rapid pulse trains of neck pressure (NP) and neck suction (NS) ranging from +40 to -80 Torr; CBR control of HR (carotid-HR) and MAP (carotid-MAP) baroreflex function curves, respectively. The maximal gain (G max ) of both carotid-HR and carotid-MAP baroreflex function curves were augmented during microgravity compared to 1g (carotid-HR, -0.53 to -0.80 beats/min/mmHg, P<0.05; carotid-MAP, -0.24 to -0.30 mmHg/mmHg, P<0.05). These findings suggest that parabolic flight-induced acute change of otolithic activity may modify CBR function and identifies that the vestibular system contributes to blood pressure regulation under fluctuations in gravitational forces.

Open-cell vs. Closed-cell Stent Design Differences in Blood Flow Velocities after Carotid Stenting

PubMed Central

Pierce, Damon S.; Rosero, Eric B; Modrall, J Gregory; Adams-Huet, Beverley; Valentine, R James; Clagett, G Patrick; Timaran, Carlos H

2009-01-01

Objective The differential effect of stent design, i.e. open-cell vs. closed-cell configuration, on carotid velocities detected by duplex ultrasonography (DUS) has not been established. To identify possible stent design differences in carotid velocities, we analyzed our experience with DUS obtained before and immediately after CAS. Methods In a series of 141 CAS procedures performed over a 3 year period, data from the first postinterventional DUS and carotid angiograms were evaluated for each patient. Peak systolic velocities (PSV), end-diastolic velocities (EDV), and internal carotid artery-to-common carotid artery (ICA-CCA) PSV ratios were compared according to stent design. Differences in carotid velocities were analyzed using nonparametric statistical tests. Results Completion angiogram revealed successful revascularization and less that 30% residual stenosis in each case. The 30-day stroke-death rate in this series was 1.6% and was unrelated to stent type. Postintervention DUS was obtained a median of 5 days after CAS (interquartile range [IQR], 1–25 days). Closed-cell stents were used in 41 cases (29%) and open-cell stents in 100 cases (71%). The median PSV was significantly higher for closed-cell stents (122cm/s; IQR, 89–143cm/s) than for open-cell stents (95.9cm/s; IQR, 77.–123) (P=.007). Median EDV (36 vs. 29 cm/s; P=.006) and median ICA-CCA PSV ratio (1.6 vs. 1.1; P=.017) were also significantly higher for closed-cell stents. 45% of closed-cell stents had carotid velocities that exceeded the threshold of 50% stenosis by DUS criteria for a nonstented artery compared to 26% of open-cell stents (P=.04). In fact, closed cell-stents had a 2.2-fold increased risk of yielding abnormally elevated carotid velocities after CAS compared with open-cell stents (odds ratio, 2.2; 95% confidence interval, 1.02–4.9). Conclusions Carotid velocities are disproportionately elevated after CAS with closed-cell stents compared with open-cell stents, which suggests that

Pulse Pressure and Carotid Artery Doppler Velocimetry as Indicators of Maternal Volume Status: A Prospective Cohort Study.

PubMed

Lappen, Justin R; Myers, Stephen A; Bolden, Norman; Shaman, Ziad; Angirekula, Venkata; Chien, Edward K

2018-03-01

Narrow pulse pressure has been demonstrated to indicate low central volume status. In critically ill patients, volume status can be qualitatively evaluated using Doppler velocimetry to assess hemodynamic changes in the carotid artery in response to autotransfusion with passive leg raise (PLR). Neither parameter has been prospectively evaluated in an obstetric population. The objective of this study was to determine if pulse pressure could predict the response to autotransfusion using carotid artery Doppler in healthy intrapartum women. We hypothesized that the carotid artery Doppler response to PLR would be greater in women with a narrow pulse pressure, indicating relative hypovolemia. Intrapartum women with singleton gestations ≥35 weeks without acute or chronic medical conditions were recruited to this prospective cohort study. Participants were grouped by admission pulse pressure as <45 mm Hg(narrow) or ≥50 mm Hg(normal). Maternal carotid artery Doppler assessment was then performed in all patients before and after PLR using a standard technique where carotid blood flow (mL/min) = π × (carotid artery diameter/2) × (velocity time integral) x (60 seconds). The velocity time integral was calculated from the Doppler waveform. The primary outcome was the change in the carotid Doppler parameters (carotid artery diameter, velocity time integral, and carotid blood flow) after PLR. Outcomes were compared between study groups with univariable and multivariable analyses with adjustment for potential confounding factors. Thirty-three women consented to participation, including 18 in the narrow and 15 in the normal pulse pressure groups (mean and standard deviation initial pulse pressure, 38.3 ± 4.4 vs 57.3 ± 4.1 mm Hg). The 2 groups demonstrated similar characteristics except for initial pulse pressure, systolic and diastolic blood pressure, and race. In response to PLR, the narrow pulse pressure group had a significantly greater increase in carotid artery diameter

Regulation of Carotid Body Oxygen Sensing by Hypoxia-Inducible Factors

PubMed Central

Prabhakar, Nanduri R.; Semenza, Gregg L.

2015-01-01

Oxygen (O2) sensing by the carotid body and its chemosensory reflex is critical for homeostatic regulation of breathing and blood pressure. Carotid body responses to hypoxia are not uniform but instead exhibit remarkable inter-individual variations. The molecular mechanisms underlying variations in carotid body O2 sensing are not known. Hypoxia-inducible factor-1 (HIF-1) and HIF-2 mediate transcriptional responses to hypoxia. This article reviews the emerging evidence that proper expression of the HIF-α isoforms is a key molecular determinant for carotid body O2 sensing. HIF-1α deficiency leads to a blunted carotid body hypoxic response, which is due to increased abundance of HIF-2α, elevated anti-oxidant enzyme activity, and a reduced intracellular redox state. Conversely, HIF-2α deficiency results in augmented carotid body sensitivity to hypoxia, which is due to increased abundance of HIF-1α, elevated pro-oxidant enzyme activity, and an oxidized intracellular redox state. Double heterozygous mice with equally reduced HIF-1α and HIF-2α showed no abnormality in redox state or carotid body O2 sensing. Thus, mutual antagonism between HIF-α isoforms determines the redox state and thereby establishes the set point for hypoxic sensing by the carotid body. PMID:26265380

White blood cell subsets are associated with carotid intima-media thickness and pulse wave velocity in an older Chinese population: the Guangzhou Biobank Cohort Study.

PubMed

Phillips, A C; Jiang, C Q; Thomas, G N; Lin, J M; Yue, X J; Cheng, K K; Jin, Y L; Zhang, W S; Lam, T H

2012-08-01

Cross-sectional associations between white blood cell (WBC) count, lymphocyte and granulocyte numbers, and carotid intima-media thickness (IMT) and brachial-ankle pulse wave velocity (PWV) were examined in a novel older Chinese community sample. A total of 817 men and 760 women from a sub-study of the Guangzhou Biobank Cohort Study had a full blood count measured by an automated hematology analyzer, carotid IMT by B-mode ultrasonography and brachial-ankle PWV by a non-invasive automatic waveform analyzer. Following adjustment for confounders, WBC count (β=0.07, P<0.001) and granulocyte (β=0.07, P<0.001) number were significantly positively related to PWV, but not lymphocyte number. Similarly, WBC count (β=0.08, P=0.03), lymphocyte (β=0.08, P=0.002) and granulocyte (β=0.03, P=0.04) number were significantly positively associated with carotid IMT, but only the association with lymphocyte count survived correction for other cardiovascular risk factors. In conclusion, higher WBC, particularly lymphocyte and granulocyte, count could be used, respectively, as markers of cardiovascular disease risk, measured through indicators of atherosclerosis and arterial stiffness. The associations for WBC count previously observed by others were likely driven by higher granulocytes; an index of systemic inflammation.

Stent-induced flow disturbances in the ipsilateral external carotid artery following internal carotid artery stenting: a temporary cause of jaw claudication.

PubMed

Giurgea, Georgiana-Aura; Haumer, Markus; Mlekusch, Irene; Sabeti-Sandor, Schila; Dick, Petra; Schillinger, Martin; Minar, Erich; Mlekusch, Wolfgang

2017-07-01

We hypothesize that stenting of the internal carotid artery can immediately impede blood flow to the external carotid artery by either plaque shift or stent coverage of the ostium, and thereby cause ischemic symptoms like ipsilateral jaw claudication. Thirty-three patients with high-grade asymptomatic stenosis of the internal carotid artery who underwent endovascular treatment were examined by ultrasound of the external carotid artery and performed an exercise test by chewing chewing gum synchronously to an electronic metronome for 3 min. Tests were performed before, the day after, and 1 week after the stenting procedure. Claudication time was defined as the timespan until occurrence of pain of the masseter muscle and/or chewing dyssynchrony to the metronome for more than 15 s. Ten patients with an isolated, atherosclerotic stenosis of the external carotid artery served as controls. A significantly reduced claudication time (in seconds) was recorded in patients who underwent carotid artery stenting compared to baseline values; median 89 (interquartile range, IQR, 57 to 124) vs. median 180 (IQR 153 to 180; p < 0.001). By categorization of the flow velocity at the external carotid artery into faster or slower as 200 cm/sec, the effect was even accentuated. Stenting values showed improvement 1 week after but did not return to baseline levels. No respective changes were found in controls. Stenting of the internal carotid artery lead to ipsilateral flow deterioration at the external carotid artery resulting in temporary jaw claudication. This impairment attenuated over the time and was significantly reduced after 1 week.

The usefulness of carotid sinus massage in different patient groups.

PubMed

Kumar, Narasimhan Pradeep; Thomas, Alan; Mudd, Paul; Morris, Robert O; Masud, Tahir

2003-11-01

to determine the positive yield of carotid sinus massage in different patient groups: unexplained syncope, falls, dizziness and controls. observational study. teaching hospital. we studied consecutive patients over the age of 60 years referred to the 'falls clinic' with a history of unexplained syncope, unexplained falls and unexplained dizziness. We also studied asymptomatic control subjects recruited from a general practice register aged 60 years and over. All patients and control subjects underwent a full clinical assessment (comprehensive history and detailed clinical examination including supine and erect blood pressure measurements) and 12-lead electrocardiography. We performed carotid sinus massage in the supine position for 5 seconds separately on both sides followed by repeating the procedure in the upright positions using a motorised tilt table. Heart rate and blood pressure were recorded using a cardiac monitor and digital plethysmography respectively. The test was considered positive if carotid sinus massage produced asystole with more than a 3 second pause (cardioinhibitory type of carotid sinus syndrome), or a fall in systolic blood pressure of more than 50 mmHg in the absence of significant cardioinhibition (vasodepressor type of carotid sinus syndrome) or where there was evidence of both vasodepressor and cardio-inhibition as above (mixed type). we studied 44 asymptomatic control subjects and 221 symptomatic patients (130 with unexplained syncope, 41 with unexplained falls and 50 with unexplained dizziness). In the overall symptomatic patient group, the positive yield (any type of carotid sinus syndrome) was 17.6% (95% CI = 12.7-22.5). The positive yield in men (26.3% (95% CI = 16.4-36.2)) was twice that in women (13.1% (95% CI = 7.6-18.6)) (P = 0.014). Overall any type of carotid sinus syndrome was present in 22.3% (n = 29) of the syncope group, 17.1% (n = 7) in the unexplained fallers group and 6% (n = 3) in the dizziness group. We also found that

Non-Newtonian blood flow dynamics in a right internal carotid artery with a saccular aneurysm

NASA Astrophysics Data System (ADS)

Valencia, Alvaro; Zarate, Alvaro; Galvez, Marcelo; Badilla, Lautaro

2006-02-01

Flow dynamics plays an important role in the pathogenesis and treatment of cerebral aneurysms. The temporal and spatial variations of wall shear stress in the aneurysm are hypothesized to be correlated with its growth and rupture. In addition, the assessment of the velocity field in the aneurysm dome and neck is important for the correct placement of endovascular coils. This work describes the flow dynamics in a patient-specific model of carotid artery with a saccular aneurysm under Newtonian and non-Newtonian fluid assumptions. The model was obtained from three-dimensional rotational angiography image data and blood flow dynamics was studied under physiologically representative waveform of inflow. The three-dimensional continuity and momentum equations for incompressible and unsteady laminar flow were solved with a commercial software using non-structured fine grid with 283 115 tetrahedral elements. The intra-aneurysmal flow shows complex vortex structure that change during one pulsatile cycle. The effect of the non-Newtonian properties of blood on the wall shear stress was important only in the arterial regions with high velocity gradients, on the aneurysmal wall the predictions with the Newtonian and non-Newtonian blood models were similar.

Internal Carotid Artery Hypoplasia: Role of Color-Coded Carotid Duplex Sonography.

PubMed

Chen, Pei-Ya; Liu, Hung-Yu; Lim, Kun-Eng; Lin, Shinn-Kuang

2015-10-01

The purpose of this study was to determine the role of color-coded carotid duplex sonography for diagnosis of internal carotid artery hypoplasia. We retrospectively reviewed 25,000 color-coded carotid duplex sonograms in our neurosonographic database to establish more diagnostic criteria for internal carotid artery hypoplasia. A definitive diagnosis of internal carotid artery hypoplasia was made in 9 patients. Diagnostic findings on color-coded carotid duplex imaging include a long segmental small-caliber lumen (52% diameter) with markedly decreased flow (13% flow volume) in the affected internal carotid artery relative to the contralateral side but without intraluminal lesions. Indirect findings included markedly increased total flow volume (an increase of 133%) in both vertebral arteries, antegrade ipsilateral ophthalmic arterial flow, and a reduced vessel diameter with increased flow resistance in the ipsilateral common carotid artery. Ten patients with distal internal carotid artery dissection showed a similar color-coded duplex pattern, but the reductions in the internal and common carotid artery diameters and increase in collateral flow from the vertebral artery were less prominent than those in hypoplasia. The ipsilateral ophthalmic arterial flow was retrograde in 40% of patients with distal internal carotid artery dissection. In addition, thin-section axial and sagittal computed tomograms of the skull base could show the small diameter of the carotid canal in internal carotid artery hypoplasia and help distinguish hypoplasia from distal internal carotid artery dissection. Color-coded carotid duplex sonography provides important clues for establishing a diagnosis of internal carotid artery hypoplasia. A hypoplastic carotid canal can be shown by thin-section axial and sagittal skull base computed tomography to confirm the final diagnosis. © 2015 by the American Institute of Ultrasound in Medicine.

Carotid Artery Stenting

PubMed Central

2018-01-01

Carotid artery stenosis is relatively common and is a significant cause of ischemic stroke, but carotid revascularization can reduce the risk of ischemic stroke in patients with significant symptomatic stenosis. Carotid endarterectomy has been and remains the gold standard treatment to reduce the risk of carotid artery stenosis. Carotid artery stenting (CAS) (or carotid artery stent implantation) is another method of carotid revascularization, which has developed rapidly over the last 30 years. To date, the frequency of use of CAS is increasing, and clinical outcomes are improving with technical advancements. However, the value of CAS remains unclear in patients with significant carotid artery stenosis. This review article discusses the basic concepts and procedural techniques involved in CAS. PMID:29171201

In vivo observation of the hypo-echoic "black hole" phenomenon in rat arterial bloodstream: a preliminary Study.

PubMed

Nam, Kweon-Ho; Paeng, Dong-Guk

2014-07-01

The "black hole," a hypo-echoic hole at the center of the bloodstream surrounded by a hyper-echoic zone in cross-sectional views, has been observed in ultrasound backscattering measurements of blood with red blood cell aggregation in in vitro studies. We investigated whether the phenomenon occurs in the in vivo arterial bloodstream of rats using a high-frequency ultrasound imaging system. Longitudinal and cross-sectional ultrasound images of the rat common carotid artery (CCA) and abdominal aorta were obtained using a 40-MHz ultrasound system. A high-frame-rate retrospective imaging mode was employed to precisely examine the dynamic changes in blood echogenicity in the arteries. When the imaging was performed with non-invasive scanning, blood echogenicity was very low in the CCA as compared with the surrounding tissues, exhibiting no hypo-echoic zone at the center of the vessel. Invasive imaging of the CCA by incising the skin and subcutaneous tissues at the imaging area provided clearer and brighter blood echo images, showing the "black hole" phenomenon near the center of the vessel in longitudinal view. The "black hole" was also observed in the abdominal aorta under direct imaging after laparotomy. The aortic "black hole" was clearly observed in both longitudinal and cross-sectional views. Although the "black hole" was always observed near the center of the arteries during the diastolic phase, it dissipated or was off-center along with the asymmetric arterial wall dilation at systole. In conclusion, we report the first in vivo observation of the hypo-echoic "black hole" caused by the radial variation of red blood cell aggregation in arterial bloodstream. Copyright © 2014 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

PRETERM BIRTH AND FUTURE MATERNAL BLOOD PRESSURE, INFLAMMATION AND INTIMAL MEDIAL THICKNESS: THE CARDIA STUDY

PubMed Central

Catov, Janet M; Lewis, Cora E; Lee, Minjae; Wellons, Melissa F; Gunderson, Erica P

2013-01-01

Preterm birth (PTB, <37 weeks) may be a marker of endothelial dysfunction and a pro-inflammatory phenotype; both are risk factors for cardiovascular disease. We studied 916 women (46% Black) with 1,181 live births between enrollment in the Coronary Artery Risk Development in Young Adults (CARDIA) study (age 18-30 years) and 20 years later. C-reactive protein (CRP) was measured at years 7, 15 and 20. Interleukin-6 (IL-6) and carotid intima-media thickness (IMT) which incorporated the common carotid arteries, bifurcations, and internal carotid arteries were measured at year 20. Blood pressure, lipids, anthropometrics, and pregnancy events were assessed at all visits. Change in risk factors and differences in inflammatory markers and IMT according to PTB were evaluated. Women with PTBs (n=226) had higher mean systolic blood pressures (SBP) before pregnancy (106 vs. 105 mmHg, respectively; p=0.03). Systolic and diastolic blood pressure increased more rapidly over 20 years compared to women with term births (p<0.01 time interaction) even after removing women with self-reported hypertension in pregnancy. Women with PTB vs. term births had similar mean IMT adjusted for age, BMI, race, lifestyle and cardiovascular risk factors. CRP and IL-6 did not differ according to PTB. Women with PTB, regardless of hypertension during pregnancy, had higher blood pressure after pregnancy compared to women with term births. In the U.S. where rates of PTB are high and race disparities persist, PTB may identify women with higher blood pressure the years after pregnancy. PMID:23319540

A pilot study of the relationship between Doppler-estimated carotid and brachial artery flow and cardiac index.

PubMed

Weber, U; Glassford, N J; Eastwood, G M; Bellomo, R; Hilton, A K

2015-10-01

We measured carotid and brachial artery blood flow by Doppler ultrasound in 11 human volunteers, and related these to cardiac index and to each other. The median (IQR [range]) carotid arterial blood flow was 0.334 (0.223-0.381 [0.052-0.563]) l.min(-1) on the right and 0.315 (0.223-0.369 [0.061-0.690]) l.min(-1) on the left. The brachial arterial blood flow was 0.049 (0.033-0.062 [0.015-0.204]) l.min(-1) on the right and 0.039 (0.027-0.054 [0.011-0.116]) on the left. Cardiac index was 3.2 (2.8-3.5 [1.9-5.4]) l.min(-1) .m(-2) . There was a moderate to good correlation between right-and left-sided flows (brachial: ρ = 0.45; carotid: ρ = 0.567). Brachial and carotid flow had no or a negative correlation with cardiac index (right brachial: ρ = -0.145, left brachial: ρ = -0.349; right carotid: ρ = -0.376, left carotid: ρ = -0.285). In contrast to some previous studies, we found that Doppler-estimated peripheral arterial blood flows only show a weak correlation with cardiac index and cannot be used to provide non-invasive estimates of cardiac index in man. © 2015 The Association of Anaesthetists of Great Britain and Ireland.

High-Resolution Observations of a Binary Black Hole Candidate

NASA Astrophysics Data System (ADS)

Tsai, Chao-Wei; Phillips, Chris; Norris, Ray; Jarrett, Thomas; Emonts, Bjorn; Cluver, Michelle; Eisenhardt, Peter; Stern, Daniel; Assef, Roberto

2012-10-01

We propose a 12-hour 2.3 GHz continuum Long Baseline Array (LBA) observation of WISE J2332-5056, a newly discovered supermassive black hole (SMBH) merger candidate that is located in the nearby universe (z = 0.3447). Our recently acquired 9 GHz ATCA map shows unusual radio morphology: a one-sided, smaller (and likely younger) FR-I jet perpendicular to a larger, Doppler-boosted FR-II jet. Follow-up Gemini-S/GMOS spectroscopy of this WISE-selected radio galaxy reveals broad emission lines blue-shifted by > 3,500 km/s with respect to the narrow lines and host galaxy, hallmarks of a dual AGN system. Combined, the optical spectroscopy and radio morphology of this object are strongly suggestive of a black hole merger system. Even in the local universe these systems are extremely difficult to identify; yet the process of supermassive blackhole growth is vital toward understanding galaxy evolution from the early to the current universe. Moreover, nearby merging SMBHs may serve as outstanding targets for gravitational wave studies. The proposed high resolution LBA map, reaching 50 pc resolution at the source redshift will allow us to investigate the SMBH merger scenario hypothesis.

Gasotransmitter Regulation of Ion Channels: A Key Step in O2 Sensing By the Carotid Body

PubMed Central

Prabhakar, Nanduri R.

2014-01-01

Carotid bodies detect hypoxia in arterial blood, translating this stimulus into physiological responses via the CNS. It is long established that ion channels are critical to this process. More recent evidence indicates that gasotransmitters exert powerful influences on O2 sensing by the carotid body. Here, we review current understanding of hypoxia-dependent production of gasotransmitters, how they regulate ion channels in the carotid body, and how this impacts carotid body function. PMID:24382871

[The effect of losartan on the intima-media thickness of carotid artery].

PubMed

Sönmez, Hulki Meltem; Turan, Filiz Canli; Köseoğlu, Kutsi

2008-06-01

There are findings about negative effects of angiotensin 1 (AT1) receptor stimulation at every stage of atherosclerosis formation. Recently, AT1 receptors, especially the effects of AT1 receptor antagonists on the regression of atherosclerosis, are being researched intensively. Measurement of carotid artery thickness has been accepted as a marker of atherosclerosis. In our study, we investigated the effect of AT1 receptor antagonist, losartan, on the carotid artery intima-media thickness of newly diagnosed hypertensive patients. We reached to 450 individuals by the stratified and random sampling method and measured their blood pressure to find out undiagnosed hypertensive patients. Fifty-one patients (mean age 54+/-9 years) were accepted to participate in our study. Forty-nine of them (33 women and 16 men) completed the study. After the measurements of the carotid artery intima-media thicknesses by B-mode Doppler ultrasonography, their blood tests were performed and arterial blood pressures were measured. Soon after, treatment with losartan as an antihypertensive agent was begun. All measurements were repeated on the eighth month of this therapy. The mean systolic and diastolic blood pressure of the cases were 167+/-14 mmHg and 102+/-8 mmHg, respectively. At the end of the eighth month these measurements regressed to 139+/-11 mmHg and 84+/-8 mmHg, respectively (p<0.05). Meaningful regression of carotid artery intima-media thickness was established. The mean regression was 0.10+/-0.19 mm (p=0.004) for women, 0.18+/-0.29 mm (p=0.007) for men and 0.13+/-0.23 mm (p<0.001) for the study population. No relation was seen between the carotid artery intima-media thickness and first systolic and diastolic blood pressure measurements of the patients (r=0.122, p=0.403 and r=0.032, p=0.828, respectively). We think that losartan should be recommended to use for protection against atherosclerosis at the young aged individuals that have multiple risks for atherosclerosis, other

Increased blood cell phosphatidylserine exposure and circulating microparticles contribute to procoagulant activity after carotid artery stenting.

PubMed

Zhao, Lu; Wu, Xiaoming; Si, Yu; Yao, Zhipeng; Dong, Zengxiang; Novakovic, Valerie A; Guo, Li; Tong, Dongxia; Chen, He; Bi, Yayan; Kou, Junjie; Shi, Huaizhang; Tian, Ye; Hu, Shaoshan; Zhou, Jin; Shi, Jialan

2017-11-01

OBJECTIVE Phosphatidylserine (PS) is a major component of the inner leaflet of membrane bilayers. During cell activation or apoptosis, PS is externalized to the outer membrane, providing an important physiological signal necessary for the release of the microparticles (MPs) that are generated through the budding of cellular membranes. MPs express PS and membrane antigens that reflect their cellular origin. PS exposure on the cell surface and the release of MPs provide binding sites for factor Xa and prothrombinase complexes that promote thrombin formation. Relatively little is known about the role of PS exposure on blood cells and MPs in patients with internal carotid artery (ICA) stenosis who have undergone carotid artery stenting (CAS). The authors aimed to investigate the extent of PS exposure on blood cells and MPs and to define its role in procoagulant activity (PCA) in the 7 days following CAS. METHODS The study included patients with ICA stenosis who had undergone CAS (n = 70), matched patients who had undergone catheter angiography only (n = 30), and healthy controls (n = 30). Blood samples were collected from all patients just before the procedure after an overnight fast and at 2, 6, 24, 48, and 72 hours and 7 days after the CAS procedure. Blood was collected from healthy controls after an overnight fast. Phosphatidylserine-positive (PS+) MPs and blood cells were analyzed by flow cytometry, while PCA was assessed with clotting time analysis, purified coagulation complex assays, and fibrin formation assays. RESULTS The authors found that levels of PS+ blood cells and PS+ blood cell-derived MPs (platelets and platelet-derived MPs [PMPs], neutrophils and neutrophil-derived MPs [NMPs], monocytes and monocyte-derived MPs [MMPs], erythrocytes and erythrocyte-derived MPs [RMPs], and endothelial cells and endothelial cell-derived MPs [EMPs]) were increased in the 7 days following the CAS procedure. Specifically, elevation of PS exposure on platelets

Determination of carotid disease with the application of STFT and CWT methods.

PubMed

Hardalaç, Firat; Yildirim, Hanefi; Serhatlioğlu, Selami

2007-06-01

In this study, Doppler signals were recorded from the output of carotid arteries of 40 subjects and transferred to a personal computer (PC) by using a 16-bit sound card. Doppler difference frequencies were recorded from each of the subjects, and then analyzed by using short-time Fourier transform (STFT) and the continuous wavelet transform (CWT) methods to obtain their sonograms. These sonograms were then used to determine the relationships of applied methods with medical conditions. The sonograms that were obtained by CWT method gave better results for spectral resolution than the STFT method. The sonograms of CWT method offer net envelope and better imaging, so that the measurement of blood flow and brain pressure can be made more accurately. Simultaneously, receiver operating characteristic (ROC) analysis has been conducted for this study and the estimation performance of the spectral resolution for the STFT and CTW has been obtained. The STFT has shown a 80.45% success for the spectral resolution while CTW has shown a 89.90% success.

Hemodynamic effects of long-term morphological changes in the human carotid sinus.

PubMed

Seong, Jaehoon; Jeong, Woowon; Smith, Nataliya; Towner, Rheal A

2015-04-13

Previous investigations of morphology for human carotid artery bifurcation from infancy to young adulthood found substantial growth of the internal carotid artery with advancing age, and the development of the carotid sinus at the root of the internal carotid artery during teenage years. Although the reasons for the appearance of the carotid sinus are not clearly understood yet, it has been hypothesized that the dilation of the carotid sinus serves to support pressure sensing, and slows the blood flow to reduce pulsatility to protect the brain. In order to understand this interesting evolvement at the carotid bifurcation in the aspects of fluid mechanics, we performed in vitro phase-contrast MR flow experiments using compliant silicone replicas of age-dependent carotid artery bifurcations. The silicone models in childhood, adolescence, and adulthood were fabricated using a rapid prototyping technique, and incorporated with a bench-top flow mock circulation loop using a computer-controlled piston pump. The results of the in vitro flow study showed highly complex flow characteristics at the bifurcation in all age-dependent models. However, the highest magnitude of kinetic energy was found at the internal carotid artery in the child model. The high kinetic energy in the internal carotid artery during childhood might be one of the local hemodynamic forces that initiate morphological long-term development of the carotid sinus in the human carotid bifurcation. Copyright © 2015 Elsevier Ltd. All rights reserved.

[Surgical Treatment of Cervical Carotid Artery Aneurysm].

PubMed

Hamasaki, Ryo; Yanagisawa, Toshiharu; Takahashi, Yusuke; Shimizu, Hiroaki

2017-08-01

Cervical carotid aneurysms are rare, and surgical treatment should be planned for each patient. The authors report 9 cases of cervical carotid aneurysm in 9 patients(mean age, 53.7 years;5 men)who were treated surgically between 2005 and 2014. The aneurysm was located in the internal carotid artery in 6 patients, the common carotid artery in 2 patients, and the carotid bifurcation in 1 patient. Four aneurysms were recurrences after a previous endovascular intervention(parent artery coil embolization, covered stent placement, or stent with coil embolization). The mean interval between the endovascular therapy and the onset of the present illness was 6 years. All the patients presented a mass effect at the neck, including lower cranial nerve dysfunction in 1 patient. Two patients presented with ischemic events presumably due to thromboembolism from the target aneurysms. Surgical treatments included local vascular reconstruction procedures in 6 patients(interposition vein or artificial graft bypass in 5 patients and in situ bypass in 1 patient). Four aneurysms were then resected. Two patients with rich collateral blood flow were treated with ligation of the parent artery proximal to the aneurysm. Surgical complications included embolic stroke and cranial nerve dysfunction in 2 patients, respectively, both presumably due to surgical manipulation. The modified Rankin scale(mRS)score at discharge was 0 in 5 patients, 1 in 1 patient, 2 in 2 patients, and 6 in 1 patient(vascular tumor). Surgical treatment of cervical carotid aneurysms seems a reasonable treatment of choice, but lower nerve dysfunction and embolism from the aneurysm should be avoided.

A randomized trial of decision-making in asymptomatic carotid stenosis.

PubMed

Silver, B; Zaman, I F; Ashraf, K; Majed, Y; Norwood, E M; Schuh, L A; Smith, B J; Smith, R E; Schultz, L R

2012-01-31

We sought to evaluate whether different presentation formats, presenter characteristics, and patient characteristics affect decision-making in asymptomatic carotid stenosis. Subjects included individuals presenting to a neurology clinic. Participants included those over age 18 without known carotid stenosis. Subjects were randomized to a 30-second video with 1 of 5 presentation formats (absolute risk, absolute event-free survival, annualized absolute risk, relative risk, and a qualitative description) delivered by 1 of 4 presenter physicians (black woman, white woman, black man, white man). Subjects then completed a one-page form regarding background demographics and their decision regarding treatment choice. A total of 409 subjects watched the video and completed the survey. Overall, 48.4% of subjects chose surgery. Presentation format strongly predicted choice of surgery (qualitative [64%], relative risk [63%], absolute risk [43%], absolute event-free survival [37%], and annualized absolute risk [35%], p < 0.001). There was a trend for younger age (mean age 52 vs 55, p = 0.054), male gender (53% vs 45%, p = 0.08), and advanced education (42% for high school education or less vs 52% for more than high school education, p = 0.052) to predict surgery choice. Gender and race of presenter, and race of subject, had no influence on the choice of treatment. Presentation format (information framing) strongly determines patient decision-making in asymptomatic carotid stenosis. Subject age, gender, and education level may also influence the decision. Clinicians should consider the influence of these variables when counseling patients.

Blood selenium concentrations in female Pacific black brant molting in Arctic Alaska: Relationships with age and habitat salinity.

PubMed

Franson, J Christian; Flint, Paul L; Schmutz, Joel A

2016-10-15

Blood samples collected from 81 female Pacific black brant (Branta bernicla nigricans) molting near Teshekpuk Lake, Alaska, were analyzed for selenium concentration. The concentration of selenium in blood of after second year (hatched two or more years ago) females (0.84μg/g wet weight) was significantly greater than the concentration in second year (hatched the previous year) females (0.61μg/g wet weight). The concentrations of selenium we found in blood of black brant were 1.5 to 2 times greater than baseline values typical of freshwater birds, but considerably lower than reported in other marine waterfowl sampled in Alaska. This finding may be attributable in part to the nearly exclusive herbivorous diet of black brant. No relationship was noted between blood selenium concentration and molting habitat salinity. We are unaware of any previous reports of blood selenium concentrations in black brant. Published by Elsevier Ltd.

Blood selenium concentrations in female Pacific black brant molting in Arctic Alaska: Relationships with age and habitat salinity

USGS Publications Warehouse

Franson, J. Christian; Flint, Paul L.; Schmutz, Joel A.

2016-01-01

Blood samples collected from 81 female Pacific black brant (Branta bernicla nigricans) molting near Teshekpuk Lake, Alaska, were analyzed for selenium concentration. The concentration of selenium in blood of after second year (hatched two or more years ago) females (0.84 μg/g wet weight) was significantly greater than the concentration in second year (hatched the previous year) females (0.61 μg/g wet weight). The concentrations of selenium we found in blood of black brant were 1.5 to 2 times greater than baseline values typical of freshwater birds, but considerably lower than reported in other marine waterfowl sampled in Alaska. This finding may be attributable in part to the nearly exclusive herbivorous diet of black brant. No relationship was noted between blood selenium concentration and molting habitat salinity. We are unaware of any previous reports of blood selenium concentrations in black brant.

Peripheral Chemoreceptors: Function and Plasticity of the Carotid Body

PubMed Central

Kumar, Prem; Prabhakar, Nanduri R.

2014-01-01

The discovery of the sensory nature of the carotid body dates back to the beginning of the 20th century. Following these seminal discoveries, research into carotid body mechanisms moved forward progressively through the 20th century, with many descriptions of the ultrastructure of the organ and stimulus-response measurements at the level of the whole organ. The later part of 20th century witnessed the first descriptions of the cellular responses and electrophysiology of isolated and cultured type I and type II cells, and there now exist a number of testable hypotheses of chemotransduction. The goal of this article is to provide a comprehensive review of current concepts on sensory transduction and transmission of the hypoxic stimulus at the carotid body with an emphasis on integrating cellular mechanisms with the whole organ responses and highlighting the gaps or discrepancies in our knowledge. It is increasingly evident that in addition to hypoxia, the carotid body responds to a wide variety of blood-borne stimuli, including reduced glucose and immune-related cytokines and we therefore also consider the evidence for a polymodal function of the carotid body and its implications. It is clear that the sensory function of the carotid body exhibits considerable plasticity in response to the chronic perturbations in environmental O2 that is associated with many physiological and pathological conditions. The mechanisms and consequences of carotid body plasticity in health and disease are discussed in the final sections of this article. PMID:23728973

PAMAM Dendrimers Cross the Blood-Brain Barrier When Administered through the Carotid Artery in C57BL/6J Mice.

PubMed

Srinageshwar, Bhairavi; Peruzzaro, Sarah; Andrews, Melissa; Johnson, Kayla; Hietpas, Allison; Clark, Brittany; McGuire, Crystal; Petersen, Eric; Kippe, Jordyn; Stewart, Andrew; Lossia, Olivia; Al-Gharaibeh, Abeer; Antcliff, Aaron; Culver, Rebecca; Swanson, Douglas; Dunbar, Gary; Sharma, Ajit; Rossignol, Julien

2017-03-14

Drug delivery into the central nervous system (CNS) is challenging due to the blood-brain barrier (BBB) and drug delivery into the brain overcoming the BBB can be achieved using nanoparticles such as dendrimers. The conventional cationic dendrimers used are highly toxic. Therefore, the present study investigates the role of novel mixed surface dendrimers, which have potentially less toxicity and can cross the BBB when administered through the carotid artery in mice. In vitro experiments investigated the uptake of amine dendrimers (G1-NH₂ and G4-NH₂) and novel dendrimers (G1-90/10 and G4-90/10) by primary cortical cultures. In vivo experiments involved transplantation of G4-90/10 into mice through (1) invasive intracranial injections into the striatum; and (2) less invasive carotid injections. The animals were sacrificed 24-h and 1-week post-transplantations and their brains were analyzed. In vivo experiments proved that the G4-90/10 can cross the BBB when injected through the carotid artery and localize within neurons and glial cells. The dendrimers were found to migrate through the corpus callosum 1-week post intracranial injection. Immunohistochemistry showed that the migrating cells are the dendrimer-infected glial cells. Overall, our results suggest that poly-amidoamine (PAMAM) dendrimers may be used as a minimally invasive means to deliver biomolecules for treating neurological diseases or disorders.

The proportion of total C18:1 trans-fatty acids in red blood cell membranes relates to carotid plaque prevalence.

PubMed

Herreras, Zoe; Cofán, Montserrat; Catalan, Marta; Calvo, Carlos; Pinyol, Montserrat; Amor, Antonio J; Gilabert, Rosa; Ros, Emilio; Sala-Vila, Aleix; Ortega, Emilio

2016-12-01

Consistent evidence supports the pro-atherogenic properties of dietary trans-fatty acids (TFAs). However, there are no clinical data on TFA intake and atheroma plaque. We cross sectionally investigated whether the proportion of total C18:1 TFA in red blood cells (RBCs), which mirrors dietary TFA intake, independently relates to carotid plaque prevalence in subjects with new-onset type 2 diabetes mellitus without prior cardiovascular disease (n=101, 56% men, mean age 61 years) and age- and sex-matched controls (n=96). RBC fatty acid composition was determined by gas chromatography. Plaque (defined as carotid intima-media thickness ≥1.5 mm) was sonographically assessed at three bilateral carotid segments. In multivariate models adjusting for group (diabetes or control) and classical cardiovascular risk factors, for each 0.1% increase in RBC total C18:1 TFA isomers, plaque prevalence increased by 53% (P=.002). In contrast, for each 0.1% increase in RBC alpha-linolenic acid, the vegetable omega-3 fatty acid, plaque prevalence decreased by 43% (P<.001). We conclude that the RBC membrane proportion of total C18:1 TFA, considered a proxy of intake, directly relates to the ultrasound feature that best predicts future cardiovascular events. Our findings support current recommendations to limit TFA intake for cardiovascular health promotion. Copyright © 2016 Elsevier Inc. All rights reserved.

Subclinical Carotid Atherosclerosis in Asymptomatic Subjects With Type 2 Diabetes Mellitus.

PubMed

Rubinat, Esther; Marsal, Josep Ramon; Vidal, Teresa; Cebrian, Cristina; Falguera, Mireia; Vilanova, Ma Belen; Betriu, Àngels; Fernández, Elvira; Franch, Josep; Mauricio, Dídac

2016-01-01

Subjects with type 2 diabetes mellitus are considered to be at high risk for cardiovascular disease. The identification of carotid atherosclerosis is a validated surrogate marker of cardiovascular disease. Nurses are key professionals in the improvement and intensification of cardiovascular preventive strategies. The aim is to study the presence of carotid atherosclerosis in a group of asymptomatic subjects with type 2 diabetes mellitus and no previous clinical cardiovascular disease. A total of 187 patients with type 2 diabetes mellitus and 187 age- and sex-matched subjects without type 2 diabetes mellitus were studied in this cross-sectional, observational, cohort study. Standard operational procedures were applied by the nursing team regarding physical examination and carotid ultrasound assessment. Common, bulb, and internal carotid arteries were explored by measuring intima-media thickness and identifying atherosclerotic plaques. Carotid intima-media thickness (c-IMT) and carotid plaque prevalence were significantly greater in diabetic subjects than in the control group. Carotid plaques and c-IMT were more frequent in men than in women and increased with increasing age. In the multivariate analysis, age, gender, waist circumference, systolic blood pressure, and hypercholesterolemia were positively associated with c-IMT, whereas age, gender, and weight were positively associated with carotid plaque. The current nurse-led study shows that subjects with type 2 diabetes mellitus have a high prevalence of subclinical atherosclerosis that is associated with cardiovascular risk factors.

Carotid intima-media thickness is a novel predictor of new onset of hypertension in normotensive subjects.

PubMed

Takase, Hiroyuki; Sugiura, Tonomori; Murai, Shunsuke; Yamashita, Sumiyo; Ohte, Nobuyuki; Dohi, Yasuaki

2017-08-01

Increased carotid intima-media thickness (IMT) in individuals without hypertension might indicate other factors promoting the atherosclerotic process that are often simultaneously clustered in individuals. The present study tested the hypothesis that carotid IMT predicts new onset of hypertension in the normotensive subjects.A total of 867 participants were enrolled from our yearly physical checkup program and their carotid IMT was measured. After a baseline examination, the subjects were followed up for a median of 1091 days with the endpoint being the development of hypertension.At baseline, the carotid IMT value was 0.75 ± 0.16 mm. Hypertension developed in 184 subjects during the follow-up (76.9/1000 person-years). The incidence of hypertension was increased across the tertiles of the carotid IMT value (39.6, 70.0, and 134.5/1000 person-years in the first, second, and third tertiles, respectively, P < .001 by log-rank test). Multivariate Cox-hazard analysis after adjustment identified carotid IMT, taken as a continuous variable, as a significant predictor of new-onset hypertension (hazard ratio = 7.08, 95% confidence interval = 3.06-15.39). Furthermore, multivariate linear regression analyses indicated a significant correlation between the carotid IMT at baseline and yearly increases in systolic blood pressure during the follow-up period (β = 0.189, P < .001).Carotid IMT is an independent predictor of hypertension onset in normotensive subjects. The findings also suggested a close association between increased carotid IMT and blood pressure.

Carotid intima-media thickness is a novel predictor of new onset of hypertension in normotensive subjects

PubMed Central

Takase, Hiroyuki; Sugiura, Tonomori; Murai, Shunsuke; Yamashita, Sumiyo; Ohte, Nobuyuki; Dohi, Yasuaki

2017-01-01

Abstract Increased carotid intima-media thickness (IMT) in individuals without hypertension might indicate other factors promoting the atherosclerotic process that are often simultaneously clustered in individuals. The present study tested the hypothesis that carotid IMT predicts new onset of hypertension in the normotensive subjects. A total of 867 participants were enrolled from our yearly physical checkup program and their carotid IMT was measured. After a baseline examination, the subjects were followed up for a median of 1091 days with the endpoint being the development of hypertension. At baseline, the carotid IMT value was 0.75 ± 0.16 mm. Hypertension developed in 184 subjects during the follow-up (76.9/1000 person-years). The incidence of hypertension was increased across the tertiles of the carotid IMT value (39.6, 70.0, and 134.5/1000 person-years in the first, second, and third tertiles, respectively, P < .001 by log-rank test). Multivariate Cox-hazard analysis after adjustment identified carotid IMT, taken as a continuous variable, as a significant predictor of new-onset hypertension (hazard ratio = 7.08, 95% confidence interval = 3.06–15.39). Furthermore, multivariate linear regression analyses indicated a significant correlation between the carotid IMT at baseline and yearly increases in systolic blood pressure during the follow-up period (β = 0.189, P < .001). Carotid IMT is an independent predictor of hypertension onset in normotensive subjects. The findings also suggested a close association between increased carotid IMT and blood pressure. PMID:28767608

Carotid intima-media thickness: ultrasound measurement, prognostic value and role in clinical practice.

PubMed

Nair, Satheesh Balakrishnan; Malik, Rayaz; Khattar, Rajdeep S

2012-12-01

Ultrasound measurement of carotid intima-media thickness (IMT) has become a valuable tool for detecting and monitoring progression of atherosclerosis and recently published recommendations provide guidance for proper standardisation of these measurements. Important determinants of carotid IMT include age, gender, systolic blood pressure, diabetes mellitus and serum cholesterol levels. Many studies have shown carotid IMT to correlate with the severity of coronary atherosclerosis assessed by CT coronary calcification scores, coronary angiography and intravascular ultrasound. Consistent with its correlation with cardiovascular risk factors and coronary artery disease, a meta-analysis of large observational studies has shown carotid IMT to be a strong predictor of future cardiovascular events. Moreover, in patients with established coronary artery disease a reduction in carotid IMT has been shown to translate into a reduction in future cardiovascular events. Consensus statements now also recommend carotid IMT measurements to further refine the prognostic assessment of patients traditionally considered to be at an intermediate risk of cardiovascular disease.

The relationship of flow velocities to vessel diameters differs between extracranial carotid and vertebral arteries of stroke patients.

PubMed

Owolabi, Mayowa O; Agunloye, Atinuke M; Ogunniyi, Adesola

2014-01-01

Chronic changes in flow rate through arteries produce adjustment of arterial diameters. We compared the relationship between flow velocity and diameter in the carotid and in the vertebral arteries of stroke patients. Using triplex ultrasonography, the internal diameter and flow velocities of the common carotid, internal carotid, and vertebral arteries of 176 consecutive stroke patients were measured. Correlations were examined with Pearson's statistics at an alpha level of 0.05. Mean age of the patients was 59.3 ± 12 years, and 66% had cerebral infarcts. Diameter and blood flow velocities showed significant negative correlations (-0.115 ≥ r ≥ -0.382) in the carotid arteries on both sides, but positive correlations (0.211 ≤ r ≤ 0.320) in the vertebral arteries, even after controlling for age, gender, and blood pressure. Our study demonstrated different diameter/flow relationships in the carotid and the vertebral arteries of stroke patients, which may suggest pathologic changes in the adaptive processes governing vessel diameter and growth, especially in the carotid arteries. Copyright © 2013 Wiley Periodicals, Inc.

Radical resection of a Shamblin type III carotid body tumour without cerebro-neurological deficit: Improved technique with preoperative embolization and carotid stenting.

PubMed

Ong, H S; Fan, X D; Ji, T

2014-12-01

The surgical resection of a large unfavourable Shamblin type III carotid body tumour (CBT) can be very challenging technically, with many potential significant complications. Preoperative embolization aids in shrinking the lesion, reducing intraoperative blood loss, and improving visualization of the surgical field. Preoperative internal carotid artery (ICA) stenting aids in reinforcing the arterial wall, thereby providing a better dissection plane. A woman presented to our institution with a large right-sided CBT. Failure of the preoperative temporary balloon occlusion (TBO) test emphasized the importance of intraoperative preservation of the ipsilateral ICA. A combination of both preoperative embolization and carotid stenting allowed a less hazardous radical resection of the CBT. An almost bloodless surgical field permitted meticulous dissection, hence reducing the risk of intraoperative vascular and nerve injury. Embolization and carotid stenting prior to surgical resection should be considered in cases with bilateral CBT or a skull base orientated high CBT, and for those with intracranial extension and patients who have failed the TBO test. Copyright © 2014 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

The potential role of IDEAL MRI for identification of lipids and hemorrhage in carotid artery plaques.

PubMed

Khosa, Faisal; Clough, Rachel E; Wang, Xiaoen; Madhuranthakam, Ananth J; Greenman, Robert L

2018-06-01

Hemorrhage and lipid deposits contribute to instability in atherosclerotic plaques. Unstable carotid artery plaques can lead to cerebral ischemic events. While MRI studies have shown the ability to identify plaque components, the identification of hemorrhage and lipids has proven to be problematic. The purpose of this study was to quantitatively evaluate the potential of the MRI fat/water separation method known as iterative decomposition of water and fat with echo asymmetry and least squares estimation (IDEAL) to complement and improve existing methods for the identification of hemorrhage and lipids in carotid artery plaques. Fifteen asymptomatic subjects with 50-79% stenosis of at least one carotid artery were enrolled. Hemorrhage and lipid components within carotid plaques were identified using previously published criteria based on the multiple contrast-weighted (MCW) method (3D Time-of-Flight (3D-TOF), T1-Weighted (T1W) and T2-Weighted (T2W)). The hemorrhage:muscle, lipid:muscle and intra-plaque lipid:hemorrhage signal intensity ratios (SIR) and contrast to noise ratios (CNR) were measured on MCW and compared to IDEAL black-blood images. No differences were found between any of the MCW methods for any of the SIRs measured. The IDEAL Fat images had higher lipid:muscle and lipid/hemorrhage SIRs (p<0.001) compared to IDEAL Water and all MCW image sequence types. The mean values of IDEAL Fat hemorrhage:muscle SIR and CNR were nearly unity (1.1±0.6) and nearly zero (0.1±1.1), respectively. The IDEAL Water imaging was not significantly different than any of the MCW methods for any of the SIRs or for the hemorrhage:muscle CNR of 3D-TOF, while its CNRs were significantly higher than IDEAL Fat lipid:muscle (p<0.05) and lipid:hemorrhage (p<0.001) and all MCW methods (p<0.001). The addition of IDEAL Water and Fat imaging to the MCW method shows potential to improve the identification of hemorrhage and lipid structures in carotid artery plaques. Copyright © 2017

Carotid bruit for detection of hemodynamically significant carotid stenosis: the Northern Manhattan Study

PubMed Central

Ratchford, Elizabeth V.; Jin, Zhezhen; Di Tullio, Marco R.; Salameh, Maya J.; Homma, Shunichi; Gan, Robert; Boden-Albala, Bernadette; Sacco, Ralph L.; Rundek, Tatjana

2009-01-01

Objective The prevalence of carotid bruits and the utility of auscultation for predicting carotid stenosis are not well known. We aimed to establish the prevalence of carotid bruits and the diagnostic accuracy of auscultation for detection of hemodynamically significant carotid stenosis, using carotid duplex as the gold standard. Methods The Northern Manhattan Study (NOMAS) is a prospective multiethnic community-based cohort designed to examine the incidence of stroke and other vascular events and the association between various vascular risk factors and subclinical atherosclerosis. Of the stroke-free cohort (n=3298), 686 were examined for carotid bruits and underwent carotid duplex. Main outcome measures included prevalence of carotid bruits and sensitivity, specificity, positive predictive value, negative predictive value and accuracy of auscultation for prediction of ipsilateral carotid stenosis. Results Among 686 subjects with a mean age of 68.2 ± 9.4 years, the prevalence of ≥60% carotid stenosis as detected by ultrasound was 2.2% and the prevalence of carotid bruits was 4.1%. For detection of carotid stenosis, sensitivity of auscultation was 56%, specificity was 98%, positive predictive value was 25%, negative predictive value was 99% and overall accuracy was 97.5%. Discussion In this ethnically diverse cohort, the prevalence of carotid bruits and hemodynamically significant carotid stenosis was low. Sensitivity and positive predictive value were also low, and the 44% false-negative rate suggests that auscultation is not sufficient to exclude carotid stenosis. While the presence of a bruit may still warrant further evaluation with carotid duplex, ultrasonography may be considered in high-risk asymptomatic patients, irrespective of findings on auscultation. PMID:19133168

Solid hemangioblastoma in the cerebellopontine angle: Importance of external carotid blood supply with regard to the probable site of origin and preoperative embolization.

PubMed

Meena, Rajesh Kumar; Dhandapani, Sivashanmugam; Gupta, Vivek; Anirudh, Srinivasan; Chatterjee, Debajyoti

2016-01-01

Hemangioblastoma (HBL) is rare in the cerebellopontine angle (CPA) with questionable origin and limited access for circumferential dissection and "en-bloc" excision. We report a case of surgical removal of large solid CPA-HBL and discuss the pattern of blood supply suggesting its origin and indicating preoperative embolization. The solid and highly vascular CPA-HBL had feeders mainly from neuromeningeal division of ascending pharyngeal branch of external carotid artery, suggesting true extra-axial origin. We could achieve "en-bloc" excision without significant blood loss or morbidity using preoperative embolization. Large solid HBL is rare in CPA necessitating arduous "en-bloc" excision. The pattern of blood supply probably indicates the site of origin and safety of preoperative embolization.

History of carotid surgery: from ancient greeks to the modern era.

PubMed

Tallarita, Tiziano; Gerbino, Maurizio; Gurrieri, Carmelina; Lanzino, Giuseppe

2013-12-01

A relationship between decreased carotid arterial flow and apoplectic manifestations was already suspected by the ancient Greeks. Early attempts at carotid surgery, however, were limited to emergency arterial ligation in patients with neck trauma. Attempts to suture arterial stumps together to restore blood flow paved the way for Carrel's revolutionary idea of reconstructing the resected or injured arterial segment with an interposition vein graft. DeBakey and Eastcott were the first to perform carotid endarterectomy in North America and the United Kingdom, respectively. In 1959, DeBakey proposed a cooperative study to assess the effectiveness of carotid endarterectomy in the treatment and prevention of ischemic cerebrovascular disease. The study was officially designated the Joint Study of Extracranial Arterial Occlusion and represented the first trial in the United States in which large numbers of patients were randomly allocated to surgical or nonsurgical therapy.

Non-ECG-gated unenhanced MRA of the carotids: optimization and clinical feasibility.

PubMed

Raoult, H; Gauvrit, J Y; Schmitt, P; Le Couls, V; Bannier, E

2013-11-01

To optimise and assess the clinical feasibility of a carotid non-ECG-gated unenhanced MRA sequence. Sixteen healthy volunteers and 11 patients presenting with internal carotid artery (ICA) disease underwent large field-of-view balanced steady-state free precession (bSSFP) unenhanced MRA at 3T. Sampling schemes acquiring the k-space centre either early (kCE) or late (kCL) in the acquisition window were evaluated. Signal and image quality was scored in comparison to ECG-gated kCE unenhanced MRA and TOF. For patients, computed tomography angiography was used as the reference. In volunteers, kCE sampling yielded higher image quality than kCL and TOF, with fewer flow artefacts and improved signal homogeneity. kCE unenhanced MRA image quality was higher without ECG-gating. Arterial signal and artery/vein contrast were higher with both bSSFP sampling schemes than with TOF. The kCE sequence allowed correct quantification of ten significant stenoses, and it facilitated the identification of an infrapetrous dysplasia, which was outside of the TOF imaging coverage. Non-ECG-gated bSSFP carotid imaging offers high-quality images and is a promising sequence for carotid disease diagnosis in a short acquisition time with high spatial resolution and a large field of view. • Non-ECG-gated unenhanced bSSFP MRA offers high-quality imaging of the carotid arteries. • Sequences using early acquisition of the k-space centre achieve higher image quality. • Non-ECG-gated unenhanced bSSFP MRA allows quantification of significant carotid stenosis. • Short MR acquisition times and ungated sequences are helpful in clinical practice. • High 3D spatial resolution and a large field of view improve diagnostic performance.

A patient with a painless neck tumour revealed as a carotid paraganglioma: a case report.

PubMed

Peric, Barbara; Marinsek, Ziva Pohar; Skrbinc, Breda; Music, Maja; Zagar, Ivana; Hocevar, Marko

2014-08-20

Carotid paragangliomas are usually slowly enlarging and painless lateral neck masses. These mostly benign lesions are recognized due to their typical location, vessel displacement and specific blood supply, features that are usually seen on different imaging modalities. Surgery for carotid paraganglioma can be associated with immediate cerebrovascular complications or delayed neurological impairment.We are reporting the case of a 36-year-old man who presented with a painless mass on the right side of his neck 11 months after being treated for testicular cancer. After a fine-needle aspiration biopsy, he was diagnosed with a testicular cancer lymph node metastasis. Neck US and fluorine [F-18]-fluorodeoxy-D-glucose (FDG) PET-CT showed no signs of hypervascularity or vessel displacement. The patient underwent a level II to V functional neck dissection. During the procedure, suspicion of a carotid paraganglioma was raised and the tumour was carefully dissected from the walls of the carotid arteries with minimal blood loss and no cranial nerve dysfunction.The histology report revealed carotid paraganglioma with no metastasis in the rest of the lymph nodes. The patient's history of testicular germ cell tumour led to a functional neck dissection during which a previously unrecognized carotid paraganglioma was removed.Surgery for carotid PG can be associated with complications that have major impact on quality of life. A thorough assessment of the patient and neck mass must therefore be performed preoperatively in order to perform the surgical procedure under optimal conditions.

Numerical study of oxygen transport in a carotid bifurcation

NASA Astrophysics Data System (ADS)

Tada, Shigeru

2010-07-01

This study investigates the oxygen mass transport in the region around the human carotid bifurcation, particularly addressing the effects of bifurcation geometry and pulsatile blood flow on the oxygen transport between the blood flow and artery wall tissue, coupled with the metabolic oxygen consumption and oxygen diffusion in the artery wall tissue. The temporal variations and spatial distributions of the oxygen tension are predicted quantitatively using a geometric model of the human carotid bifurcation and realistic blood flow waveforms. Results reveal that the flow separation at the outside wall of the sinus of the internal carotid artery (ICA) can markedly alter the flow pattern, oxygen tension and the oxygen wall flux. Results also clarify that the flow unsteadiness has a secondary effect on the oxygen tension inside the wall. The non-dimensional oxygen flux, the Sherwood number Sh, at the outside wall of the ICA sinus, takes markedly lower values of about 45 than at other sites because the rates of oxygen transport by the convective flow are reduced at the outside wall of the ICA sinus. The transverse distributions of the oxygen tension inside the artery wall show parabolic profiles having minima in the middle of the wall thickness, with the lowest value of 35 mmHg. These predicted distributions of the oxygen tension inside the wall closely resemble those obtained from experiments. The results demonstrate that hypoxic zones appear inside the artery walls at locations where atherosclerotic lesions are prone to develop.

Predicting carotid artery disease and plaque instability from cell-derived microparticles.

PubMed

Wekesa, A L; Cross, K S; O'Donovan, O; Dowdall, J F; O'Brien, O; Doyle, M; Byrne, L; Phelan, J P; Ross, M D; Landers, R; Harrison, M

2014-11-01

Cell-derived microparticles (MPs) are small plasma membrane-derived vesicles shed from circulating blood cells and may act as novel biomarkers of vascular disease. We investigated the potential of circulating MPs to predict (a) carotid plaque instability and (b) the presence of advanced carotid disease. This pilot study recruited carotid disease patients (aged 69.3 ± 1.2 years [mean ± SD], 69% male, 90% symptomatic) undergoing endarterectomy (n = 42) and age- and sex-matched controls (n = 73). Plaques were classified as stable (n = 25) or unstable (n = 16) post surgery using immunohistochemistry. Blood samples were analysed for MP subsets and molecular biomarkers. Odds ratios (OR) are expressed per standard deviation biomarker increase. Endothelial MP (EMP) subsets, but not any vascular, inflammatory, or proteolytic molecular biomarker, were higher (p < .05) in the unstable than the stable plaque patients. The area under the receiver operator characteristic curve for CD31(+)41(-) EMP in discriminating an unstable plaque was 0.73 (0.56-0.90, p < .05). CD31(+)41(-) EMP predicted plaque instability (OR = 2.19, 1.08-4.46, p < .05) and remained significant in a multivariable model that included transient ischaemic attack symptom status. Annexin V(+) MP, platelet MP (PMP) subsets, and C-reactive protein were higher (p < .05) in cases than controls. Annexin V(+) MP (OR = 3.15, 1.49-6.68), soluble vascular cell adhesion molecule-1 (OR = 1.64, 1.03-2.59), and previous smoking history (OR = 3.82, 1.38-10.60) independently (p < .05) predicted the presence of carotid disease in a multivariable model. EMP may have utility in predicting plaque instability in carotid patients and annexin V(+) MPs may predict the presence of advanced carotid disease in aging populations, independent of established biomarkers. Copyright © 2014 European Society for Vascular Surgery. Published by Elsevier Ltd. All rights reserved.

The critical role of the external carotid artery in cerebral perfusion of patients with total occlusion of the internal carotid artery.

PubMed

Dalainas, I; Avgerinos, E D; Daskalopoulos, M E; Papapetrou, A; Papasideris, C P; Katsikas, V; Xiromeritis, K; Moulakakis, K; Gianakopoulos, T; Liapis, C D

2012-02-01

The ipsilateral external carotid artery (ECA) can potentially provide an important collateral pathway for cerebral blood flow in the presence of occlusion or severe stenosis of the internal carotid artery (ICA), recovering up to 15% of the middle cerebral arterial flow. The aim of the study is to elucidate the role of ECA in cerebral flow of patients with total ICA occlusion. Retrospective study of prospectively collected data of 139 patients with total ICA occlusions. The patients were divided to symptomatic and asymptomatic and were categorized in four subgroups according to the stenosis rates: A) ipsilateral ECA<70% and contralateral internal carotid artery stenosis <70%; B) ipsilateral ECA stenosis <70% and contralateral internal carotid artery stenosis ≥70%; C) ipsilateral ECA stenosis ≥70% and contralateral ICA stenosis <70%; D) ipsilateral ECA stenosis ≥70% and contralateral ICA stenosis ≥75%. Fifty eight (41.7%) patients were asymptomatic. The highest rate (48.2%) of asymptomatic patients was in Group A. Among patients with strokes, the highest rate belonged in groups C and D (44.4% and 50% respectively) where ipsilateral ECA stenosis was ≥70% irrespectively of the contralateral ICA patency. Ipsilateral external carotid artery stenosis ≥70% proved to be and independent risk factor for symptom presentation (P=0.013). The study reveals the significant role of ECA patency in cerebral flow in patients with ICA occlusion.

Clinical results of carotid artery stenting versus carotid endarterectomy

PubMed Central

Akinci, Tuba; Derle, Eda; Kibaroğlu, Seda; Harman, Ali; Kural, Feride; Cınar, Pınar; Kilinc, Munire; Akay, Hakki T.; Can, Ufuk; Benli, Ulku S.

2016-01-01

Objective: To review our results of carotid artery stenting (CAS) and carotid endarterectomy (CEA). Methods: We evaluated the medical records of patients undergoing carotid artery revascularization procedure, between 2001 and 2013 in Baskent University Hospital, Ankara, Turkey. Carotid artery stenting or CEA procedures were performed in patients with asymptomatic carotid stenosis (≥70%) or symptomatic stenosis (≥50%). Demographic data, procedural details, and clinical outcomes were recorded. Primary outcome measures were in 30-day stroke/transient ischemic attacks (TIA)/amaurosis fugax or death. Secondary outcome measures were nerve injury, bleeding complications, length of stay in hospital, stroke, restenosis (ICA patency), and all-cause death during long-term follow-up. Results: One hundred ninety-four CEA and 115 CAS procedures were performed for symptomatic and/or asymptomatic carotid artery stenosis. There is no significant differences 30-day mortality and neurologic morbidity between CAS (13%) and CEA procedures (7.7%). Length of stay in hospital were significantly longer in CEA group (p=0.001). In the post-procedural follow up, only in symptomatic patients, restenosis rate was higher in the CEA group (p=.045). The other endpoints did not differ significantly. Conclusions: Endovascular stent treatment of carotid artery atherosclerotic disease is an alternative for vascular surgery, especially for patients that are high risk for standard CEA. The increasing experience, development of cerebral protection systems and new treatment protocols increases CAS feasibility. PMID:27744460

Carotid body chemoreflex: a driver of autonomic abnormalities in sleep apnoea.

PubMed

Prabhakar, Nanduri R

2016-08-01

What is the topic of this review? This article presents emerging evidence for heightened carotid body chemoreflex activity as a major driver of sympathetic activation and hypertension in sleep apnoea patients. What advances does it heighlight? This article discusses the recent advances on cellular, molecular and epigenetic mechanisms underlying the exaggerated chemoreflex in experimental models of sleep apnoea. The carotid bodies are the principal peripheral chemoreceptors for detecting changes in arterial blood oxygen concentration, and the resulting chemoreflex is a potent regulator of the sympathetic tone, blood pressure and breathing. Sleep apnoea is a disease of the respiratory system that affects several million adult humans. Apnoeas occur during sleep, often as a result of obstruction of the upper airway (obstructive sleep apnoea) or because of defective respiratory rhythm generation by the CNS (central sleep apnoea). Patients with sleep apnoea exhibit several co-morbidities, with the most notable among them being heightened sympathetic nerve activity and hypertension. Emerging evidence suggests that intermittent hypoxia resulting from periodic apnoea stimulates the carotid body, and the ensuing chemoreflex mediates the increased sympathetic tone and hypertension in sleep apnoea patients. Rodent models of intermittent hypoxia that simulate the O2 saturation profiles encountered during sleep apnoea have provided important insights into the cellular and molecular mechanisms underlying the heightened carotid body chemoreflex. This article describes how intermittent hypoxia affects the carotid body function and discusses the cellular, molecular and epigenetic mechanisms underlying the exaggerated chemoreflex. © 2016 The Authors. Experimental Physiology © 2016 The Physiological Society.

Ultra High-Resolution In vivo Computed Tomography Imaging of Mouse Cerebrovasculature Using a Long Circulating Blood Pool Contrast Agent

PubMed Central

Starosolski, Zbigniew; Villamizar, Carlos A.; Rendon, David; Paldino, Michael J.; Milewicz, Dianna M.; Ghaghada, Ketan B.; Annapragada, Ananth V.

2015-01-01

Abnormalities in the cerebrovascular system play a central role in many neurologic diseases. The on-going expansion of rodent models of human cerebrovascular diseases and the need to use these models to understand disease progression and treatment has amplified the need for reproducible non-invasive imaging methods for high-resolution visualization of the complete cerebral vasculature. In this study, we present methods for in vivo high-resolution (19 μm isotropic) computed tomography imaging of complete mouse brain vasculature. This technique enabled 3D visualization of large cerebrovascular networks, including the Circle of Willis. Blood vessels as small as 40 μm were clearly delineated. ACTA2 mutations in humans cause cerebrovascular defects, including abnormally straightened arteries and a moyamoya-like arteriopathy characterized by bilateral narrowing of the internal carotid artery and stenosis of many large arteries. In vivo imaging studies performed in a mouse model of Acta2 mutations demonstrated the utility of this method for studying vascular morphometric changes that are practically impossible to identify using current histological methods. Specifically, the technique demonstrated changes in the width of the Circle of Willis, straightening of cerebral arteries and arterial stenoses. We believe the use of imaging methods described here will contribute substantially to the study of rodent cerebrovasculature. PMID:25985192

[Analysis of 24-hour blood pressure profile, heart rate variability and carotid atherosclerosis in hypertensive patients among native and nonnative population living in Yamalo-Nenets autonomous district].

PubMed

Gapon, L I; Sereda, T V; Leont'eva, A V

2014-01-01

To study special characteristics of the course of arterial hypertension (AH) among native and nonnative population of Yamalo-Nenets autonomous district. We examined 100 residents of Far North with AH (men and women aged 21-55, mean age 44.08 ± 1.15 years). All patients were divided into 2 equal groups by 50 subjects: group I consisted of representatives of native and group II--nonnative population. Examination was carried out in outpatient clinic in Salekhard and included 24-hour ambulatory blood pressure monitoring (ABPM), registration of heart rate variability, duplex scanning of brachiocephalic arteries, and assessment of blood lipid profile. The groups were matched by age, gender and disease duration. Analysis of heart rate variability detected significant degree of strain of regulatory systems in most patients of both groups. According to results of ABPM "non-dipper" patients prevailed in group I compared to group II (p = 0.01). Common carotid artery intima-media complex was significantly greater compared to normal value in all patients; it was thicker in group I (p < 0.03), but number of carotid artery stenoses was similar in both groups. No dyslipoproteinemia was detected. Compared with group of representatives of nonnative (adopted) population group of native subjects with AH was characterized by greater carotid intima media thickness and prevalence of "non-dipper" patients.

Image-derived input function in PET brain studies: blood-based methods are resistant to motion artifacts.

PubMed

Zanotti-Fregonara, Paolo; Liow, Jeih-San; Comtat, Claude; Zoghbi, Sami S; Zhang, Yi; Pike, Victor W; Fujita, Masahiro; Innis, Robert B

2012-09-01

Image-derived input function (IDIF) from carotid arteries is an elegant alternative to full arterial blood sampling for brain PET studies. However, a recent study using blood-free IDIFs found that this method is particularly vulnerable to patient motion. The present study used both simulated and clinical [11C](R)-rolipram data to assess the robustness of a blood-based IDIF method (a method that is ultimately normalized with blood samples) with regard to motion artifacts. The impact of motion on the accuracy of IDIF was first assessed with an analytical simulation of a high-resolution research tomograph using a numerical phantom of the human brain, equipped with internal carotids. Different degrees of translational (from 1 to 20 mm) and rotational (from 1 to 15°) motions were tested. The impact of motion was then tested on the high-resolution research tomograph dynamic scans of three healthy volunteers, reconstructed with and without an online motion correction system. IDIFs and Logan-distribution volume (VT) values derived from simulated and clinical scans with motion were compared with those obtained from the scans with motion correction. In the phantom scans, the difference in the area under the curve (AUC) for the carotid time-activity curves was up to 19% for rotations and up to 66% for translations compared with the motionless simulation. However, for the final IDIFs, which were fitted to blood samples, the AUC difference was 11% for rotations and 8% for translations. Logan-VT errors were always less than 10%, except for the maximum translation of 20 mm, in which the error was 18%. Errors in the clinical scans without motion correction appeared to be minor, with differences in AUC and Logan-VT always less than 10% compared with scans with motion correction. When a blood-based IDIF method is used for neurological PET studies, the motion of the patient affects IDIF estimation and kinetic modeling only minimally.

Cerebral blood flow with [15O]water PET studies using an image-derived input function and MR-defined carotid centerlines

NASA Astrophysics Data System (ADS)

Fung, Edward K.; Carson, Richard E.

2013-03-01

Full quantitative analysis of brain PET data requires knowledge of the arterial input function into the brain. Such data are normally acquired by arterial sampling with corrections for delay and dispersion to account for the distant sampling site. Several attempts have been made to extract an image-derived input function (IDIF) directly from the internal carotid arteries that supply the brain and are often visible in brain PET images. We have devised a method of delineating the internal carotids in co-registered magnetic resonance (MR) images using the level-set method and applying the segmentations to PET images using a novel centerline approach. Centerlines of the segmented carotids were modeled as cubic splines and re-registered in PET images summed over the early portion of the scan. Using information from the anatomical center of the vessel should minimize partial volume and spillover effects. Centerline time-activity curves were taken as the mean of the values for points along the centerline interpolated from neighboring voxels. A scale factor correction was derived from calculation of cerebral blood flow (CBF) using gold standard arterial blood measurements. We have applied the method to human subject data from multiple injections of [15O]water on the HRRT. The method was assessed by calculating the area under the curve (AUC) of the IDIF and the CBF, and comparing these to values computed using the gold standard arterial input curve. The average ratio of IDIF to arterial AUC (apparent recovery coefficient: aRC) across 9 subjects with multiple (n = 69) injections was 0.49 ± 0.09 at 0-30 s post tracer arrival, 0.45 ± 0.09 at 30-60 s, and 0.46 ± 0.09 at 60-90 s. Gray and white matter CBF values were 61.4 ± 11.0 and 15.6 ± 3.0 mL/min/100 g tissue using sampled blood data. Using IDIF centerlines scaled by the average aRC over each subjects’ injections, gray and white matter CBF values were 61.3 ± 13.5 and 15.5 ± 3.4 mL/min/100 g tissue. Using global

Contemporary medical therapies of atherosclerotic carotid artery disease.

PubMed

Cheng, Suk F; Brown, Martin M

2017-03-01

Contemporary medical therapy consists of identification and treatment of all patient-modifiable vascular risk factors. Specific atherosclerotic disease therapies are designed to reduce the risk of thrombosis, and the disease progression in order to reduce the risk of future cardiovascular events. Contemporary medical management emphasizes the need to support the patient in achieving lifestyle modifications and to adjust medication to achieve individualized target values for specific quantifiable risk factors. Antiplatelet therapy in the form of aspirin or clopidogrel is routinely used for the prevention of ischemic stroke in patients who have had a transient ischemic attack or stroke. There is evidence from a recent trial that the use of combination antiplatelet therapy with aspirin and clopidogrel started within 24 hours of minor stroke or transient ischemic attack reduces the risk of recurrent stroke compared to the use of aspirin alone, and therefore we use aspirin plus clopidogrel in recently symptomatic patients with carotid stenosis pending carotid revascularization. Anticoagulation with heparins or vitamin K antagonist is not recommended except in patients at risk for cardio-embolic events. Lowering blood pressure to target levels has been shown to slow down the progression of carotid artery stenosis and reduces the intima-media thickness of the carotid plaque, while lowering lipid levels with statins has become an essential element in the medical therapy of carotid artery stenosis. Diabetes management should be optimized. Lifestyle choices, including tobacco smoking, physical inactivity, unhealthy diet, obesity, and excessive alcohol intake, are all important modifiable vascular risk factors. The combination of dietary modification, physical exercise, and use of aspirin, a statin, and an antihypertensive agent can be expected to give a cumulative relative stroke risk reduction of 80%. The evidence suggests that intensive medical therapy is so effective that

The Effect of Spatial and Temporal Resolution of Cine Phase Contrast MRI on Wall Shear Stress and Oscillatory Shear Index Assessment

PubMed Central

Gijsen, Frank J.; Marquering, Henk; van Ooij, Pim; vanBavel, Ed; Wentzel, Jolanda J.; Nederveen, Aart J.

2016-01-01

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. MRI measurement planes were placed at the common carotid artery (CCA) and internal carotid artery (ICA). Two-dimensional PC-MRI measurements were performed with thirty different spatiotemporal resolution settings. The MRI flow measurement was validated with ultrasound probe measurements. Mean flow, peak flow, flow waveform, WSS and OSI were compared for these spatiotemporal resolutions using regression analysis. The slopes of the regression lines were reported in %/mm and %/100ms. The distribution of low and high WSS and OSI was compared between different spatiotemporal resolutions. Results The mean PC-MRI CCA flow (2.5±0.2mL/s) agreed with the ultrasound probe measurements (2.7±0.02mL/s). Mean flow (mL/s) depended only on spatial resolution (CCA:-13%/mm, ICA:-49%/mm). Peak flow (mL/s) depended on both spatial (CCA:-13%/mm, ICA:-17%/mm) and temporal resolution (CCA:-19%/100ms, ICA:-24%/100ms). Mean WSS (Pa) was in inverse relationship only with spatial resolution (CCA:-19%/mm, ICA:-33%/mm). OSI was dependent on spatial resolution for CCA (-26%/mm) and temporal resolution for ICA (-16%/100ms). The regions of low and high WSS and OSI matched for most of the spatiotemporal resolutions (CCA:30/30, ICA:28/30 cases for WSS; CCA:23/30, ICA:29/30 cases for OSI). Conclusion We show that both mean flow and mean WSS are independent of temporal resolution. Peak flow and OSI are dependent on both spatial and temporal resolution. However, the magnitude of mean and peak flow, WSS and

Temporary clamping of external carotid artery in convexity, parasagittal and temporal base meningioma.

PubMed

Yadav, Yad Ram; Parihar, Vijay; Agarwal, Moneet; Bhatele, Pushp Raj

2012-01-01

The management of intraoperative bleeding during removal of a large hyper vascular meningioma is crucial for safe and efficient surgery. Preoperative embolization of meningioma is the best way to reduce vascularity of meningiomas but this technique is not readily available, costly and has its own limitations. The study is aimed to evaluate the use of temporary clamping of external carotid artery to reduce blood loss and operating time during excision of large convexity, parasagittal or temporal base meningiomas. A prospective study of 115 consecutively operated meningiomas of size 5 cms or more were operated from January 2002 to December2010. Temporary clamping of external carotid artery was done in 61 while 51 cases were managed without clamping. There was significant reduction of blood loss, operative time and blood transfusion given in the temporary clipping group compared to non clipping group. There was stitch abscess in two patients each in clamping, and non clamping group. There was no scalp necrosis or mortality in any of the group. Temporary clamping of external carotid artery is a safe, simple and cost-effective alternative to embolization for the surgery of large meningiomas. This can be practiced at all the centers.

Relation between vegetarian/nonvegetarian diets and blood pressure in black and white adults.

PubMed Central

Melby, C L; Goldflies, D G; Hyner, G C; Lyle, R M

1989-01-01

We examined the possible interaction of race and diet on blood pressure (BP) in volunteer Black Seventh Day Adventists compared to volunteer White church members. Height, weight, waist and hip circumference, and resting seated BP were recorded in Black vegetarians (n = 55; age: 54.7 +/- 16.9 yrs), Black nonvegetarians (n = 59; 56.1 +/- 14.1 yrs), White vegetarians (n = 164; 52.2 +/- 16.7 yrs), and White nonvegetarians (n = 100; 52.6 +/- 15.6 yrs) attending a regional conference. Forty-four percent of the Black nonvegetarians were medicated hypertensives, compared to only 18 percent of the Black vegetarians, 7 percent of the White vegetarians, and 22 percent of the White nonvegetarians. Black vegetarians exhibited lower age and sex-adjusted systolic BP (means = 122.9/74.4 mm Hg) than Black nonvegetarians (means = 132.2/75.9 mm Hg). After further adjusting BP for body mass index and waist/hip ratio, the systolic BP among Black vegetarians remained lower (122.8) than Black nonvegetarians (129.7) but higher than that of the Whites who showed no diet-related BP differences. PMID:2764208

Fast carotid artery MR angiography with compressed sensing based three-dimensional time-of-flight sequence.

PubMed

Li, Bo; Li, Hao; Dong, Li; Huang, Guofu

2017-11-01

In this study, we sought to investigate the feasibility of fast carotid artery MR angiography (MRA) by combining three-dimensional time-of-flight (3D TOF) with compressed sensing method (CS-3D TOF). A pseudo-sequential phase encoding order was developed for CS-3D TOF to generate hyper-intense vessel and suppress background tissues in under-sampled 3D k-space. Seven healthy volunteers and one patient with carotid artery stenosis were recruited for this study. Five sequential CS-3D TOF scans were implemented at 1, 2, 3, 4 and 5-fold acceleration factors for carotid artery MRA. Blood signal-to-tissue ratio (BTR) values for fully-sampled and under-sampled acquisitions were calculated and compared in seven subjects. Blood area (BA) was measured and compared between fully sampled acquisition and each under-sampled one. There were no significant differences between the fully-sampled dataset and each under-sampled in BTR comparisons (P>0.05 for all comparisons). The carotid vessel BAs measured from the images of CS-3D TOF sequences with 2, 3, 4 and 5-fold acceleration scans were all highly correlated with that of the fully-sampled acquisition. The contrast between blood vessels and background tissues of the images at 2 to 5-fold acceleration is comparable to that of fully sampled images. The images at 2× to 5× exhibit the comparable lumen definition to the corresponding images at 1×. By combining the pseudo-sequential phase encoding order, CS reconstruction, and 3D TOF sequence, this technique provides excellent visualizations for carotid vessel and calcifications in a short scan time. It has the potential to be integrated into current multiple blood contrast imaging protocol. Copyright © 2017. Published by Elsevier Inc.

Exploring opinions and beliefs about cord blood donation among Hispanic and non-Hispanic black women.

PubMed

Rucinski, Dianne; Jones, Risé; Reyes, Brenda; Tidwell, Lawon; Phillips, RoiAnn; Delves, Denise

2010-05-01

Despite higher birth rates among non-Hispanic blacks and Hispanics, the availability of umbilical cord blood from these groups is lower due to lower donation rates than that of non-Hispanic whites. Similar racial and ethnic disparities in donation rates have been found for blood and organ donation. This study is among the first to explore beliefs and attitudes toward umbilical cord blood donation among Hispanic and non-Hispanic black women. Five focus groups composed of Hispanic and non-Hispanic black women were conducted to explore how women conceptualize information needs about umbilical cord blood donation and from whom women want to receive information about donation. Participants were adult women who had given birth within the past year or were pregnant. Lack of basic information regarding umbilical cord blood, its harvesting and use, and the steps and conditions necessary to donate were primary barriers to donation. Women expressed confusion over the differences between "donation" and "banking." The social value of donation was explicitly weighed in terms of the cost of the donation effort. Doctors were viewed as critical sources for information about donation, although women expressed skepticism about doctors' ability to convey sufficient information during short office visits. Efforts to increase donation rates among Hispanic and non-Hispanic black women should include information about both the technical aspects and the social value of donation. The specific terms "umbilical" and "donation" should be used consistently to prevent misunderstanding. Information should be provided by physicians with follow-up by other health providers.

Subjective Stress and Coping Resources Interact To Predict Blood Pressure Reactivity in Black College Students.

ERIC Educational Resources Information Center

Clark, Rodney

2003-01-01

Examined the effects of subjective stress and coping resources on blood pressure reactivity among black college students. The interactive effects of subjective stress and coping resources predicted diastolic blood pressure reactivity. Higher levels of problem-focused coping related to more marked diastolic blood pressure changes under conditions…

Acute effects of oral melatonin administration on arterial distensibility, as determined by carotid-femoral pulse wave velocity, in healthy young men

PubMed Central

Yildiz, Mustafa; Sahin, Banu; Sahin, Alparslan

2006-01-01

The aim of the present study was to investigate the effects of melatonin administration on arterial distensibility by using carotid-femoral (aortic) pulse wave velocity (PWV) measurements in healthy young men. Ten men were studied (five men in the melatonin group and five men in the placebo group) by physicians. Carotid-femoral (aortic) PWV, blood pressure and plasma melatonin were measured in the supine position before and 60 min after oral administration of melatonin or placebo. Although carotid-femoral (aortic) PWV, systolic blood pressure and mean blood pressure were decreased, pulse wave propagation time and plasma melatonin levels were increased at 60 min after oral melatonin (1 mg) administration (P=0.04, P=0.04, P=0.04, P=0.04 and P=0.04, respectively). No significant differences were found between all parameters in the placebo group (P>0.05). In conclusion, these findings indicate that melatonin administration, compared with placebo, decreased carotid-femoral PWV and systolic blood pressure in the supine position in healthy young men. Administration of melatonin may have an inhibitory effect on sympathetic tone. PMID:18651024

Machine Learning Based Single-Frame Super-Resolution Processing for Lensless Blood Cell Counting

PubMed Central

Huang, Xiwei; Jiang, Yu; Liu, Xu; Xu, Hang; Han, Zhi; Rong, Hailong; Yang, Haiping; Yan, Mei; Yu, Hao

2016-01-01

A lensless blood cell counting system integrating microfluidic channel and a complementary metal oxide semiconductor (CMOS) image sensor is a promising technique to miniaturize the conventional optical lens based imaging system for point-of-care testing (POCT). However, such a system has limited resolution, making it imperative to improve resolution from the system-level using super-resolution (SR) processing. Yet, how to improve resolution towards better cell detection and recognition with low cost of processing resources and without degrading system throughput is still a challenge. In this article, two machine learning based single-frame SR processing types are proposed and compared for lensless blood cell counting, namely the Extreme Learning Machine based SR (ELMSR) and Convolutional Neural Network based SR (CNNSR). Moreover, lensless blood cell counting prototypes using commercial CMOS image sensors and custom designed backside-illuminated CMOS image sensors are demonstrated with ELMSR and CNNSR. When one captured low-resolution lensless cell image is input, an improved high-resolution cell image will be output. The experimental results show that the cell resolution is improved by 4×, and CNNSR has 9.5% improvement over the ELMSR on resolution enhancing performance. The cell counting results also match well with a commercial flow cytometer. Such ELMSR and CNNSR therefore have the potential for efficient resolution improvement in lensless blood cell counting systems towards POCT applications. PMID:27827837

Blood donation practices, motivations and beliefs in Montreal's Black communities: the modern gift under a new light.

PubMed

Tran, Nathalie Y L; Charbonneau, Johanne; Valderrama-Benitez, Valeria

2013-01-01

Through the conceptual lens of the archaic and modern gift, this study aims to examine perceived limitations and facilitators to increasing blood donations within Black communities in Montreal, Canada. The overall objective is to support blood agencies, such as Héma-Québec, in understanding the challenges and opportunities they face in promoting blood donation among Black communities in pluralistic societies. Thirty-three semi-structured qualitative interviews were conducted with donors and leaders of ethnocultural groups in Montreal: of these, 6 were Héma-Québec employees; 3 were Caribbean blood drive organizers; 14 were leaders of African, Caribbean or Black multiethnic churches and community groups; and finally, 10 were donors, including 2 African, 4 French-speaking Haitian and 4 English-speaking Caribbean. The existence of multiple Black communities in Montreal reflects the various facilitators and obstacles facing Héma-Québec. Caribbean and African communities have their own experiences with regard to blood donation as well as different relationships with the broader Quebec society, both of which have great impact on how they perceive the cause. Questions of trust, of giving to the family and to the community, as well as perceived social exclusion appear to be fundamental issues for our informants. The current participation of groups interested in bettering the lives of those affected by sickle cell anaemia combined with the fact that leaders felt more comfortable donating to someone close to the community suggests that the promotion of blood donation through this angle would be well received. Trust issues, perceived discrimination and social exclusion have structural and historical roots that can only be partly overcome with long-term efforts to increase awareness, develop collaborative partnerships and increase institutional efforts to adapt to the challenges of blood donation from Black citizens.

Early control of distal internal carotid artery during carotid endarterectomy: does it reduce cerebral microemboli?

PubMed

Mommertz, G; Das, M; Langer, S; Koeppel, T A; Krings, T; Mess, W H; Schiefer, J; Jacobs, M J

2010-06-01

According to the results of the large trials on carotid endarterectomy (CEA), this type of surgery is only warranted if perioperative mortality and morbidity are kept considerably low. Less attention has been paid to methods of cerebral protection during CEA, although intraoperative transcranial Doppler (TCD) can visualise intracerebral microemboli (MES) during routine carotid dissection, although MES occur throughout the CEA, only those during dissection are related to neurological outcome. Prevention of MES by means of early control of the distal internal carotid artery dislodging from the carotid artery plaque during dissection is very likely the mechanism behind an eventual benefit from this approach. Hence, the amount of MES might serve as a surrogate parameter for the risk of periprocedural neurological events. So, the aim of the present study was to evaluate whether early control of the distal carotid artery during CEA is capable of reducing the number of MES by means of a prospective randomised trial. Twenty-eight patients (29 procedures) could be prospectively included in our study. Before surgery we randomly assigned the patients to two groups: group A (N.=12): CEA by means of early control of the distal internal carotid artery; group B (N.=17): CEA with dissection of the total carotid bifurcation before clamping the arteries. Periprocedurally, we continuously monitored the cerebral blood flow in the ipsilateral middle cerebral artery by means of TCD. Pre- and postoperative morbidity were independently verified by a neurologist <2 days before and not later than five days after the procedure. Values of microembolic signs during dissection were summarised with arithmetic means and standard deviations. For further analysis non parametric Wilcoxon test was performed between both methods. P-values <0.05 were considered as statistically significant. Wilcoxon test was performed to compare both methods concerning clamp- and procedure times. We performed EEA 26

Carotid stenosis assessment with multi-detector CT angiography: comparison between manual and automatic segmentation methods.

PubMed

Zhu, Chengcheng; Patterson, Andrew J; Thomas, Owen M; Sadat, Umar; Graves, Martin J; Gillard, Jonathan H

2013-04-01

Luminal stenosis is used for selecting the optimal management strategy for patients with carotid artery disease. The aim of this study is to evaluate the reproducibility of carotid stenosis quantification using manual and automated segmentation methods using submillimeter through-plane resolution Multi-Detector CT angiography (MDCTA). 35 patients having carotid artery disease with >30 % luminal stenosis as identified by carotid duplex imaging underwent contrast enhanced MDCTA. Two experienced CT readers quantified carotid stenosis from axial source images, reconstructed maximum intensity projection (MIP) and 3D-carotid geometry which was automatically segmented by an open-source toolkit (Vascular Modelling Toolkit, VMTK) using NASCET criteria. Good agreement among the measurement using axial images, MIP and automatic segmentation was observed. Automatic segmentation methods show better inter-observer agreement between the readers (intra-class correlation coefficient (ICC): 0.99 for diameter stenosis measurement) than manual measurement of axial (ICC = 0.82) and MIP (ICC = 0.86) images. Carotid stenosis quantification using an automatic segmentation method has higher reproducibility compared with manual methods.

Nondipping pattern and carotid atherosclerosis in a middle-aged population: OPERA Study.

PubMed

Vasunta, Riitta-Liisa; Kesäniemi, Y Antero; Ylitalo, Antti; Ukkola, Olavi

2012-01-01

BACKGROUND The lack of dropping in night-time blood pressure of 10% or more (nondipping) seems to associate with cardiovascular risk factors. The relationship between the dipping pattern and atherosclerosis is not clear. The night-time systolic blood pressure (SBP) determines the dipping status. We investigated the connection between intima-media thickness (IMT) and dipping status (dipper, nondipper) taking into account covariates known to associate with hypertension and early atherosclerosis. 900 middle-aged (446 men, 454 women) were studied, 51% of them using blood pressure lowering medication. IMT was measured by a duplex ultrasound from the common carotid artery (CCA), the internal carotid artery (ICA) and the bifurcation enlargement (BIF). The mean IMT was defined as the mean of ICA, BIF, and the 3 highest CCA measurements. Ambulatory blood pressure (ABP) was recorded using the fully automatic SpaceLabs90207 oscillometric unit. Nondippers had lower high-density lipoprotein cholesterol (P = 0.02), higher triglycerides (P < 0.01), body mass index (P < 0.0001) and higher night-time blood pressure (P < 0.0001) than dippers and they were more often nonsmokers (P = 0.01). Increased mean IMT in carotid artery was associated with ABP nondipping pattern (P < 0.01) regardless of conventional cardiovascular risk factors, antihypertensive or lipid lowering medications. Nocturnal blood pressure elevation was independently associated with IMT (P < 0.01). When sexes were analysed separately, the association was seen in men but was only a trend among women. Nondipping status in ABP monitoring is independently associated with early atherosclerosis. Whether nondipping pattern is a predictor of atherosclerosis remains to be explored in a future prospective follow-up of this cohort.

[Measurements of blood velocities using duplex sonography in carotid artery stents: analysis of reliability in an in-vitro model and computational fluid dynamics (CFD)].

PubMed

Schönwald, U G; Jorczyk, U; Kipfmüller, B

2011-01-01

Stents are commonly used for the treatment of occlusive artery diseases in carotid arteries. Today, there is a controversial discussion as to whether duplex sonography (DS) displays blood velocities (BV) that are too high in stented areas. The goal of this study was to evaluate the effect of stenting on DS with respect to BV in artificial carotid arteries. The results of computational fluid dynamics (CFD) were also used for the comparison. To analyze BV using DS, a phantom with a constant flow (70 cm/s) was created. Three different types of stents for carotid arteries were selected. The phantom fluid consisted of 67 % water and 33 % glycerol. All BV measurements were carried out on the last third of the stents. Furthermore, all test runs were simulated using CFD. All measurements were statistically analyzed. DS-derived BV values increased significantly after the placement of the Palmaz Genesis stent (77.6 ± 4.92 cm/sec, p = 0.03). A higher increase in BV values was registered when using the Precise RX stent (80.1 ± 2.01 cm/sec, p < 0.0001). The Strecker Tantalum stent (85.9 ± 1.95 cm/sec, p < 0.0001) generated the highest BV values. CFD simulations showed similar results. Stents have a significant impact on BV, but no effect on DS. The main factor of the blood flow acceleration is the material thickness of the stents. Therefore, different stents need different velocity criteria. Furthermore, the results of computational fluid dynamics prove that CFD can be used to simulate BV in stented silicone tubes. © Georg Thieme Verlag KG Stuttgart · New York.

Cerebral hematocrit decreases with hemodynamic compromise in carotid artery occlusion: a PET study.

PubMed

Yamauchi, H; Fukuyama, H; Nagahama, Y; Katsumi, Y; Okazawa, H

1998-01-01

This study investigated whether in patients with internal carotid artery occlusion the regional cerebral hematocrit correlates with cerebral hemodynamics or metabolic state and, if so, how the regional cerebral hematocrit changes in the hemodynamically compromised region. We used positron emission tomography to study seven patients with unilateral internal carotid artery occlusion and no cortical infarction in the chronic stage. The distributions of red blood cell and plasma volumes were assessed using oxygen-15-labeled carbon monoxide and copper-62-labeled human serum albumin-dithiosemicarbazone tracers, respectively. The calculated hematocrit value was compared with the hemodynamic and metabolic parameters measured with the oxygen-15 steady-state technique. In the cerebral cortex, the value of the cerebral hematocrit varied but was correlated with the hemodynamic and metabolic status. Stepwise regression analysis revealed that the large vessel hematocrit, the cerebral metabolic rate of oxygen, and the cerebral blood flow or the oxygen extraction fraction accounted for a significant proportion of variance of the cerebral hematocrit. The oxygen extraction fraction and the cerebral metabolic rate of oxygen negatively correlated with the cerebral hematocrit, whereas the cerebral blood flow correlated positively: patients with reduced blood supply relative to metabolic demand (decreased blood flow with increased oxygen extraction fraction) showed low hematocrit values. In carotid artery occlusion in the chronic stage, regional cerebral hematocrit may vary according to cerebral hemodynamics and metabolic status. Regional cerebral hematocrit may decrease with hemodynamic compromise unless oxygen metabolism concomitantly decreases.

Effect of Cervical Siphon of External and Internal Carotid Arteries.

PubMed

Singh, Rajani; Tubbs, Richard Shane

2017-10-01

Variant courses, configuration, and branching pattern of the external and internal carotid arteries, especially when curved in S-shape, are important for hemodynamic changes and clinical implications. Therefore, the aim of the study is to report abnormal cervical siphons observed in external and internal carotid arteries to explore clinical significance by review of literature and hemodynamic changes theoretically.The right common carotid artery bifurcated into external and internal carotid arteries at the level of the upper border of thyroid cartilage in a 70-year-old female cadaver. After bifurcation, the external carotid artery underwent severe tortuosity coursing through 5 bends at points A, B, C, D, and E from its origin to termination and 2 bends at A' and B' in internal carotid artery in the cervical region. The angles between inflow and out flow of the blood at the bends were measured and the change in velocity at each bend was computed for both arteries. Hemodynamic changes were calculated, compared and relevant clinical complications were theoretically correlated.The angles of 20°, 30°, 51°, 52°, 60°, and 28°, 48° were formed by 5 bends of external and 2 bends of internal carotid arteries, respectively. The curved courses of these arteries caused reduction in velocity/stasis, turbulence, and low shear stress. Such kinks might cause stroke, ischemia and mistaken for tumors and abscess in imagery leading to or otherwise producing iatrogenic repercussions. This study will be useful for anatomists, clinicians, and radiologists.

The Relationship of Carotid Arterial Stiffness and Left Ventricular Concentric Hypertrophy in Hypertension.

PubMed

Jaroch, Joanna; Łoboz-Grudzień, Krystyna; Magda, Stefania; Florescu, Maria; Bociąga, Zbigniew; Ciobanu, Andrea O; Kruszyńska, Ewa; Dudek, Krzysztof; Vinereanu, Dragos

2016-01-01

Left ventricular hypertrophy (LVH) and geometry patterns vary in different hemodynamic profiles The concentric hypertrophy (CH) pattern has been proved to have the worst prognosis. The aim of the study was to test the hypothesis that carotid artery stiffness, as a marker of vascular damage, is associated with CH, independently of other potential determinants such as demographic factors (age, sex, BMI), clinical parameters (smoking, diabetes, creatinine level) and hemodynamic variables (blood pressure, pulse pressure [PP]). The study involved 262 subjects (89 men): 202 patients with hypertension (153 untreated, 49 on medication), aged 55.7 ± 10 years, and 60 age-matched normal controls. The subjects were examined by echocardiography and carotid ultrasound with a high-resolution echo-tracking system. Based on the left ventricular mass index (LVMI) and relative wall thickness (RWT), the patients with hypertension were divided into four patterns of LVH and geometry: normal geometry (N, n = 57), concentric remodeling (CR, n = 48), concentric hypertrophy CH (n = 62) and eccentric hypertrophy (EH, n = 35). Intima-media thickness (IMT) and the parameters of arterial stiffness were also assessed using the β stiffness index (β), Young elastic modulus (Ep), arterial compliance (AC), one-point pulse wave velocity (PWVβ) and the wave reflection augmentation index (AI). Univariate analysis showed that the following variables are significant in determining CH: β > 8.4, Ep > 136 kPa, PWVβ > 7.1 m/s, AI > 21.9%, systolic BP > 151 mm Hg, PP > 54, IMT > 0.56 and the presence of diabetes. However, by multivariate analysis only AI (OR 3.65, p = 0.003), PWVβ > 7.1 m/s (OR 2.86, p = 0.014), systolic BP (OR 3.12, p = 0037) and the presence of diabetes (OR 3.75, p = 0.007) were associated independently with the occurrence of CH. Concentric hypertrophy in hypertension is strongly associated with carotid arterial stiffness and wave reflection parameters, independently of the influence

Baseline blood Pb levels of black-necked stilts on the upper Texas coast

USGS Publications Warehouse

Riecke, Thomas V.; Conway, Warren C.; Haukos, David A.; Moon, Jena A.; Comer, Christopher E.

2015-01-01

There are no known biological requirements for lead (Pb), and elevated Pb levels in birds can cause a variety of sub-lethal effects and mortality. Historic and current levels of Pb in mottled ducks (Anas fulvigula) suggest that environmental sources of Pb remain available on the upper Texas coast. Because of potential risks of Pb exposure among coexisting marsh birds, black-necked stilt (Himantopus mexicanus) blood Pb concentrations were measured during the breeding season. Almost 80 % (n = 120) of 152 sampled stilts exceeded the background threshold (>20 μg/dL) for Pb exposure. However, blood Pb concentrations did not vary by age or gender, and toxic or potentially lethal concentrations were rare (<5 %). Consistent, low-level blood Pb concentrations of black-necked stilts in this study suggest the presence of readily bioavailable sources of Pb, although potential impacts on local stilt populations remain unclear.

Contemporary carotid imaging: from degree of stenosis to plaque vulnerability.

PubMed

Brinjikji, Waleed; Huston, John; Rabinstein, Alejandro A; Kim, Gyeong-Moon; Lerman, Amir; Lanzino, Giuseppe

2016-01-01

Carotid artery stenosis is a well-established risk factor of ischemic stroke, contributing to up to 10%-20% of strokes or transient ischemic attacks. Many clinical trials over the last 20 years have used measurements of carotid artery stenosis as a means to risk stratify patients. However, with improvements in vascular imaging techniques such as CT angiography and MR angiography, ultrasonography, and PET/CT, it is now possible to risk stratify patients, not just on the degree of carotid artery stenosis but also on how vulnerable the plaque is to rupture, resulting in ischemic stroke. These imaging techniques are ushering in an emerging paradigm shift that allows for risk stratifications based on the presence of imaging features such as intraplaque hemorrhage (IPH), plaque ulceration, plaque neovascularity, fibrous cap thickness, and presence of a lipid-rich necrotic core (LRNC). It is important for the neurosurgeon to be aware of these new imaging techniques that allow for improved patient risk stratification and outcomes. For example, a patient with a low-grade stenosis but an ulcerated plaque may benefit more from a revascularization procedure than a patient with a stable 70% asymptomatic stenosis with a thick fibrous cap. This review summarizes the current state-of-the-art advances in carotid plaque imaging. Currently, MRI is the gold standard in carotid plaque imaging, with its high resolution and high sensitivity for identifying IPH, ulceration, LRNC, and inflammation. However, MRI is limited due to time constraints. CT also allows for high-resolution imaging and can accurately detect ulceration and calcification, but cannot reliably differentiate LRNC from IPH. PET/CT is an effective technique to identify active inflammation within the plaque, but it does not allow for assessment of anatomy, ulceration, IPH, or LRNC. Ultrasonography, with the aid of contrast enhancement, is a cost-effective technique to assess plaque morphology and characteristics, but it is

Reversible cerebral vasoconstriction syndrome with involvement of external carotid artery branches.

PubMed

Shaik, S; Chhetri, S K; Roberts, G; Wuppalapati, S; Emsley, H C A

2014-07-01

A 44-year-old woman presented with recurrent episodes of thunderclap headache. Neurological examination and computed tomography brain imaging were unremarkable. Cerebrospinal fluid findings were consistent with subarachnoid hemorrhage. Computed tomography angiography of the circle of Willis showed multiple areas of segmental vasoconstriction. This finding was confirmed on cerebral catheter angiography, with segmental vasoconstriction involving bilateral internal carotid, posterior cerebral, and external carotid branches. No aneurysm or other vascular abnormality was identified. She received treatment with nimodipine. A selective serotonin reuptake inhibitor, started 4 weeks earlier, was discontinued. Follow-up angiography after 3 months demonstrated complete resolution of the segmental vasoconstriction, confirming the diagnosis of reversible cerebral vasoconstriction syndrome (RCVS). She remained headache free at follow-up. To our knowledge, external carotid artery branch involvement in RCVS has been described only in one previous occasion.

Spatial variability of the Black Sea surface temperature from high resolution modeling and satellite measurements

NASA Astrophysics Data System (ADS)

Mizyuk, Artem; Senderov, Maxim; Korotaev, Gennady

2016-04-01

Large number of numerical ocean models were implemented for the Black Sea basin during last two decades. They reproduce rather similar structure of synoptical variability of the circulation. Since 00-s numerical studies of the mesoscale structure are carried out using high performance computing (HPC). With the growing capacity of computing resources it is now possible to reconstruct the Black Sea currents with spatial resolution of several hundreds meters. However, how realistic these results can be? In the proposed study an attempt is made to understand which spatial scales are reproduced by ocean model in the Black Sea. Simulations are made using parallel version of NEMO (Nucleus for European Modelling of the Ocean). A two regional configurations with spatial resolutions 5 km and 2.5 km are described. Comparison of the SST from simulations with two spatial resolutions shows rather qualitative difference of the spatial structures. Results of high resolution simulation are compared also with satellite observations and observation-based products from Copernicus using spatial correlation and spectral analysis. Spatial scales of correlations functions for simulated and observed SST are rather close and differs much from satellite SST reanalysis. Evolution of spectral density for modelled SST and reanalysis showed agreed time periods of small scales intensification. Using of the spectral analysis for satellite measurements is complicated due to gaps. The research leading to this results has received funding from Russian Science Foundation (project № 15-17-20020)

High-resolution ultrasound imaging and noninvasive optoacoustic monitoring of blood variables in peripheral blood vessels

NASA Astrophysics Data System (ADS)

Petrov, Irene Y.; Petrov, Yuriy; Prough, Donald S.; Esenaliev, Rinat O.

2011-03-01

Ultrasound imaging is being widely used in clinics to obtain diagnostic information non-invasively and in real time. A high-resolution ultrasound imaging platform, Vevo (VisualSonics, Inc.) provides in vivo, real-time images with exceptional resolution (up to 30 microns) using high-frequency transducers (up to 80 MHz). Recently, we built optoacoustic systems for probing radial artery and peripheral veins that can be used for noninvasive monitoring of total hemoglobin concentration, oxyhemoglobin saturation, and concentration of important endogenous and exogenous chromophores (such as ICG). In this work we used the high-resolution ultrasound imaging system Vevo 770 for visualization of the radial artery and peripheral veins and acquired corresponding optoacoustic signals from them using the optoacoustic systems. Analysis of the optoacoustic data with a specially developed algorithm allowed for measurement of blood oxygenation in the blood vessels as well as for continuous, real-time monitoring of arterial and venous blood oxygenation. Our results indicate that: 1) the optoacoustic technique (unlike pure optical approaches and other noninvasive techniques) is capable of accurate peripheral venous oxygenation measurement; and 2) peripheral venous oxygenation is dependent on skin temperature and local hemodynamics. Moreover, we performed for the first time (to the best of our knowledge) a comparative study of optoacoustic arterial oximetry and a standard pulse oximeter in humans and demonstrated superior performance of the optoacoustic arterial oximeter, in particular at low blood flow.

Carotid artery stenting vs. carotid endarterectomy in the management of carotid artery stenosis: Lessons learned from randomized controlled trials

PubMed Central

Salem, Mohamed M.; Alturki, Abdulrahman Y.; Fusco, Matthew R.; Thomas, Ajith J.; Carter, Bob S.; Chen, Clark C.; Kasper, Ekkehard M.

2018-01-01

Background: Carotid artery stenosis, both symptomatic and asymptomatic, has been well studied with several multicenter randomized trials. The superiority of carotid endarterectomy (CEA) to medical therapy alone in both symptomatic and asymptomatic carotid artery stenosis has been well established in previous trials in the 1990s. The consequent era of endovascular carotid artery stenting (CAS) has offered another option for treating carotid artery stenosis. A series of randomized trials have now been conducted to compare CEA and CAS in the treatment of carotid artery disease. The large number of similar trials has created some confusion due to inconsistent results. Here, the authors review the trials that compare CEA and CAS in the management of carotid artery stenosis. Methods: The PubMed database was searched systematically for randomized controlled trials published in English that compared CEA and CAS. Only human studies on adult patients were assessed. The references of identified articles were reviewed for additional manuscripts to be included if inclusion criteria were met. The following terms were used during search: carotid stenosis, endarterectomy, stenting. Retrospective or single-center studies were excluded from the review. Results: Thirteen reports of seven large-scale prospective multicenter studies, comparing both interventions for symptomatic or asymptomatic extracranial carotid artery stenosis, were identified. Conclusions: While the superiority of intervention to medical management for symptomatic patients has been well established in the literatures, careful selection of asymptomatic patients for intervention should be undertaken and only be pursued after institution of appropriate medical therapy until further reports on trials comparing medical therapy to intervention in this patient group are available. PMID:29740506

A Prospective, Multicenter Study of a Novel Mesh-Covered Carotid Stent: The CGuard CARENET Trial (Carotid Embolic Protection Using MicroNet).

PubMed

Schofer, Joachim; Musiałek, Piotr; Bijuklic, Klaudija; Kolvenbach, Ralf; Trystula, Mariusz; Siudak, Zbigniew; Sievert, Horst

2015-08-17

This study sought to evaluate the feasibility of the CGuard Carotid Embolic Protective Stent system-a novel thin strut nitinol stent combined with a polyethylene terephthalate mesh covering designed to prevent embolic events from the target lesion in the treatment of carotid artery lesions in consecutive patients suitable for carotid artery stenting. The risk of cerebral embolization persists throughout the carotid artery stenting procedure and remains during the stent healing period. A total of 30 consecutive patients (age 71.6 ± 7.6 years, 63% male) meeting the conventional carotid artery stenting inclusion criteria were enrolled in 4 centers in Germany and Poland. The primary combined endpoint was the procedure success of the CGuard system and the number and volume of new lesions on the ipsilateral side assessed by diffusion-weighted magnetic resonance imaging at 48 h post-procedure and at 30 days. The secondary endpoint was 30-day major adverse cardiac or cerebrovascular events (death, stroke, or myocardial infarction). Protection devices were used in all procedures. Procedure success was 100%, with 0% procedural complications. The 30-day major adverse cardiac or cerebrovascular events rate was 0%. New ipsilateral ischemic lesions at 48 h occurred in 37.0% of patients and the average lesion volume was 0.039 ± 0.08 cm(3). The 30-day diffusion-weighted magnetic resonance imaging showed complete resolution of all but 1 periprocedural lesion and only 1 new minor (0.116 cm(3)) lesion in relation to the 48-h scan. The use of the CGuard system in patients undergoing carotid artery stenting is feasible. In addition, the benefit of using CGuard may extend throughout the stent healing period. Copyright © 2015 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

A High Resolution Study of Black Sea Circulation and Hypothetical Oil Spills

NASA Astrophysics Data System (ADS)

Dietrich, D. E.; Bowman, M. J.; Korotenko, K. A.

2008-12-01

A 1/24 deg resolution adaptation of the DieCAST ocean model simulates a realistically intense Rim Current and ubiquitous mesoscale coastal anticyclonic eddies that result from anticyclonic vorticity generation by laterally differential bottom drag forces that are amplified near Black Sea coastal headlands. Climatological and synoptic surface forcings are compared. The effects of vertical momentum transfer by known (by Synop region fishermen, as reported by Ballard National Geographic article) big amplitude internal waves are parameterized by big vertical viscosity. Sensitivity to vertical viscosity is shown. Results of simulated hypothetical oil spills are shown. A simple method to nowcast/forecast the Black Sea currents is described and early results are shown.

[Association between the level of fasting blood glucose over 35-year-old and carotid intima-media thickness in Han, Uygur and Kazak population from Xinjiang Uygur Autonomous Region from 2007 to 2010].

PubMed

Li, Xiaomei; Li, Haixia; Liu, Fen; Chen, Bangdang; Yang, Yining; Ma, Yitong

2014-10-01

To analyze the relationship between different levels of fasting blood glucose over 35-year old and carotid intima-media thickness (IMT) in Han, Uygur and Kazak adult population from Xinjiang Uygur Autonomous Region. From October 2007 to April 2010, the present study was performed in 13 935 inhabitants among Han, Uygur and Kazak adult population of aged 35 years old and over by multi-stage stratified cluster random sampling principles from 7 regions in Xinjiang Uygur Autonomous and we excluded the IMT over 0.9 millimeter, long-term out and the floating population. All subjects were measured fasting blood glucose and IMT values of carotid artery. The subjects were divided into three groups according to different fasting blood glucose levels: normal, impaired fasting glucose (IFG) and diabetes mellitus (DM) and we used the analysis of variance to compare the differences among groups of IMT. Multiple linear regression model was used to explore factors of carotid IMT. The IMT of males of Han, Uygur and Kazak were (0.81 ± 0.29), (0.71 ± 0.27) and (0.79 ± 0.21) mm respectively, the differences were significant (F = 88.50, P < 0.05) . The IMT in DM group ((0.82 ± 0.29) mm) was significantly higher than the normal ((0.77 ± 0.26) mm) and the IFG groups ((0.79 ± 0.27) mm) (F = 7.49, P < 0.05). The IMT of females of Han, Uygur and Kazak were (0.72 ± 0.27), (0.63 ± 0.25) and (0.77 ± 0.22) mm, respectively, the differences were significant (F = 173.93, P < 0.05) . The IMT in DM group ((0.75 ± 0.29) mm) and the IFG groups ((0.74 ± 0.26) mm) were significantly higher than the normal group ((0.70 ± 0.25) mm) (F = 10.46, P < 0.05). Multivariate regression analysis showed that diastolic blood pressure (β = 0.101, P < 0.01) , total cholesterol (β = 0.056, P < 0.05) and fasting blood glucose (β = 0.023, P = 0.009) were independent risk factors of IMT. The level of fasting blood glucose was an independent influence factor of carotid IMT and had a positive correlation in

Obesity and overweight associated with increased carotid diameter and decreased arterial function in young otherwise healthy men.

PubMed

Kappus, Rebecca M; Fahs, Christopher A; Smith, Denise; Horn, Gavin P; Agiovlasitis, Stomatis; Rossow, Lindy; Jae, Sae Y; Heffernan, Kevin S; Fernhall, Bo

2014-04-01

Obesity is linked to cardiovascular disease, stroke, increased mortality and vascular remodeling. Although increased arterial diameter is associated with multiple cardiovascular risk factors and obesity, it is unknown whether lumen enlargement is accompanied by unfavorable vascular changes in young and otherwise healthy obese individuals. The purpose of this study was to compare carotid and brachial artery diameter, blood pressure, arterial stiffness, and endothelial function in young, apparently healthy, normal-weight, overweight, and obese male subjects. One hundred sixty-five male subjects (27.39±0.59 years) were divided into 3 groups (normal weight, overweight, and obese) according to body mass index. Subjects underwent cardiovascular measurements to determine arterial diameter, function, and stiffness. After adjusting for age, the obese group had significantly greater brachial, carotid, and aortic pressures, brachial pulse wave velocity, carotid intima media thickness, and carotid arterial diameter compared with both the overweight and normal-weight groups. Obesity is associated with a much worse arterial profile, as an increased carotid lumen size was accompanied by higher blood pressure, greater arterial stiffness, and greater carotid intima media thickness in obese compared with overweight or normal-weight individuals. These data suggest that although obesity may be a factor in arterial remodeling, such remodeling is also accompanied by other hemodynamic and arterial changes consistent with reduced arterial function and increased cardiovascular risk.

Obesity and Overweight Associated With Increased Carotid Diameter and Decreased Arterial Function in Young Otherwise Healthy Men

PubMed Central

2014-01-01

BACKGROUND Obesity is linked to cardiovascular disease, stroke, increased mortality and vascular remodeling. Although increased arterial diameter is associated with multiple cardiovascular risk factors and obesity, it is unknown whether lumen enlargement is accompanied by unfavorable vascular changes in young and otherwise healthy obese individuals. The purpose of this study was to compare carotid and brachial artery diameter, blood pressure, arterial stiffness, and endothelial function in young, apparently healthy, normal-weight, overweight, and obese male subjects. METHODS One hundred sixty-five male subjects (27.39±0.59 years) were divided into 3 groups (normal weight, overweight, and obese) according to body mass index. Subjects underwent cardiovascular measurements to determine arterial diameter, function, and stiffness. RESULTS After adjusting for age, the obese group had significantly greater brachial, carotid, and aortic pressures, brachial pulse wave velocity, carotid intima media thickness, and carotid arterial diameter compared with both the overweight and normal-weight groups. CONCLUSIONS Obesity is associated with a much worse arterial profile, as an increased carotid lumen size was accompanied by higher blood pressure, greater arterial stiffness, and greater carotid intima media thickness in obese compared with overweight or normal-weight individuals. These data suggest that although obesity may be a factor in arterial remodeling, such remodeling is also accompanied by other hemodynamic and arterial changes consistent with reduced arterial function and increased cardiovascular risk. PMID:24048148

Cerebral hemodynamic changes and electroencephalography during carotid endarterectomy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Algotsson, L.; Messeter, K.; Rehncrona, S.

Some patients undergoing endarterectomy for occlusive carotid artery disease run a risk of brain ischemia during cross-clamping of the artery. The present study of 15 patients was undertaken to evaluate changes in cerebral blood flow (CBF), as measured with an intravenous (IV) tracer (133Xenon) technique, and to relate CBF changes to changes in the electroencephalogram (EEG). CBF was measured before and after induction of anesthesia, during cross-clamping of the carotid artery, after release of the clamps, and at 24 hours after the operation. All the patients were anesthetized with methohexitone, fentanyl, and nitrous oxide and oxygen. EEG was continuously recordedmore » during the operation. Carotid artery shunts were not used. In 8 patients, cross-clamping of the carotid artery did not influence the EEG. In this group of patients, induction of anesthesia caused a 38% decrease in CBF, which presumably reflects the normal reaction to the anesthetic agent given. There were no further changes in CBF during cross-clamping. In 7 patients, the EEG showed signs of deterioration during the intraoperative vascular occlusion. In these patients, anesthesia did not cause any CBF change, whereas cross-clamping the artery induced a 33% decrease in CBF. In individual patients, the severity of EEG changes correlated with the decrease in CBF. The absence of a change in CBF by anesthesia and a decrease due to cross-clamping of the carotid artery may be explained by the presence of a more advanced cerebrovascular disease and an insufficiency to maintain CBF during cross-clamping.« less

Carotid DSA based CFD simulation in assessing the patient with asymptomatic carotid stenosis: a preliminary study.

PubMed

Zhang, Dong; Xu, Pengcheng; Qiao, Hongyu; Liu, Xin; Luo, Liangping; Huang, Wenhua; Zhang, Heye; Shi, Changzheng

2018-03-12

Cerebrovascular events are frequently associated with hemodynamic disturbance caused by internal carotid artery (ICA) stenosis. It is challenging to determine the ischemia-related carotid stenosis during the intervention only using digital subtracted angiography (DSA). Inspired by the performance of well-established FFRct technique in hemodynamic assessment of significant coronary stenosis, we introduced a pressure-based carotid arterial functional assessment (CAFA) index generated from computational fluid dynamic (CFD) simulation in DSA data, and investigated its feasibility in the assessment of hemodynamic disturbance preliminarily using pressure-wired measurement and arterial spin labeling (ASL) MRI as references. The cerebral multi-delay multi-parametric ASL-MRI and carotid DSA including trans-stenotic pressure-wired measurement were implemented on a 65-year-old man with asymptomatic unilateral (left) ICA stenosis. A CFD simulation using simplified boundary condition was performed in DSA data to calculate the CAFA index. The cerebral blood flow (CBF) and arterial transit time (ATT) of ICA territories were acquired. CFD simulation showed good correlation (r = 0.839, P = 0.001) with slight systematic overestimation (mean difference - 0.007, standard deviation 0.017) compared with pressure-wired measurement. No significant difference was observed between them (P = 0.09). Though the narrowing degree of in the involved ICA was about 70%, the simulated and measured CAFA (0.942/0.937) revealed a functionally nonsignificant stenosis which was also verified by a compensatory final CBF (fronto-temporal/fronto-parietal region: 51.58/45.62 ml/100 g/min) and slightly prolonged ATT (1.23/1.4 s) in the involved territories, together with a normal left-right percentage difference (2.1-8.85%). The DSA based CFD simulation showed good consistence with invasive approach and could be used as a cost-saving and efficient way to study the relationship between

Early improvement in carotid plaque echogenicity by acarbose in patients with acute coronary syndromes.

PubMed

Hirano, Mitsumasa; Nakamura, Takamitsu; Obata, Jyun-ei; Fujioka, Daisuke; Saito, Yukio; Kawabata, Ken-ichi; Watanabe, Kazuhiro; Watanabe, Yosuke; Kugiyama, Kiyotaka

2012-01-01

The resolution of hyperglycemia is associated with suppression of in-hospital cardiac complications in patients with acute coronary syndromes (ACS). This study evaluated carotid artery plaque echolucency using ultrasound in patients with ACS and type 2 diabetes mellitus (DM) to determine whether acarbose, an α-glucosidase inhibitor, may rapidly stabilize unstable atherosclerotic plaques. ACS patients with type 2 DM and carotid plaques (n=44) were randomly assigned to treatment with acarbose (150 or 300 mg/day, n=22) or a control group (no acarbose, n=22). Acarbose treatment was initiated within 5 days after the onset of ACS. Unstable carotid plaques were assessed by measuring plaque echolucency using carotid ultrasound with integrated backscatter (IBS) before, and at 2 weeks, 1 and 6 months after the initiation of treatment. An increase in the IBS value reflected an increase in carotid plaque echogenicity. As results, the IBS value of echolucent carotid plaques showed a significant increase at 1 month and a further increase at 6 months after treatment in the acarbose group, but there was minimal change in the control group. The increase in IBS values was significantly correlated with a decrease in C-reactive protein levels. Acarbose rapidly improved carotid plaque echolucency within 1 month of therapy in patients with ACS and type 2 DM.

Ultrasonographic character of carotid plaque and postprocedural brain embolisms in carotid artery stenting and carotid endarterectomy.

PubMed

Mitsuoka, Hiroshi; Shintani, Tsunehiro; Furuya, Hidekazu; Nakao, Yoshinaga; Higashi, Shigeki

2011-01-01

To investigate ultrasonographic character of carotid plaques, and incidences of brain embolism in carotid angioplasty and stenting (CAS) and carotid endarterectomy (CEA). CEA (22/25 symptomatic lesions) and CAS (17/20 symptomatic lesions) between 2007 and 2010. Embolic protection devices (15 occlusion and 5 filtering devices) were used during CAS. Carotid plaques were classified into three categories (I: calcificated, II: intermediately echogenic, III: echolucent). Magnetic resonance imaging (MRI) was used to investigate brain emboli. Ultrasonographic character of the plaques in CEA cases (I: 4%, II: 88%, III: 8%) was different from the one in CAS cases (I: 10%, II: 90%, III: 0%). The incidence of brain embolism in the CAS cases was 52.6% while 0% in the CEA cases (p = 0.00037). CAS had high incidences of brain embolism in any plaques (I: 100%, II: 43.8%). In the most recent 9 procedures of CAS using occlusion devices, averaged number of embolic lesion was 1.0 (0 post operative day; 0 POD). The number increased as 1.4 (1 POD) and 2.0 (7 POD). CEA should be currently the first choice for most patients with a high-grade and symptomatic carotid artery stenosis.

Panoramic images of white and black post-menopausal females evidencing carotid calcifications are at high risk of comorbid osteopenia of the femoral neck

PubMed Central

Friedlander, AH; Chang, TI; Aghazadehsanai, N; Berenji, GR; Harada, ND; Garrett, NR

2013-01-01

Objectives: Femoral neck fractures in older females resulting from decreased bone mineral density (BMD; osteopenia) are associated with increased morbidity and mortality. Bone mineralization inhibition is probably controlled by proteins which also foster vascular calcification. Therefore, we evaluated the relationship between calcified carotid artery plaque (CCAP) on panoramic images and BMD on dual energy X-ray absorptiometry (DXA) bone scans. Methods: Images and hospital records identified by dentists defined two study groups (20 white females and 24 black females) having CCAP and an incidentally obtained bone scan. Ethnically matched (age±7 years, body mass index ±3 units) control groups with panoramic images devoid of CCAP and accompanying DXA scan were likewise constituted. A physician determined the BMD on the DXA. Results: Females with CCAP had significantly (p = 0.03) poorer BMD at the femoral neck than those without CCAP. Although mean femoral neck BMD was significantly lower (p = 0.009) for white than for black females, there was no significant interaction between race and CCAP (p = 0.80). Conclusion: We observed a significant inverse association between the CCAP on panoramic images and femoral neck BMD in post-menopausal white females. PMID:23571481

Panoramic images of white and black post-menopausal females evidencing carotid calcifications are at high risk of comorbid osteopenia of the femoral neck.

PubMed

Friedlander, A H; Chang, T I; Aghazadehsanai, N; Berenji, G R; Harada, N D; Garrett, N R

2013-01-01

Femoral neck fractures in older females resulting from decreased bone mineral density (BMD; osteopenia) are associated with increased morbidity and mortality. Bone mineralization inhibition is probably controlled by proteins which also foster vascular calcification. Therefore, we evaluated the relationship between calcified carotid artery plaque (CCAP) on panoramic images and BMD on dual energy X-ray absorptiometry (DXA) bone scans. Images and hospital records identified by dentists defined two study groups (20 white females and 24 black females) having CCAP and an incidentally obtained bone scan. Ethnically matched (age±7 years, body mass index ±3 units) control groups with panoramic images devoid of CCAP and accompanying DXA scan were likewise constituted. A physician determined the BMD on the DXA. Females with CCAP had significantly (p = 0.03) poorer BMD at the femoral neck than those without CCAP. Although mean femoral neck BMD was significantly lower (p = 0.009) for white than for black females, there was no significant interaction between race and CCAP (p = 0.80). We observed a significant inverse association between the CCAP on panoramic images and femoral neck BMD in post-menopausal white females.

Biological Antioxidant Potential Negatively Correlates With Carotid Artery Intima-Media Thickness.

PubMed

Yagi, Hideki; Sumino, Hiroyuki; Yoshida, Kensuke; Aoki, Tomoyuki; Tsunekawa, Katsuhiko; Araki, Osamu; Kimura, Takao; Nara, Makoto; Nakajima, Katsuyuki; Murakami, Masami

2016-01-01

Oxidative stress is a crucial factor in the pathogenesis and development of cardiovascular disease. Recently, simplified methods for the detection of reactive oxygen species (ROS) using the derivatives of reactive oxygen metabolites (d-ROMs) test as an index of ROS products and the biological antioxidant potential (BAP) test as an index of antioxidant potential have been utilized. These methods are easy to perform, quick, inexpensive since they use small equipment, and provide reliable results compared with established oxidative stress and antioxidant markers. Because oxidative stress has been shown to represent the balance of production of ROS and antioxidant capacity, it is more appropriate to evaluate ROS and antioxidant capacity simultaneously. However, no study has examined the associations among d-ROMs, BAP values, and carotid artery intima-media thickness (IMT) concurrently. Therefore, we studied the associations among d-ROMs, BAP values, and the carotid artery IMT. Carotid artery IMT, blood pressure (BP), fasting circulating d-ROMs, BAP, glucose metabolism, lipid, and C-reactive protein levels were measured in 95 subjects (age: 49.5 ± 13.8 years; men: 41; women: 54), including 42 healthy subjects and 53 patients with hypertension, dyslipidemia, and diabetes mellitus who were not on medication. The results of multiple regression analysis revealed that dependent carotid artery IMT determinants remained significantly associated with age, systolic BP, total cholesterol, and BAP, whereas dependent BAP determinants remained significantly associated with body mass index and carotid artery IMT. BAP was strongly correlated with carotid artery IMT in our cohort. Our results suggest that BAP may be a useful risk marker for carotid atherosclerosis.

Association between body mass index and presence of carotid plaque among low-income adults aged 45 years and older: a population-based cross-sectional study in rural China.

PubMed

Lou, Yongzhong; Li, Bin; Su, Lan; Mu, Zhenhong; Sun, Minghao; Gu, Hongfei; Ni, Jingxian; Wu, Yanan; Tu, Jun; Wang, Jinghua; Ning, Xianjia

2017-10-06

Carotid plaque is a good surrogate endpoint for assessing arterial atherosclerosis, and atherosclerosis is a reliable predictor of cardiovascular diseases. However, the effect of body mass index on carotid plaque is unknown. Therefore, we aimed to explore the association between body mass index and carotid plaque in a low-income Chinese population. Residents aged ≥45 years and free of stroke and cardiovascular diseases were enrolled and divided into four groups based on body mass index. B-mode ultrasonography was performed to measure carotid plaque. The mean age of participants was 59.92 years overall. Significant correlations were observed between the presence of carotid plaque and male sex, older age, systolic blood pressure, fasting plasma glucose, and low-density lipoprotein cholesterol among the different BMI subgroups. Male sex increased the risk of carotid plaque in the overweight and obese groups. Older age and high level of low-density lipoprotein cholesterol were the independent risk factor for carotid plaque in four groups. Increased systolic blood pressure was an independent risk factor in the normal-weight, overweight, and obese groups; however, fasting plasma glucose was only significant in the normal-weight group. Thus, controlling the levels of low-density lipoprotein cholesterol, systolic blood pressure, and fasting plasma glucose is required to reduce carotid plaque risk.

Increased Expression of Interleukin-18 mRNA is Associated with Carotid Artery Stenosis

PubMed

Arapi, Berk; Bayoğlu, Burcu; Cengiz, Müjgan; Dirican, Ahmet; Deser, Serkan Burç; Junusbekov, Yerik; Arslan, Caner

2018-05-29

Carotid artery stenosis is the atherosclerotic narrowing of the proximal internal carotid artery and one of the primary causes of stroke. Elevated expression of the pleiotropic proinflammatory cytokine interleukin-18 has been demonstrated in human atherosclerotic plaques. To investigate whether the mRNA expression levels of interleukin-18 and interleukin-18-binding protein and interleukin-18 −137 G/C (rs187238) variants are associated with carotid artery stenosis development. Case-control study. The mRNA expression levels of interleukin-18 and interleukin-18-binding protein and interleukin-18 rs187238 variants were evaluated by quantitative real-time polymerase chain reaction and real-time polymerase chain reaction, respectively, in the peripheral blood mononuclear cells of 70 patients with carotid artery stenosis (36 symptomatic, 34 asymptomatic) and 75 healthy controls. Interleukin-18 mRNA expression was significantly increased in carotid artery stenosis patients compared to that in healthy controls (p=0.01). However, no significant difference was observed between interleukin-18-binding protein mRNA expression levels in patients with carotid artery stenosis and those in controls (p=0.101). Internal carotid artery stenosis severity was significantly higher in symptomatic patients than that in asymptomatic patients (p<0.001). A significant relationship was identified between interleukin-18 expression and internal carotid artery stenosis severity in patients with carotid artery stenosis (p=0.051). Interleukin-18 rs187238 polymorphism genotype frequencies did not significantly differ between patients with carotid artery stenosis and controls (p=0.246). A significant difference was identified between interleukin-18-binding protein gene expression and symptomatic and asymptomatic patients (p=0.026), but there was no difference in interleukin-18 expression between the symptomatic and asymptomatic subgroups (p=0.397). Interleukin-18 mRNA expression may affect carotid

PLACD-7T Study: Atherosclerotic Carotid Plaque Components Correlated with Cerebral Damage at 7 Tesla Magnetic Resonance Imaging.

PubMed

den Hartog, A G; Bovens, S M; Koning, W; Hendrikse, J; Pasterkamp, G; Moll, F L; de Borst, G J

2011-02-01

In patients with carotid artery stenosis histological plaque composition is associated with plaque stability and with presenting symptomatology. Preferentially, plaque vulnerability should be taken into account in pre-operative work-up of patients with severe carotid artery stenosis. However, currently no appropriate and conclusive (non-) invasive technique to differentiate between the high and low risk carotid artery plaque in vivo is available. We propose that 7 Tesla human high resolution MRI scanning will visualize carotid plaque characteristics more precisely and will enable correlation of these specific components with cerebral damage. The aim of the PlaCD-7T study is 1: to correlate 7T imaging with carotid plaque histology (gold standard); and 2: to correlate plaque characteristics with cerebral damage ((clinically silent) cerebral (micro) infarcts or bleeds) on 7 Tesla high resolution (HR) MRI. We propose a single center prospective study for either symptomatic or asymptomatic patients with haemodynamic significant (70%) stenosis of at least one of the carotid arteries. The Athero-Express (AE) biobank histological analysis will be derived according to standard protocol. Patients included in the AE and our prospective study will undergo a pre-operative 7 Tesla HR-MRI scan of both the head and neck area. We hypothesize that the 7 Tesla MRI scanner will allow early identification of high risk carotid plaques being associated with micro infarcted cerebral areas, and will thus be able to identify patients with a high risk of periprocedural stroke, by identification of surrogate measures of increased cardiovascular risk.

PLACD-7T Study: Atherosclerotic Carotid Plaque Components Correlated with Cerebral Damage at 7 Tesla Magnetic Resonance Imaging

PubMed Central

den Hartog, A.G; Bovens, S.M; Koning, W; Hendrikse, J; Pasterkamp, G; Moll, F.L; de Borst, G.J

2011-01-01

Introduction: In patients with carotid artery stenosis histological plaque composition is associated with plaque stability and with presenting symptomatology. Preferentially, plaque vulnerability should be taken into account in pre-operative work-up of patients with severe carotid artery stenosis. However, currently no appropriate and conclusive (non-) invasive technique to differentiate between the high and low risk carotid artery plaque in vivo is available. We propose that 7 Tesla human high resolution MRI scanning will visualize carotid plaque characteristics more precisely and will enable correlation of these specific components with cerebral damage. Study objective: The aim of the PlaCD-7T study is 1: to correlate 7T imaging with carotid plaque histology (gold standard); and 2: to correlate plaque characteristics with cerebral damage ((clinically silent) cerebral (micro) infarcts or bleeds) on 7 Tesla high resolution (HR) MRI. Design: We propose a single center prospective study for either symptomatic or asymptomatic patients with haemodynamic significant (70%) stenosis of at least one of the carotid arteries. The Athero-Express (AE) biobank histological analysis will be derived according to standard protocol. Patients included in the AE and our prospective study will undergo a pre-operative 7 Tesla HR-MRI scan of both the head and neck area. Discussion: We hypothesize that the 7 Tesla MRI scanner will allow early identification of high risk carotid plaques being associated with micro infarcted cerebral areas, and will thus be able to identify patients with a high risk of periprocedural stroke, by identification of surrogate measures of increased cardiovascular risk. PMID:22294972

Duplex scanning diagnosis of internal carotid artery dissections. A case control study.

PubMed

Alecu, C; Fortrat, J O; Ducrocq, X; Vespignani, H; de Bray, J M

2007-01-01

The reliability of duplex scanning (DS) for the diagnosis of internal carotid artery dissections (ICAD) is not clear. Nine DS signs known to be suggestive for the diagnosis of ICAD were compared between 70 patients with ICAD and 70 matched patients without dissection. Visible internal tapering occlusion, regular eccentric narrowing channel, ectasia beyond the carotid bulb, resistive index asymmetry, blood flow slowdown, ophthalmic artery blood flow inversion, and biphasic flow are more frequent in cases than in controls (p < 0.001). Atheroma plaques were absent in 80% of ICAD. When DS direct signs and hemodynamic signs were studied, sensitivity was 90% and specificity 60%. Diagnosis of ICAD by DS could be improved if direct signs were combined with hemodynamic signs, giving a high sensitivity and a rather good specificity. Copyright 2007 S. Karger AG, Basel.

Carotid-cardiac baroreflex response and LBNP tolerance following resistance training

NASA Technical Reports Server (NTRS)

Tatro, D. L.; Dudley, G. A.; Convertino, V. A.

1992-01-01

The purpose of this study was to examine the effect of lower body resistance training on cardiovascular control mechanisms and blood pressure maintenance during an orthostatic challenge. Lower body negative pressure (LBNP) tolerance, carotid-cardiac baroreflex function (using neck chamber pressure), and calf compliance were measured in eight healthy males before and after 19 wk of knee extension and leg press training. Resistance training sessions consisted of four or five sets of 6-12 repetitions of each exercise, performed two times per week. Training increased strength 25 +/- 3 (SE) percent (P = 0.0003) and 31 +/- 6 percent (P = 0.0004), respectively, for the leg press and knee extension exercises. Average fiber size in biopsy samples of m. vastus lateralis increased 21 +/- 5 percent (P = 0.0014). Resistance training had no significant effect on LBNP tolerance. However, calf compliance decreased in five of the seven subjects measured, with the group average changing from 4.4 +/- 0.6 ml.mm Hg-1 to 3.9 +/- 0.3 ml.mm Hg-1 (P = 0.3826). The stimulus-response relationship of the carotid-cardiac baroreflex response shifted to the left on the carotid pressure axis as indicated by a reduction of 6 mm Hg in baseline systolic blood pressure (P = 0.0471). In addition, maximum slope increased from 5.4 +/- 1.3 ms.mm Hg-1 before training to 6.6 +/- 1.6 ms.mm Hg-1 after training (P = 0.0141). Our results suggest the possibility that high resistance, lower extremity exercise training can cause a chronic increase in sensitivity and resetting of the carotid-cardiac baroreflex.

Carotid rupture following electrical injury: a report of two cases.

PubMed

Toy, Jonathan; Ball, Brandon J; Tredget, Edward E

2012-01-01

Electrical injuries often result in extensive tissue damage where vascular damage may occur and result in thrombosis and spontaneous rupture of blood vessels. Rupture of the brachial, radial, ulnar, internal mammary, and obturator arteries has been reported in the literature. The authors present two cases of carotid artery rupture following high-voltage electrical injuries. The first case is a 21-year-old man who was climbing a fence near a high-voltage power line when a gold chain he was wearing around his neck caught on the power line, resulting in a 10% circumferential electrical injury to his neck. He presented with visible arterial bleeding from the large neck wound and was taken to the operating room, where a 1-cm laceration to the carotid artery was repaired with a vein patch. On the second postoperative day, the patch dislodged, and a spontaneous rupture of the common carotid artery occurred. The damaged artery was subsequently ligated. The patient recovered with no neurological sequelae. The second case is a 43-year-old man who suffered a high-voltage injury while working on an electrical panel, resulting in a 50% TBSA full-thickness burn to the face, scalp, trunk, and extremities. Four weeks after admission, a latissimus dorsi myocutaneous free flap was used for coverage of exposed outer table of the skull. Intraoperatively, the carotid artery spontaneously ruptured proximal to where the dissection was being carried out. The patient recovered with no neurological sequelae. High-voltage electrical injury results in significant damage to blood vessels via a number of mechanisms. Rupture of a major vessel is a rare, life-threatening sequelae of electrical injury.

[A case of internal carotid artery stenosis with discontinuance of carotid endarterectomy due to the tight adhesions around the internal carotid artery].

PubMed

Kohri, Ryusuke; Miyazono, Masayuki; Hatae, Ryusuke; Maeda, Kazushi; Takahira, Asuka; Maeda, Yasuhiro; Mizota, Takamitsu; Naito, Shinji

2012-05-01

A 73-year-old female visited her local doctor after repeatedly experiencing temporary weakness in her left upper and lower extremities. The patient underwent a cervical magnetic resonance imaging (MRI) scan and was diagnosed with right internal carotid artery stenosis. Despite administration of antiplatelet drugs, her symptoms continued, and she was referred to our department for medical treatment. Her medical history revealed hypertension, hyperlipidemia, and cholesteatoma. We diagnosed symptomatic internal carotid artery stenosis and performed carotid endarterectomy (CEA). However, tight adhesions between the carotid artery and surrounding tissue made separation difficult, and surgery had to be discontinued. Some of the extracted adherent tissue consisted of hyalinized fibrous tissue that had the appearance of soft tissue which had organized because of inflammation. Although there have been no reports of cholesteatoma directly causing adhesion around the internal carotid artery, it has been reported to have led to abscess formation in the parapharyngeal space adjacent to the carotid space. Because the boundaries of the parapharyngeal space and carotid space are anatomically incomplete, inflammation often affects the area between them. As far as we know, this report, which also includes a discussion of the literature, is the first to indicate that cholesteatoma causes strong adhesions around the carotid artery.

[The state of carotid arteries in young men with arterial hypertension].

PubMed

Safarova, A F; Iurtaeva, V R; Kotovskaia, Iu V; Kobalava, Zh D

2012-01-01

To study elastic properties of carotid arteries in young men with arterial hypertension (AH). We examined men aged 18-25 years (mean 21.1+/-0.14 years): 36 with normal blood pressure (BP), 123 with stable and 51 with unstable AH. Parameters studied comprised intima-media thickness (IMT) of carotid arteries, their M-mode measured maximal systolic and minimal diastolic diameters (Ds and Dd), stiffness of common carotid artery (CCA) wall determined on the basis of analysis of elasticity and distensibility coefficients (CC and DC), Peterson's and Young's modules of elasticity (Ep and E), and index of flow deformation (CS). Compared with young men with normal BP and unstable AH patients with stable AH had abnormal elastic properties of CCA and increased IMT. Stable AH in young men is associated with signs of remodeling of CCA walls and increase of their rigidity.

Comparison of carotid plaque ulcer detection using contrast-enhanced and time-of-flight MRA techniques.

PubMed

Etesami, M; Hoi, Y; Steinman, D A; Gujar, S K; Nidecker, A E; Astor, B C; Portanova, A; Qiao, Y; Abdalla, W M A; Wasserman, B A

2013-01-01

Ulceration in carotid plaque is a risk indicator for ischemic stroke. Our aim was to compare plaque ulcer detection by standard TOF and CE-MRA techniques and to identify factors that influence its detection. Carotid MR imaging scans were acquired on 2066 participants in the ARIC study. We studied the 600 thickest plaques. TOF-MRA, CE-MRA, and black-blood MR images were analyzed together to define ulcer presence (plaque surface niche ≥2 mm in depth). Sixty ulcerated arteries were detected. These arteries were randomly assigned, along with 40 nonulcerated plaques from the remaining 540, for evaluation of ulcer presence by 2 neuroradiologists. Associations between ulcer detection and ulcer characteristics, including orientation, location, and size, were determined and explored by CFD modeling. One CE-MRA and 3 TOF-MRAs were noninterpretable and excluded. Of 71 ulcers in 56 arteries, readers detected an average of 39 (55%) on both TOF-MRA and CE-MRA, 26.5 (37.5%) only on CE-MRA, and 1 (1.5%) only on TOF-MRA, missing 4.5 (6%) ulcers by both methods. Ulcer detection by TOF-MRA was associated with its orientation (distally pointing versus perpendicular: OR = 5.57 [95% CI, 1.08-28.65]; proximally pointing versus perpendicular: OR = 0.21 [95% CI, 0.14-0.29]); location relative to point of maximum stenosis (distal versus isolevel: OR = 5.17 [95% CI, 2.10-12.70]); and neck-to-depth ratio (OR = 1.96 [95% CI, 1.11-3.45]) after controlling for stenosis and ulcer volume. CE-MRA detects more ulcers than TOF-MRA in carotid plaques. Missed ulcers on TOF-MRA are influenced by ulcer orientation, location relative to point of maximum stenosis, and neck-to-depth ratio.

Preliminary application of hybrid operation in the treatment of carotid artery stenosis in patients with complex ischemic cerebrovascular diseases

PubMed Central

Zhang, Liyong; Xing, Tao; Geng, Fenyang; Du, Lixin; Wang, Jiyue

2014-01-01

Along with the recent development of intraluminal interventional techniques and correlated imaging methods, one-stop hybrid operation has become a new focus in clinical settings. The aim of this study is to discuss the clinical significance of the one-stop hybrid endarterectomy surgery in the treatment of complex ischemic cerebrovascular diseases. In this study, clinical data from 10 patients with complex ischemic cerebrovascular diseases (including multi-vessel severe stenosis of the internal extracranial carotid artery, single vessel series stenosis of the internal extracranial carotid artery, in-stent restenosis, complete occlusion of the common carotid or the internal carotid artery) admitted to Beijing Xuanwu Hospital and Liaocheng Brain Hospital, were retrospectively analyzed. All enrolled subjects underwent three types of hybrid operations. The clinical efficacy of this surgery was subsequently assessed in this clinical trial. The results indicated that no related surgical complications were noted during the perioperative period. Intraoperative and postoperative imaging revealed no signs of vascular stenosis, the blood supply recovered, and clinical symptoms were alleviated. The follow-up lasted for 6 to 12 months. Imaging re-examination showed no evidence of re-stenosis and good blood circulation was present in the recanalized blood vessels. Favorable treatment efficacy was achieved. The intracranial blood supply was significantly improved postoperatively. In conclusion, one-stop hybrid operation plays an important role in treating complex stenosis cerebrovascular diseases. PMID:25197423

Common Carotid Artery Diameter and Risk of Cardiovascular Events and Mortality: Pooled Analyses of Four Cohort Studies.

PubMed

Sedaghat, Sanaz; van Sloten, Thomas T; Laurent, Stéphane; London, Gérard M; Pannier, Bruno; Kavousi, Maryam; Mattace-Raso, Francesco; Franco, Oscar H; Boutouyrie, Pierre; Ikram, M Arfan; Stehouwer, Coen D A

2018-05-21

Carotid arterial diameter enlargement is a manifestation of arterial remodeling and may be a risk factor for cardiovascular disease (CVD). We evaluated the association between carotid artery diameter and risk of stroke, coronary heart disease, CVD, and all-cause mortality and explored whether the associations could be explained by processes involved in arterial remodeling, that is, blood pressure-related media thickening, arterial stiffness, arterial wall stress, and atherosclerosis. We included 4887 participants (mean age 67±9 years; 54% women) from 4 cohort studies: Rotterdam Study, NEPHROTEST, Hoorn Study, and a study by Blacher et al. Common carotid artery properties were measured using echotracking. Incident cases were recorded based on medical records. We used Cox proportional hazard models adjusting for cardiovascular risk factors and estimates of processes underlying arterial remodeling. During follow-up (mean, 11 years), 379 (8%) individuals had a stroke, 516 had a (11%) coronary heart disease, 807 had a (17%) CVD, and 1486 (30%) had died. After adjustment for cardiovascular risk factors, individuals in the highest tertile of carotid diameter (diameter >8 mm) compared with those in the lowest tertile (diameter <7 mm) had a higher incidence of stroke (hazard ratio, 1.5; 95% confidence interval, 1.1-2.0). From all estimates of processes underlying arterial remodeling, adjustment for carotid intima-media thickness attenuated this association (hazard ratio after adjustment for intima-media thickness, 1.2; 95% confidence interval, 0.9-1.6). Larger carotid diameter was associated with risk of CVD and mortality but not clearly with coronary heart disease risk. We showed that a larger carotid diameter is associated with incident stroke, CVD, and mortality. Carotid intima-media thickness, a measure of blood pressure-related media thickening, partially explained the association with stroke incidence. © 2018 American Heart Association, Inc.

Factors Influencing Decision Making for Carotid Endarterectomy versus Stenting in the Very Elderly

PubMed Central

Heo, Sung Hyuk; Bushnell, Cheryl D.

2017-01-01

As the population ages worldwide, the number of elderly patients with carotid stenosis is also increasing. There have been many large clinical trials comparing carotid endarterectomy (CAE) versus stenting, but the inclusion criteria (i.e., symptomatic or asymptomatic), stenting methods (i.e., protection device), and primary end point (i.e., the definition of myocardial infarction and follow-up period) were different between trials. Therefore, the interpretation of those results is difficult and requires attention. When it comes to age, the patients older than 80 years were excluded or stratified to a high risk group in previous landmark trials. However, a recent guideline recommended that endarterectomy may be associated with lower stroke risk compared with carotid artery stenting in patients older than 70 years with symptomatic carotid disease. The annual risk of stroke in individuals with asymptomatic carotid stenosis is about 1–3% but the risk is about 4–12% with symptomatic stenosis without carotid intervention. Although the outcome of CAE is better than that of carotid stenting in patients older than 70 years, the perioperative risk is higher in older patients. Therefore, it is important to classify high risk patients and consider underlying disability and life expectancy of very elderly patients before deciding whether to undergo a carotid intervention. In addition, we should also consider that the stroke rate with intensive medical treatment is unknown and is currently being investigated in randomized controlled trials. Intensive medical treatment includes high intensity statins, diabetes and blood pressure control, and aggressive antiplatelet treatment. The aim of this review is to report the factors that may be responsible for the variability in the treatment of carotid stenosis, particularly in the elderly population. This will allow the readers to integrate the current available evidence to individualize the treatment of carotid stenosis in

Sleep Characteristics and Carotid Atherosclerosis Among Midlife Women.

PubMed

Thurston, Rebecca C; Chang, Yuefang; von Känel, Roland; Barinas-Mitchell, Emma; Jennings, J Richard; Hall, Martica H; Santoro, Nanette; Buysse, Daniel J; Matthews, Karen A

2017-02-01

Midlife, which encompasses the menopause transition in women, can be a time of disrupted sleep and accelerated atherosclerosis accumulation. Short or poor sleep quality has been associated with cardiovascular disease (CVD) risk; few studies have investigated relations among midlife women. We tested whether shorter actigraphy sleep time or poorer subjective sleep quality was associated with carotid atherosclerosis among midlife women. Two hundred fifty-six peri- and postmenopausal women aged 40-60 years completed 3 days of wrist actigraphy, hot flash monitoring, questionnaires (Pittsburgh Sleep Quality Index [PSQI], Berlin), a blood draw, and carotid ultrasound [intima media thickness (IMT), plaque]. Associations of objective (actigraphy) and subjective (PSQI) sleep with IMT/plaque were tested in regression models (covariates: age, race, education, body mass index, blood pressure, lipids, insulin resistance, medications, snoring, depressive symptoms, sleep hot flashes, and estradiol). Shorter objective sleep time was associated with higher odds of carotid plaque (for each hour shorter sleep, plaque score ≥ 2, odds ratio (OR) [95% confidence interval, CI] = 1.58 [1.11-2.27], p = .01; plaque score = 1, OR [95% CI] = 0.95 [0.68-1.32], p = .75, vs. no plaque, multivariable). Poorer subjective sleep quality was associated with higher mean IMT [β, b (standard error, SE) = 0.004 (0.002), p = .03], maximal IMT [b (SE) = 0.009 (0.003), p = .005], and plaque [plaque score ≥ 2, OR (95% CI) = 1.23 (1.09-1.40), p = .001; score = 1, OR (95% CI) = 1.06 (0.93-1.21), p = .37, vs. no plaque] in multivariable models. Findings persisted additionally adjusting for sleep hot flashes and estradiol. Shorter actigraphy-assessed sleep time and poorer subjective sleep quality were associated with increased carotid atherosclerosis among midlife women. Associations persisted adjusting for CVD risk factors, hot flashes, and estradiol. © Sleep Research Society 2016. Published by Oxford

Endovascular Patch Embolization for Blood Blister-Like Aneurysms in Dorsal Segment of Internal Carotid Artery.

PubMed

Hao, Xudong; Li, Guilin; Ren, Jian; Li, Jingwei; He, Chuan; Zhang, Hong-Qi

2018-05-01

Blood blister-like aneurysms (BBAs) in the dorsal segment of the internal carotid artery are fragile and difficult to treat, and the optimal treatment for BBAs is still controversial. We report clinical and angiographic results with procedural details for the treatment of BBA by using the endovascular patch embolization method. We retrospectively reviewed patients who presented with subarachnoid hemorrhage caused by internal carotid artery-BBAs and were treated with the endovascular patch embolization method in our center from October 2011 to March 2015. Clinical records, angiographic findings, procedural details, and follow-up results are reported in this study. Eight patients were enrolled in this study. All patients were treated with the endovascular patch embolization method. The key points of this method are step-by-step stent deployment and swaying of the microcatheter to coil the aneurysm sac and the wedge-shaped space between the stent and parent artery and, thereby, in the aneurysm sac and parent artery around the aneurysm neck. When the stent is completely deployed, an endovascular patch is formed and anchored around the neck of the BBA. The procedure was successful in all cases. No acute complications developed in any case. No rerupture or recurrence of the BBA occurred during follow-up. One patient with Hunt-Hess V subarachnoid hemorrhage died of multiple organ failure 4 months post treatment. Another patient died of intracranial infection related to the ventricle-peritoneal shunt. The remaining 6 patients had good clinical outcomes (modified Rankin Scale score of zero). Endovascular patch embolization is an improvement on stent-assisted coil embolization, which could be successfully performed only with extensive skill and patience. Endovascular patch embolization could be an effective method in BBA treatment. However, its efficacy and safety should be verified in a larger patient cohort and long-term follow-up study. Copyright © 2018. Published by

Assessment of the carotid artery intima-media complex through ultrasonography and the relationship with Pathobiological Determinants of Atherosclerosis in Youth.

PubMed

Ramos, Thacira D A; Dantas, Tatianne M E; Simões, Mônica O S; Carvalho, Danielle F; Medeiros, Carla C M

2016-10-01

To evaluate the presence of carotid thickening and its relationship with the Pathobiological Determinants of Atherosclerosis in Youth score. We carried out a cross-sectional study involving 512 brazilian adolescents. Variables such as sex, body mass index, concentrations of non-high-density lipoprotein and high-density lipoprotein cholesterol, blood pressure, blood glucose and glycated haemoglobin A1c levels that make up the score, and carotid thickening through the intima-media complex measured by ultrasound were evaluated. We adopted two cut-off points to evaluate carotid thickening, being considered altered for those higher or equal to the z-score 2+ and ⩾75th percentile. The association was assessed using the χ2 test and univariate and multivariate logistic regression analyses. High cardiovascular risk was present in 10.2% of the adolescents; carotid thickness was present in 4.3% determined by the z-score 2+ and in 25.0% determined by the 75th percentile. When measured by the z-score, carotid thickening was associated with high systolic blood pressure (p=0.024), high-non-high density lipoprotein cholesterol (p=0.039), and high cardiovascular risk assessed by the score and by the 75th percentile, with body mass index >30 (p=0.005). In the multivariate analysis, high cardiovascular risk was found to be independently associated with the presence of carotid thickness evaluated by the z-score, with risk four times greater (p=0.010) of presenting with this condition compared with individuals with low risk, and this fact was not observed when factors were analysed alone. The presence of high cardiovascular risk in adolescents assessed by the Pathobiological Determinants of Atherosclerosis in Youth score was associated with marked thickening of the carotid artery in healthy adolescents.

Impaired ventilatory acclimatization to hypoxia in female mice overexpressing erythropoietin: unexpected deleterious effect of estradiol in carotid bodies.

PubMed

Gassmann, Max; Pfistner, Christine; Doan, Van Diep; Vogel, Johannes; Soliz, Jorge

2010-12-01

Apart from enhancing the production of red blood cells, erythropoietin (Epo) alters the ventilatory response when oxygen supply is reduced. We recently demonstrated that Epo's beneficial effect on the ventilatory response to acute hypoxia is sex dependent, with female mice being better able to cope with reduced oxygenation. In the present work, we hypothesized that ventilatory acclimatization to chronic hypoxia (VAH) in transgenic female mice (Tg6) harboring high levels of Epo in the brain and blood will also be improved compared with wild-type (WT) animals. Surprisingly, VAH was blunted in Tg6 female mice. To define whether this phenomenon had a central (brain stem respiratory centers) and/or peripheral (carotid bodies) origin, a bilateral transection of carotid sinus nerve (chemodenervation) was performed. This procedure allowed the analysis of the central response in the absence of carotid body information. Interestingly, chemodenervation restored the VAH in Tg6 mice, suggesting that carotid bodies were responsible for the blunted response. Coherently with this observation, the sensitivity to oxygen alteration in arterial blood (Dejour test) after chronic hypoxia was lower in transgenic carotid bodies compared with the WT control. As blunted VAH occurred in female but not male transgenic mice, the involvement of sex female steroids was obvious. Indeed, measurement of sexual female hormones revealed that the estradiol serum level was 4 times higher in transgenic mice Tg6 than in WT animals. While ovariectomy decreased VAH in WT females, this treatment restored VAH in Tg6 female mice. In line with this observation, injections of estradiol in ovariectomized Tg6 females dramatically reduced the VAH. We concluded that during chronic hypoxia, estradiol in carotid bodies suppresses the Epo-mediated elevation of ventilation. Considering the increased application of recombinant Epo for a variety of disorders, our data imply the need to take the patient's hormonal status

Effects of organic and inorganic nitrate on aortic and carotid haemodynamics in heart failure with preserved ejection fraction.

PubMed

Chirinos, Julio A; Londono-Hoyos, Francisco; Zamani, Payman; Beraun, Melissa; Haines, Philip; Vasim, Izzah; Varakantam, Swapna; Phan, Timothy S; Cappola, Thomas P; Margulies, Kenneth B; Townsend, Raymond R; Segers, Patrick

2017-11-01

To assess the haemodynamic effects of organic vs. inorganic nitrate administration among patients with heart failure with preserved ejection fraction (HFpEF). We assessed carotid and aortic pressure-flow relations non-invasively before and after the administration of 0.4 mg of sublingual nitroglycerin (n = 26), and in a separate sub-study, in response to 12.9 mmoL of inorganic nitrate (n = 16). Nitroglycerin did not consistently reduce wave reflections arriving at the proximal aorta (change in real part of reflection coefficient, 1st harmonic: -0.09; P = 0.01; 2nd harmonic: -0.045, P = 0.16; 3rd harmonic: +0.087; P = 0.05), but produced profound vasodilatation in the carotid territory, with a significant reduction in systolic blood pressure (133.6 vs. 120.5 mmHg; P = 0.011) and a marked reduction in carotid bed vascular resistance (19 580 vs. 13 078 dynes · s/cm 5 ; P = 0.001) and carotid characteristic impedance (3440 vs. 1923 dynes · s/cm 5 ; P = 0.002). Inorganic nitrate, in contrast, consistently reduced wave reflections across the first three harmonics (change in real part of reflection coefficient, 1st harmonic: -0.12; P = 0.03; 2nd harmonic: -0.11, P = 0.01; 3rd harmonic: -0.087; P = 0.09) and did not reduce blood pressure, carotid bed vascular resistance, or carotid characteristic impedance (P = NS). Nitroglycerin produces marked vasodilatation in the carotid circulation, with a pronounced reduction in blood pressure and inconsistent effects on central wave reflections. Inorganic nitrate, in contrast, produces consistent reductions in wave reflections, and unlike nitroglycerin, it does so without significant hypotension or cerebrovascular dilatation. These haemodynamic differences may underlie the different effects on exercise capacity and side effect profile of inorganic vs. organic nitrate in HFpEF. © 2017 The Authors. European Journal of Heart Failure © 2017 European Society of Cardiology.

Association between cardiovascular risk factors and carotid intima-media thickness in prepubertal Brazilian children.

PubMed

Gazolla, Fernanda Mussi; Neves Bordallo, Maria Alice; Madeira, Isabel Rey; de Miranda Carvalho, Cecilia Noronha; Vieira Monteiro, Alexandra Maria; Pinheiro Rodrigues, Nádia Cristina; Borges, Marcos Antonio; Collett-Solberg, Paulo Ferrez; Muniz, Bruna Moreira; de Oliveira, Cecilia Lacroix; Pinheiro, Suellen Martins; de Queiroz Ribeiro, Rebeca Mathias

2015-05-01

Early exposure to cardiovascular risk factors creates a chronic inflammatory state that could damage the endothelium followed by thickening of the carotid intima-media. To investigate the association of cardiovascular risk factors and thickening of the carotid intima. Media in prepubertal children. In this cross-sectional study, carotid intima-media thickness (cIMT) and cardiovascular risk factors were assessed in 129 prepubertal children aged from 5 to 10 year. Association was assessed by simple and multivariate logistic regression analyses. In simple logistic regression analyses, body mass index (BMI) z-score, waist circumference, and systolic blood pressure (SBP) were positively associated with increased left, right, and average cIMT, whereas diastolic blood pressure was positively associated only with increased left and average cIMT (p<0.05). In multivariate logistic regression analyses increased left cIMT was positively associated to BMI z-score and SBP, and increased average cIMT was only positively associated to SBP (p<0.05). BMI z-score and SBP were the strongest risk factors for increased cIMT.

Chronic exposure to biomass fuel is associated with increased carotid artery intima-media thickness and a higher prevalence of atherosclerotic plaque

PubMed Central

Painschab, Matthew S; Davila-Roman, Victor G; Gilman, Robert H; Vasquez-Villar, Angel D; Pollard, Suzanne L; Wise, Robert A; Miranda, J Jaime; Checkley, William

2015-01-01

Background Biomass fuels are used for cooking in the majority of rural households worldwide. While their use is associated with an increased risk of lung diseases and all-cause mortality, the effects on cardiovascular disease (CVD) are not well characterised. Exposure to biomass fuel smoke has been associated with lung-mediated inflammation and oxidative stress, which may increase the risk of atherosclerosis as evaluated by carotid intima-media thickness (CIMT), carotid atherosclerotic plaque prevalence and blood pressure. Methods A cross-sectional study was performed in 266 adults aged ≥35 years in Puno, Peru (3825 m above sea level). We stratified participants by their long-term history of exposure to clean fuel (n=112) or biomass fuel (n=154) and measured 24 h indoor particulate matter (PM2.5) in a random subset (n=84). Participants completed questionnaires and underwent a clinical assessment, laboratory analyses and carotid artery ultrasound. The main outcome measures were CIMT, carotid plaque and blood pressure. Results The groups were similar in age and gender. The biomass fuel group had greater unadjusted mean CIMT (0.66 vs 0.60 mm; p<0.001), carotid plaque prevalence (26% vs 14%; p=0.03), systolic blood pressure (118 vs 111 mm Hg; p<0.001) and median household PM2.5 (280 vs 14 μg/m3; p<0.001). In multivariable regression, the biomass fuel group had greater mean CIMT (mean difference=0.03 mm, 95% CI 0.01 to 0.06; p=0.02), a higher prevalence of carotid plaques (OR=2.6, 95% CI 1.1 to 6.0; p=0.03) and higher systolic blood pressure (mean difference=9.2 mm Hg, 95% CI 5.4 to 13.0; p<0.001). Conclusions Chronic exposure to biomass fuel was associated with increased CIMT, increased prevalence of atherosclerotic plaques and higher blood pressure. These findings identify biomass fuel use as a risk factor for CVD, which may have important global health implications. PMID:23619984

Urinary Sodium and Potassium Excretion and Carotid Atherosclerosis in Chinese Men and Women

PubMed Central

Dai, Xiao-Wei; Wang, Cheng; Xu, Ying; Guan, Ke; Su, Yi-Xiang; Chen, Yu-Ming

2016-01-01

Limited studies have examined the association between sodium (Na) and potassium (K) levels and the risk of atherosclerosis. This study examined whether higher Na and Na/K levels and low K levels were independent risk factors for atherosclerosis. This community-based cross-sectional study included 3290 subjects (1067 men and 2223 women) 40 to 75 years of age in Guangzhou, China, between 2011 and 2013. Urinary excretion of Na and K were measured from the first morning void, and creatinine-adjusted values were used. The intima-media thickness (IMT) of the carotid common artery and the carotid bifurcation was measured with high-resolution B-mode ultrasonography. Dietary K and Na intake and other covariates were obtained by face-to-face interviews. A significant positive association was seen between urinary Na excretion and carotid atherosclerosis after adjustment for age, sex, and other lifestyle covariates. The odds ratios (OR) and 95% confidence interval (CI) of the highest (vs. lowest) quartile of urinary Na were 1.32 (1.04–1.66) for carotid plaques, 1.48 (1.18–1.87) for increased common carotid artery IMT, and 1.55 (1.23–1.96) for increased carotid bifurcation IMT (all p-trend < 0.01). A similar positive association was observed between urinary Na/K levels and carotid plaque and increased IMT, and between dietary Na intake and increased bifurcation IMT. Regarding potassium data, we only found a significantly lower presence of carotid plaque (OR 0.72, 95% CI 0.57–0.91) for quartile 2 (vs. 1) of urinary K. Our findings suggest that higher levels of urinary excretion Na and Na/K are significantly associated with greater presence of carotid atherosclerosis in Chinese adults. PMID:27706075

Assessment of shear stress related parameters in the carotid bifurcation using mouse-specific FSI simulations.

PubMed

De Wilde, David; Trachet, Bram; Debusschere, Nic; Iannaccone, Francesco; Swillens, Abigail; Degroote, Joris; Vierendeels, Jan; De Meyer, Guido R Y; Segers, Patrick

2016-07-26

The ApoE(-)(/)(-) mouse is a common small animal model to study atherosclerosis, an inflammatory disease of the large and medium sized arteries such as the carotid artery. It is generally accepted that the wall shear stress, induced by the blood flow, plays a key role in the onset of this disease. Wall shear stress, however, is difficult to derive from direct in vivo measurements, particularly in mice. In this study, we integrated in vivo imaging (micro-Computed Tomography-µCT and ultrasound) and fluid-structure interaction (FSI) modeling for the mouse-specific assessment of carotid hemodynamics and wall shear stress. Results were provided for 8 carotid bifurcations of 4 ApoE(-)(/)(-) mice. We demonstrated that accounting for the carotid elasticity leads to more realistic flow waveforms over the complete domain of the model due to volume buffering capacity in systole. The 8 simulated cases showed fairly consistent spatial distribution maps of time-averaged wall shear stress (TAWSS) and relative residence time (RRT). Zones with reduced TAWSS and elevated RRT, potential indicators of atherosclerosis-prone regions, were located mainly at the outer sinus of the external carotid artery. In contrast to human carotid hemodynamics, no flow recirculation could be observed in the carotid bifurcation region. Copyright © 2015 Elsevier Ltd. All rights reserved.

Infrasonic analysis of carotid vibration as a diagnostic method in carotid insufficiency syndrome.

PubMed

Anastassiades, A J; Petounis, A D

1976-01-01

The infrasonic part of the spectrum of the carotid artery wall vibration in the neck was obtained. Differences between the spectral content and vibrational amplitude in normal and occluded carotids were found. The application of this technique in clinical practice could be useful in the detection of the carotid insufficiency syndrome.

Arterial function of carotid and brachial arteries in postmenopausal vegetarians.

PubMed

Su, Ta-Chen; Torng, Pao-Ling; Jeng, Jiann-Shing; Chen, Ming-Fong; Liau, Chiau-Suong

2011-01-01

Vegetarianism is associated with a lower risk of cardiovascular disease. However, studies of arterial function in vegetarians are limited. This study investigated arterial function in vegetarianism by comparing 49 healthy postmenopausal vegetarians with 41 age-matched omnivores. The arterial function of the common carotid artery was assessed by carotid duplex, while the pulse dynamics method was used to measure brachial artery distensibility (BAD), compliance (BAC), and resistance (BAR). Fasting blood levels of glucose, lipids, lipoprotein (a), high-sensitivity C-reactive protein, homocysteine, and vitamin B12 were also measured. Vegetarians had significantly lower serum cholesterol, high-density and low-density lipoprotein, and glucose compared with omnivores. They also had lower vitamin B12 but higher homocysteine levels. Serum levels of lipoprotein (a) and high-sensitivity C-reactive protein were no different between the two groups. There were no significant differences in carotid beta stiffness index, BAC, and BAD between the two groups even after adjustment for associated covariates. However, BAR was significantly lower in vegetarians than in omnivores. Multiple linear regression analysis revealed that age and pulse pressure were two important determinants of carotid beta stiffness index and BAD. Vegetarianism is not associated with better arterial elasticity. Apparently healthy postmenopausal vegetarians are not significantly better in terms of carotid beta stiffness index, BAC, and BAD, but have significantly decreased BAR than omnivores. Prevention of vitamin B12 deficiency might be beneficial for cardiovascular health in vegetarians.

Interaction of workplace demands and cardiovascular reactivity in progression of carotid atherosclerosis: population based study.

PubMed Central

Everson, S. A.; Lynch, J. W.; Chesney, M. A.; Kaplan, G. A.; Goldberg, D. E.; Shade, S. B.; Cohen, R. D.; Salonen, R.; Salonen, J. T.

1997-01-01

OBJECTIVE: To examine the combined influence of workplace demands and changes in blood pressure induced by stress on the progression of carotid atherosclerosis. DESIGN: Population based follow up study of unestablished as well as traditional risk factors for carotid atherosclerosis, ischaemic heart disease, and other outcomes. SETTING: Eastern Finland. SUBJECTS: 591 men aged 42-60 who were fully employed at baseline and had complete data on the measures of carotid atherosclerosis, job demands, blood pressure reactivity, and covariates. MAIN OUTCOME MEASURES: Change in ultrasonographically assessed intima-media thickness of the right and left common carotid arteries from baseline to 4 year follow up. RESULTS: Significant interactions between workplace demands and stress induced reactivity were observed for all measures of progression (P < 0.04). Men with large changes in systolic blood pressure (20 mm Hg or greater) in anticipation of a maximal exercise test and with high job demands had 10-40% greater progression of mean (0.138 v 0.123 mm) and maximum (0.320 v 0.261 mm) intima-media thickness and plaque height (0.347 v 0.264) than men who were less reactive and had fewer job demands. Similar results were obtained after excluding men with prevalent ischaemic heart disease at baseline. Findings were strongest among men with at least 20% stenosis or non-stenotic plaque at baseline. In this subgroup reactive men with high job demands had more than 46% greater atherosclerotic progression than the others. Adjustment for atherosclerotic risk factors did not alter the results. CONCLUSIONS: Men who showed stress induced blood pressure reactivity and who reported high job demands experienced the greatest atherosclerotic progression, showing the association between dispositional risk characteristics and contextual determinants of disease and suggesting that behaviourally evoked cardiovascular reactivity may have a role in atherogenesis. PMID:9055713

Trajectories of Vasomotor Symptoms and Carotid Intima Media Thickness in the Study of Women's Health Across the Nation.

PubMed

Thurston, Rebecca C; El Khoudary, Samar R; Tepper, Ping Guo; Jackson, Elizabeth A; Joffe, Hadine; Chen, Hsiang-Yu; Matthews, Karen A

2016-01-01

Emerging work has linked menopausal vasomotor symptoms (VMS) to subclinical cardiovascular disease (CVD) among women. However, VMS are dynamic over time. No studies have considered how temporal patterns of VMS may relate to subclinical CVD. We tested how temporal patterns of VMS assessed over 13 years were related to carotid intima media thickness (IMT) among midlife women. The Study of Women's Health Across the Nation is a longitudinal cohort study of midlife women. Eight hundred and eleven white, black, Hispanic, and Chinese participants with a well-characterized final menstrual period completed measures of VMS, a blood draw, and physical measures approximately annually for 13 years. Women underwent a carotid artery ultrasound at study visit 12. Four trajectories of VMS were identified by trajectory analysis (consistently high, early-onset, late-onset, persistently low VMS) and tested in relation to carotid indices in linear regression models. Results indicated that women with early-onset VMS had both greater mean IMT (beta, b [standard error, SE]=0.03 [0.01], P=0.03) and greater maximal IMT (b [SE]=0.04 [0.01], P=0.008) than women with consistently low VMS, adjusting for demographics and CVD risk factors. This is the first study to test trajectories of VMS in relation to subclinical CVD. Women with VMS early in the menopause transition had higher mean IMT and maximal IMT than those with consistently low VMS across the transition. Associations were not accounted for by demographic factors nor by CVD risk factors. Results can signal to women in need of early CVD risk reduction. © 2015 American Heart Association, Inc.

Reduced subclinical carotid vascular disease and arterial stiffness in vegetarian men: The CARVOS Study.

PubMed

Acosta-Navarro, Julio; Antoniazzi, Luiza; Oki, Adriana Midori; Bonfim, Maria Carlos; Hong, Valeria; Acosta-Cardenas, Pedro; Strunz, Celia; Brunoro, Eleonora; Miname, Marcio Hiroshi; Filho, Wilson Salgado; Bortolotto, Luiz Aparecido; Santos, Raul D

2017-03-01

Dietary habits play an important role in the development of atherosclerosis, the most important cause of morbidity and mortality in the world. The objective of this study was to verify if vegetarian (VEG) diet could be related a better profile of subclinical vascular disease evaluated by arterial stiffness and functional and structural properties of carotid arteries, compared to omnivorous (OMN) diet. In this cross-sectional study, 44 VEG and 44 OMN apparently healthy men ≥35years of age, in order to not have confounding risk factors of subclinical atherosclerosis, were assessed for anthropometric data, blood pressure, blood lipids, glucose, C reactive protein (CRP), and arterial stiffness determined by carotid-femoral pulse wave velocity (PWV). Also, carotid intima-media thickness (c-IMT) and distensibility were evaluated. VEG men had lower body mass index, systolic and diastolic blood pressures, fasting serum total cholesterol, LDL and non-HDL-cholesterol, apolipoprotein B, glucose and glycated hemoglobin values in comparison with OMN individuals (all p values <0.05). Markers of vascular structure and function were different between VEG and OMN: PWV 7.1±0.8m/s vs. 7.7±0.9m/s (p<0.001); c-IMT 593±94 vs. 661±128μm (p=0.003); and relative carotid distensibility 6.39±1.7 vs. 5.72±1.8% (p=0.042), respectively. After a multivariate linear regression analysis, a VEG diet was independently and negatively associated with PWV (p value 0.005). A VEG diet is associated with a more favorable cardiovascular diseases biomarker profile and better vascular structural and functional parameters. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Evidence for a carotid body homolog in the lizard Tupinambis merianae.

PubMed

Reichert, Michelle N; Brink, Deidre L; Milsom, William K

2015-01-15

The homolog to the mammalian carotid body has not yet been identified in lizards. Observational studies and evolutionary history provide indirect evidence for the existence of a chemoreceptor population at the first major bifurcation of the common carotid artery in lizards, but a chemoreceptive role for this area has not yet been definitively demonstrated. We explored this possibility by measuring changes in cardiorespiratory variables in response to focal arterial injections of the hypoxia mimic sodium cyanide (NaCN) into the carotid artery of 12 unanesthetized specimens of Tupinambis merianae. These injections elicited increases in heart rate (f(H); 101±35% increase) and respiratory rate (f(R); 620±119% increase), but not mean arterial blood pressure (MAP). These responses were eliminated by vagal denervation. Similar responses were elicited by injections of the neurotransmitters acetylcholine (ACh) and serotonin (5-HT) but not norepinephrine. Heart rate and respiratory rate increases in response to NaCN could be blocked or reduced by antagonists to ACh (atropine) and/or 5-HT (methysergide). Finally, using immunohistochemistry, we demonstrate the presence of putative chemoreceptive cells immunopositive for the cholinergic cell marker vesicular ACh transporter (VAChT) and 5-HT on internal lattice-like structures at the carotid bifurcation. These results provide evidence in lizards for the existence of dispersed chemoreceptor cells at the first carotid bifurcation in the central cardiovascular area that have similar properties to known carotid body homologs, adding to the picture of chemoreceptor evolution in vertebrates. © 2015. Published by The Company of Biologists Ltd.

Carotid intima-media thickness and elastic properties of aortas in normotensive children of hypertensive parents.

PubMed

Yildirim, Ali; Kosger, Pelin; Ozdemir, Gokmen; Sahin, Fezan Mutlu; Ucar, Birsen; Kilic, Zubeyir

2015-09-01

A significant correlation between hypertension history and high blood pressure has been observed with regard to age, race and gender. Investigating carotid intima-media thickness and aortic stiffness prior to the development of hypertension in children of hypertensive parents enabled us to evaluate these patients for subclinical atherosclerosis. We compared carotid intima-media thickness, aortic strain, distensibility, stiffness indices and elastic modulus in 67 normotensive children whose parents had a diagnosis of essential hypertension and 39 normotensive children with no parental history of hypertension. Although there were no significant differences between the two groups in terms of systolic blood pressure, diastolic blood pressure, average blood pressure and pulse pressure (P>0.05), systolic blood pressures were higher among patients 15 years and older in the study group. No significant differences were noted between the control and study groups regarding interventricular septal thickness, left-ventricular posterior wall thickness, left-ventricular systolic and diastolic diameter and aortic annulus diameter (P>0.05). The left atrium diameter was larger in the study group compared with that in the control group, mainly because of the values of the 15-year-old and older children (P=0.01). The mean, maximum and minimum values of carotid intima-media thickness were significantly different in the study group compared with the control group among all age groups (P<0.001, P<0.001, P=0.006, respectively). Aortic systolic and diastolic diameters were larger in normotensive children of hypertensive parents compared with the control group (P=0.014, P=0.001, respectively). Although there were no differences between the study and control groups regarding aortic strain, aortic distensibility, elastic modulus and stiffness indices (P>0.05), aortic distensibility was lower, and aortic stiffness indices were higher among children 15 years and older in the study group. An

Race/Ethnic Differences in the Associations of the Framingham Risk Factors with Carotid IMT and Cardiovascular Events

PubMed Central

Hoefer, Imo E.; Eijkemans, Marinus J. C.; Asselbergs, Folkert W.; Anderson, Todd J.; Britton, Annie R.; Dekker, Jacqueline M.; Engström, Gunnar; Evans, Greg W.; de Graaf, Jacqueline; Grobbee, Diederick E.; Hedblad, Bo; Holewijn, Suzanne; Ikeda, Ai; Kitagawa, Kazuo; Kitamura, Akihiko; de Kleijn, Dominique P. V.; Lonn, Eva M.; Lorenz, Matthias W.; Mathiesen, Ellisiv B.; Nijpels, Giel; Okazaki, Shuhei; O’Leary, Daniel H.; Pasterkamp, Gerard; Peters, Sanne A. E.; Polak, Joseph F.; Price, Jacqueline F.; Robertson, Christine; Rembold, Christopher M.; Rosvall, Maria; Rundek, Tatjana; Salonen, Jukka T.; Sitzer, Matthias; Stehouwer, Coen D. A.; Bots, Michiel L.; den Ruijter, Hester M.

2015-01-01

Background Clinical manifestations and outcomes of atherosclerotic disease differ between ethnic groups. In addition, the prevalence of risk factors is substantially different. Primary prevention programs are based on data derived from almost exclusively White people. We investigated how race/ethnic differences modify the associations of established risk factors with atherosclerosis and cardiovascular events. Methods We used data from an ongoing individual participant meta-analysis involving 17 population-based cohorts worldwide. We selected 60,211 participants without cardiovascular disease at baseline with available data on ethnicity (White, Black, Asian or Hispanic). We generated a multivariable linear regression model containing risk factors and ethnicity predicting mean common carotid intima-media thickness (CIMT) and a multivariable Cox regression model predicting myocardial infarction or stroke. For each risk factor we assessed how the association with the preclinical and clinical measures of cardiovascular atherosclerotic disease was affected by ethnicity. Results Ethnicity appeared to significantly modify the associations between risk factors and CIMT and cardiovascular events. The association between age and CIMT was weaker in Blacks and Hispanics. Systolic blood pressure associated more strongly with CIMT in Asians. HDL cholesterol and smoking associated less with CIMT in Blacks. Furthermore, the association of age and total cholesterol levels with the occurrence of cardiovascular events differed between Blacks and Whites. Conclusion The magnitude of associations between risk factors and the presence of atherosclerotic disease differs between race/ethnic groups. These subtle, yet significant differences provide insight in the etiology of cardiovascular disease among race/ethnic groups. These insights aid the race/ethnic-specific implementation of primary prevention. PMID:26134404

Race/Ethnic Differences in the Associations of the Framingham Risk Factors with Carotid IMT and Cardiovascular Events.

PubMed

Gijsberts, Crystel M; Groenewegen, Karlijn A; Hoefer, Imo E; Eijkemans, Marinus J C; Asselbergs, Folkert W; Anderson, Todd J; Britton, Annie R; Dekker, Jacqueline M; Engström, Gunnar; Evans, Greg W; de Graaf, Jacqueline; Grobbee, Diederick E; Hedblad, Bo; Holewijn, Suzanne; Ikeda, Ai; Kitagawa, Kazuo; Kitamura, Akihiko; de Kleijn, Dominique P V; Lonn, Eva M; Lorenz, Matthias W; Mathiesen, Ellisiv B; Nijpels, Giel; Okazaki, Shuhei; O'Leary, Daniel H; Pasterkamp, Gerard; Peters, Sanne A E; Polak, Joseph F; Price, Jacqueline F; Robertson, Christine; Rembold, Christopher M; Rosvall, Maria; Rundek, Tatjana; Salonen, Jukka T; Sitzer, Matthias; Stehouwer, Coen D A; Bots, Michiel L; den Ruijter, Hester M

2015-01-01

Clinical manifestations and outcomes of atherosclerotic disease differ between ethnic groups. In addition, the prevalence of risk factors is substantially different. Primary prevention programs are based on data derived from almost exclusively White people. We investigated how race/ethnic differences modify the associations of established risk factors with atherosclerosis and cardiovascular events. We used data from an ongoing individual participant meta-analysis involving 17 population-based cohorts worldwide. We selected 60,211 participants without cardiovascular disease at baseline with available data on ethnicity (White, Black, Asian or Hispanic). We generated a multivariable linear regression model containing risk factors and ethnicity predicting mean common carotid intima-media thickness (CIMT) and a multivariable Cox regression model predicting myocardial infarction or stroke. For each risk factor we assessed how the association with the preclinical and clinical measures of cardiovascular atherosclerotic disease was affected by ethnicity. Ethnicity appeared to significantly modify the associations between risk factors and CIMT and cardiovascular events. The association between age and CIMT was weaker in Blacks and Hispanics. Systolic blood pressure associated more strongly with CIMT in Asians. HDL cholesterol and smoking associated less with CIMT in Blacks. Furthermore, the association of age and total cholesterol levels with the occurrence of cardiovascular events differed between Blacks and Whites. The magnitude of associations between risk factors and the presence of atherosclerotic disease differs between race/ethnic groups. These subtle, yet significant differences provide insight in the etiology of cardiovascular disease among race/ethnic groups. These insights aid the race/ethnic-specific implementation of primary prevention.

Proximal protection with hybrid stent, a safer combination for carotid artery stenting against carotid endarterectomy?

PubMed

Gürkaş, E; Ak, F; Orhan, G; Bozkurt, E; Ulusoy, E K

2015-12-01

Carotid revascularization is an established theurapeutic modality in preventing stroke and death among patients with severe carotid stenosis. Although carotid endarterectomy remains as the primary option, carotid stenting is accepted as an alternative for patients with high risk for carotid endarterectomy. Recently published reports have better results with proximal protection devices when compared with distal protection devices. These studies have revealed less microembolic signals and less periprocedural new ischemic lesions on diffusion weighted magnetic resonance imaging. Stent choice may be also important for these procedures as open cell stent design has advantage of better flexibility whereas closed cell systems have an advantage of better scaffolding. Hybrid stents which are composed of open cells in the proximal and distal part and closed cells in the middle may carry both advantages. The aim of this study is to demonstrate whether combination of proximal protection devices with hybrid stents can be a safe alternative for carotid stenting in terms of periprocedural and 30-day outcomes. Here we retrospectively evaluated 68 symptomatic carotid stenosis patients undergoing carotid stenting with hybrid stent (Cristallo Ideale®, Invatec s.r.l., Medtronic, Italy) and proximal protection device (MO.MA®, Invatec s.r.l., Medtronic, Italy). Our results showed only 1 minor stroke in the periprocedural period and during the first 30-day after stenting, with no death or myocardial infarction. Although our case number is not large, we propose that carotid stenting may be safer with utilization of proximal protection system and hybrid type carotid stents.

The influence of the nasal mucosa and the carotid rete upon hypothalamic temperature in sheep

PubMed Central

Baker, Mary Ann; Hayward, James N.

1968-01-01

1. In chronically-prepared sheep, intracranial temperatures were measured in the cavernous sinus among the vessels of the carotid rete and at the circle of Willis extravascularly, and in the preoptic area and in other brain stem regions. Extracranial temperatures were measured intravascularly in the carotid or internal maxillary arteries and on the nasal mucosa and the skin of the ear. 2. At 20° C ambient temperature, shifts in temperature of the hypothalamus and of other brain sites paralleled temperature shifts in the cerebral arterial blood which was cooler than central arterial blood. During periods of arousal and of paradoxical sleep, vasoconstriction of the nasal mucosa and the ear skin occurred and temperatures at the cerebral arteries and in the brain rose without a comparable rise in central arterial blood temperature. 3. Anaesthetic doses of barbiturate abolished the temperature oscillations in the cerebral arterial blood and the brain. When air was blown rapidly over the nasal mucosa in anaesthetized animals, temperatures dropped precipitously in the cavernous sinus, at the cerebral arteries, and in the brain, while central arterial temperature fell only slightly. Injections of latex into the facial venous system demonstrated a venous pathway from the nasal mucosa to the cavernous sinus. 4. When sheep were exposed to 45-50° C ambient temperature, respiratory rate increased 5-10 times and the temperature gradient between central and cerebral arterial blood widened. 5. It is concluded that venous blood returning from the nasal mucosa and the skin of the head to the cavernous sinus cools the central arterial blood in the carotid rete. This is an important factor in the maintenance of hypothalamic temperature in the wool-covered, long-nosed, panting sheep and undoubtedly affects hypothalamic thermoreceptors and temperature regulation in artiodactyls. PMID:5685288

Glossopharyngeal schwannoma of the suprahyoid carotid space: case report and discussion of the relationship to the carotid artery.

PubMed

Nagamine, Wayde H; Conneely, Mark F; Petruzzelli, Guy J; Hacein-Bey, Lotfi

2009-04-01

The distinction between lesions of the deep parotid space and those of the carotid space has been greatly facilitated by cross-sectional imaging, particularly magnetic resonance imaging (MRI), due to 1) good assessment of parapharyngeal fat displacement, and 2) reliable and consistent identification of the carotid artery. While masticator space masses consistently displace the carotid artery posteriorly, it is generally assumed that carotid space masses, particularly schwannomas, displace the carotid artery anteriorly. We report on a patient with a rare glossopharyngeal schwannoma of the carotid space that caused posterior displacement of the carotid artery. A 38-year-old female presented with headaches and a pharyngeal sensation of a foreign body without dysgeusia and dysphagia. Computed tomography (CT) and MRI showed a left carotid space mass, suggestive of a schwannoma, although the internal carotid artery was displaced posteriorly. The mass was hypovascular at angiography. The patient underwent surgical excision of her lesion via a left cervical-parotid approach. In our patient with a carotid space mass, all imaging features suggested a schwannoma, except for posterior displacement of the carotid artery. A glossopharyngeal nerve schwannoma was found at surgery. Schwannomas of the glossopharyngeal nerve are uncommon, and those originating from the extracranial course of the nerve are extremely rare. Schwannomas of the suprahyoid carotid space most commonly arise from the vagus nerve and have a typical pattern, which includes anterior displacement of the carotid artery. A rare exception to this has been reported in schwannomas of the sympathetic nerve, which may displace the carotid artery posteromedially. Our patient had a schwannoma of the extracranial glossopharyngeal nerve, which caused posterolateral carotid displacement.

Carotid Plaque Morphology in Asymptomatic Patients with and without Metabolic Syndrome.

PubMed

Cury, Marcus Vinícius Martins; Presti, Calógero; Bonadiman, Suellen Stevam Timotheo; Casella, Ivan Benaduce; Benabou, Joseph Elias; da Silva, Erasmo Simão; de Luccia, Nelson; Puech-Leão, Pedro

2017-02-01

The aim of this study was to determine the impact of metabolic syndrome (MetS) on the morphology of carotid plaques, as evaluated using duplex ultrasound (DUS) with computer-assisted analysis. In this cross-sectional observational study, we analyzed 148 carotid artery plaques in asymptomatic patients. Data were obtained via clinical and laboratory examinations, and DUS was performed by a single operator. All plaques were scanned in a longitudinal fashion, and the best segment was selected, recorded, and evaluated using dedicated software. The main software-based analyses included gray-scale median (GSM) measurements and carotid plaque morphology histograms. MetS was identified in 51.8% of patients. Comparisons of patients with MetS and patients without MetS indicated that the former patients used more classes of antihypertensive drugs (2.49 vs. 1.93; P = 0.004) and were treated with statins for a longer period (71.08 vs. 49.17 months; P = 0.003). Most patients of both types exhibited moderate carotid artery stenosis ranging from 50% to 69% (n = 62; 37.3%), and MetS was not associated with an increased prevalence of severe carotid artery stenosis. The mean GSM was greater in the MetS group than in the non-MetS group (74.18 vs. 61.63; P = 0.012). The histogram analysis revealed that there were lower quantities of blood and fat (2.91 vs. 3.88; P = 0.006; 10.21 vs. 15.08; P = 0.004, respectively) and more fibrous tissue (19.93 vs. 14.55; P = 0.015) in the carotid plaques of patients with MetS than in the carotid plaques of patients without MetS. The present study demonstrated that MetS did not affect the stenosis grade or did it lead to unstable carotid plaques. Copyright © 2016 Elsevier Inc. All rights reserved.

Safety Outcomes Using a Proximal Protection Device in Carotid Stenting of Long Carotid Stenoses

PubMed Central

Atchaneeyasakul, Kunakorn; Khandelwal, Priyank; Ambekar, Sudheer; Ramdas, Kevin; Guada, Luis; Yavagal, Dileep

2016-01-01

Background Embolic protection devices can prevent atherosclerotic emboli during carotid stenting. Newer proximal protection devices reverse flow in the internal carotid artery (ICA), leading to reduction in perioperative microemboli. The risk of stroke is high for carotid stenting of ICA lesions with a length >10 mm and/or angiographic string sign. Objective We aimed to evaluate the safety outcomes of proximal embolic protection device usage in this high-risk group. Methods This is a retrospective analysis of patients who underwent carotid stenting procedures with proximal embolic protection devices at a tertiary care center. High-risk features for adverse events with carotid stenting were identified. Peri- and postprocedural outcomes were recorded. We further compared outcomes in patients with a carotid stenosis length >10 mm to those with shorter stenosis. Results From January 2011 to December 2014, we included 27 patients; 96.3% were symptomatic and 3.7% were asymptomatic. There was a stent placement technical success rate of 100%. No major stroke or coronary events were recorded. One minor stroke event developed in one patient. A carotid lesion length >10 mm and/or angiographic string sign was noted in 21/27 patients, with an average lesion length of 14.4 mm. One patient (4.8%) in this group developed a minor stroke event. Neither a coronary nor a major stroke event was recorded in this group. There was no significant difference in the complication rate between the long lesion and the control group. Conclusion In our patient cohort, it was found that a proximal embolic protection device is safe for patients with carotid stenosis, including those with a carotid lesion length >10 mm and/or angiographic string sign. PMID:27781040

Elevated red blood cell 2,3-diphosphoglycerate levels in black blood donors.

PubMed

Wallas, C H

1978-01-01

Mean levels of 2,3-diphosphoglycerate (DPG) were significantly increased in erythrocytes (RBC) from 43 nonanemic black blood donors (4.80 +/- 0.06 micromoles/l RBC) compared with 22 white donors 4.47 +/- 0.08 micromoles/l RBCs from eight of the 12 black donors with DPG levels greater than 5 micromoles/l RBC. Although a potentially hemolytic disorder could be defined in four (AS hemoglobin, beta-Thalassemia minor, G6PD deficiency), reticulocyte counts were normal. However, when RBCs from the subgroup were compared to RBCs from an additional 25 unselected white donors, the following suggested an abnormally large population of young RBCs in the subgroup: 1) normal or elevated RBC-ATP with normal serum phosphate level; 2) significantly increased activities of RBC age-dependent enzymes hexokinase (p less than 0.02), pyruvate kinase (p less than 0.05), and glutamicoxaloacetic transaminase (p less than 0.01), with normal activity of phosphoglycerate kinase, an age-independent enzyme; 3) decreased dense (older) RBCs as determined by sedimentation in phthalate esters. Since DPG is increased in young RBCs and falls as the RBC ages, loss of older relatively DPG depleted RBCs due to shortened survival could account for the elevated DPG levels seen in the subgroup.

Prospects for in vivo blood velocimetry using acoustic resolution photoacoustic Doppler

NASA Astrophysics Data System (ADS)

Brunker, J.; Beard, P.

2016-03-01

Acoustic resolution photoacoustic Doppler flowmetry (AR-PAF) is a technique that has the potential to overcome the spatial resolution and depth penetration limitations of current blood flow measuring methods. Previous work has shown the potential of the technique using blood-mimicking phantoms, but it has proved difficult to make accurate measurements in blood, and thus in vivo application has not yet been possible. One explanation for this difficulty is that whole blood is insufficiently heterogeneous. Through experimental measurements in red blood cell suspensions of different concentrations, as well as in whole blood, we provide new insight and evidence that refutes this assertion. We show that the velocity measurement accuracy is influenced by bandlimiting not only due to the detector frequency response, but also due to spatial averaging of absorbers within the detector field-of-view. In addition, there is a detrimental effect of limited light penetration, but this can be mitigated by selecting less attenuated wavelengths of light, and also by employing range-gating signal processing. By careful choice of these parameters as well as the detector centre frequency, bandwidth and field-of-view, it is possible to make AR-PAF measurements in whole blood using transducers with bandwidths in the tens of MHz range. These findings have profound implications for the prospects of making deep tissue measurements of blood flow relevant to the study of microcirculatory abnormalities associated with cancer, diabetes, atherosclerosis and other conditions.

Relationship between increased carotid artery stiffness and idiopathic subjective tinnitus.

PubMed

Bayraktar, C; Taşolar, S

2017-05-01

Tinnitus is defined as perception of sound with no external stimulus, and can separate into pulsatile and non-pulsatile types. Arterial stiffness is a parameter that can predict the cardiovascular event and associated with incidence of stroke. It has been shown that increased arterial stiffness may lead to microvascular damage in brain. Our aim was to assess the arterial stiffness of the carotid system in the development and severity of idiopathic subjective tinnitus. Forty subjective tinnitus patients and 40 age- and sex-matched controls were enrolled in the study. The parameters obtained from the participants included pure tone hearing (dB), serum lipid profile (mg/dl), fasting glucose (mg/dl), blood pressure (mmHg), and body mass index (BMI, kg/m 2 ). The common carotid artery (CCA) stiffness index, Young's elastic modulus (YEM), common carotid intima-media thickness (CIMT), peak systolic velocity (PSV), end-diastolic velocity (EDV), resistive index (RI), pulsatility index (PI), vessel diameter, mean velocity (MV), and volume flow (VF) were measured in both the right and left common carotid arteries in both groups. The CCA stiffness index, YEM measurements, right CIMT, and left PI were found to be significantly higher in the patients than those in the control group (p < 0.05). With regard to the severity of the tinnitus and the patient characteristics, there was a significant positive correlation with the CCA stiffness index, YEM measurements, left CIMT, and neutrophil-to-lymphocyte ratio (NLR). However, only the right and left CCA stiffness parameters were found to be statistically significant in the multivariate analysis as independent predictors of a moderate to high degree of tinnitus. The increased stiffness index of the common carotid arteries was significantly associated with the formation and severity of tinnitus. Therefore, an assessment of the carotideal system may be helpful in these patients.

Periodontal bacteria in human carotid atherothrombosis as a potential trigger for neutrophil activation.

PubMed

Rangé, Hélène; Labreuche, Julien; Louedec, Liliane; Rondeau, Philippe; Planesse, Cynthia; Sebbag, Uriel; Bourdon, Emmanuel; Michel, Jean-Baptiste; Bouchard, Philippe; Meilhac, Olivier

2014-10-01

Epidemiological, biological and clinical links between periodontal and cardiovascular diseases are now well established. Several human studies have detected bacterial DNA corresponding to periodontal pathogens in cardiovascular samples. Intraplaque hemorrhage has been associated with a higher risk of atherosclerotic plaque rupture, potentially mediated by neutrophil activation. In this study, we hypothesized that plaque composition may be related to periodontal pathogens. Carotid culprit plaque samples were collected from 157 patients. Macroscopic characterization was performed at the time of collection: presence of blood, lipid core, calcification and fibrosis. Markers of neutrophil activation released by carotid samples were quantified (myeloperoxidase or MPO, cell-free DNA and DNA-MPO complexes). PCR analysis using specific primers for Porphyromonas gingivalis, Aggregatibacter actinomycetemcommitans, Treponema denticola, Prevotella intermedia and Tannerella forsythia was used to detect DNA from periodontal pathogens in carotid tissues. In addition, bacterial lipopolysaccharide (LPS) and Immunoglobulins G against T. forsythia were quantified in atherosclerotic carotid conditioned medium. Intraplaque hemorrhage was present in 73/157 carotid samples and was associated with neutrophil activation, reflected by the release of MPO, cell-free DNA and MPO-DNA complexes. LPS levels were also linked to intraplaque hemorrhage but not with the neutrophil activation markers. Seventy-three percent of the carotid samples were positive for periodontal bacterial DNA. Furthermore, hemoglobin levels were associated with the detection of T. forsythia and neutrophil activation/inflammation markers. This study suggests a potential role of periodontal microorganisms, especially T. forsythia, in neutrophil activation within hemorrhagic atherosclerotic carotid plaques. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Bilateral Internal Carotid Artery Occlusion, External Carotid Artery Stenosis, and Vertebral Artery Kinking: May It Be Asymptomatic?

PubMed

Fatic, Nikola; Jaffer, Usman; Ivana, Saicic; Gordana, Globarevic-Vukcevic; Markovic, Dragan; Kostic, Dusan; Davidovic, Lazar

2017-10-01

The clinical spectrum of internal carotid artery occlusion ranges from being a completely asymptomatic occlusion to a devastating stroke or death. The prevalence of asymptomatic internal carotid artery occlusion is unknown, particularly for bilateral occlusion. The distal branches of the external carotid artery anastomose with distal branches of the internal carotid artery provide important sources of collateral circulation to the brain. Stenosis of the external carotid artery with ipsilateral/bilateral internal occlusion may result in ischemic sequelae. Coiling or kinking of the vertebral artery is a rare morphological entity that is infrequently reported because it remains asymptomatic and has no clinical relevance. Currently, there is little evidence to support management strategies for this disease entity and no official recommendations for asymptomatic bilateral carotid artery occlusion. We present a case of a 62-year-old female with asymptomatic bilateral internal carotid artery occlusion, bilateral external carotid artery stenoses, and bilateral kinking of the vertebral artery at the V2 segment, who has been successfully managed conservatively for over 5 years. An individualized approach to management of patients with bilateral internal carotid artery occlusion, especially in combination with external carotid artery stenosis and elongation malformations of the vertebral artery is key to a successful strategy. Copyright © 2017 Elsevier Inc. All rights reserved.

Management of Carotid Artery Trauma

PubMed Central

Lee, Thomas S.; Ducic, Yadranko; Gordin, Eli; Stroman, David

2014-01-01

With increased awareness and liberal screening of trauma patients with identified risk factors, recent case series demonstrate improved early diagnosis of carotid artery trauma before they become problematio. There remains a need for unified screening criteria for both intracranial and extracranial carotid trauma. In the absence of contraindications, antithrombotic agents should be considered in blunt carotid artery injuries, as there is a significant risk of progression of vessel injury with observation alone. Despite CTA being used as a common screening modality, it appears to lack sufficient sensitivity. DSA remains to be the gold standard in screening. Endovascular techniques are becoming more widely accepted as the primary surgical modality in the treatment of blunt extracranial carotid injuries and penetrating/blunt intracranial carotid lessions. Nonetheless, open surgical approaches are still needed for the treatment of penetrating extracranial carotid injuries and in patients with unfavorable lesions for endovascular intervention. PMID:25136406

Carotid revascularization: risks and benefits

PubMed Central

O’Brien, Marlene; Chandra, Ankur

2014-01-01

Despite a decline during the recent decades in stroke-related death, the incidence of stroke has remained unchanged or slightly increased, and extracranial carotid artery stenosis is implicated in 20%–30% of all strokes. Medical therapy and risk factor modification are first-line therapies for all patients with carotid occlusive disease. Evidence for the treatment of patients with symptomatic carotid stenosis greater than 70% with either carotid artery stenting (CAS) or carotid endarterectomy (CEA) is compelling, and several trials have demonstrated a benefit to carotid revascularization in the symptomatic patient population. Asymptomatic carotid stenosis is more controversial, with the largest trials only demonstrating a 1% per year risk stroke reduction with CEA. Although there are sufficient data to advocate for aggressive medical therapy as the primary mode of treatment for asymptomatic carotid stenosis, there are also data to suggest that certain patient populations will benefit from a stroke risk reduction with carotid revascularization. In the United States, consensus and practice guidelines dictate that CEA is reasonable in patients with high-grade asymptomatic stenosis, a reasonable life expectancy, and perioperative risk of less than 3%. Regarding CAS versus CEA, the best-available evidence demonstrates no difference between the two procedures in early perioperative stroke, myocardial infarction, or death, and no difference in 4-year ipsilateral stroke risk. However, because of the higher perioperative risks of stroke in patients undergoing CAS, particularly in symptomatic, female, or elderly patients, it is difficult to recommend CAS over CEA except in populations with prohibitive cardiac risk, previous carotid surgery, or prior neck radiation. Current treatment paradigms are based on identifying the magnitude of perioperative risk in patient subsets and on using predictive factors to stratify patients with high-risk asymptomatic stenosis. PMID

Carotid Stenosis And Ulcer Detectability As A Function Of Pixel Size

NASA Astrophysics Data System (ADS)

Mintz, Leslie J.; Enzmann, Dieter R.; Keyes, Gary S.; Mainiero, Louis M.; Brody, William R.

1981-11-01

Digital radiography, in conjunction with digital subtraction methods can provide high quality images of the vascular system,1-4 Spatial resolution is one important limiting factor of this imaging technique. Since spatial resolution of a digital image is a function of pixel size, it is important to determine the pixel size threshold necessary to provide information comparable to that of conventional angiograms. This study was designed to establish the pixel size necessary to identify accurately stenotic and ulcerative lesions of the carotid artery.

[CHANGES OF CAROTID AND VERTEBRAL ARTERIES IN PATENTS WITH ARTERIAL HYPERTENSION AND HEPATOBILIARY PATHOLOGY].

PubMed

Polyakov, V Ya; Nikolaev, Yu A; Pegova, S V; Matsievskaya, T R; Obukhov, I V

2016-01-01

The study included 1172 patients (410 men and 762 women) at the mean age of 60.3 ± 10.4 years with grade I-II (stage I-II) arterial hypertension (AH) admitted to the clinic of Institute of Experimental Medicine. The patients were divided into 2 groups based on the results of clinical and laboratory diagnostics. Group 1 (n = 525) included patients with AH and hepatobiliary system (HBS) diseases, group 2 (n = 647) patients with AH without HBS diseases. The patients group 1 had a thicker intima-media complex of carotid arteries, higher peak systolic bloodflow rate in the internal and vertebral carotid arteries, more pronounced coiling of internal carotid arteries than patients of group 2. Patients with AH and HBS diseases exhibited correlation between bloodflow rate in external carotid arteries and atherogenicity coefficient. Duplex scanning of neck vessels of in patients with AH without HBS diseases revealed peculiar changes of the intima-media thickness and hemodynamically significant changes of the blood flow in the internal carotid arteries that may be of prognostic value in this nosological syntropy and require the personified approach to diagnostics, treatment, and prevention of these conditions.

Red Blood Cell Eicosapentaenoic Acid Inversely Relates to MRI-Assessed Carotid Plaque Lipid Core Burden in Elders at High Cardiovascular Risk.

PubMed

Bargalló, Núria; Gilabert, Rosa; Romero-Mamani, Edwin-Saúl; Cofán, Montserrat; Calder, Philip C; Fitó, Montserrat; Corella, Dolores; Salas-Salvadó, Jordi; Ruiz-Canela, Miguel; Estruch, Ramon; Ros, Emilio; Sala-Vila, Aleix

2017-09-20

Supplemental marine omega-3 eicosapentaenoic acid (EPA) has an anti-atherosclerotic effect. Clinical research on EPA supplied by the regular diet and atherosclerosis is scarce. In the framework of the PREvención con DIeta MEDiterránea (PREDIMED) trial, we conducted a cross-sectional study in 161 older individuals at high vascular risk grouped into different stages of carotid atherosclerosis severity, including those without ultrasound-detected atheroma plaque ( n = 38), with plaques <2.0 mm thick ( n = 65), and with plaques ≥2.0 mm ( n = 79). The latter were asked to undergo contrast-enhanced 3T magnetic resonance imaging (MRI) and were subsequently grouped into absence ( n = 31) or presence ( n = 27) of MRI-detectable plaque lipid, a main feature of unstable atheroma plaques. We determined the red blood cell (RBC) proportion of EPA (a valid marker of long-term EPA intake) at enrolment by gas chromatography. In multivariate models, EPA related inversely to MRI-assessed plaque lipid volume, but not to maximum intima-media thickness of internal carotid artery, plaque burden, or MRI-assessed normalized wall index. The inverse association between EPA and plaque lipid content in patients with advanced atherosclerosis supports the notion that this fatty acid might improve cardiovascular health through stabilization of advanced atheroma plaques.

Red Blood Cell Eicosapentaenoic Acid Inversely Relates to MRI-Assessed Carotid Plaque Lipid Core Burden in Elders at High Cardiovascular Risk

PubMed Central

Bargalló, Núria; Gilabert, Rosa; Romero-Mamani, Edwin-Saúl; Calder, Philip C.; Fitó, Montserrat; Estruch, Ramon; Ros, Emilio; Sala-Vila, Aleix

2017-01-01

Supplemental marine omega-3 eicosapentaenoic acid (EPA) has an anti-atherosclerotic effect. Clinical research on EPA supplied by the regular diet and atherosclerosis is scarce. In the framework of the PREvención con DIeta MEDiterránea (PREDIMED) trial, we conducted a cross-sectional study in 161 older individuals at high vascular risk grouped into different stages of carotid atherosclerosis severity, including those without ultrasound-detected atheroma plaque (n = 38), with plaques <2.0 mm thick (n = 65), and with plaques ≥2.0 mm (n = 79). The latter were asked to undergo contrast-enhanced 3T magnetic resonance imaging (MRI) and were subsequently grouped into absence (n = 31) or presence (n = 27) of MRI-detectable plaque lipid, a main feature of unstable atheroma plaques. We determined the red blood cell (RBC) proportion of EPA (a valid marker of long-term EPA intake) at enrolment by gas chromatography. In multivariate models, EPA related inversely to MRI-assessed plaque lipid volume, but not to maximum intima-media thickness of internal carotid artery, plaque burden, or MRI-assessed normalized wall index. The inverse association between EPA and plaque lipid content in patients with advanced atherosclerosis supports the notion that this fatty acid might improve cardiovascular health through stabilization of advanced atheroma plaques. PMID:28930197

Bondi or not Bondi: the impact of resolution on accretion and drag force modelling for supermassive black holes

NASA Astrophysics Data System (ADS)

Beckmann, R. S.; Slyz, A.; Devriendt, J.

2018-07-01

Whilst in galaxy-size simulations, supermassive black holes (SMBHs) are entirely handled by sub-grid algorithms, computational power now allows the accretion radius of such objects to be resolved in smaller scale simulations. In this paper, we investigate the impact of resolution on two commonly used SMBH sub-grid algorithms; the Bondi-Hoyle-Lyttleton (BHL) formula for accretion on to a point mass, and the related estimate of the drag force exerted on to a point mass by a gaseous medium. We find that when the accretion region around the black hole scales with resolution, and the BHL formula is evaluated using local mass-averaged quantities, the accretion algorithm smoothly transitions from the analytic BHL formula (at low resolution) to a supply-limited accretion scheme (at high resolution). However, when a similar procedure is employed to estimate the drag force, it can lead to significant errors in its magnitude, and/or apply this force in the wrong direction in highly resolved simulations. At high Mach numbers and for small accretors, we also find evidence of the advective-acoustic instability operating in the adiabatic case, and of an instability developing around the wake's stagnation point in the quasi-isothermal case. Moreover, at very high resolution, and Mach numbers above M_∞ ≥ 3, the flow behind the accretion bow shock becomes entirely dominated by these instabilities. As a result, accretion rates on to the black hole drop by about an order of magnitude in the adiabatic case, compared to the analytic BHL formula.

Bondi or not Bondi: the impact of resolution on accretion and drag force modelling for Supermassive Black Holes

NASA Astrophysics Data System (ADS)

Beckmann, R. S.; Slyz, A.; Devriendt, J.

2018-04-01

Whilst in galaxy-size simulations, supermassive black holes (SMBH) are entirely handled by sub-grid algorithms, computational power now allows the accretion radius of such objects to be resolved in smaller scale simulations. In this paper, we investigate the impact of resolution on two commonly used SMBH sub-grid algorithms; the Bondi-Hoyle-Lyttleton (BHL) formula for accretion onto a point mass, and the related estimate of the drag force exerted onto a point mass by a gaseous medium. We find that when the accretion region around the black hole scales with resolution, and the BHL formula is evaluated using local mass-averaged quantities, the accretion algorithm smoothly transitions from the analytic BHL formula (at low resolution) to a supply limited accretion (SLA) scheme (at high resolution). However, when a similar procedure is employed to estimate the drag force it can lead to significant errors in its magnitude, and/or apply this force in the wrong direction in highly resolved simulations. At high Mach numbers and for small accretors, we also find evidence of the advective-acoustic instability operating in the adiabatic case, and of an instability developing around the wake's stagnation point in the quasi-isothermal case. Moreover, at very high resolution, and Mach numbers above M_∞ ≥ 3, the flow behind the accretion bow shock becomes entirely dominated by these instabilities. As a result, accretion rates onto the black hole drop by about an order of magnitude in the adiabatic case, compared to the analytic BHL formula.

Pharmacological profile of the receptors that mediate external carotid vasoconstriction by 5-HT in vagosympathectomized dogs.

PubMed Central

Villalón, C. M.; Ramírez-San Juan, E.; Castillo, C.; Castillo, E.; López-Muñoz, F. J.; Terrón, J. A.

1995-01-01

1. 5-Hydroxytryptamine (5-HT) can produce vasodilatation or vasoconstriction of the canine external carotid bed depending upon the degree of carotid sympathetic tone. Hence, external carotid vasodilatation to 5-HT in dogs with intact sympathetic tone is primarily mediated by prejunctional 5-HT1-like receptors similar to the 5-HT1D subtype, which inhibit the carotid sympathetic outflow. The present investigation is devoted to the pharmacological analysis of the receptors mediating external carotid vasoconstriction by 5-HT in vagosympathectomized dogs. 2. Intracarotid (i.c.) infusions for 1 min of 5-HT (0.3, 1, 3, 10, 30 and 100 micrograms) resulted in dose-dependent decreases in both external carotid blood flow and the corresponding conductance; both mean arterial blood pressure and heart rate remained unchanged during the infusions of 5-HT. These responses to 5-HT were resistant to blockade by antagonists at 5-HT2 (ritanserin) and 5-HT3/5-HT4 (tropisetron) receptors, but were partly blocked by the 5-HT1-like and 5-HT2 receptor antagonist, methiothepin (0.3 mg kg-1); higher doses of methiothepin (1 and 3 mg kg-1) caused little, if any, further blockade. These methiothepin (3 mg kg-1)-resistant responses to 5-HT were not significantly antagonized by MDL 72222 (0.3 mg kg-1) or tropisetron (3 mg kg-1). 3. The external carotid vasoconstrictor effects of 5-HT were mimicked by the selective 5-HT1-like receptor agonist, sumatriptan (3, 10, 30 and 100 micrograms during 1 min, i.c.), which produced dose-dependent decreases in external carotid blood flow and the corresponding conductance; these effects of sumatriptan were dose-dependently antagonized by methiothepin (0.3, 1 and 3 mg kg-1), but not by 5-HT1D-like receptor blocking doses of metergoline (0.1 mg kg-1). 4. The above vasoconstrictor effects of 5-HT remained unaltered after administration of phentolamine, propranolol, atropine, hexamethonium, brompheniramine, cimetidine and haloperidol, thus excluding the

Carotid intima-media thickness in young survivors of childhood cancer.

PubMed

Krawczuk-Rybak, Maryna; Tomczuk-Ostapczuk, Monika; Panasiuk, Anna; Goscik, Elzbieta

2017-02-01

Radiotherapy (RT) and some chemotherapy regimens are known risk factors predisposing to the development of premature arterial disease. Vascular ultrasound measurement of carotid intima-media thickness (IMT) is a non-invasive technique, useful to detect early subclinical symptoms of atherosclerosis that can appear in the paediatric population. We analysed the influence of chemotherapy and moderate doses of head or neck irradiation in childhood cancer survivors on the possibility of premature carotid artery disease. Ultrasound measurements of the intima-media thickness (IMT) in the common carotid artery (CCA), bulb and internal carotid artery (ICA) were performed in 74 young cancer survivors and in 48 age- and sex-matched controls. In the whole study group, we observed higher IMT in all positions as compared with the control, except for comparable thickness in the CCA (bilaterally). We failed to find any differences in IMT between irradiated and non-irradiated females. In irradiated males, all IMT measurements on the right side were higher than in non-irradiated patients. There was no effect of body mass index, blood pressure, serum cholesterol, triglycerides, fibrinogen and thyroid hormones on IMT. In the irradiated group, a positive correlation was observed between IMT in the right bulb and the post-radiation time. Anticancer treatment during childhood, especially including irradiation to the mediastinum, head or neck, affects the IMT, particularly in males. This suggests a possible role of irradiation in the premature development of carotid artery disease. © 2016 The Royal Australian and New Zealand College of Radiologists.

Noninvasive assessment of normal carotid bifurcation hemodynamics with color-flow ultrasound imaging.

PubMed

Zierler, R E; Phillips, D J; Beach, K W; Primozich, J F; Strandness, D E

1987-08-01

The combination of a B-mode imaging system and a single range-gate pulsed Doppler flow velocity detector (duplex scanner) has become the standard noninvasive method for assessing the extracranial carotid artery. However, a significant limitation of this approach is the small area of vessel lumen that can be evaluated at any one time. This report describes a new duplex instrument that displays blood flow as colors superimposed on a real-time B-mode image. Returning echoes from a linear array of transducers are continuously processed for amplitude and phase. Changes in phase are produced by tissue motion and are used to calculate Doppler shift frequency. This results in a color assignment: red and blue indicate direction of flow with respect to the ultrasound beam, and lighter shades represent higher velocities. The carotid bifurcations of 10 normal subjects were studied. Changes in flow velocities across the arterial lumen were clearly visualized as varying shades of red or blue during the cardiac cycle. A region of flow separation was observed in all proximal internal carotids as a blue area located along the outer wall of the bulb. Thus, it is possible to detect the localized flow patterns that characterize normal carotid arteries. Other advantages of color-flow imaging include the ability to rapidly identify the carotid bifurcation branches and any associated anatomic variations.

Recanalization of acute carotid stent occlusion using Penumbra 4Max aspiration catheter: technical report and review of rescue strategies for acute carotid stent occlusion.

PubMed

Munich, Stephan; Moftakhar, Roham; Lopes, Demetrius

2014-10-01

Carotid artery stenting (CAS) has become a widely used treatment for carotid artery stenosis, especially in high-risk patients. Acute in-stent and distal protection device occlusion are potentially catastrophic complications of this procedure. Previously described rescue strategies have included administration of antiplatelet agents (eg, abciximab) with/without thrombolytics and removal of the filter. Here we describe the successful resolution of in-stent occlusion by mechanical thrombolysis using the Penumbra 4Max aspiration catheter. Distal flow was subsequently restored with minimal residual stenosis. The patient did not suffer any consequent neurological deficits. The different strategies that could be used in this critical situation are reviewed. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Is Carotid Stenosis in Women a Gender-Related Condition?

PubMed

Tromba, Luciana; Tartaglia, Francesco; Blasi, Sara; Giuliani, Alessandro; Carbotta, Sabino; Kiltzanidi, Demetra; Cavaiola, Stefania; Tortorelli, Giovanni; Carbotta, Giovanni; Pelle, Fabio

2016-04-01

We set out to study, through ultrasound examinations, the carotid bifurcation in men and women with/without carotid stenosis to look for anatomical and electrophysiologic differences. We evaluated other variables to look for differences that might explain the dissimilar behavior of this disease in the two sexes and the presence and impact of risk factors. We examined 974 subjects aged 25 to 88 years (478 men and 496 women) in whom we considered heart rate, smoking status, and the presence of hypertension, diabetes, hypercholesterolemia, and hypertriglyceridemia. Ultrasound examination of the neck vessels included measurement of intimal medial thickness (IMT), vessel diameter, and outflow area/inflow area ratio. We established plaque location, echogenicity and echostructure, and the percentage of stenosis owing to plaque and measured systolic velocity, flow direction, and the depth of detection of these parameters. We used the apnea and hyperpnea test to assess cerebrovascular reactivity. Hypertension and hypercholesterolemia were the most frequent risk factors. Women had a higher heart rate, whereas men had significantly greater IMT. The presence of atheromatous plaque was significantly correlated with age in both sexes, with men having a higher prevalence of carotid plaques. The sexes differed significantly with regard to plaque location, echogenicity, echostructure, and intracranial circulation. Women had a slightly higher blood flow velocity in the intracranial arteries. Risk factors affected plaque formation and extent more in men than in women. These findings suggest that carotid stenosis is a gender-related trait.

Carotid Web (Intimal Fibromuscular Dysplasia) Has High Stroke Recurrence Risk and Is Amenable to Stenting.

PubMed

Haussen, Diogo C; Grossberg, Jonathan A; Bouslama, Mehdi; Pradilla, Gustavo; Belagaje, Samir; Bianchi, Nicolas; Allen, Jason W; Frankel, Michael; Nogueira, Raul G

2017-11-01

Carotid webs have been increasingly recognized as a cause of recurrent stroke, but evidence remains scarce. We aim to report the clinical outcomes and first series of carotid stenting in a cohort of patients with strokes from symptomatic carotid webs. Prospective and consecutive data of patients <65 years old with cryptogenic stroke admitted within September 2014 to May 2017. Carotid web was defined by a shelf-like/linear filling defect in the posterior internal carotid artery bulb by computed tomographic angiography. Twenty-four patients were identified (91.6% strokes/8.4% transient ischemic attacks [TIAs]). Median age was 46 (41-59) years, 61% were female, and 75% were black. Median National Institutes of Health Stroke Scale score was 10.5 (3.0-16.0) and ASPECTS (Alberta Stroke Program Early CT Score) was 8 (7-8). There were no parenchymal hemorrhages, and 96% of patients were independent at 3 months. All webs caused <50% stenosis. In patients with bilateral webs (58%), median ipsilateral web length was larger than contralateral (3.1 [3.0-4.5] mm versus 2.6 [1.85-2.9] mm; P =0.01), respectively. Twenty-nine percent of patients had thrombus superimposed on the symptomatic carotid web. A recurrent stroke/TIA involving the territory of the previously symptomatic web occurred in 7 (32%; 6 strokes/1 TIA) patients: 3 <1 week, 2 1 year of follow-up. Two recurrences occurred on dual antiplatelet therapy, 3 on antiplatelet monotherapy, 1 within 24 hours of thrombolysis, and 1 off antithrombotics. Median follow-up was 12.2 (8.0-18.0) months. Sixteen (66%) patients were stented at a median 12.2 (7.0-18.7) days after stroke with no periprocedural complications. No recurrent strokes/TIAs occurred in stented individuals (median follow-up of 4 [2.4-12.0] months). Carotid web is associated with high recurrent stroke/TIA risk, despite antithrombotic use, and is amenable to carotid stenting. © 2017 American Heart Association, Inc.

Decision Tree Analysis of Traditional Risk Factors of Carotid Atherosclerosis and a Cutpoint-Based Prevention Strategy

PubMed Central

Lv, Lihong; Xiao, Yufei; Tu, Jiangfeng; Tao, Lisha; Wu, Jiaqi; Tang, Xiaoxiao; Pan, Wensheng

2014-01-01

Background Reducing the exposure to risk factors for the prevention of cardio-cerebral vascular disease is a crucial issue. Few reports have described practical interventions for preventing cardiovascular disease in different genders and age groups, particularly detailed and specific cutpoint-based prevention strategies. Methods We collected the health examination data of 5822 subjects between 20 and 80 years of age. The administration of medical questionnaires and physical examinations and the measurement of blood pressure, fasting plasma glucose (FPG) and blood lipids [total cholesterol (TC), triglycerides (TG), high density lipoprotein–cholesterol (HDL-C), and low density lipoprotein-cholesterol (LDL-C)] were performed by physicians. Carotid ultrasound was performed to examine the carotid intima-media thickness (CIMT), which was defined as carotid atherosclerosis when CIMT ≥0.9 mm. Decision tree analysis was used to screen for the most important risk factors for carotid atherosclerosis and to identify the relevant cutpoints. Results In the study population, the incidence of carotid atherosclerosis was 12.20% (men: 14.10%, women: 9.20%). The statistical analysis showed significant differences in carotid atherosclerosis incidence between different genders (P<0.0001) and age groups (P<0.001). The decision tree analysis showed that in men, the most important traditional risk factors for carotid atherosclerosis were TC (cutpoint [CP]: 6.31 mmol/L) between the ages of 20–40 and FPG (CP: 5.79 mmol/L) between the ages of 41–59. By comparison, LDL-C (CP: 4.27 mmol/L) became the major risk factor when FPG ≤5.79 mmol/L. FPG (CP: 5.52 mmol/L) and TG (CP: 1.51 mmol/L) were the most important traditional risk factors for women between 20–40 and 41–59 years of age, respectively. Conclusion Traditional risk factors and relevant cutpoints were not identical in different genders and age groups. A specific gender and age group-based cutpoint strategy might contribute

Inhibitory effect of chronic oral treatment with fluoxetine on capsaicin-induced external carotid vasodilatation in anaesthetised dogs.

PubMed

Muñoz-Islas, Enriqueta; González-Hernández, Abimael; Lozano-Cuenca, Jair; Ramírez-Rosas, Martha Beatríz; Medina-Santillán, Roberto; Centurión, David; MaassenVanDenBrink, Antoinette; Villalón, Carlos M

2015-10-01

During migraine, capsaicin-sensitive trigeminal sensory nerves release calcitonin gene-related peptide (CGRP), resulting in cranial vasodilatation and central nociception. Moreover, 5-HT is involved in the pathophysiology of migraine and depression. Interestingly, some limited lines of evidence suggest that fluoxetine may be effective in migraine prophylaxis, but the underlying mechanisms are uncertain. Hence, this study investigated the canine external carotid vasodilator responses to capsaicin, α-CGRP and acetylcholine before and after acute and chronic oral treatment with fluoxetine. Forty-eight vagosympathectomised male mongrel dogs were prepared to measure blood pressure, heart rate and external carotid blood flow. The thyroid artery was cannulated for infusions of agonists. In 16 of these dogs, a spinal cannula was inserted (C1-C3) for infusions of 5-HT. The external carotid vasodilator responses to capsaicin, α-CGRP and acetylcholine remained unaffected after intracarotid or i.v. fluoxetine. In contrast, the vasodilator responses to capsaicin, but not those to α-CGRP or acetylcholine, were inhibited after chronic oral treatment with fluoxetine (300 µg/kg; for 90 days) or intrathecal 5-HT. Chronic oral fluoxetine inhibited capsaicin-induced external carotid vasodilatation, and this inhibition could partly explain its potential prophylactic antimigraine action. © International Headache Society 2015.

Sympathoinhibition and hypotension in carotid sinus hypersensitivity

NASA Technical Reports Server (NTRS)

Smith, M. L.; Ellenbogen, K. A.; Eckberg, D. L.

1992-01-01

Carotid sinus reflex hypersensitivity is a known cause of syncope in humans. The condition is characterized by cardioinhibition and vasodepression, each to varying degrees. The extent and importance of sympathoinhibition has not been determined in patients with carotid sinus hypersensitivity. This study reports on the extent of sympathoinhibition measured directly directly during carotid massage with and without atrioventricular sequential pacing, in a patient with symptomatic carotid sinus reflex hypersensitivity. Carotid massage elicited asystole, hypotension and complete inhibition of muscle sympathetic nerve activity. Carotid massage during atrioventricular pacing produced similar sympathoinhibition, but with minimal hypotension. Therefore, sympathoinhibition did not contribute importantly to the hypotension during carotid massage in the supine position in this patient. Further investigations are required to elucidate the relation of sympathoinhibition to hypotension in patients with carotid sinus hypersensitivity in the upright position.

Endovascular treatment of the extracranial carotid pseudoaneurysms resulting from stab penetrating injury using overlapping bare stents.

PubMed

Pan, Yao-hua; Lin, Yong; Ding, Sheng-hao; Chen, Lei; Liang, Yu-ming; Yin, Yu-hua; Bao, Ying-hui; Gao, Guo-Yi; Qiu, Yong-ming; Jiang, Ji-yao

2014-05-01

Injury pertaining to the common carotid artery may result in complete or partial arterial transection, pseudoaneurysms, or arteriovenous connections. Endovascular treatment option of the pseudoaneurysm has already been established with favorable success rate and minimal morbidity. Our purpose is to report one 18-year-old male patient having 2 traumatic pseudoaneurysms as a result of penetrating stab injury in the extracranial common carotid. The patient was successfully treated using 2 overlapping bare-metal stents. The 2 common carotid pseudoaneurysms had different degree inflow angles defined as the space between the lines indicating the direction of blood flow from the parent artery and through the aneurysmal neck to the dome. Computed tomography angiography was utilized to follow the evolution of the pseudoaneurysms until total occlusion was demonstrated. The treatment modality used in this report represents an alternative approach of the endovascular treatment for the extracranial carotid pseudoaneurysm.

Whole Blood ω-3 Fatty Acids Are Inversely Associated with Carotid Intima-Media Thickness in Indigenous Mexican Women.

PubMed

Monge, Adriana; Harris, William S; Ortiz-Panozo, Eduardo; Yunes, Elsa; Cantu-Brito, Carlos; Catzin-Kuhlmann, Andres; López-Ridaura, Ruy; Lajous, Martín

2016-07-01

Long-chain ω-3 (n-3) polyunsaturated fatty acids (PUFAs) may reduce the risk of atherosclerosis. The association between n-3 PUFAs and cardiovascular disease may vary across different populations, and there is limited information on Hispanic individuals with mixed Amerindian and European origin. We evaluated the cross-sectional relations between whole blood n-3 PUFAs and carotid intima-media thickness (IMT) in Mexican women living in Mexico and assessed whether this relation was different in women who spoke an indigenous language compared with women who did not. In 2012-2013, we assessed the association between blood n-3 PUFAs and IMT in 1306 women free of disease in Chiapas and Yucatan, Mexico. We categorized blood n-3 PUFAs (% of total FAs) in quartiles and adjusted linear regression models by age, indigenous language, site, socioeconomic status, education, smoking, menopause, diabetes, hypertension, hypercholesterolemia, body mass index, physical activity, and diet. We stratified analyses by indigenous/nonindigenous language speakers (n = 315 of 991). Whole blood n-3 PUFAs (means ± SDs) were 3.58% ± 0.78% of total FAs. We did not observe a significant association between n-3 PUFAs and IMT in the overall study population. However, the adjusted mean difference of IMT was -6.5% (95% CI: -10.7%, -2.3%; P-trend < 0.0001) for indigenous women in the highest quartile compared with the lowest quartile of blood n-3 PUFAs. In nonindigenous women, we did not observe an association (-0.6%; 95% CI: -3.0%, 1.8%, comparing extreme quartiles; P-trend = 1.00). Overall, circulating n-3 PUFAs were not associated with IMT. However, we observed a strong statistically significant inverse association with IMT in indigenous Mexican women. Future studies should evaluate genetic markers that may reflect differences in n-3 PUFA metabolism across populations. © 2016 American Society for Nutrition.

Histological and morphometric analyses for rat carotid balloon injury model.

PubMed

Tulis, David A

2007-01-01

Experiments aimed at analyzing the response of blood vessels to mechanical injury and ensuing remodeling responses often employ the highly characterized carotid artery balloon injury model in laboratory rats. This approach utilizes luminal insertion of a balloon embolectomy catheter into the common carotid artery with inflation and withdrawal resulting in an injury characterized by vascular endothelial cell (EC) denudation and medial wall distension. The adaptive response to this injury is typified by robust vascular smooth muscle cell (SMC) replication and migration, SMC apoptosis and necrosis, enhanced synthesis and deposition of extracellular matrix (ECM) components, partial vascular EC regeneration from the border zones, luminal narrowing, and establishment of a neointima in time-dependent fashion. Evaluation of these adaptive responses to blood vessel injury can include acute and longer term qualitative and quantitative measures including expression analyses, activity assays, immunostaining for a plethora of factors and signals, and morphometry of neointima formation and gross mural remodeling. This chapter presents a logical continuation of Chapter 1 that offers details for performing the rat carotid artery balloon injury model in a standard laboratory setting by providing commonly used protocols for performing histological and morphometric analyses in such studies. Moreover, procedures, caveats, and considerations included in this chapter are highly relevant for alternative animal vascular physiology/pathophysiology studies and in particular those related to mechanisms of vascular injury and repair. Included in this chapter are specifics for in situ perfusion-fixation, tissue harvesting and processing for both snap-frozen and paraffin-embedded protocols, specimen embedding and sectioning, slide preparation, several standard histological staining steps, and routine morphological assessment.

[Effects of carotid endarterectomy on cognitive function in patients with carotid stenosis].

PubMed

Wang, Qi; Zhang, Ming; Huang, Dian; Zhou, Yu; Qiao, Tong

2014-08-01

To investigate the theraputic effects of carotid endarterectomy (CEA) on cognitive function in patients with carotid stenosis (CAS) and congnitive impairment. CEA was performed on 38 patients with CAS from December 2011 to July 2013. There were 26 male and 12 female patients, with an average age of (70 ± 7) years. Patients was underwent neuropsychological examinations (NPEs) including Mini-Mental State Examination (MMSE) and Montreal Cognitive Assessment (MoCA) at 1 week before and 6 weeks after treatment. Cerebral perfusion was assessed with MR perfusion-weighted imaging and diffusion-weighted inmaging at 1 week before and 6 weeks after treatment. All of the 38 patients completed NPEs and MRI at baseline and 6 weeks after CEA. After therapy, the parameters and the extents of abnormal perfusion was improved, including the decrease of time to peak (29 ± 9 vs. 23 ± 4), relative mean transit time (22 ± 8 vs. 14 ± 6), arrive time (21 ± 8 vs. 15 ± 4) and relative cerebral blood volume (11.6 ± 3.5 vs. 7.5 ± 3.2) (t = 1.31 to 5.24, all P < 0.05). Significant improvement in MoCA (20.4 ± 1.5 vs. 22.0 ± 1.6, t = -4.25, P = 0.000) but MMSE (26.16 ± 1.35 vs. 26.47 ± 1.52, t = -0.96, P = 0.341) was observed. CEA significantly improved the assessment of visuospacial/constructive abilities (2.4 ± 0.9 vs. 2.8 ± 0.7), naming (2.0 ± 0.7 vs. 2.3 ± 0.6), abstraction (1.2 ± 0.7 vs. 1.6 ± 0.6) and attention (2.3 ± 0.6 vs. 2.6 ± 0.5) (t = 0.015 to 0.029, P = 0.015). CEA can improve the cognitive function of patients with carotid stenosis as well as the cerebral perfusion of patients and has therapeutic effects on vascular mild cognitive impairment.

Angioplasty and stent placement - carotid artery

MedlinePlus

... medlineplus.gov/ency/article/002953.htm Angioplasty and stent placement - carotid artery To use the sharing features ... to remove plaque buildup ( endarterectomy ) Carotid angioplasty with stent placement Description Carotid angioplasty and stenting (CAS) is ...

Interaction of central venous pressure, intramuscular pressure, and carotid baroreflex function

NASA Technical Reports Server (NTRS)

Shi, X.; Foresman, B. H.; Raven, P. B.; Blomqvist, C. G. (Principal Investigator)

1997-01-01

Seven healthy volunteer men participated in an experiment involving lower body positive pressure (LBPP) of 30 Torr and acute volume expansions of 5-6% (VE-I) and 9-10% (VE-II) of their total blood volume (TBV) to differentiate the effect of increased intramuscular pressure and central venous pressure (CVP) on the maximal gain (Gmax) of the carotid baroreflex. During each experimental condition, the heart rate (HR), mean arterial pressure (MAP; intraradial artery or Finapres), and CVP (at the 3rd-4th intercostal space) were monitored continuously. Gmax was derived from the logistic modeling of the HR and MAP responses to ramped changes in carotid sinus transmural pressure using a protocol of pulsatile changes in neck chamber pressure from +40 to -65 Torr. The increase in CVP during +30-Torr LBPP was 1.5 mmHg (P < 0.05) and was similar to that observed during VE-I (1.7 mmHg, P > 0.05). The Gmax of the carotid baroreflex of HR and MAP was significantly decreased during LBPP by -0.145 +/- 0.039 beats x min(-1) x mmHg(-1) (38%) and -0.071 +/- 0.013 mmHg/mmHg (25%), respectively; however, VE-I did not affect Gmax. During VE-II, CVP was significantly greater than that elicited by LBPP, and the Gmax of the carotid baroreflex of the HR and MAP responses was significantly reduced. We conclude that carotid baroreflex responsiveness was selectively inhibited by increasing intramuscular pressure, possibly resulting in an activation of the intramuscular mechanoreceptors during LBPP. Furthermore, it would appear that the inhibition of the carotid baroreflex, via cardiopulmonary baroreceptor loading (increased CVP), occurred when a threshold pressure (CVP) was achieved.

Analyzing Transient Turbuelnce in a Stenosed Carotid Artery by Proper Orthogonal Decomposition

NASA Astrophysics Data System (ADS)

Grinberg, Leopold; Yakhot, Alexander; Karniadakis, George

2009-11-01

High resolution 3D simulation (involving 100M degrees of freedom) were employed to study transient turbulent flow in a carotid arterial bifurcation with a stenosed internal carotid artery (ICA). In the performed simulation an intermittent (in space and time) laminar-turbulent-laminar regime was observed. The simulation reveals the mechanism of the onset of turbulent flow in the stenosed ICA where the narrowing in the artery generates a strong jet flow. Time- and space-window Proper Orthogonal Decomposition (POD) was applied to quantify the different flow regimes in the occluded artery. A simplified version of the POD analysis that utilizes 2D slices only - more appropriate in the clinical setting - was also investigated.

Body water conservation through selective brain cooling by the carotid rete: a physiological feature for surviving climate change?

PubMed Central

Hetem, Robyn S.; Mitchell, Duncan; Maloney, Shane K.; O'Brien, Haley D.; Meyer, Leith C. R.; Fuller, Andrea

2017-01-01

Abstract Some mammals have the ability to lower their hypothalamic temperature below that of carotid arterial blood temperature, a process termed selective brain cooling. Although the requisite anatomical structure that facilitates this physiological process, the carotid rete, is present in members of the Cetartiodactyla, Felidae and Canidae, the carotid rete is particularly well developed in the artiodactyls, e.g. antelopes, cattle, sheep and goats. First described in the domestic cat, the seemingly obvious function initially attributed to selective brain cooling was that of protecting the brain from thermal damage. However, hyperthermia is not a prerequisite for selective brain cooling, and selective brain cooling can be exhibited at all times of the day, even when carotid arterial blood temperature is relatively low. More recently, it has been shown that selective brain cooling functions primarily as a water-conservation mechanism, allowing artiodactyls to save more than half of their daily water requirements. Here, we argue that the evolutionary success of the artiodactyls may, in part, be attributed to the evolution of the carotid rete and the resulting ability to conserve body water during past environmental conditions, and we suggest that this group of mammals may therefore have a selective advantage in the hotter and drier conditions associated with current anthropogenic climate change. A better understanding of how selective brain cooling provides physiological plasticity to mammals in changing environments will improve our ability to predict their responses and to implement appropriate conservation measures. PMID:29383253

Cerebral misery perfusion due to carotid occlusive disease

PubMed Central

Maddula, Mohana; Sprigg, Nikola; Bath, Philip M; Munshi, Sunil

2017-01-01

Purpose Cerebral misery perfusion (CMP) is a condition where cerebral autoregulatory capacity is exhausted, and cerebral blood supply in insufficient to meet metabolic demand. We present an educational review of this important condition, which has a range of clinical manifestations. Method A non-systematic review of published literature was undertaken on CMP and major cerebral artery occlusive disease, using Pubmed and Sciencedirect. Findings Patients with CMP may present with strokes in watershed territories, collapses and transient ischaemic attacks or episodic movements associated with an orthostatic component. While positron emission tomography is the gold standard investigation for misery perfusion, advanced MRI is being increasingly used as an alternative investigation modality. The presence of CMP increases the risk of strokes. In addition to the devastating effect of stroke, there is accumulating evidence of impaired cognition and quality of life with carotid occlusive disease (COD) and misery perfusion. The evidence for revascularisation in the setting of complete carotid occlusion is weak. Medical management constitutes careful blood pressure management while addressing other vascular risk factors. Discussion The evidence for the management of patients with COD and CMP is discussed, together with recommendations based on our local experience. In this review, we focus on misery perfusion due to COD. Conclusion Patients with CMP and COD may present with a wide-ranging clinical phenotype and therefore to many specialties. Early identification of patients with misery perfusion may allow appropriate management and focus on strategies to maintain or improve cerebral blood flow, while avoiding potentially harmful treatment. PMID:28959496

First-ever ischemic stroke in elderly patients: predictors of functional outcome following carotid artery stenting

PubMed Central

Lin, Chih-Ming; Chang, Yu-Jun; Liu, Chi-Kuang; Yu, Cheng-Sheng; Lu, Henry Horng-Shing

2016-01-01

Age is an important risk factor for stroke, and carotid artery stenosis is the primary cause of first-ever ischemic stroke. Timely intervention with stenting procedures can effectively prevent secondary stroke; however, the impact of stenting on various periprocedural physical functionalities has never been thoroughly investigated. The primary aim of this study was to investigate whether prestenting characteristics were associated with long-term functional outcomes in patients presenting with first-ever ischemic stroke. The secondary aim was to investigate whether patient age was an important factor in outcomes following stenting, measured by the modified Rankin scale (mRS). In total, 144 consecutive patients with first-ever ischemic stroke who underwent carotid artery stenting from January 2010 to November 2014 were included. Clinical data were obtained by review of medical records. The Barthel index (BI) and mRS were used to assess disability before stenting and at 12-month follow-up. In total, 72/144 patients showed improvement (mRS[+]), 71 showed stationary and one showed deterioration in condition (mRS[−]). The prestenting parameters, ratio of cerebral blood volume (1.41 vs 1.2 for mRS[−] vs mRS[+]), BI (75 vs 85), and high-sensitivity C-reactive protein (hsCRP 5.0 vs 3.99), differed significantly between the two outcome groups (P<0.05). The internal carotid artery/common carotid artery ratio (P=0.011), BI (P=0.019), ipsilateral internal carotid artery resistance index (P=0.003), and HbA1c (P=0.039) were all factors significantly associated with patient age group. There was no significant association between age and poststenting outcome measured by mRS with 57% of patients in the ≥75 years age group showing mRS(−) and 43% showing mRS(+) (P=0.371). Our findings indicate that in our elderly patient series, carotid artery stenting may benefit a significant proportion of carotid stenotic patients regardless of age. Ratio of cerebral blood volume, BI, and

The effect of (+)-lysergic acid diethylamide and other drugs on the carotid sinus reflex

PubMed Central

Ginzel, K. H.

1958-01-01

In cats, lysergic acid diethylamide (LSD) selectively blocked the reflex blood pressure rise following carotid chemoreceptor stimulation. It also reduced or abolished the chemoreceptor component of the pressor response to occlusion of the common carotid arteries. It did not inhibit the respiratory reflexes arising from the carotid chemoreceptors, unless spontaneous respiration was interfered with as a whole. The site of action was central, probably below the intercollicular level, regardless of whether the drug was administered by the intravenous route or into the lateral ventricle of the brain. LSD did not block the baroreceptor depressor reflex elicited by stimulation of one carotid sinus nerve. LSD frequently caused the systemic pressure to fall, even after vagotomy and atropine, and this effect might account for the occasional reduction of the baroreceptor component of the carotid occlusion response. On the other hand, no relationship was found between the action of LSD on vasomotor tone and its blocking effect on the chemoreceptor pressor reflex. Some derivatives of LSD produced effects similar to those described for LSD, whether or not they possessed a psychotropic action in man, and independently of their efficiency as antagonists to 5-hydroxytryptamine. Of a series of compounds chemically unrelated to LSD, chlorpromazine was found to block the chemoreceptor pressor rise after intracerebroventricular injection. PMID:13584725

The effect of (+)-lysergic acid diethylamide and other drugs on the carotid sinus reflex.

PubMed

GINZEL, K H

1958-09-01

In cats, lysergic acid diethylamide (LSD) selectively blocked the reflex blood pressure rise following carotid chemoreceptor stimulation. It also reduced or abolished the chemoreceptor component of the pressor response to occlusion of the common carotid arteries. It did not inhibit the respiratory reflexes arising from the carotid chemoreceptors, unless spontaneous respiration was interfered with as a whole. The site of action was central, probably below the intercollicular level, regardless of whether the drug was administered by the intravenous route or into the lateral ventricle of the brain.LSD did not block the baroreceptor depressor reflex elicited by stimulation of one carotid sinus nerve. LSD frequently caused the systemic pressure to fall, even after vagotomy and atropine, and this effect might account for the occasional reduction of the baroreceptor component of the carotid occlusion response. On the other hand, no relationship was found between the action of LSD on vasomotor tone and its blocking effect on the chemoreceptor pressor reflex.Some derivatives of LSD produced effects similar to those described for LSD, whether or not they possessed a psychotropic action in man, and independently of their efficiency as antagonists to 5-hydroxytryptamine. Of a series of compounds chemically unrelated to LSD, chlorpromazine was found to block the chemoreceptor pressor rise after intracerebroventricular injection.

Carotid Disease Management: Surgery, Stenting, or Medication.

PubMed

Khandelwal, Priyank; Chaturvedi, Seemant

2015-09-01

Internal carotid artery stenosis accounts for about 7-10 % of ischemic strokes. Conventional risk factors such as aging, hypertension, diabetes mellitus, and smoking increase the risk for carotid atherosclerosis. All patients with carotid stenosis should receive aggressive medical therapy. Carotid revascularization with either endarterectomy or stenting can benefit select patients with severe stenosis. New clinical trials will examine the contemporary role of carotid revascularization relative to optimal medical therapy.

Perioperative Embolization Load and S-100β Do Not Predict Cognitive Outcome after Carotid Revascularization.

PubMed

Plessers, Maarten; Van Herzeele, Isabelle; Hemelsoet, Dimitri; Vingerhoets, Guy; Vermassen, Frank

2016-10-01

Cognitive changes after carotid revascularization have been reported in 10-20% of patients. The etiology of cognitive impairments remains largely unknown. This study evaluates the predictive value of S-100β serum values and perioperative microembolization on cognition after carotid revascularization. Forty-six patients with significant carotid stenosis underwent carotid endarterectomy (CEA, n = 26), transfemoral carotid artery stenting with distal protection (CASdp, n = 10), or transcervical carotid stenting with dynamic flow reversal (CASfr, n = 10). Twenty-six matched vascular patients without carotid stenosis were recruited as controls. All patients underwent comprehensive cognitive testing on the day before and 1 month after carotid revascularization. S-100β analysis was performed in 31 cases pre-, peri-, and 2, 6, and 24 hr after carotid surgery, and in 25 patients transcranial Doppler monitoring was done during surgery. In the 3 treatment groups similar transient increases in S-100β values were observed. CASdp was associated with a higher embolic load than CEA and CASfr, while CEA was also associated with less microembolization than CASfr. Cognitive improvement or deterioration could not be predicted by S-100β or perioperative embolic load for any of the investigated cognitive domains. Cognitive deterioration could not be predicted using perioperative embolic load and S-100β changes. A similar inverted u-curve of the S-100β levels was observed in the 3 groups and may be caused by impairment in the blood-brain barrier during intervention, and not due to cerebral infarction. Distal protection CAS is associated with a higher embolic load than transcervical CAS using dynamic flow reversal and CEA, but the long-term impact of this higher embolic load is yet unknown. Perfusion-related measures seem promising in their ability to predict cognitive decline. Copyright © 2016 Elsevier Inc. All rights reserved.

Techniques for Nonterminal Blood Sampling in Black-Tailed Prairie Dogs (Cynomys ludovicianus).

PubMed

Head, Valerie; Eshar, David; Nau, Melissa R

2017-03-01

Black-tailed prairie dogs (Cynomys ludovicianus) are used as an animal model for research on gallbladder stones and several infectious diseases. A comprehensive, instructive resource regarding the appropriate techniques for venipuncture and collection of nonterminal blood samples in this species has not yet been published. Blood samples (1 mL or larger) were readily obtained from the jugular vein, femoral vein, or cranial vena cava, whereas peripheral sites, such as the cephalic vein, saphenous vein, and tarsal vein, mainly were useful for obtaining smaller volumes. The detailed and illustrated information presented here can aid clinicians and researchers in performing venipuncture, anesthesia, and handling of this species.

Ethnic differences in blood lipids and dietary intake between UK children of black African, black Caribbean, South Asian, and white European origin: the Child Heart and Health Study in England (CHASE).

PubMed

Donin, Angela S; Nightingale, Claire M; Owen, Christopher G; Rudnicka, Alicja R; McNamara, Mary C; Prynne, Celia J; Stephen, Alison M; Cook, Derek G; Whincup, Peter H

2010-10-01

Ischemic heart disease (IHD) rates are lower in UK black Africans and black Caribbeans and higher in South Asians when compared with white Europeans. Ethnic differences in lipid concentrations may play a part in these differences. The objective was to investigate blood lipid and dietary patterns in UK children from different ethnic groups. This was a cross-sectional study in 2026 UK children (including 285 black Africans, 188 black Caribbeans, 534 South Asians, and 512 white Europeans) attending primary schools in London, Birmingham, and Leicester. We measured fasting blood lipid concentrations and collected 24-h dietary recalls. In comparison with white Europeans, black African children had lower total cholesterol (-0.14 mmol/L; 95% CI: -0.25, -0.04 mmol/L), LDL-cholesterol (-0.10 mmol/L; 95% CI: -0.20, -0.01 mmol/L), and triglyceride concentrations (proportional difference: -0.11 mmol/L; 95% CI: -0.16, -0.06 mmol/L); HDL-cholesterol concentrations were similar. Lower saturated fat intakes (-1.4%; 95% CI: -1.9%, -0.9%) explained the differences between total and LDL cholesterol. Black Caribbean children had total, LDL-cholesterol, HDL-cholesterol, and triglyceride concentrations similar to those for white Europeans, with slightly lower saturated fat intakes. South Asian children had total and LDL-cholesterol concentrations similar to those for white Europeans, lower HDL-cholesterol concentrations (-0.7 mmol/L; 95% CI: -0.11, -0.03 mmol/L), and elevated triglyceride concentrations (proportional difference: 0.14 mmol/L; 95% CI: 0.09, 0.20 mmol/L); higher polyunsaturated and monounsaturated fat intakes did not explain these lipid differences. Only black African children had a blood lipid profile and associated dietary pattern likely to protect against future IHD. The loss of historically lower LDL-cholesterol concentrations among UK black Caribbeans and South Asians may have important adverse consequences for future IHD risk in these groups.

Dependence of morphological changes of the carotid arteries on essential hypertension and accompanying risk factors.

PubMed

Zizek, B; Poredos, P

2002-03-01

to evaluate morphological changes (intima-media thickness, IMT) of the carotid arteries in patients being treated for essential hypertension (EH), and to discover whether this abnormality can be detected in normotensive offspring of subjects with EH (familial trait, FT); and to investigate the interrelationship between IMT and accompanying risk factors. cross-sectional study. angiology department, university teaching hospital. the study encompassed 172 subjects, of whom 46 were treated hypertonics aged 40-55 (49) years, and 44 age matched, normotensive volunteers as controls. We also investigated 41 normotensives with FT for essential hypertension aged 20-30 (25) years and 41 age- and sex-matched controls without FT. the hypertensive subjects were being treated either with long-acting calcium-channel antagonists or ACE-inhibitors. using high resolution ultrasound, IMT of the carotid bifurcation and of the common carotid artery was measured. In the hypertensives, the mean IMT was greater than that in the controls (0.92 (0.10) mm vs 0.72 (0.07) mm; p<0.00005). The IMT was independently related to accompanying risk factors: a positive family history of hypertension, age of the patient, duration of EH and the level of systolic/diastolic blood pressure (BP), body mass index and total/LDL-cholesterol. In subjects with FT, IMT was also greater compared to the control group (0.60 (0.05) mm vs 0.55 (0.04) mm; p<0.00005). IMT was not related to BP values. In treated essential patients with the EH, the IMT was increased. Individuals with FT also had greater IMT in the absence of elevated BP. The IMT in hypertensives was related to accompanying risk factors, which could be pathogenetic determinants of EH and/or its complications.

Ideal Cardiovascular Health and Subclinical Markers of Carotid Structure and Function: The Paris Prospective Study III.

PubMed

Gaye, Bamba; Mustafic, Hazrije; Laurent, Stéphane; Perier, Marie-Cécile; Thomas, Frédérique; Guibout, Catherine; Tafflet, Muriel; Pannier, Bruno; Boutouyrie, Pierre; Jouven, Xavier; Empana, Jean-Philippe

2016-10-01

We hypothesized that subclinical markers of vascular structure and function, which are independent predictors of cardiovascular disease, would be less frequent in subjects with ideal than poor cardiovascular health (CVH) as defined by the American Heart Association (AHA). Carotid parameters were measured using high-precision echotracking device in 9155 nonreferred participants attending a health checkup in a large health center in Paris (France) between 2008 and 2012. According to the AHA, participants with 0 to 2, 3 to 4, and 5 to 7 metrics (smoking, physical activity, body mass index, diet, blood glucose and total cholesterol, blood pressure) at the ideal level were categorized as having poor, intermediate, and ideal CVH. Carotid parameters were dichotomized according to their median value, and multivariable logistic regression analysis was performed. Mean age was 59.5 (SD 6.3) years; 39% were females, and ideal CVH was present in 10.11% of the study participants. After adjustment for age, sex, education, and living alone and compared with a poor CVH, an ideal CVH was associated with lower common carotid artery intima-media thickness (odds ratio=1.64; 95% confidence interval 1.40, 1.93), absence of carotid plaques (odds ratio=2.14; 95% confidence interval 1.60, 2.87), lower Young's elastic modulus (odds ratio=2.43; 95% confidence interval 2.07, 2.84), and higher carotid distensibility coefficient (odds ratio=2.90; 95% confidence interval 2.47, 3.41). In community subjects aged 50 to 75 years, ideal CVH was associated with substantially less arterial stiffness and thickness. These associations might contribute to the lower risk of cardiovascular diseases in subjects with ideal CVH. © 2016 American Heart Association, Inc.

Acceptability and feasibility of a culturally tailored Internet-delivered intervention to promote blood donation in Blacks.

PubMed

Robbins, Mark L; Paiva, Andrea L; Amoyal, Nicole R; Brick, Leslie; Kessler, Debra A; Burditt, Caitlin; Caltabiano, Melinda; Shaz, Beth H

2015-03-01

A pilot test of a computer-tailored intervention designed to promote blood donation among Blacks was conducted. Intervention content, based on the transtheoretical model, offered participants individually and culturally tailored information on blood donation with emphasis on need specific to race (e.g., sickle-cell disease). Black adults (N = 150) with a diversity of blood donation experience were recruited from a blood center and a survey recruitment website. Posttest assessment included a 14-item evaluation and transtheoretical model questions. Participants rated the program positively (81.3% to 98.7% of participants agreeing or strongly agreeing with evaluation items). For example, 98.7% of respondents reported that the program gave sound advice and that personal feedback was easily understood, and 87.3% felt the program was designed for people like themselves. Ninety-five percent of participants reported that they would recommend the program to others. There were no significant differences in ratings based on demographics. Qualitative responses support program acceptability. Furthermore, pre- and postprogram assessments indicated an increase in intention to donate, t(149) = 3.56, p = .001, d = .29. With acceptability and feasibility confirmed, the next steps are to test efficacy and cost-effectiveness for use to increase blood donation, particularly in priority populations. © 2014 Society for Public Health Education.

Long-term effect of prazosin and losartan administration on blood pressure, heart, carotid artery, and acetylcholine induced dilation of cardiovascular system of young Wistar rats and SHR.

PubMed

Kristek, Frantisek; Malekova, Magdalena; Cacanyiova, Sona

2013-06-01

The long-term effects of prazosin and losartan administration on blood pressure, trophicity of the heart and carotid arteries, and responses of the cardiovascular system to acetylcholine, were studied in Wistar rats and spontaneously hypertensive rats (SHRs). Four-week-old rats were treated with prazosin (10 mg/kg b.w./day in tap water) or losartan (20 mg/kg b.w./day in tap water) for 5-6 weeks. BP was measured by plethysmographic method. Ten animals of each group were subjected to in vivo studies and subsequent to morphological investigations. The right jugular vein was cannulated for administration of acetylcholine (0.1, 1, and 10 µg). After perfusion with a glutaraldehyde fixative (120 mmHg), the carotid arteries were embedded in Durcupan ACM, and the inner diameter (ID), wall thickness (WT) (tunica intima and media), cross sectional area (CSA) (tunica intima and media), and WT/ID ratio were calculated. In Wistar rats and SHRs, prazosin and losartan administration produced a decrease in the blood pressure and trophicity of the heart. In Wistar rats, both drugs decreased the WT, CSA, and the WT/ID ratio. In addition, these drugs increased the circumferential stress of the artery without affecting the ID. In contrast, in the SHRs, only losartan administration produced these effects. Importantly, both the drugs improved the responses to acetylcholine in SHRs.

Carotid artery stenting: current and emerging options

PubMed Central

Morr, Simon; Lin, Ning; Siddiqui, Adnan H

2014-01-01

Carotid artery stenting technologies are rapidly evolving. Options for endovascular surgeons and interventionists who treat occlusive carotid disease continue to expand. We here present an update and overview of carotid stenting devices. Evidence supporting carotid stenting includes randomized controlled trials that compare endovascular stenting to open surgical endarterectomy. Carotid technologies addressed include the carotid stents themselves as well as adjunct neuroprotective devices. Aspects of stent technology include bare-metal versus covered stents, stent tapering, and free-cell area. Drug-eluting and cutting balloon indications are described. Embolization protection options and new direct carotid access strategies are reviewed. Adjunct technologies, such as intravascular ultrasound imaging and risk stratification algorithms, are discussed. Bare-metal and covered stents provide unique advantages and disadvantages. Stent tapering may allow for a more fitted contour to the caliber decrement between the common carotid and internal carotid arteries but also introduces new technical challenges. Studies regarding free-cell area are conflicting with respect to benefits and associated risk; clinical relevance of associated adverse effects associated with either type is unclear. Embolization protection strategies include distal filter protection and flow reversal. Though flow reversal was initially met with some skepticism, it has gained wider acceptance and may provide the advantage of not crossing the carotid lesion before protection is established. New direct carotid access techniques address difficult anatomy and incorporate sophisticated flow-reversal embolization protection techniques. Carotid stenting is a new and exciting field with rapidly advancing technologies. Embolization protection, low-risk deployment, and lesion assessment and stratification are active areas of research. Ample room remains for further innovations and developments. PMID:25349483

Mildly Elevated Serum Bilirubin Levels Are Negatively Associated with Carotid Atherosclerosis among Elderly Persons

PubMed Central

Kawamoto, Ryuichi; Ninomiya, Daisuke; Hasegawa, Yoichi; Kasai, Yoshihisa; Kusunoki, Tomo; Ohtsuka, Nobuyuki; Kumagi, Teru; Abe, Masanori

2014-01-01

Serum bilirubin may have a beneficial role in preventing oxidative changes in atherosclerosis. Limited information is available on whether serum total bilirubin is an independent confounding factor for carotid atherosclerosis {for example, intima-media thickness (IMT), plaque} measured noninvasively by B-mode ultrasonography only among elderly persons. The study subjects were 325 men aged 79±8 (mean ± standard deviation) years and 509 women aged 81±8 years that were enrolled consecutively from patients aged ≥60 years in the medical department. Carotid IMT and plaque were derived via B-mode ultrasonography. Multiple linear regression analysis showed that in men age (β = 0.199, p = 0.002), smoking status (β = 0.154, p = 0.006), GGT (β = -0.139, p = 0.039), and GGT (β = -0.133, p = 0.022) were significantly and independently associated with carotid IMT, and in women age (β = 0.186, p<0.001), systolic blood pressure (β = 0.104, p = 0.046), diastolic blood pressure (β = -0.148, p = 0.004), prevalence of antihypertensive medication (β = 0.126, p = 0.004), fasting plasma glucose (β = 0.135, p = 0.003), GGT (β = -0.104, p = 0.032), estimated glomerular filtration rate, serum bilirubin (β = -0.119, p = 0.006), and prevalence of cardiovascular disease (CVD) (β = 0.103, p = 0.017) were also independently associated with carotid IMT. The odds ratios (ORs) {95% confidence interval (CI)} of increasing serum bilirubin category were negatively associated with carotid IMT ≥1.0 mm and plaque in both genders. Compared to subjects with a serum bilirubin of Quartile-1, the multivariate-OR (95% CI) of carotid plaque was 0.25 (0.11–0.57) in the Quartile-4 male group, and 0.41 (0.21–0.78) in the Quartile-2 female group, 0.51 (0.26–0.98) in the Quartile-3 female group, and 0.46 (0.24–0.89) in the Quartile-4 female group. Our data demonstrated an independently negative

Night Blood Pressure Responses to Atenolol and Hydrochlorothiazide in Black and White Patients With Essential Hypertension

PubMed Central

2014-01-01

BACKGROUND Night blood pressure (BP) predicts patient outcomes. Variables associated with night BP response to antihypertensive agents have not been fully evaluated in essential hypertension. METHODS We sought to measure night BP responses to hydrochlorothiazide (HCTZ), atenolol (ATEN), and combined therapy using ambulatory blood pressure (ABP) monitoring in 204 black and 281 white essential hypertensive patients. Initial therapy was randomized; HCTZ and ATEN once daily doses were doubled after 3 weeks and continued for 6 more weeks with the alternate medication added for combined therapy arms. ABP was measured at baseline and after completion of each drug. Night, day, and night/day BP ratio responses (treatment − baseline) were compared in race/sex subgroups. RESULTS Baseline night systolic BP and diastolic BP, and night/day ratios were greater in blacks than whites (P < 0.01, all comparisons). Night BP responses to ATEN were absent and night/day ratios increased significantly in blacks (P < 0.05). At the end of combined therapy, women, blacks, and those starting with HCTZ as opposed to ATEN had significantly greater night BP responses (P < 0.01). Variables that significantly associated with ATEN response differed from those that associated with HCTZ response and those that associated with night BP response differed from those that associated with day BP response. CONCLUSIONS In summary, after completion of HCTZ and ATEN therapy, women, blacks, and those who started with HCTZ had greater night BP responses. Reduced night BP response and increased night/day BP ratios occured with ATEN in blacks. Given the prognostic significance of night BP, strategies for optimizing night BP antihypertensive therapy should be considered. CLINICAL TRIAL REGISTRATION Clinicaltrials.gov identifier NCT00246519 PMID:23886594

Flow diversion in the treatment of carotid injury and carotid-cavernous fistula after transsphenoidal surgery

PubMed Central

Lum, Cheemum; Ahmed, Muhammad E; Glikstein, Rafael; dos Santos, Marlise P; Lesiuk, Howard; Labib, Mohamed; Kassam, Amin B

2015-01-01

We describe a case of iatrogenic carotid injury with secondary carotid-cavernous fistula (CCF) treated with a silk flow diverter stent placed within the injured internal carotid artery and coils placed within the cavernous sinus. Flow diverters may offer a simple and potentially safe vessel-sparing option in this rare complication of transsphenoidal surgery. The management options are discussed and the relevant literature is reviewed. PMID:26015526

When is carotid angioplasty and stenting the cost-effective alternative for revascularization of symptomatic carotid stenosis? A Canadian health system perspective.

PubMed

Almekhlafi, M A; Hill, M D; Wiebe, S; Goyal, M; Yavin, D; Wong, J H; Clement, F M

2014-02-01

Carotid revascularization procedures can be complicated by stroke. Additional disability adds to the already high costs of the procedure. To weigh the cost and benefit, we estimated the cost-utility of carotid angioplasty and stenting compared with carotid endarterectomy among patients with symptomatic carotid stenosis, with special emphasis on scenario analyses that would yield carotid angioplasty and stenting as the cost-effective alternative relative to carotid endarterectomy. A cost-utility analysis from the perspective of the health system payer was performed by using a Markov analytic model. Clinical estimates were based on a meta-analysis. The procedural costs were derived from a microcosting data base. The costs for hospitalization and rehabilitation of patients with stroke were based on a Canadian multicenter study. Utilities were based on a randomized controlled trial. In the base case analysis, carotid angioplasty and stenting were more expensive (incremental cost of $6107) and had a lower utility (-0.12 quality-adjusted life years) than carotid endarterectomy. The results are sensitive to changes in the risk of clinical events and the relative risk of death and stroke. Carotid angioplasty and stenting were more economically attractive among high-risk surgical patients. For carotid angioplasty and stenting to become the preferred option, their costs would need to fall from more than $7300 to $4350 or less and the risks of the periprocedural and annual minor strokes would have to be equivalent to that of carotid endarterectomy. In the base case analysis, carotid angioplasty and stenting were associated with higher costs and lower utility compared with carotid endarterectomy for patients with symptomatic carotid stenosis. Carotid angioplasty and stenting were cost-effective for patients with high surgical risk.

Motivators and deterrents to blood donation among Black South Africans: a qualitative analysis of focus group data.

PubMed

Muthivhi, T N; Olmsted, M G; Park, H; Sha, M; Raju, V; Mokoena, T; Bloch, E M; Murphy, E L; Reddy, R

2015-08-01

South Africa has a markedly skewed representation where the majority of blood (62%) is presently collected from an ethnically White minority. This study seeks to identify culturally specific factors affecting motivation of donors in South Africa. We performed a qualitative study to evaluate motivators and deterrents to blood donation among Black South Africans. A total of 13 focus groups, comprising a total of 97 Black South Africans, stratified by age and geographic location were conducted. Transcripts of the interviews were analysed using a coding framework by Bednall & Bove. Participants made 463 unique comments about motivators focusing primarily on promotional communications (28%), incentives (20%) and prosocial motivation (16%). Participants made 376 comments about deterrents which focused primarily on fear (41%), negative attitudes (14%) and lack of knowledge (10%). Although prosocial motivation (altruism) was the most frequently mentioned individual motivator, promotional communication elicited more overall comments by participants. As reported by many authors, fear and lack of awareness were strong deterrents, but scepticism engendered by perceived racial discrimination in blood collection were unique to the South African environment. © 2015 British Blood Transfusion Society.

Blood Pressure Control

NASA Technical Reports Server (NTRS)

1986-01-01

Engineering Development Laboratory developed a system for the cardiovascular study of weightless astronauts. This was designed to aid people with congestive heart failure and diabetes. While in space, astronauts' blood pressure rises, heart rate becomes unstable, and there are sometimes postflight lightheadedness or blackouts. The Baro-Cuff studies the resetting of blood pressure. When a silicone rubber chamber is strapped to the neck, the Baro-Cuff stimulates the carotid arteries by electronically controlled pressure application. Blood pressure controls in patients may be studied.

A new length scale for quantum gravity: A resolution of the black hole information loss paradox

NASA Astrophysics Data System (ADS)

Singh, Tejinder P.

We show why and how Compton wavelength and Schwarzschild radius should be combined into one single new length scale, which we call the Compton-Schwarzschild length. Doing so offers a resolution of the black hole information loss paradox, and suggests Planck mass remnant black holes as candidates for dark matter. It also compels us to introduce torsion, and identify the Dirac field with a complex torsion field. Dirac equation and Einstein equations, are shown to be mutually dual limiting cases of an underlying gravitation theory which involves the Compton-Schwarzschild length scale, and includes a complex torsion field.

Serum Carotenoids Reduce Progression of Early Atherosclerosis in the Carotid Artery Wall among Eastern Finnish Men

PubMed Central

Karppi, Jouni; Kurl, Sudhir; Ronkainen, Kimmo; Kauhanen, Jussi; Laukkanen, Jari A.

2013-01-01

Background Several previous epidemiologic studies have shown that high blood levels of carotenoids may be protective against early atherosclerosis, but results have been inconsistent. We assessed the association between atherosclerotic progression, measured by intima-media thickness of the common carotid artery wall, and serum levels of carotenoids. Methods We studied the effect of carotenoids on progression of early atherosclerosis in a population-based study. The association between concentrations of serum carotenoids, and intima-media thickness of the common carotid artery wall was explored in 840 middle-aged men (aged 46–65 years) from Eastern Finland. Ultrasonography of the common carotid arteries were performed at baseline and 7-year follow-up. Serum levels of carotenoids were analyzed at baseline. Changes in mean and maximum intima media thickness of carotid artery wall were related to baseline serum carotenoid levels in covariance analyses adjusted for covariates. Results In a covariance analysis with adjustment for age, ultrasound sonographer, maximum intima media thickness, examination year, body mass index, systolic blood pressure, smoking, physical activity, serum LDL cholesterol, family history of coronary heart disease, antihypertensive medication and serum high sensitivity C-reactive protein, 7-year change in maximum intima media thickness was inversely associated with lycopene (p = 0.005), α-carotene (p = 0.002) and β-carotene (p = 0.019), respectively. Conclusions The present study shows that high serum concentrations of carotenoids may be protective against early atherosclerosis. PMID:23700460

Inflammation, homocysteine and carotid intima-media thickness.

PubMed

Baptista, Alexandre P; Cacdocar, Sanjiva; Palmeiro, Hugo; Faísca, Marília; Carrasqueira, Herménio; Morgado, Elsa; Sampaio, Sandra; Cabrita, Ana; Silva, Ana Paula; Bernardo, Idalécio; Gome, Veloso; Neves, Pedro L

2008-01-01

Cardiovascular disease is the main cause of morbidity and mortality in chronic renal patients. Carotid intima-media thickness (CIMT) is one of the most accurate markers of atherosclerosis risk. In this study, the authors set out to evaluate a population of chronic renal patients to determine which factors are associated with an increase in intima-media thickness. We included 56 patients (F=22, M=34), with a mean age of 68.6 years, and an estimated glomerular filtration rate of 15.8 ml/min (calculated by the MDRD equation). Various laboratory and inflammatory parameters (hsCRP, IL-6 and TNF-alpha) were evaluated. All subjects underwent measurement of internal carotid artery intima-media thickness by high-resolution real-time B-mode ultrasonography using a 10 MHz linear transducer. Intima-media thickness was used as a dependent variable in a simple linear regression model, with the various laboratory parameters as independent variables. Only parameters showing a significant correlation with CIMT were evaluated in a multiple regression model: age (p=0.001), hemoglobin (p=00.3), logCRP (p=0.042), logIL-6 (p=0.004) and homocysteine (p=0.002). In the multiple regression model we found that age (p=0.001) and homocysteine (p=0.027) were independently correlated with CIMT. LogIL-6 did not reach statistical significance (p=0.057), probably due to the small population size. The authors conclude that age and homocysteine correlate with carotid intima-media thickness, and thus can be considered as markers/risk factors in chronic renal patients.

A comparison of visible wavelength reflectance hyperspectral imaging and Acid Black 1 for the detection and identification of blood stained fingerprints.

PubMed

Cadd, Samuel; Li, Bo; Beveridge, Peter; O Hare, William T; Campbell, Andrew; Islam, Meez

2016-07-01

Bloodstains are often encountered at scenes of violent crime and have significant forensic value for criminal investigations. Blood is one of the most commonly encountered types of biological evidence and is the most commonly observed fingerprint contaminant. Presumptive tests are used to test blood stain and blood stained fingerprints are targeted with chemical enhancement methods, such as acid stains, including Acid Black 1, Acid Violet 17 or Acid Yellow 7. Although these techniques successfully visualise ridge detail, they are destructive, do not confirm the presence of blood and can have a negative impact on DNA sampling. A novel application of visible wavelength hyperspectral imaging (HSI) is used for the non-contact, non-destructive detection and identification of blood stained fingerprints on white tiles both before and after wet chemical enhancement using Acid Black 1. The identification was obtained in a non-contact and non-destructive manner, based on the unique visible absorption spectrum of haemoglobin between 400 and 500nm. Results from the exploration of the selectivity of the setup to detect blood against ten other non-blood protein contaminants are also presented. A direct comparison of the effectiveness of HSI with chemical enhancement using Acid Black 1 on white tiles is also shown. Copyright © 2016 The Chartered Society of Forensic Sciences. Published by Elsevier Ireland Ltd. All rights reserved.

Ambulatory versus home versus clinic blood pressure: the association with subclinical cerebrovascular diseases: the Ohasama Study.

PubMed

Hara, Azusa; Tanaka, Kazushi; Ohkubo, Takayoshi; Kondo, Takeo; Kikuya, Masahiro; Metoki, Hirohito; Hashimoto, Takanao; Satoh, Michihiro; Inoue, Ryusuke; Asayama, Kei; Obara, Taku; Hirose, Takuo; Izumi, Shin-Ichi; Satoh, Hiroshi; Imai, Yutaka

2012-01-01

The usefulness of ambulatory, home, and casual/clinic blood pressure measurements to predict subclinical cerebrovascular diseases (silent cerebrovascular lesions and carotid atherosclerosis) was compared in a general population. Data on ambulatory, home, and casual/clinic blood pressures and brain MRI to detect silent cerebrovascular lesions were obtained in 1007 subjects aged ≥55 years in a general population of Ohasama, Japan. Of the 1007 subjects, 583 underwent evaluation of the extent of carotid atherosclerosis. Twenty-four-hour, daytime, and nighttime ambulatory and home blood pressure levels were closely associated with the risk of silent cerebrovascular lesions and carotid atherosclerosis (all P<0.05). When home and one of the ambulatory blood pressure values were simultaneously included in the same regression model, each of the ambulatory blood pressure values remained a significant predictor of silent cerebrovascular lesions, whereas home blood pressure lost its predictive value. Of the ambulatory blood pressure values, nighttime blood pressure was the strongest predictor of silent cerebrovascular lesions. The home blood pressure value was more closely associated with the risk of carotid atherosclerosis than any of the ambulatory blood pressure values when home and one of the ambulatory blood pressure values were simultaneously included in the same regression model. The casual/clinic blood pressure value had no significant association with the risk of subclinical cerebrovascular diseases. Although the clinical indications for ambulatory blood pressure monitoring and home blood pressure measurements may overlap, the clinical significance of each method for predicting target organ damage may differ for different target organs.

Inherent variations in CO-H2S-mediated carotid body O2 sensing mediate hypertension and pulmonary edema

PubMed Central

Peng, Ying-Jie; Makarenko, Vladislav V.; Nanduri, Jayasri; Vasavda, Chirag; Raghuraman, Gayatri; Yuan, Guoxiang; Gadalla, Moataz M.; Kumar, Ganesh K.; Snyder, Solomon H.; Prabhakar, Nanduri R.

2014-01-01

Oxygen (O2) sensing by the carotid body and its chemosensory reflex is critical for homeostatic regulation of breathing and blood pressure. Humans and animals exhibit substantial interindividual variation in this chemosensory reflex response, with profound effects on cardiorespiratory functions. However, the underlying mechanisms are not known. Here, we report that inherent variations in carotid body O2 sensing by carbon monoxide (CO)-sensitive hydrogen sulfide (H2S) signaling contribute to reflex variation in three genetically distinct rat strains. Compared with Sprague-Dawley (SD) rats, Brown-Norway (BN) rats exhibit impaired carotid body O2 sensing and develop pulmonary edema as a consequence of poor ventilatory adaptation to hypobaric hypoxia. Spontaneous Hypertensive (SH) rat carotid bodies display inherent hypersensitivity to hypoxia and develop hypertension. BN rat carotid bodies have naturally higher CO and lower H2S levels than SD rat, whereas SH carotid bodies have reduced CO and greater H2S generation. Higher CO levels in BN rats were associated with higher substrate affinity of the enzyme heme oxygenase 2, whereas SH rats present lower substrate affinity and, thus, reduced CO generation. Reducing CO levels in BN rat carotid bodies increased H2S generation, restoring O2 sensing and preventing hypoxia-induced pulmonary edema. Increasing CO levels in SH carotid bodies reduced H2S generation, preventing hypersensitivity to hypoxia and controlling hypertension in SH rats. PMID:24395806

Dietary fat intake and carotid artery wall thickness: the Atherosclerosis Risk in Communities (ARIC) Study.

PubMed

Tell, G S; Evans, G W; Folsom, A R; Shimakawa, T; Carpenter, M A; Heiss, G

1994-05-15

Associations between atherosclerosis and dietary fat and cholesterol have been demonstrated in numerous animal experiments. The relation between these dietary components and atherosclerosis has not previously been reported in a population-based study among human beings. The associations of dietary fat and cholesterol with carotid artery wall thickness (atherosclerosis) were investigated in a population-based study, the Atherosclerosis Risk in Communities (ARIC) Study, from 1987 to 1989. Participants were 2,095 black women, 5,146 white women, 1,318 black men and 4,589 white men, aged 45-64 years, recruited from four US communities: Jackson, Mississippi; Forsyth County, North Carolina; Washington County, Maryland; and Minneapolis, Minnesota. Habitual diet was assessed with a food frequency questionnaire. Wall thickness was measured with B-mode ultrasound. After adjustment for age and energy intake, animal fat, saturated fat, monounsaturated fat, cholesterol, and Keys' score were positively related to wall thickness, while vegetable fat and polyunsaturated fat were inversely related to wall thickness. These associations persisted after further adjustment for smoking and hypertension and were consistent across the four race and sex groups. Thus, elements of habitual dietary intake were consistently associated with carotid artery wall thickness, compatible with their putatively atherogenic and antiatherogenic properties.

Diagnosis of carotid sinus hypersensitivity in older adults: carotid sinus massage in the upright position is essential

PubMed Central

Parry, S; Richardson, D; O'Shea, D; Sen, B; Kenny, R

2000-01-01

OBJECTIVE—To assess the diagnostic value of supine and upright carotid sinus massage in elderly patients.
DESIGN—Prospective controlled cohort study.
SETTING—Three inner city accident and emergency departments and a dedicated syncope facility.
PATIENTS—1375 consecutive patients aged > 55 years presenting with unexplained syncope and drop attacks; 25 healthy controls.
INTERVENTIONS—Bilateral supine carotid sinus massage, repeated in the 70° head up tilt position if the initial supine test was not diagnostic of cardioinhibitory and mixed carotid sinus hypersensitivity.
MAIN OUTCOME MEASURES—Diagnosis of cardioinhibitory or mixed carotid sinus hypersensitivity; clinical characteristics of supine v upright positive groups.
RESULTS—226 patients were excluded for contraindications to carotid sinus massage. Of 1149 patients undergoing massage, 223 (19%) had cardioinhibitory or mixed carotid sinus hypersensitivity; 70 (31%) of these had a positive response to massage with head up tilt following negative supine massage (95% confidence interval, 25.3% to 37.5%). None of the healthy controls showed carotid sinus hypersensitivity on erect or supine massage. The initially positive supine test had 74% specificity and 100% sensitivity; these were both 100% for the upright positive test. The clinical characteristics of the supine v upright positive subgroups were similar.
CONCLUSIONS—The diagnosis of carotid sinus hypersensitivity amenable to treatment by pacing may be missed in one third of cases if only supine massage is performed. Massage should be done routinely in the head up tilt position if the initial supine test is negative.


Keywords: carotid sinus; tilt table testing; syncope; elderly patients PMID:10618329

The assessment of circulating volume using inferior vena cava collapse index and carotid Doppler velocity time integral in healthy volunteers: a pilot study.

PubMed

Peachey, Tom; Tang, Andrew; Baker, Elinor C; Pott, Jason; Freund, Yonathan; Harris, Tim

2016-09-02

Assessment of circulating volume and the requirement for fluid replacement are fundamental to resuscitation but remain largely empirical. Passive leg raise (PLR) may determine fluid responders while avoiding potential fluid overload. We hypothesised that inferior vena cava collapse index (IVCCI) and carotid artery blood flow would change predictably in response to PLR, potentially providing a non-invasive tool to assess circulating volume and identifying fluid responsive patients. We conducted a prospective proof of concept pilot study on fasted healthy volunteers. One operator measured IVC diameter during quiet respiration and sniff, and carotid artery flow. Stroke volume (SV) was also measured using suprasternal Doppler. Our primary endpoint was change in IVCCI after PLR. We also studied changes in IVCCI after "sniff", and correlation between carotid artery flow and SV. Passive leg raise was associated with significant reduction in the mean inferior vena cava collapsibility index from 0.24 to 0.17 (p < 0.01). Mean stroke volume increased from 56.0 to 69.2 mL (p < 0.01). There was no significant change in common carotid artery blood flow. Changes in physiology consequent upon passive leg raise normalised rapidly. Passive leg raise is associated with a decrease of IVCCI and increase in stroke volume. However, the wide range of values observed suggests that factors other than circulating volume predominate in determining the proportion of collapse with respiration. In contrast to other studies, we did not find that carotid blood flow increased with passive leg raise. Rapid normalisation of post-PLR physiology may account for this.

Mass Transport and Shear Stress in the Carotid Artery Bifurcation

NASA Astrophysics Data System (ADS)

Gorder, Riley; Aliseda, Alberto

2010-11-01

The carotid artery bifurcation (CAB) is one of the leading sites for atherosclerosis, a major cause of death and disability in the developed world. The specific processes by which the complex flow found at the bifurcation and carotid sinus promotes plaque formation and growth are not fully understood. Shear stress, mass transport, and flow residence times are considered key factors. Although the governing equations closely link shear stress and mass transfer, the pulsatile, transitional, and detached flow found at the CAB can lead to differences between regions of WSS and mass transfer statistics. In this study, CAB geometries are reconstructed from patient specific 3D ultrasound medical imaging. Using ANSYS FLUENT, the fluid flow and scalar transport was solved using realistic flow conditions and various mass transfer boundary conditions. The spatial and temporal resolution was validated against the analytical solution of the Graetz-Nusselt problem with constant wall flux to ensure the scalar transport is resolved for a Peclet number up to 100,000. High residence time regions are investigated by determining the number of cardiac cycles required to flush out the carotid sinus. The correlations between regions of low WSS, high OSI, and scalar concentration are computed and interpreted in the context of atherosclerotic plaque origin and progression.

National variation in preoperative imaging, carotid duplex ultrasound criteria, and threshold for surgery for asymptomatic carotid artery stenosis.

PubMed

Arous, Edward J; Simons, Jessica P; Flahive, Julie M; Beck, Adam W; Stone, David H; Hoel, Andrew W; Messina, Louis M; Schanzer, Andres

2015-10-01

Carotid endarterectomy (CEA) for asymptomatic carotid artery stenosis is among the most common procedures performed in the United States. However, consensus is lacking regarding optimal preoperative imaging, carotid duplex ultrasound criteria, and ultimately, the threshold for surgery. We sought to characterize national variation in preoperative imaging, carotid duplex ultrasound criteria, and threshold for surgery for asymptomatic CEA. The Society for Vascular Surgery Vascular Quality Initiative (VQI) database was used to identify all CEA procedures performed for asymptomatic carotid artery stenosis between 2003 and 2014. VQI currently captures 100% of CEA procedures performed at >300 centers by >2000 physicians nationwide. Three analyses were performed to quantify the variation in (1) preoperative imaging, (2) carotid duplex ultrasound criteria, and (3) threshold for surgery. Of 35,695 CEA procedures in 33,488 patients, the study cohort was limited to 19,610 CEA procedures (55%) performed for asymptomatic disease. The preoperative imaging modality used before CEA varied widely, with 57% of patients receiving a single preoperative imaging study (duplex ultrasound imaging, 46%; computed tomography angiography, 7.5%; magnetic resonance angiography, 2.0%; cerebral angiography, 1.3%) and 43% of patients receiving multiple preoperative imaging studies. Of the 16,452 asymptomatic patients (89%) who underwent preoperative duplex ultrasound imaging, there was significant variability between centers in the degree of stenosis (50%-69%, 70%-79%, 80%-99%) designated for a given peak systolic velocity, end diastolic velocity, and internal carotid artery-to-common carotid artery ratio. Although 68% of CEA procedures in asymptomatic patients were performed for an 80% to 99% stenosis, 26% were performed for a 70% to 79% stenosis, and 4.1% were performed for a 50% to 69% stenosis. At the surgeon level, the range in the percentage of CEA procedures performed for a <80% asymptomatic

Establishing an endovascular carotid stent program.

PubMed

Raabe, Rod; Chong, Brian

2004-12-01

FDA approval of carotid stent and distal protection devices has transformed carotid artery stenting (CAS) from an investigational procedure to a practical application. Recent approval by the Center for Medicare Services (CMS) has ensured that CAS will be a part of everyday practice throughout the country. To establish a competitive endovascular carotid stent program, one needs to develop an effective strategy. The key to success is substance and service. A high-quality clinical program with excellent communication between the patient and referring physician is essential. You must first get access to the patient by establishing a clinical practice. As a radiologist, you have the advantage of gaining access by identifying appropriate patients through noninvasive vascular labs, CTA, and MRA. An algorithm-driven evaluation and treatment protocol with good pre- and postoperative care, along with a quality assurance program, will ensure that your carotid stent program has substance and delivers optimal service. With good planning, you will have a firm clinical foundation for treatment of carotid artery stenosis in your community. Putting all of the ingredients together will ensure a successful carotid endovascular program.

Management of carotid stenosis in women

PubMed Central

Brown, Martin M.; Didier, Leys; Howard, Virginia J.; Moore, Wesley S.; Paciaroni, Maurizio; Ringleb, Peter; Rockman, Caron; Caso, Valeria

2013-01-01

Objective: Specific guidelines for management of cerebrovascular risk in women are currently lacking. This study aims to provide a consensus expert opinion to help make clinical decisions in women with carotid stenosis. Methods: Proposals for the use of carotid endarterectomy (CEA), carotid stenting (CAS), and medical therapy for stroke prevention in women with carotid stenosis were provided by a group of 9 international experts with consensus method. Results: Symptomatic women with severe carotid stenosis can be managed by CEA provided that the perioperative risk of the operators is low (<4%). Periprocedural stroke risks may be increased in symptomatic women if revascularization is performed by CAS; however, the choice of CAS vs CEA can be tailored in subgroups best fit for each procedure (e.g., women with restenosis or severe coronary disease, best suited for CAS; women with tortuous vessels or old age, best suited for CEA). There is currently limited evidence to consider medical therapy alone as the best choice for women with neurologically severe asymptomatic carotid stenosis, who should be best managed within randomized trials including a medical arm. Medical management and cardiovascular risk factor control must be implemented in all women with carotid stenosis in periprocedural period and lifelong regardless of whether or not intervention is planned. Conclusions: The suggestions provided in this article may constitute a decision-making basis for planning treatment of carotid stenosis in women. Most recommendations are of limited strength; however, it is unlikely that new robust data will emerge soon to induce relevant changes. PMID:23751919

Effects of mecamylamine on responses of carotid body chemoreceptors in vivo to physiological and pharmacological stimuli

PubMed Central

Sampson, S. R.

1971-01-01

1. Effects of mecamylamine on the spontaneous discharge rate of afferent fibres of carotid body chemoreceptors in vivo and their responses to ACh, NaCN, HCl and hypoxia were studied in sixteen cats. 2. Cats were anaesthetized with sodium pentobarbitone, paralysed with gallamine triethiodide and artificially ventilated. Chemoreceptor excitants were injected into the common carotid artery; mecamylamine was given intravenously. 3. Mecamylamine, 230 μg/kg or greater, failed to diminish either the rate of spontaneous discharge of carotid body chemoreceptors at high arterial oxygen tensions (greater than 130 mm Hg), or the responses of these receptors to NaCN (0·5-25 μg), HCl or hypoxic blood. 4. Responses of chemoreceptor afferent fibres to ACh (1·0-50 μg) in the same preparations were either completely abolished or considerably reduced by mecamylamine. 5. These data do not support the hypothesis of a cholinergic mechanism for the initiation of chemosensory discharges in the carotid body, either at rest or in response to stimuli such as NaCN, acid or hypoxia. PMID:5557066

Quantification of the Interrelationship between Brachial-Ankle and Carotid-Femoral Pulse Wave Velocity in a Workplace Population.

PubMed

Cheng, Yi-Bang; Li, Yan; Sheng, Chang-Sheng; Huang, Qi-Fang; Wang, Ji-Guang

2016-04-01

Brachial-ankle pulse wave velocity (PWV) is increasingly used for the measurement of arterial stiffness. In the present study, we quantified the interrelationship between brachial-ankle and carotid-femoral PWV in a workplace population, and investigated the associations with cardiovascular risk factors and carotid intima-media thickness (IMT). Brachial-ankle and carotid-femoral PWV were measured using the Omron-Colin VP1000 and SphygmoCor devices, respectively. We investigated the interrelationship by the Pearson's correlation analysis and Bland-Altman plot, and performed sensitivity and specificity analyses. The 954 participants (mean ± standard deviation age 42.6 ± 14.2 years) included 630 (66.0%) men and 203 (21.3%) hypertensive patients. Brachial-ankle (13.4 ± 2.7 m/s) and carotid-femoral PWV (7.3 ± 1.6 m/s) were significantly correlated in all subjects (r = 0.75) as well as in men (r = 0.72) and women (r = 0.80) separately. For arterial stiffness defined as a carotid-femoral PWV of 10 m/s or higher, the sensitivity and specificity of brachial-ankle PWV of 16.7 m/s or higher were 72 and 94%, respectively. The area under the receiver operating characteristic curve was 0.953. In multiple stepwise regression, brachial-ankle and carotid-femoral PWV were significantly (p < 0.001) associated with age (partial r = 0.33 and 0.34, respectively) and systolic blood pressure (partial r = 0.71 and 0.66, respectively). In addition, brachial-ankle and carotid-femoral PWV were significantly (p < 0.001) associated with carotid IMT (r = 0.57 and 0.55, respectively) in unadjusted analysis, but not in analysis adjusted for cardiovascular risk factors (p ≥ 0.08). Brachial-ankle and carotid-femoral PWV were closely correlated, and had similar determinants. Brachial-ankle PWV can behave as an ease-of-use alternative measure of arterial stiffness for assessing cardiovascular risk.

A new voluntary blood collection method for the Andean bear (Tremarctos ornatus) and Asiatic black bear (Ursus thibetanus).

PubMed

Otaki, Yusuke; Kido, Nobuhide; Omiya, Tomoko; Ono, Kaori; Ueda, Miya; Azumano, Akinori; Tanaka, Sohei

2015-01-01

Various training methods have been developed for animal husbandry and health care in zoos and one of these trainings is blood collection. One training method, recently widely used for blood collection in Ursidae, requires setting up a sleeve outside the cage and gives access to limited blood collection sites. A new voluntary blood collection method without a sleeve was applied to the Andean bear (Tremarctos ornatus) and Asiatic black bear (Ursus thibetanus) with access to various veins at the same time. The present study evaluated the effectiveness of this new method and suggests improvements. Two Andean and two Asiatic black bears in Yokohama and Nogeyama Zoological Gardens, respectively, were trained to hold a bamboo pipe outside their cages. We could, thereby, simultaneously access superficial dorsal veins, the dorsal venous network of the hand, the cephalic vein from the carpal joint, and an area approximately 10 cm proximal to the carpal joint. This allowed us to evaluate which vein was most suitable for blood collection. We found that the cephalic vein, approximately 10 cm proximal to the carpal joint, was the most suitable for blood collection. This new method requires little or no modification of zoo facilities and provides a useful alternative method for blood collection. It could be adapted for use in other clinical examinations such as ultrasound examination. © 2015 Wiley Periodicals, Inc.

[A clinical study on the effect of nattokinase on carotid artery atherosclerosis and hyperlipidaemia].

PubMed

Ren, N N; Chen, H J; Li, Y; Mcgowan, G W; Lin, Y G

2017-07-11

Objective: To evaluate the efficacy of oral nattokinase (NK) in the reduction of common carotid artery intimal medial thickness (CCA-IMT) and carotid artery plaque size and in lowering blood lipids, and to explore the underlying mechanism of actions of NK and its potential clinical use. Methods: All enrolled patients were from the Out-Patient Clinic of the Department of TCM at the 3(rd) Affiliated Hospital of Sun Yat-sen University. Using randomised picking method, all patients were randomly assigned to one of two groups, NK and Statin (ST) group. NK Group-patients were given NK at a daily dose of 6 000 FU and ST Group-patients were treated with statin (simvastatin 20 mg) daily. The treatment course was 26 weeks. CCA-IMT, carotid plaque size and blood lipid profile of the patients were measured before and after treatment. Results: A total of 82 patients were enrolled in the study and 76 patients (NK 39, ST 37) completed the study. Following the treatments for 26 weeks, there was a significant reduction in CCA-IMT and carotid plaque size in both groups compared with the baseline before treatment. The carotid plaque size and CCA-IMT reduced from(0.25±0.12)cm(2) to (0.16±0.10)cm(2) and from (1.13±0.12)mm to (1.01±0.11)mm, repectively. The reduction in the NK group was significantly profound ( P <0.01, 36.6% reduction in plaque size in NK group versus 11.5% change in ST group). Both treatments reduced total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C) and triglyceride (TG). While the reduction in both groups was shown to be statistically significant ( P <0.01), the reduction of TC, LDL-C and TG in ST group was significantly greater ( P <0.05). In addition, NK significantly increased the level of high-density lipoprotein cholesterol (HDL-C) ( P <0.05), in contrast, HDL-C in the ST group did not change. The lipid lowering effect observed in the NK group was not correlated to the reduction of CCA-IMT and carotid artery plaque size ( r =0.35, P =0

Mining data from CFD simulation for aneurysm and carotid bifurcation models.

PubMed

Miloš, Radović; Dejan, Petrović; Nenad, Filipović

2011-01-01

Arterial geometry variability is present both within and across individuals. To analyze the influence of geometric parameters, blood density, dynamic viscosity and blood velocity on wall shear stress (WSS) distribution in the human carotid artery bifurcation and aneurysm, the computer simulations were run to generate the data pertaining to this phenomenon. In our work we evaluate two prediction models for modeling these relationships: neural network model and k-nearest neighbor model. The results revealed that both models have high prediction ability for this prediction task. The achieved results represent progress in assessment of stroke risk for a given patient data in real time.

Computational solution of the velocity and wall shear stress distribution inside a left carotid artery under pulsatile flow conditions

NASA Astrophysics Data System (ADS)

Arslan, Nurullah; Turmuş, Hakan

2014-08-01

Stroke is still one of the leading causes for death after heart diseases and cancer in all over the world. Strokes happen because an artery that carries blood uphill from the heart to the head is clogged. Most of the time, as with heart attacks, the problem is atherosclerosis, hardening of the arteries, calcified buildup of fatty deposits on the vessel wall. In this study, the fluid dynamic simulations were done in a left carotid bifurcation under the pulsatile flow conditions computationally. Pulsatile flow waveform is given in the paper. In vivo geometry and boundary conditions were obtained from a patient who has stenosis located at external carotid artery (ECA) and internal carotid artery (ICA) of his common carotid artery (CCA). The location of critical flow fields such as low wall shear stress (WSS), stagnation regions and separation regions were detected near the highly stenosed region and at branching region.

Diffuse large B-cell non-Hodgkin lymphoma involving the unilateral carotid space in an elderly man: A case report.

PubMed

Chen, Bo; Zou, Chunying; Wu, Jianqing

2017-01-01

An 84-year-old man presented with a history of repeated syncope and decreased heart rate and blood pressure over the last month. On physical examination, a mass sized ~3×3 cm was palpable in the left submandibular area; the mass was hard, poorly mobile, without tenderness or local skin irritation. The computed tomography angiography examination revealed a soft tissue mass in the neck, at the level of the left carotid bifurcation and above. The left common carotid artery bifurcation and internal and external carotid artery segment were embedded in the mass, and there were multiple enlarged lymph nodes in the left neck. The diagnosis of diffuse large B-cell non-Hodgkin lymphoma was confirmed by a percutaneous biopsy of the left submandibular mass. To the best of our knowledge, this is the first reported case of non-Hodgkin lymphoma involvign the carotid space.

Ischemic stroke risk reduction following cardiac surgery by carotid compression

NASA Astrophysics Data System (ADS)

Isingoma, Paul

Every year over 500,000 cardiovascular procedures requiring cardiopulmonary bypass (CPB) are performed in the United States. CPB is a technique that temporarily takes over the function of the heart and lungs during surgery, maintaining the circulation of blood and the oxygen content of the body. During CPB, an aortic cross-clamp is used to clamp the aorta and separate the systemic circulation from the outflow of the heart. Unfortunately, these procedures have been found to cause most cerebral emboli, which produce clinical, subclinical and silent neurologic injuries. Many clinical neurologic injuries occur in the postoperative period, with over 20% of the clinical strokes occurring during this period. In this study, we focus on visualizing the flow distribution in the aortic arch, the effect of carotid compression and the influence of compression time and MAP during CPB on reducing cerebral emboli. Experiments are performed with an aortic arch model in a mock cardiovascular system. Fluorescent particles are used to simulate emboli that are released into circulation immediately after carotid compression. The LVAD is used as the pump to produce flow in the system by gradually adjusting the speed to maintain desired clinical conditions. Aortic and proximal branches MAP of 65.0 +/- 5.0 mmHg (normal MAP) or 95.0 +/- 5.0 mmHg (high MAP), aortic flow of 4.0 +/- 0.5 L/min, and all branches flow (left and right carotids, and subclavian arteries) of 10% of the aortic flow. Flow distribution of particles is visualized using LaVision's DaVis imaging software and analyzed using imagej's particle analysis tool to track, count, and record particle properties from the aortic arch. Carotid compression for 10-20 seconds reduces the number of particles entering the carotid arteries by over 73% at normal MAP, and by over 85% at high MAP. A higher MAP resulted in fewer particles entering the branching vessels both at baseline and during occlusion conditions. A compression duration of

Alternation of histone and DNA methylation in human atherosclerotic carotid plaques.

PubMed

Greißel, A; Culmes, M; Napieralski, R; Wagner, E; Gebhard, H; Schmitt, M; Zimmermann, A; Eckstein, H-H; Zernecke, A; Pelisek, J

2015-08-01

Little is known about epigenetics and its possible role in atherosclerosis. We here analysed histone and DNA methylation and the expression of corresponding methyltransferases in early and advanced human atherosclerotic carotid lesions in comparison to healthy carotid arteries. Western Blotting was performed on carotid plaques from our biobank with early (n=60) or advanced (n=60) stages of atherosclerosis and healthy carotid arteries (n=12) to analyse di-methylation patterns of histone H3 at positions K4, K9 and K27. In atherosclerotic lesions, di-methylation of H3K4 was unaltered and that of H3K9 and H3K27 significantly decreased compared to control arteries. Immunohistochemistry revealed an increased appearance of di-methylated H3K4 in smooth muscle cells (SMCs), a decreased expression of di-methylated H3K9 in SMCs and inflammatory cells, and reduced di-methylated H3K27 in inflammatory cells in advanced versus early atherosclerosis. Expression of corresponding histone methyltransferases MLL2 and G9a was increased in advanced versus early atherosclerosis. Genomic DNA hypomethylation, as determined by PCR for methylated LINE1 and SAT-alpha, was observed in early and advanced plaques compared to control arteries and in cell-free serum of patients with high-grade carotid stenosis compared to healthy volunteers. In contrast, no differences in DNA methylation were observed in blood cells. Expression of DNA-methyltransferase DNMT1 was reduced in atherosclerotic plaques versus controls, DNMT3A was undetectable, and DNMT3B not altered. DNA-demethylase TET1 was increased in atherosclerosisc plaques. The extent of histone and DNA methylation and expression of some corresponding methyltransferases are significantly altered in atherosclerosis, suggesting a possible contribution of epigenetics in disease development.

Difference in blood pressure response to ACE-Inhibitor monotherapy between black and white adults with arterial hypertension: a meta-analysis of 13 clinical trials.

PubMed

Peck, Robert N; Smart, Luke R; Beier, Rita; Liwa, Anthony C; Grosskurth, Heiner; Fitzgerald, Daniel W; Schmidt, Bernhard M W

2013-09-26

Among African-Americans adults, arterial hypertension is both more prevalent and associated with more complications than among white adults. Hypertension is also epidemic among black adults in sub-Saharan Africa. The treatment of hypertension among black adults may be complicated by lesser response to certain classes of anti-hypertensive agents. We systematically searched literature for clinical trials of ACE-inhibitors among hypertensive adults comparing blood pressure response between whites and blacks. Meta-analysis was performed to determine the difference in systolic and diastolic blood pressure response. Further analysis including meta-regressions, funnel plots, and one-study-removed analyses were performed to investigate possible sources of heterogeneity or bias. In a meta-analysis of 13 trials providing 17 different patient groups for evaluation, black race was associated with a lesser reduction in systolic (mean difference: 4.6 mmHg (95% CI 3.5-5.7)) and diastolic (mean difference: 2.8 mmHg (95% CI 2.2-3.5)) blood pressure response to ACE-inhibitors, with little heterogeneity. Meta-regression revealed only ACE-inhibitor dosage as a significant source of heterogeneity. There was little evidence of publication bias. Black race is consistently associated with a clinically significant lesser reduction in both systolic and diastolic blood pressure to ACE-inhibitor therapy in clinical trials in the USA and Europe. In black adults requiring monotherapy for uncomplicated hypertension, drugs other than ACE-inhibitors may be preferred, though the proven benefits of ACE-inhibitors in some sub-groups and the large overlap of response between blacks and whites must be remembered. These data are particularly important for interpretation of clinical drug trials for hypertensive black adults in sub-Saharan Africa and for the development of treatment recommendations in this population.

Incidence of New Ischaemic Brain Lesions After Carotid Artery Stenting with the Micromesh Roadsaver Carotid Artery Stent: A Prospective Single-Centre Study

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ruffino, Maria Antonella, E-mail: mruffino@cittadellasalute.to.it; Faletti, Riccardo; Bergamasco, Laura

AimsSeveral randomized trials of patients with carotid stenosis show increased adverse neurological events with stenting versus endarterectomy in the 30-day post-procedure. This study examines the incidence of new ischaemic lesions in patients treated in our centre using the new Roadsaver stent.Methods and resultsBetween September 2015 and January 2016, 23 consecutive patients (age 74.3 ± 7.3 years, 17.4 % female) underwent carotid artery stenting with the Roadsaver stent, a nitinol double-layer micromesh device. A distal protection device was used in all cases. Diffusion-weighted magnetic resonance imaging was performed 24 h before, and 24 h and 30 days after the procedure. The 24-h post-procedure imaging showed 15 new ipsilateralmore » ischaemic lesions in 7 (30.4 %) patients: median volume 0.076 cm{sup 3} (interquartile range 0.065–0.146 cm{sup 3}). All lesions were asymptomatic. The 30-day imaging showed complete resolution of all lesions and no new ischaemic lesions. Follow-up clinical and ultrasound examinations at 30 days and 6 months recorded no adverse cardiac or cerebrovascular events.ConclusionsProtected stenting with micromesh Roadsaver stent showed good safety and efficacy in the treatment of carotid stenosis, with a low incidence of delayed embolic events and new ipsilateral ischaemic brain lesions. These preliminary results are encouraging, but need to be confirmed with larger populations.« less

Towards the Sensory Nature of the Carotid Body: Hering, De Castro and Heymans†

PubMed Central

de Castro, Fernando

2009-01-01

The carotid body or glomus caroticum is a chemosensory organ bilaterally located between the external and internal carotid arteries. Although known by anatomists since the report included by Von Haller and Taube in the mid XVIII century, its detailed study started the first quarter of the XX. The Austro-German physiologist Heinrich E. Hering studied the cardio-respiratory reflexes searched for the anatomical basis of this reflex in the carotid sinus, while the Ghent School leaded by the physio-pharmacologists Jean-François Heymans and his son Corneille focussed in the cardio-aortic reflexogenic region. In 1925, Fernando De Castro, one of the youngest and more brilliant disciples of Santiago Ramón y Cajal at the Laboratorio de Investigaciones Biológicas (Madrid, Spain), profited from some original novelties in histological procedures to study the fine structure and innervation of the carotid body. De Castro unravelled them in a series of scientific papers published between 1926 and 1929, which became the basis to consider the carotid body as a sensory receptor (or chemoreceptor) to detect the chemical changes in the composition of the blood. Indeed, this was the first description of arterial chemoreceptors. Impressed by the novelty and implications of the work of De Castro, Corneille Heymans invited the Spanish neurologist to visit Ghent on two occasions (1929 and 1932), where both performed experiences together. Shortly after, Heymans visited De Castro at the Instituto Cajal (Madrid). From 1932 to 1933, Corneille Heymans focused all his attention on the carotid body his physiological demonstration of De Castro's hypothesis regarding chemoreceptors was awarded with the Nobel Prize in Physiology or Medicine in 1938, just when Spain was immersed in its catastrophic Civil War. PMID:20057927

The effect of intermittent intraabdominal pressure elevations and low cardiac output on the femoral to carotid arterial blood pressure difference in piglets.

PubMed

Aksakal, Devrim; Hückstädt, Thomas; Richter, Steffen; Klitscher, Daniela; Wowra, Tobias; Schier, Felix; Wessel, Lucas M; Kubiak, Rainer

2016-11-01

Our previous work in a laparoscopic setting in piglets revealed that the systolic femoral artery pressure was approximately 5 % higher than its carotid counterpart, whereas the mean and diastolic values showed no significant difference. This remained idem when the intraabdominal pressure (IAP) was gradually increased. In this study, we aimed to investigate the effect of (1) intermittent IAP elevations and (2) a low cardiac output (CO) on the blood pressure (BP) difference cranially (carotid artery) and caudally (femoral artery) of a capnoperitoneum (ΔP = P a fem -P a carot ). A total of twenty-two piglets (mean body weight 11.0 kg; range 8.9-13.3 kg) were studied. Of these, 14 underwent intermittent IAP elevations at 8 and 16 mmHg, and ΔP was measured. In another 8 piglets, a model of reduced CO was created by introducing an air embolism (2 ml/kg over 30 s) in the inferior caval vein (VCI) at 12 mmHg IAP to further assess the influence of this variable on ΔP. Systolic ΔP remained at a mean of 5.6 mmHg and was not significantly affected by insufflation or exsufflation up to an IAP of 16 mmHg. Diastolic and mean values showed no differences between P a carot and P a fem . P a fem, systol remained higher than its carotid counterpart as long as the cardiac index (CI) was above 1.5 l/min/m 2 , but fell significantly below P a carot, systol at a low CI. There was no CO-dependent effect on diastolic and mean ΔP. Repeated IAP elevations do not significantly influence ΔP. Intermittent IAP elevations do not significantly influence ΔP. Despite of a CO-dependent inversion of systolic ΔP, mean BP measurements at the leg during laparoscopy remain representative even at low CO values.

Carotid bypass: a safe and durable solution for recurrent carotid stenosis.

PubMed

Spinelli, Francesco; Martelli, Eugenio; Stilo, Francesco; Pipitò, Narayana; Benedetto, Filippo; Spinelli, Domenico; Squillaci, Domenico; De Caridi, Giovanni; Barillà, David

2014-07-01

The long-term results of carotid artery stenting (CAS) for post-carotid endarterectomy (CEA) restenosis are disappointing (4-year patency rates: ∼75%). Since 1988, our group has offered carotid bypass (CB) as an alternative to redo CEA and later also to CAS in this setting. The aim of this retrospective study was to investigate early and late outcomes associated with CB in this population. Data were collected from patients treated with CB in the year 2000-2012 for significant/symptomatic post-CEA restenosis (or intra-stent restenosis [ISR] after CAS for post-CEA restenosis). All patients had good life expectancy. CB was performed under loco-regional anesthesia. With the aid of sequential vessel clamping, the graft (great saphenous vein [GSV] or polytetrafluoroethylene) was anastomosed with the common carotid artery (side-to-end) and the distal internal carotid artery (end-to-side). Patients were followed with clinical and duplex scan assessments at 1, 3, and 6 months and yearly thereafter. The study population comprised 21 patients (mean age 67.3 years; 17 men). CB was performed for post-CEA restenosis (or ISR after CAS for post-CEA restenosis, n=3) 51.2 months (mean) after the previous operation. GSV grafts were used in half of the cases (n=11; 52.4%); temporary shunting was used in 4 (19%) patients. Intraoperative complications (none fatal) occurred in 4 (19%) patients (3 transient peripheral nerve injuries, 1 cervical hematoma). During follow-up (mean 64.8 months), there were no neurologic complications or restenoses. Overall mortality was 33.3% (6 deaths from acute myocardial infarctions, 1 from a ruptured abdominal aortic aneurysm). For post-CEA restenosis (or ISR after CAS for post-CEA restenosis), CB offers superior long-term patency rates than CAS (or redo angioplasty) and an acceptable risk of cranial nerve damage. Copyright © 2014 Elsevier Inc. All rights reserved.

Fatal carotid dissection after blunt head trauma.

PubMed

Tartara, F; Regolo, P; Servadei, F; Versari, P P; Giovanelli, M

2000-06-01

Occurrence of internal carotid artery injuries associated with skull base fracture has been reported. A. report a case of fatal intracranial carotid dissection related to petrous fracture involving the carotid canal. Identification of carotid lesions may be difficult and generally related to appearance of unexpected neurological deficit. Skull base fractures may be considered an indirect sign for detection of vascular injury. Patterns of the fracture are of paramount importance; routine CT scan may fail to detect basilar fractures and high definition fine-cut CT scan should be executed to carefully identify and evaluate fractures. Temporal and sphenoid bone fractures are common in head trauma and involvement of the course of the carotid artery is frequent. The involvement of the intracranial carotid artery course represents a direct risk factor for lesions of the petrous, lacerum and cavernous segments of the carotid artery. Early diagnosis of post-traumatic vascular injury may lead to prognosis improvement because of effectiveness of heparin anticoagulant therapy. Then vascular screening is recommendable in cases with complex fractures of the skull base and particularly fracturing along the course of the carotid artery. Magnetic resonance angiography may be considered the first line diagnostic tools for vascular screening. Angiography may be reserved for patients with a proven lesion or rapid neurological deterioration taking into account the possibility of interventional treatment.

Percutaneous Injection of Lidocaine Within the Carotid Body Area in Carotid Artery Stenting: An 'Old-New' Technique

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mourikis, Dimitrios; Chatoupis, Konstantinos, E-mail: kchatoupis@yahoo.g; Katsenis, Konstantinos

2008-07-15

Severe bradycardia is a common untoward effect during balloon angioplasty when performing carotid artery stenting. Therefore atropine injection even before dilatation and the presence of an anesthesiologist are advocated in all patients. In the surgical literature, injection of a local anesthetic agent into the carotid sinus before carotid endarterectomy was performed in an attempt to ameliorate perioperative hemodynamic instability. This study was undertaken to test the hypothesis that percutaneous infiltration of the carotid sinus with local anesthetic immediately before balloon dilatation reduces bradycardia and ameliorates the need for atropine injection or the presence of an anesthesiologist. Infiltration of the carotidmore » sinus with 5 ml of 1% lidocaine, 3 min before dilatation, was performed in 30 consecutive patients. No one exhibited any significant rhythm change that required atropine injection. The anesthesiologist did not face any hemodynamic instability during the carotid artery stenting procedure.« less

Post-processing method to reduce noise while preserving high time resolution in aethalometer real-time black carbon data

EPA Science Inventory

Real-time aerosol black carbon (BC) data, presented at time resolutions on the order of seconds to minutes, is desirable in field and source characterization studies measuring rapidly varying concentrations of BC. The Optimized Noise-reduction Averaging (ONA) algorithm has been d...

Aspirin inhibits human telomerase activation in unstable carotid plaques

PubMed Central

LI, FANGMING; GUO, YI; JIANG, XIN; ZHONG, JIANXIN; LI, GUANDONG; SUN, SHENGGANG

2013-01-01

The activation of telomerase in unstable plaques is an important factor in atherosclerosis, and may be predictive of the risk of cerebrovascular diseases. Human telomerase reverse transcriptase (hTERT) is a subunit of telomerase that is essential for telomerase activation. The aim of the present study was to investigate whether aspirin inhibits the activation of telomerase and hTERT in unstable carotid plaques. Polymorphonuclear neutrophils (PMNs) derived from carotid plaques were isolated from the washing medium of angioplasty balloons, while circulating PMNs, isolated from arterial blood, served as the controls. A polymerase chain reaction-based telomeric repeat amplification protocol (TRAP) enzyme-linked immunosorbent assay (ELISA) was used to measure the telomerase activity in the cells following treatment with aspirin. The mRNA and protein expression of hTERT were detected by a reverse transcription-polymerase chain reaction (RT-PCR) and western blot analysis, respectively. The results revealed that the atherosclerotic plaques were positive for telomerase activity, and that aspirin inhibited the telomerase activity of the PMNs derived from the plaques. In addition, aspirin was demonstrated to inhibit the mRNA and protein expression of hTERT through the suppression of hTERT transcriptional activity; however, it had no inhibitory effect on the telomerase activity of the circulating PMNs. Thus, the activation of telomerase in resident PMNs is critical in the instability of carotid plaques. The upregulation of telomerase and hTERT during the progression of atherosclerosis may indicate a role for telomerase in the vascular remodeling that occurs during atherogenesis. Aspirin was demonstrated to inhibit the activation of telomerase via an hTERT-dependent manner in the PMN cells of unstable carotid plaques, and thus hTERT may be considered as a target in the treatment of cerebrovascular diseases. PMID:23935747

Freehand three-dimensional ultrasound imaging of carotid artery using motion tracking technology.

PubMed

Chung, Shao-Wen; Shih, Cho-Chiang; Huang, Chih-Chung

2017-02-01

Ultrasound imaging has been extensively used for determining the severity of carotid atherosclerotic stenosis. In particular, the morphological characterization of carotid plaques can be performed for risk stratification of patients. However, using 2D ultrasound imaging for detecting morphological changes in plaques has several limitations. Due to the scan was performed on a single longitudinal cross-section, the selected 2D image is difficult to represent the entire morphology and volume of plaque and vessel lumen. In addition, the precise positions of 2D ultrasound images highly depend on the radiologists' experience, it makes the serial long-term exams of anti-atherosclerotic therapies are difficult to relocate the same corresponding planes by using 2D B-mode images. This has led to the recent development of three-dimensional (3D) ultrasound imaging, which offers improved visualization and quantification of complex morphologies of carotid plaques. In the present study, a freehand 3D ultrasound imaging technique based on optical motion tracking technology is proposed. Unlike other optical tracking systems, the marker is a small rigid body that is attached to the ultrasound probe and is tracked by eight high-performance digital cameras. The probe positions in 3D space coordinates are then calibrated at spatial and temporal resolutions of 10μm and 0.01s, respectively. The image segmentation procedure involves Otsu's and the active contour model algorithms and accurately detects the contours of the carotid arteries. The proposed imaging technique was verified using normal artery and atherosclerotic stenosis phantoms. Human experiments involving freehand scanning of the carotid artery of a volunteer were also performed. The results indicated that compared with manual segmentation, the lowest percentage errors of the proposed segmentation procedure were 7.8% and 9.1% for the external and internal carotid arteries, respectively. Finally, the effect of handshaking was

Carotid artery Doppler ultrasonography in retinal macroaneurysms.

PubMed

Thurairajan, G; Potamitis, T; Naylor, G; Gibson, J

1998-01-01

It is postulated that retinal arterial macroaneurysms (RAMs) occur at the site of incomplete embolic occlusion of a branch retinal artery. Embolic events of the retinal vessels are related to the state of the carotid artery tree and therefore Doppler ultrasonography of the carotid arteries in these patients is of particular interest. We have examined 13 patients with retinal artery macroaneurysms with carotid artery Doppler ultrasonography (CADU). Eight of these patients (61.5%) exhibited atheromatous plaques on the same side as the RAM with a moderate degree of arterial narrowing. Although our group of patients did not show advanced carotid artery disease, alterations of the arterial wall found at the level of the carotid artery were higher than expected in a similar hypertensive population. To our knowledge this is the first study of the carotid arterial tree in these patients. Our results support the theory that RAMs may be of embolic origin. Furthermore they demonstrate that CADU is a useful investigation in patients with RAMs.

Real-time monitoring of human blood-brain barrier disruption

PubMed Central

Kiviniemi, Vesa; Korhonen, Vesa; Kortelainen, Jukka; Rytky, Seppo; Keinänen, Tuija; Tuovinen, Timo; Isokangas, Matti; Sonkajärvi, Eila; Siniluoto, Topi; Nikkinen, Juha; Alahuhta, Seppo; Tervonen, Osmo; Turpeenniemi-Hujanen, Taina; Myllylä, Teemu; Kuittinen, Outi; Voipio, Juha

2017-01-01

Chemotherapy aided by opening of the blood-brain barrier with intra-arterial infusion of hyperosmolar mannitol improves the outcome in primary central nervous system lymphoma. Proper opening of the blood-brain barrier is crucial for the treatment, yet there are no means available for its real-time monitoring. The intact blood-brain barrier maintains a mV-level electrical potential difference between blood and brain tissue, giving rise to a measurable electrical signal at the scalp. Therefore, we used direct-current electroencephalography (DC-EEG) to characterize the spatiotemporal behavior of scalp-recorded slow electrical signals during blood-brain barrier opening. Nine anesthetized patients receiving chemotherapy were monitored continuously during 47 blood-brain barrier openings induced by carotid or vertebral artery mannitol infusion. Left or right carotid artery mannitol infusion generated a strongly lateralized DC-EEG response that began with a 2 min negative shift of up to 2000 μV followed by a positive shift lasting up to 20 min above the infused carotid artery territory, whereas contralateral responses were of opposite polarity. Vertebral artery mannitol infusion gave rise to a minimally lateralized and more uniformly distributed slow negative response with a posterior-frontal gradient. Simultaneously performed near-infrared spectroscopy detected a multiphasic response beginning with mannitol-bolus induced dilution of blood and ending in a prolonged increase in the oxy/deoxyhemoglobin ratio. The pronounced DC-EEG shifts are readily accounted for by opening and sealing of the blood-brain barrier. These data show that DC-EEG is a promising real-time monitoring tool for blood-brain barrier disruption augmented drug delivery. PMID:28319185

SPACE-2: A Missed Opportunity to Compare Carotid Endarterectomy, Carotid Stenting, and Best Medical Treatment in Patients with Asymptomatic Carotid Stenoses.

PubMed

Eckstein, H-H; Reiff, T; Ringleb, P; Jansen, O; Mansmann, U; Hacke, W

2016-06-01

Because of recent advances in best medical treatment (BMT), it is currently unclear whether any additional surgical or endovascular interventions confer additional benefit, in terms of preventing late ipsilateral carotid territory ischemic stroke in asymptomatic patients with significant carotid stenoses. The aim was to compare the stroke-preventive effects of BMT alone, with that of BMT in combination with carotid endarterectomy (CEA) or carotid artery stenting (CAS) in patients with high grade asymptomatic extracranial carotid artery stenosis. SPACE-2 was planned as a three-armed, randomized controlled trial (BMT alone vs. CEA plus BMT vs. CAS plus BMT, ISRCTN 78592017). However, because of slow patient recruitment, the three-arm study design was amended (July 2013) to become two parallel randomized studies (BMT alone vs. CEA plus BMT, and BMT alone vs. CAS plus BMT). The change in study design did not lead to any significant increase in patient recruitment, and trial recruitment ceased after recruiting 513 patients over a 5 year period (CEA vs. BMT (n = 203); CAS vs. BMT (n = 197), and BMT alone (n = 113)). The 30 day rate of death/stroke was 1.97% for patients undergoing CEA, and 2.54% for patients undergoing CAS. No strokes or deaths occurred in the first 30 days after randomization in patients randomized to BMT. There were several potential reasons for the low recruitment rates into SPACE-2, including the ability for referring doctors to refer their patients directly for CEA or CAS outwith the trial, an inability to convince patients (who had come "mentally prepared" that an intervention was necessary) to accept BMT, and other economic constraints. Because of slow recruitment rates, SPACE-2 had to be stopped after randomizing only 513 patients. The German Research Foundation will provide continued funding to enable follow up of all recruited patients, and it is also planned to include these data in any future meta-analysis prepared by the Carotid

Carotid body, insulin, and metabolic diseases: unraveling the links

PubMed Central

Conde, Sílvia V.; Sacramento, Joana F.; Guarino, Maria P.; Gonzalez, Constancio; Obeso, Ana; Diogo, Lucilia N.; Monteiro, Emilia C.; Ribeiro, Maria J.

2014-01-01

The carotid bodies (CB) are peripheral chemoreceptors that sense changes in arterial blood O2, CO2, and pH levels. Hypoxia, hypercapnia, and acidosis activate the CB, which respond by increasing the action potential frequency in their sensory nerve, the carotid sinus nerve (CSN). CSN activity is integrated in the brain stem to induce a panoply of cardiorespiratory reflexes aimed, primarily, to normalize the altered blood gases, via hyperventilation, and to regulate blood pressure and cardiac performance, via sympathetic nervous system (SNS) activation. Besides its role in the cardiorespiratory control the CB has been proposed as a metabolic sensor implicated in the control of energy homeostasis and, more recently, in the regulation of whole body insulin sensitivity. Hypercaloric diets cause CB overactivation in rats, which seems to be at the origin of the development of insulin resistance and hypertension, core features of metabolic syndrome and type 2 diabetes. Consistent with this notion, CB sensory denervation prevents metabolic and hemodynamic alterations in hypercaloric feed animal. Obstructive sleep apnea (OSA) is another chronic disorder characterized by increased CB activity and intimately related with several metabolic and cardiovascular abnormalities. In this manuscript we review in a concise manner the putative pathways linking CB chemoreceptors deregulation with the pathogenesis of insulin resistance and arterial hypertension. Also, the link between chronic intermittent hypoxia (CIH) and insulin resistance is discussed. Then, a final section is devoted to debate strategies to reduce CB activity and its use for prevention and therapeutics of metabolic diseases with an emphasis on new exciting research in the modulation of bioelectronic signals, likely to be central in the future. PMID:25400585

An efficient data mining framework for the characterization of symptomatic and asymptomatic carotid plaque using bidimensional empirical mode decomposition technique.

PubMed

Molinari, Filippo; Raghavendra, U; Gudigar, Anjan; Meiburger, Kristen M; Rajendra Acharya, U

2018-02-23

Atherosclerosis is a type of cardiovascular disease which may cause stroke. It is due to the deposition of fatty plaque in the artery walls resulting in the reduction of elasticity gradually and hence restricting the blood flow to the heart. Hence, an early prediction of carotid plaque deposition is important, as it can save lives. This paper proposes a novel data mining framework for the assessment of atherosclerosis in its early stage using ultrasound images. In this work, we are using 1353 symptomatic and 420 asymptomatic carotid plaque ultrasound images. Our proposed method classifies the symptomatic and asymptomatic carotid plaques using bidimensional empirical mode decomposition (BEMD) and entropy features. The unbalanced data samples are compensated using adaptive synthetic sampling (ADASYN), and the developed method yielded a promising accuracy of 91.43%, sensitivity of 97.26%, and specificity of 83.22% using fourteen features. Hence, the proposed method can be used as an assisting tool during the regular screening of carotid arteries in hospitals. Graphical abstract Outline for our efficient data mining framework for the characterization of symptomatic and asymptomatic carotid plaques.

A manual carotid compression technique to overcome difficult filter protection device retrieval during carotid artery stenting.

PubMed

Nii, Kouhei; Nakai, Kanji; Tsutsumi, Masanori; Aikawa, Hiroshi; Iko, Minoru; Sakamoto, Kimiya; Mitsutake, Takafumi; Eto, Ayumu; Hanada, Hayatsura; Kazekawa, Kiyoshi

2015-01-01

We investigated the incidence of embolic protection device retrieval difficulties at carotid artery stenting (CAS) with a closed-cell stent and demonstrated the usefulness of a manual carotid compression assist technique. Between July 2010 and October 2013, we performed 156 CAS procedures using self-expandable closed-cell stents. All procedures were performed with the aid of a filter design embolic protection device. We used FilterWire EZ in 118 procedures and SpiderFX in 38 procedures. The embolic protection device was usually retrieved by the accessory retrieval sheath after CAS. We applied a manual carotid compression technique when it was difficult to navigate the retrieval sheath through the deployed stent. We compared clinical outcomes in patients where simple retrieval was possible with patients where the manual carotid compression assisted technique was used for retrieval. Among the 156 CAS procedures, we encountered 12 (7.7%) where embolic protection device retrieval was hampered at the proximal stent terminus. Our manual carotid compression technique overcame this difficulty without eliciting neurologic events, artery dissection, or stent deformity. In patients undergoing closed-cell stent placement, embolic protection device retrieval difficulties may be encountered at the proximal stent terminus. Manual carotid compression assisted retrieval is an easy, readily available solution to overcome these difficulties. Copyright © 2015 National Stroke Association. Published by Elsevier Inc. All rights reserved.

Association of glycated hemoglobin with carotid intimal medial thickness in Asian Indians with normal glucose tolerance.

PubMed

Venkataraman, Vijayachandrika; Amutha, Anandakumar; Anbalagan, Viknesh Prabu; Deepa, Mohan; Anjana, Ranjit Mohan; Unnikrishnan, Ranjit; Vamsi, Mamilla; Mohan, Viswananthan

2012-01-01

To assess the association of glycated hemoglobin (HbA1c) levels with carotid intimal medial thickness (CIMT) in Asian Indians with normal glucose tolerance (NGT). Subjects with NGT were recruited from the Chennai Urban Rural Epidemiology Study carried out on a representative population of Chennai, South India. All subjects had fasting plasma glucose <100 mg/dl (5.6 mmol/l) and 2-h post load plasma glucose <140 mg/dl (7.8 mmol/l). HbA1c was measured using the Biorad Variant machine. CIMT was measured on the right common carotid artery using high-resolution B-mode ultrasonography. The study group included 1383 NGT subjects, of whom 760 (54.9%) were women. The mean CIMT value in the 1st quartile of HbA1c (<5.2%) was 0.65 and it increased significantly to 0.73 in the last quartile of HbA1c (>5.8) (p<0.001). Regression analysis showed that HbA1c had a strong association with CIMT after adjusting for age, gender, waist circumference, systolic and diastolic blood pressure, LDL cholesterol, serum triglycerides, HOMA-IR and smoking (ß - 0.046, p=0.047). Even among subjects with NGT, there is a significant increase in CIMT with increasing levels of HbA1c, showing the value of using HbA1c for diagnosis of glucose intolerance. Copyright © 2012 Elsevier Inc. All rights reserved.

Comparative Analysis of the Biaxial Mechanical Behavior of Carotid Wall Tissue and Biological and Synthetic Materials Used for Carotid Patch Angioplasty

PubMed Central

Kamenskiy, Alexey V.; Pipinos, Iraklis I.; MacTaggart, Jason N.; Jaffar Kazmi, Syed A.; Dzenis, Yuris A.

2011-01-01

Patch angioplasty is the most common technique used for the performance of carotid endarterectomy. A large number of patching materials are available for use while new materials are being continuously developed. Surprisingly little is known about the mechanical properties of these materials and how these properties compare with those of the carotid artery wall. Mismatch of the mechanical properties can produce mechanical and hemodynamic effects that may compromise the long-term patency of the endarterectomized arterial segment. The aim of this paper was to systematically evaluate and compare the biaxial mechanical behavior of the most commonly used patching materials. We compared PTFE (n = 1), Dacron (n = 2), bovine pericardium (n = 10), autogenous greater saphenous vein (n = 10), and autogenous external jugular vein (n = 9) with the wall of the common carotid artery (n = 18). All patching materials were found to be significantly stiffer than the carotid wall in both the longitudinal and circumferential directions. Synthetic patches demonstrated the most mismatch in stiffness values and vein patches the least mismatch in stiffness values compared to those of the native carotid artery. All biological materials, including the carotid artery, demonstrated substantial nonlinearity, anisotropy, and variability; however, the behavior of biological and biologically-derived patches was both qualitatively and quantitatively different from the behavior of the carotid wall. The majority of carotid arteries tested were stiffer in the circumferential direction, while the opposite anisotropy was observed for all types of vein patches and bovine pericardium. The rates of increase in the nonlinear stiffness over the physiological stress range were also different for the carotid and patching materials. Several carotid wall samples exhibited reverse anisotropy compared to the average behavior of the carotid tissue. A similar characteristic was observed for

A Novel Carotid Device for Embolic Diversion: Lessons Learned from a 'First in Man' Trial in Patients with Atrial Fibrillation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sievert, Horst, E-mail: info@cvcfrankfurt.de; Franke, Jennifer; Grad, Ygael

Purpose: This study was designed to investigate a novel device that was developed to direct emboli away from the internal carotid artery to the external carotid artery to prevent embolic stroke while avoiding the necessity for anticoagulation with warfarin. Methods: A stent-like, self-expandable filter was developed consisting of fine cobalt alloy mesh. After promising preclinical animal testing, the device was implanted into the common carotid artery extending into the external carotid artery in three patients with atrial fibrillation, each of whom were at high-risk for cerebral emboli and were suboptimal candidates for anticoagulation. Follow-up was performed clinically and with carotidmore » duplex ultrasound. Results: The implantation was successful in all three patients. Unrestricted flow through the filter was demonstrated in each patient at 6 months by duplex sonography. However, at 7 months ultrasound demonstrated occlusion of the internal carotid artery filter in one patient, which was subsequently confirmed by angiography. Subtotal filter occlusion occurred in a second patient at 14 months. Neither patient had clinical symptoms. Both internal carotid arteries were successfully recanalized using standard angioplasty techniques without complication. The third patient had completely normal carotid blood flow at 29 months follow-up. Conclusions: Implantation of a novel device intended to divert emboli away from the internal carotid artery was feasible, but resulted in occlusive neointimal proliferation in two of three patients. These results demonstrate a discrepancy from the findings of preclinical animal studies and human investigation.« less

A Unique Case of Carotid Splaying by a Cervical Vagal Neurofibroma and the Role of Neuroradiology in Surgical Management

PubMed Central

Buehler, Mark; Mrak, Robert E; Mansour, Tarek R; Medhkour, Yacine; Medhkour, Azedine

2017-01-01

tumor with minimal blood loss and no complications. Postoperative histologic examination confirmed a neurofibroma and definitively ruled out a carotid body tumor. This case highlights the importance of utilizing MRA whenever carotid splaying is seen on MRI and supports the consideration of neurofibromas in the differential for this finding.  PMID:29147633

Carotid Endarterectomy and Carotid Artery Stenting in the US Medicare Population, 1999-2014

PubMed Central

Jones, Michael R.; Leifheit, Erica C.; Sheffet, Alice J.; Howard, George; Lal, Brajesh K.; Howard, Virginia J.; Wang, Yun; Curtis, Jeptha; Brott, Thomas G.

2017-01-01

Importance Carotid endarterectomy and carotid artery stenting are the leading approaches to revascularization for carotid stenosis, yet contemporary data on trends in rates and outcomes are limited. Objective To describe US national trends in performance and outcomes of carotid endarterectomy and stenting among Medicare beneficiaries from 1999 to 2014. Design, Setting, and Participants Serial cross-sectional analysis of Medicare fee-for-service beneficiaries aged 65 years or older from 1999 to 2014 using the Medicare Inpatient and Denominator files. Spatial mixed models adjusted for age, sex, and race were fit to calculate county-specific risk-standardized revascularization rates. Mixed models were fit to assess trends in outcomes after adjustment for demographics, comorbidities, and symptomatic status. Exposures Carotid endarterectomy and carotid artery stenting. Main Outcomes and Measures Revascularization rates per 100 000 beneficiary-years of fee-for-service enrollment, in-hospital mortality, 30-day stroke or death, 30-day stroke, myocardial infarction, or death, 30-day all-cause mortality, and 1-year stroke. Results During the study, 937 111 unique patients underwent carotid endarterectomy (mean age, 75.8 years; 43% women) and 231 077 underwent carotid artery stenting (mean age, 75.4 years; 49% women). There were 81 306 patients who underwent endarterectomy in 1999 and 36 325 in 2014; national rates per 100 000 beneficiary-years decreased from 298 in 1999-2000 to 128 in 2013-2014 (P < .001). The number of patients who underwent stenting ranged from 10 416 in 1999 to 22 865 in 2006 (an increase per 100 000 beneficiary-years from 40 in 1999-2000 to 75 in 2005-2006; P < .001); by 2014, there were 10 208 patients who underwent stenting and the rate decreased to 38 per 100 000 beneficiary-years (P < .001). Outcomes improved over time despite increases in vascular risk factors (eg, hypertension prevalence increased from 67% to 81

Carotid body denervation prevents fasting hyperglycemia during chronic intermittent hypoxia.

PubMed

Shin, Mi-Kyung; Yao, Qiaoling; Jun, Jonathan C; Bevans-Fonti, Shannon; Yoo, Doo-Young; Han, Woobum; Mesarwi, Omar; Richardson, Ria; Fu, Ya-Yuan; Pasricha, Pankaj J; Schwartz, Alan R; Shirahata, Machiko; Polotsky, Vsevolod Y

2014-10-01

Obstructive sleep apnea causes chronic intermittent hypoxia (IH) and is associated with impaired glucose metabolism, but mechanisms are unknown. Carotid bodies orchestrate physiological responses to hypoxemia by activating the sympathetic nervous system. Therefore, we hypothesized that carotid body denervation would abolish glucose intolerance and insulin resistance induced by chronic IH. Male C57BL/6J mice underwent carotid sinus nerve dissection (CSND) or sham surgery and then were exposed to IH or intermittent air (IA) for 4 or 6 wk. Hypoxia was administered by decreasing a fraction of inspired oxygen from 20.9% to 6.5% once per minute, during the 12-h light phase (9 a.m.-9 p.m.). As expected, denervated mice exhibited blunted hypoxic ventilatory responses. In sham-operated mice, IH increased fasting blood glucose, baseline hepatic glucose output (HGO), and expression of a rate-liming hepatic enzyme of gluconeogenesis phosphoenolpyruvate carboxykinase (PEPCK), whereas the whole body glucose flux during hyperinsulinemic euglycemic clamp was not changed. IH did not affect glucose tolerance after adjustment for fasting hyperglycemia in the intraperitoneal glucose tolerance test. CSND prevented IH-induced fasting hyperglycemia and increases in baseline HGO and liver PEPCK expression. CSND trended to augment the insulin-stimulated glucose flux and enhanced liver Akt phosphorylation at both hypoxic and normoxic conditions. IH increased serum epinephrine levels and liver sympathetic innervation, and both increases were abolished by CSND. We conclude that chronic IH induces fasting hyperglycemia increasing baseline HGO via the CSN sympathetic output from carotid body chemoreceptors, but does not significantly impair whole body insulin sensitivity. Copyright © 2014 the American Physiological Society.

[Comparison of blood pressure profiles with flunitrazepam/fentanyl/nitrous oxide vs cervical epidural anesthesia in surgery of the carotid artery].

PubMed

Pluskwa, F; Bonnet, F; Abhay, K; Touboul, C; Rey, B; Marcandoro, J; Becquemin, J B

1989-01-01

A study was carried out to compare the evolution of arterial blood pressure during carotid endarterectomy performed under either general anaesthesia (GA) or cervical epidural anaesthesia (CEA). 20 patients were randomly assigned to two equal groups. In the CEA group, 15 ml of 0.375% bupivacaine and 150 micrograms fentanyl were injected into the epidural space at C7-D1 level. In the GA group, patients were anaesthetized with 0.2 mg.kg-1 flunitrazepam and 5 micrograms.kg-1 fentanyl; intubation was carried out using 0.08 mg.kg-1 vecuronium, and the patients were ventilated with a mixture of nitrous oxide and oxygen (50% of each). Further injections, every 30 min, of 2 micrograms.kg-1 fentanyl were given to the patients in group GA. Blood pressure was monitored continuously, up to 4 h postoperatively, with a radial arterial catheter. Per- or postoperative hypertension was defined as a rise in systolic arterial blood pressure (Pasys) over 180 mmHg for greater than 3 min; this was treated with 20 mg nifedipine intranasally (group CEA) or 100 micrograms fentanyl with 0.5 mg flunitrazepam with or without nifedipine (group GA). Per- or postoperative hypotension was defined as a fall in Pasys below 100 mmHg and or a 30% fall in mean arterial blood pressure for greater than 3 min; this was treated, in both groups, with an intravenous bolus of 3 mg ephedrine. Patients in group CEA experienced more frequent episodes of peroperative hypertension (8/2; p less than 0.02) and postoperative hypotension (5/1) than group GA.(ABSTRACT TRUNCATED AT 250 WORDS)

Artificial Intelligence Estimation of Carotid-Femoral Pulse Wave Velocity using Carotid Waveform.

PubMed

Tavallali, Peyman; Razavi, Marianne; Pahlevan, Niema M

2018-01-17

In this article, we offer an artificial intelligence method to estimate the carotid-femoral Pulse Wave Velocity (PWV) non-invasively from one uncalibrated carotid waveform measured by tonometry and few routine clinical variables. Since the signal processing inputs to this machine learning algorithm are sensor agnostic, the presented method can accompany any medical instrument that provides a calibrated or uncalibrated carotid pressure waveform. Our results show that, for an unseen hold back test set population in the age range of 20 to 69, our model can estimate PWV with a Root-Mean-Square Error (RMSE) of 1.12 m/sec compared to the reference method. The results convey the fact that this model is a reliable surrogate of PWV. Our study also showed that estimated PWV was significantly associated with an increased risk of CVDs.

Carotid artery stenting compared with endarterectomy in patients with symptomatic carotid stenosis (International Carotid Stenting Study): an interim analysis of a randomised controlled trial

PubMed Central

2010-01-01

Summary Background Stents are an alternative treatment to carotid endarterectomy for symptomatic carotid stenosis, but previous trials have not established equivalent safety and efficacy. We compared the safety of carotid artery stenting with that of carotid endarterectomy. Methods The International Carotid Stenting Study (ICSS) is a multicentre, international, randomised controlled trial with blinded adjudication of outcomes. Patients with recently symptomatic carotid artery stenosis were randomly assigned in a 1:1 ratio to receive carotid artery stenting or carotid endarterectomy. Randomisation was by telephone call or fax to a central computerised service and was stratified by centre with minimisation for sex, age, contralateral occlusion, and side of the randomised artery. Patients and investigators were not masked to treatment assignment. Patients were followed up by independent clinicians not directly involved in delivering the randomised treatment. The primary outcome measure of the trial is the 3-year rate of fatal or disabling stroke in any territory, which has not been analysed yet. The main outcome measure for the interim safety analysis was the 120-day rate of stroke, death, or procedural myocardial infarction. Analysis was by intention to treat (ITT). This study is registered, number ISRCTN25337470. Findings The trial enrolled 1713 patients (stenting group, n=855; endarterectomy group, n=858). Two patients in the stenting group and one in the endarterectomy group withdrew immediately after randomisation, and were not included in the ITT analysis. Between randomisation and 120 days, there were 34 (Kaplan-Meier estimate 4·0%) events of disabling stroke or death in the stenting group compared with 27 (3·2%) events in the endarterectomy group (hazard ratio [HR] 1·28, 95% CI 0·77–2·11). The incidence of stroke, death, or procedural myocardial infarction was 8·5% in the stenting group compared with 5·2% in the endarterectomy group (72 vs 44 events

Carotid artery stenting compared with endarterectomy in patients with symptomatic carotid stenosis (International Carotid Stenting Study): an interim analysis of a randomised controlled trial.

PubMed

Ederle, Jörg; Dobson, Joanna; Featherstone, Roland L; Bonati, Leo H; van der Worp, H Bart; de Borst, Gert J; Lo, T Hauw; Gaines, Peter; Dorman, Paul J; Macdonald, Sumaira; Lyrer, Philippe A; Hendriks, Johanna M; McCollum, Charles; Nederkoorn, Paul J; Brown, Martin M

2010-03-20

Stents are an alternative treatment to carotid endarterectomy for symptomatic carotid stenosis, but previous trials have not established equivalent safety and efficacy. We compared the safety of carotid artery stenting with that of carotid endarterectomy. The International Carotid Stenting Study (ICSS) is a multicentre, international, randomised controlled trial with blinded adjudication of outcomes. Patients with recently symptomatic carotid artery stenosis were randomly assigned in a 1:1 ratio to receive carotid artery stenting or carotid endarterectomy. Randomisation was by telephone call or fax to a central computerised service and was stratified by centre with minimisation for sex, age, contralateral occlusion, and side of the randomised artery. Patients and investigators were not masked to treatment assignment. Patients were followed up by independent clinicians not directly involved in delivering the randomised treatment. The primary outcome measure of the trial is the 3-year rate of fatal or disabling stroke in any territory, which has not been analysed yet. The main outcome measure for the interim safety analysis was the 120-day rate of stroke, death, or procedural myocardial infarction. Analysis was by intention to treat (ITT). This study is registered, number ISRCTN25337470. The trial enrolled 1713 patients (stenting group, n=855; endarterectomy group, n=858). Two patients in the stenting group and one in the endarterectomy group withdrew immediately after randomisation, and were not included in the ITT analysis. Between randomisation and 120 days, there were 34 (Kaplan-Meier estimate 4.0%) events of disabling stroke or death in the stenting group compared with 27 (3.2%) events in the endarterectomy group (hazard ratio [HR] 1.28, 95% CI 0.77-2.11). The incidence of stroke, death, or procedural myocardial infarction was 8.5% in the stenting group compared with 5.2% in the endarterectomy group (72 vs 44 events; HR 1.69, 1.16-2.45, p=0.006). Risks of any

Air-sea exchange over Black Sea estimated from high resolution regional climate simulations

NASA Astrophysics Data System (ADS)

Velea, Liliana; Bojariu, Roxana; Cica, Roxana

2013-04-01

Black Sea is an important influencing factor for the climate of bordering countries, showing cyclogenetic activity (Trigo et al, 1999) and influencing Mediterranean cyclones passing over. As for other seas, standard observations of the atmosphere are limited in time and space and available observation-based estimations of air-sea exchange terms present quite large ranges of uncertainty. The reanalysis datasets (e.g. ERA produced by ECMWF) provide promising validation estimates of climatic characteristics against the ones in available climatic data (Schrum et al, 2001), while cannot reproduce some local features due to relatively coarse horizontal resolution. Detailed and realistic information on smaller-scale processes are foreseen to be provided by regional climate models, due to continuous improvements of physical parameterizations and numerical solutions and thus affording simulations at high spatial resolution. The aim of the study is to assess the potential of three regional climate models in reproducing known climatological characteristics of air-sea exchange over Black Sea, as well as to explore the added value of the model compared to the input (reanalysis) data. We employ results of long-term (1961-2000) simulations performed within ENSEMBLE project (http://ensemblesrt3.dmi.dk/) using models ETHZ-CLM, CNRM-ALADIN, METO-HadCM, for which the integration domain covers the whole area of interest. The analysis is performed for the entire basin for several variables entering the heat and water budget terms and available as direct output from the models, at seasonal and annual scale. A comparison with independent data (ERA-INTERIM) and findings from other studies (e.g. Schrum et al, 2001) is also presented. References: Schrum, C., Staneva, J., Stanev, E. and Ozsoy, E., 2001: Air-sea exchange in the Black Sea estimated from atmospheric analysis for the period 1979-1993, J. Marine Systems, 31, 3-19 Trigo, I. F., T. D. Davies, and G. R. Bigg (1999): Objective

Increased Carotid Intima-Media Thickness and Reduced Distensibility in Human Class III Obesity: Independent and Differential Influences of Adiposity and Blood Pressure on the Vasculature

PubMed Central

Moore, Xiao L.; Michell, Danielle; Lee, Sabrina; Skilton, Michael R.; Nair, Rajesh; Dixon, John B.; Dart, Anthony M.; Chin-Dusting, Jaye

2013-01-01

Carotid intima-media-thickness (cIMT) and carotid distensibility (distensibility), structural and functional properties of carotid arteries respectively, are early markers, as well as strong predictors of cardiovascular disease (CVD). The characteristic of these two parameters in individuals with BMI>40.0 kg/m2 (Class III obesity), however, are largely unknown. The present study was designed to document cIMT and distensibility in this population and to relate these to other factors with established association with CVD in obesity. The study included 96 subjects (65 with BMI>40.0 kg/m2 and 31, age- and gender-matched, with BMI of 18.5 to 30.0 kg/m2). cIMT and distensibility were measured by non-invasive high resolution ultrasonography, circulatory CD133+/KDR+ angiogenic cells and endothelial microparticles (EMP) by flow cytometry, and plasma levels of adipokines, growth factors and cytokines by Luminex immunoassay kits. The study results demonstrated increased cIMT (0.62±0.11 mm vs. 0.54±0.08 mm, P = 0.0002) and reduced distensibility (22.52±10.79 10−3kpa−1 vs. 29.91±12.37 10−3kpa−1, P<0.05) in individuals with BMI>40.0 kg/m2. Both cIMT and distensibility were significantly associated with traditional CVD risk factors, adiposity/adipokines and inflammatory markers but had no association with circulating angiogenic cells. We also demonstrated, for the first time, elevated plasma EMP levels in individuals with BMI>40.0 kg/m2. In conclusion, cIMT is increased and distensibility reduced in Class III obesity with the changes predominantly related to conventional CVD risk factors present in this condition, demonstrating that both cIMT and distensibility remain as CVD markers in Class III obesity. PMID:23342053

National trends in carotid artery revascularization surgery.

PubMed

Dumont, Travis M; Rughani, Anand I

2012-06-01

Several randomized trials have emerged with conflicting data on the overall safety of carotid artery stenting (CAS) in comparison with carotid endarterectomy (CEA). The authors hypothesize that changes in national trends correspond to publication of randomized trials, including an increase in utilization of CAS after publication of trials favorable to CAS (for example, Carotid and Vertebral Artery Transluminal Angioplasty Study [CAVATAS] and Stenting and Angioplasty with Protection in Patients at High Risk for Endarterectomy [SAPPHIRE]) and decrease in utilization of CAS after publication of trials favorable to CEA (for example, Endarterectomy versus Stenting in Patients with Symptomatic Severe Carotid Stenosis [EVA3-S] and Stent-Supported Percutaneous Angioplasty of the Carotid Artery versus Endarterectomy [SPACE]). The Nationwide Inpatient Sample was obtained for the years 1998-2008. Individual cases were isolated for principal diagnosis of unilateral or bilateral carotid artery stenosis or occlusion undergoing CEA or CAS. The percentage of CAS for all carotid revascularization procedures was calculated for each year. Perioperative inpatient morbidity, including stroke or death, were calculated and compared. The percentage of patients undergoing CAS increased yearly from the start of the observed period to the end, with the exception of a decrease in 2007. The peak utilization of CAS for carotid artery revascularization procedures was 15% of all cases in 2006. The stroke or death rate was consistent at 5% among all patients undergoing CEA for all years, while the incidence of stroke or death decreased among patients undergoing CAS from 9% in 1998 to 5% in 2008. The practice of CAS in the US is expanding, from less than 3% of all carotid artery revascularization procedures to 13% in 2008. The utilization of CAS was seen to correlate with publication of randomized trials. Utilization nearly doubled in 2005 after publication of the CAS-favorable SAPPHIRE in 2004

Markers of insulin resistance and carotid atherosclerosis. A comparison of the homeostasis model assessment and triglyceride glucose index.

PubMed

Irace, C; Carallo, C; Scavelli, F B; De Franceschi, M S; Esposito, T; Tripolino, C; Gnasso, A

2013-07-01

The present investigation was designed to test the association between carotid atherosclerosis and two simple markers of insulin resistance, i.e. HOMA-Index and TyG-Index. The study was performed in two different cohorts. In the first cohort, 330 individuals were enrolled. Blood pressure, lipids, glucose, waist and cigarette smoking were evaluated. HOMA-IR and TyG-Index were calculated as markers of prevalent hepatic and muscular insulin resistance respectively. Carotid atherosclerosis was assessed by Doppler ultrasonography. The association between cardiovascular risk factors, markers of insulin resistance and carotid atherosclerosis was assessed by multiple logistic regression analyses. In the second cohort, limited to the evaluation of TyG-Index, 1432 subjects were studied. In the first cohort, TyG-Index was significantly associated with carotid atherosclerosis in a model including age, sex, diabetes, cigarette smoking and LDL cholesterol, while HOMA-IR was not. When components of metabolic syndrome were added to the model as dichotomous variables (absent/present), TyG-Index retained its predictive power. The same result was obtained when the metabolic syndrome was added to the model (absence/presence). The association between TyG-Index and carotid atherosclerosis was confirmed in the second cohort. The present findings suggest that TyG-Index is better associated with carotid atherosclerosis than HOMA-IR. © 2013 John Wiley & Sons Ltd.

MR coil sensitivity inhomogeneity correction for plaque characterization in carotid arteries

NASA Astrophysics Data System (ADS)

Salvado, Olivier; Hillenbrand, Claudia; Suri, Jasjit; Wilson, David L.

2004-05-01

We are involved in a comprehensive program to characterize atherosclerotic disease using multiple MR images having different contrast mechanisms (T1W, T2W, PDW, magnetization transfer, etc.) of human carotid and animal model arteries. We use specially designed intravascular and surface array coils that give high signal-to-noise but suffer from sensitivity inhomogeneity. With carotid surface coils, challenges include: (1) a steep bias field with an 80% change; (2) presence of nearby muscular structures lacking high frequency information to distinguish bias from anatomical features; (3) many confounding zero-valued voxels subject to fat suppression, blood flow cancellation, or air, which are not subject to coil sensitivity; and (4) substantial noise. Bias was corrected using a modification of the adaptive fuzzy c-mean method reported by Pham et al. (IEEE TMI, 18:738-752), whereby a bias field modeled as a mechanical membrane was iteratively improved until cluster means no longer changed. Because our images were noisy, we added a noise reduction filtering step between iterations and used about 5 classes. In a digital phantom having a bias field measured from our MR system, variations across an area comparable to a carotid artery were reduced from 50% to <5% with processing. Human carotid images were qualitatively improved and large regions of skeletal muscle were relatively flat. Other commonly applied techniques failed to segment the images or introduced strong edge artifacts. Current evaluations include comparisons to bias as measured by a body coil in human MR images.

Cerebral intolerance during flow arrested carotid angioplasty.

PubMed

St Louis, Myron; Park, Brian D; Dahn, Michael; Bozeman, Patricia

2012-01-01

The use of flow arrest as a means of providing cerebral protection during carotid angioplasty offers the advantages of improved efficiency of debris removal and the ability to provide protection under unfavorable (tortuous) anatomic circumstances. However, in contrast to the filtration methods of cerebral protection, this modality requires complete interruption of antegrade carotid artery flow during balloon angioplasty and stent deployment. We report our experience with 9 patients undergoing carotid angioplasty with the Mo.Ma device, which utilizes common and external carotid artery balloon occlusion during the angioplasty procedure. We assessed the clinical outcomes and intraprocedural hemodynamic data. The average duration of carotid occlusion was 8.3 minutes. Of the 9 patients, 2 patients (22%) experienced cerebral intolerance. No stroke occurred in this patient cohort. There appeared to be a poor relationship between procedure intolerance and the presence of significant contralateral stenosis or low carotid back pressure. Furthermore, the incidence of postangioplasty hypotension was not clearly related to cerebral intolerance. Carotid angioplasty with stenting can be safely conducted with flow arrest as an alternative to filter-type cerebral protection devices. However, because cerebral intolerance is not an infrequent occurrence with this approach, clinicians must be cognizant of management strategies for transient cerebral intolerance.

The role of blood vessels in high-resolution volume conductor head modeling of EEG.

PubMed

Fiederer, L D J; Vorwerk, J; Lucka, F; Dannhauer, M; Yang, S; Dümpelmann, M; Schulze-Bonhage, A; Aertsen, A; Speck, O; Wolters, C H; Ball, T

2016-03-01

Reconstruction of the electrical sources of human EEG activity at high spatio-temporal accuracy is an important aim in neuroscience and neurological diagnostics. Over the last decades, numerous studies have demonstrated that realistic modeling of head anatomy improves the accuracy of source reconstruction of EEG signals. For example, including a cerebro-spinal fluid compartment and the anisotropy of white matter electrical conductivity were both shown to significantly reduce modeling errors. Here, we for the first time quantify the role of detailed reconstructions of the cerebral blood vessels in volume conductor head modeling for EEG. To study the role of the highly arborized cerebral blood vessels, we created a submillimeter head model based on ultra-high-field-strength (7T) structural MRI datasets. Blood vessels (arteries and emissary/intraosseous veins) were segmented using Frangi multi-scale vesselness filtering. The final head model consisted of a geometry-adapted cubic mesh with over 17×10(6) nodes. We solved the forward model using a finite-element-method (FEM) transfer matrix approach, which allowed reducing computation times substantially and quantified the importance of the blood vessel compartment by computing forward and inverse errors resulting from ignoring the blood vessels. Our results show that ignoring emissary veins piercing the skull leads to focal localization errors of approx. 5 to 15mm. Large errors (>2cm) were observed due to the carotid arteries and the dense arterial vasculature in areas such as in the insula or in the medial temporal lobe. Thus, in such predisposed areas, errors caused by neglecting blood vessels can reach similar magnitudes as those previously reported for neglecting white matter anisotropy, the CSF or the dura - structures which are generally considered important components of realistic EEG head models. Our findings thus imply that including a realistic blood vessel compartment in EEG head models will be helpful to

Results of Early High-Flow Bypass and Trapping for Ruptured Blood Blister-Like Aneurysms of the Internal Carotid Artery.

PubMed

Kikkawa, Yuichiro; Ikeda, Toshiki; Takeda, Ririko; Nakajima, Hiroyuki; Ogura, Takeshi; Ooigawa, Hidetoshi; Kurita, Hiroki

2017-09-01

The aim of this study is to clarify the efficacy and safety of early surgery using trapping of the affected internal carotid artery (ICA) and high-flow bypass between the second portion of the middle cerebral artery and cervical external carotid artery with radial artery graft for ruptured blood blister-like aneurysms (BBAs) arising from the anterior wall of the ICA. Medical charts of 16 consecutive patients (7 men and 9 women; mean, 59 years) with subarachnoid hemorrhage (World Federation of Neurosurgical Societies grade I, n = 2; grade II, n = 5; grade III, n = 2; grade IV, n = 4; grade V, n = 3) caused by ruptured BBA surgically treated between July 2010 and October 2015 were retrospectively reviewed. Eleven patients underwent acute surgery within 24 hours after the onset, whereas surgery was performed between 3 and 17 days after the onset because of referral delay or associated vasospasm in 5 patients. All patients underwent the same surgical procedure. Elimination of the BBA and patency of the bypass were achieved in all patients. Postoperatively, 2 patients showed small infarction in the Heubner artery area, and 2 others suffered symptomatic vasospasm, but no patient suffered infarction in the posterior communicating/anterior choroidal artery territories. Identically, no patient showed ischemic optic neuropathy. At the last follow-up (mean, 36 months), favorable clinical outcome (good recovery or mild disability in Glasgow Outcome Scale) was achieved in 14 (88%) of the patients without rebleeding or refilling of the aneurysms. Early surgical repair of BBAs by trapping of the affected ICA with high-flow bypass is safe and effective treatment with satisfactory midterm outcome. Copyright © 2017 Elsevier Inc. All rights reserved.

[Analysis of brain hemometabolism behavior during carotid endarterectomy with temporary clamping.].

PubMed

Duval Neto, Gastão Fernandes; Niencheski, Augusto H

2004-04-01

Carotid endarterectomy with temporary clamping changes cerebral blood flow and cerebral metabolic oxygen demand ratio with consequent oligemic hypoxia or hemometabolic uncoupling. This study aimed at identifying changes in brain hemometabolism, evaluated through changes in oxyhemoglobin saturation in internal jugular vein bulb (SvjO2) during carotid endarterectomy with clamping, and at correlating these changes with potentially interfering factors, mainly end tidal CO2 pressure (P ET CO2) and cerebral perfusion pressure (CPP). Sixteen patients with unilateral carotid stenotic disease scheduled to carotid endarterectomy with carotid arterial clamping were enrolled in this study. Parameters including internal jugular bulb oxyhemoglobin saturation, stump pressure and end tidal CO2 pressure were measured at the following moments: M1 - pre-clamping; M2 - 3 minutes after clamping; M3 - pre-unclamping; M4 - post-unclamping). The comparison among SvjO2 (%, mean +/- SD) in all studied periods has shown differences between those recorded in moments M1 (52.25 +/- 7.87) and M2 (47.43 +/- 9.19). This initial decrease stabilized during temporary clamping, showing decrease in the comparison between M2 and M3 (46.56 +/- 9.25), without statistical significance (p = ns). At post-unclamping, M4 (47.68 +/- 9.12), SvjO2 was increased as compared to M2 and M3 clamping stages, however it was still lower than that of pre-clamping stage M1.(M4 x M1 - p < 0.04) This SvjO2 decrease was followed by significant cerebral perfusion pressure (stump pressure) decrease. Factors influencing this brain hemometabolic uncoupling trend were correlated to P ET CO2. The comparison between CPP and SvjO2 showed weak correlation devoid of statistical significance. In the conditions of our study, SvjO2 measurement is a fast and effective way of clinically monitoring changes in CBF/CMRO2 ratio. Temporary carotid clamping implies in a trend towards brain hemometabolic uncoupling and, as a consequence, to

Reliability of panoramic radiograph for carotid atheroma detection: a study in patients who fulfill the criteria for carotid endarterectomy.

PubMed

Damaskos, Spyros; Griniatsos, John; Tsekouras, Nikolaos; Georgopoulos, Sotirios; Klonaris, Chris; Bastounis, Elias; Tsiklakis, Kostas

2008-11-01

To evaluate the reliability of panoramic radiograph (PR) for carotid artery atheroma detection, by comparing its results with the carotid-vertebral digital subtraction angiography (DSA) findings, as well as with the detected calcium deposition in the carotid plaques, which were surgically resected, using direct radiographs. Forty consecutive patients suffering from carotid artery atherosclerotic occlusive disease confirmed by preoperative DSA, fulfilling the criteria for carotid endarterectomy, were operated on. Preoperatively, all of the patients had undergone PR, while postoperatively all of the surgically resected carotid plaques were radiographed using radiographic films and submitted to histologic examination. Compared with the DSA and the radiographic film findings, the PR results were classified as: 1) true-positive; 2) true-negative; 3) false-positive; or 4) false-negative. Panoramic radiograph has low sensitivity and specificity compared with the DSA findings and the direct radiographs results. However, a positive predictive value (PPV) of 100% per patient as well as for luminal stenosis >80% was documented. Even in the subgroup of patients who fulfill the criteria for carotid endarterectomy, PR has a low sensitivity and specificity; therefore, it cannot be considered to be a useful screening tool for atheroma detection in the general dental population. However, the 100% PPV per patient and for luminal stenosis >80%, indicates that positive calcification PR findings at the C(3)-C(4) region are highly suggestive for carotid artery atherosclerotic occlusive disease. Therefore, especially asymptomatic patients should be referred for further examination.

Flow Characterization of Severe Carotid Artery Stenosis in Pre- and Post-operative Phantoms by Using Magnetic Resonance Velocimetry

NASA Astrophysics Data System (ADS)

Ko, Seungbin; Song, Simon; Kim, Doosang

2016-11-01

It is remained unknown that the flow characteristics changes between pre- and post-operative severe carotid artery stenosis could affect the long-term patency or failure. However, in-vivo clinical experiments to uncover the flow details are far from bed-side due to limited measurement resolutions, blurring artifact, etc. We studied detailed flow characteristics of more than 75% severe carotid artery stenosis before and after surgical treatments. Real-size flow phantoms for 10 patients, who underwent carotid endarterectomy with patch/no patch closure, were prepared by using a 3D rapid-prototype machine from CT scanned images. The working fluid is a glycerin aqueous solution, and patient-specific pulsatile flows were applied to the phantoms, based on ultrasonic flow rate measurements. The flows were visualized with magnetic resonance velocimetry (MRV). The detailed flow characteristics are presented for both pre- and post-operative carotid arteries along with visualization data of 3 dimensional, 3 component velocity fields. This work was supported by the National Research Foundation of Korea (NRF) Grant funded by the Korea government (MSIP) (No. 2016R1A2B3009541).

Comparative Review of the Treatment Methodologies of Carotid Stenosis

PubMed Central

Bae, Coney; Szuchmacher, Mauricio; Chang, John B.

2015-01-01

The treatment of carotid stenosis entails three methodologies, namely, medical management, carotid angioplasty and stenting (CAS), as well as carotid endarterectomy (CEA). The North American Symptomatic Carotid Endarterectomy Trial (NASCET) and European Carotid Surgery Trial (ECST) have shown that symptomatic carotid stenosis greater than 70% is best treated with CEA. In asymptomatic patients with carotid stenosis greater than 60%, CEA was more beneficial than treatment with aspirin alone according to the Asymptomatic Carotid Atherosclerosis (ACAS) and Asymptomatic Carotid Stenosis Trial (ACST) trials. When CAS is compared with CEA, the CREST resulted in similar rates of ipsilateral stroke and death rates regardless of symptoms. However, CAS not only increased adverse effects in women, it also amplified stroke rates and death in elderly patients compared with CEA. CAS can maximize its utility in treating focal restenosis after CEA and patients with overwhelming cardiac risk or prior neck irradiation. When performing CEA, using a patch was equated to a more durable result than primary closure, whereas eversion technique is a new methodology deserving a spotlight. Comparing the three major treatment strategies of carotid stenosis has intrinsic drawbacks, as most trials are outdated and they vary in their premises, definitions, and study designs. With the newly codified best medical management including antiplatelet therapies with aspirin and clopidogrel, statin, antihypertensive agents, strict diabetes control, smoking cessation, and life style change, the current trials may demonstrate that asymptomatic carotid stenosis is best treated with best medical therapy. The ongoing trials will illuminate and reshape the treatment paradigm for symptomatic and asymptomatic carotid stenosis. PMID:26417191

Diagnosis and management of carotid stenosis: a review.

PubMed

Nussbaum, E S

2000-01-01

Since its introduction in the 1950s, carotid endarterectomy has become one of the most frequently performed operations in the United States. The tremendous appeal of a procedure that decreases the risk of stroke, coupled with the large number of individuals in the general population with carotid stenosis, has contributed to its popularity. To provide optimal patient care, the practicing physician must have a firm understanding of the proper evaluation and management of carotid stenosis. Nevertheless, because of the large number of clinical trials performed over the last decade addressing the treatment of stroke and carotid endarterectomy, the care of patients with carotid stenosis remains a frequently misunderstood topic. This review summarizes the current evaluation and treatment options for carotid stenosis and provides a rational management algorithm for this prevalent disease process.

Lipoprotein(a) and HIV: Allele-Specific Apolipoprotein(a) Levels Predict Carotid Intima-Media Thickness in HIV-Infected Young Women in the Women's Interagency HIV Study.

PubMed

Enkhmaa, Byambaa; Anuurad, Erdembileg; Zhang, Wei; Li, Chin-Shang; Kaplan, Robert; Lazar, Jason; Merenstein, Dan; Karim, Roksana; Aouizerat, Brad; Cohen, Mardge; Butler, Kenneth; Pahwa, Savita; Ofotokun, Igho; Adimora, Adaora A; Golub, Elizabeth; Berglund, Lars

2017-05-01

In the general population, lipoprotein(a) [Lp(a)] has been established as an independent causal risk factor for cardiovascular disease. Lp(a) levels are to a major extent regulated by a size polymorphism in the apolipoprotein(a) [apo(a)] gene. The roles of Lp(a)/apo(a) in human immunodeficiency virus (HIV)-related elevated cardiovascular disease risk remain unclear. The associations between total plasma Lp(a) level, allele-specific apo(a) level, an Lp(a) level carried by individual apo(a) alleles, and common carotid artery intima-media thickness were assessed in 150 HIV-infected and 100 HIV-uninfected women in the WIHS (Women's Interagency HIV Study). Linear regression analyses with and without adjustments were used. The cohort was young (mean age, ≈31 years), with the majority being Blacks (≈70%). The prevalence of a small size apo(a) (≤22 Kringle repeats) or a high Lp(a) level (≥30 mg/dL) was similar by HIV status. Total plasma Lp(a) level ( P =0.029) and allele-specific apo(a) level carried by the smaller apo(a) sizes ( P =0.022) were significantly associated with carotid artery intima-media thickness in the HIV-infected women only. After accounting for confounders (age, race, smoking, body mass index, blood pressure, hepatitis C virus coinfection, menopause, plasma lipids, treatment status, CD4 + T cell count, and HIV/RNA viral load), the association remained significant for both Lp(a) ( P =0.035) and allele-specific apo(a) level carried by the smaller apo(a) sizes ( P =0.010) in the HIV-infected women. Notably, none of the other lipids/lipoproteins was associated with carotid artery intima-media thickness. Lp(a) and allele-specific apo(a) levels predict carotid artery intima-media thickness in HIV-infected young women. Further research is needed to identify underlying mechanisms of an increased Lp(a) atherogenicity in HIV infection. © 2017 American Heart Association, Inc.

Postoperative Dysphagia in Debranching Thoracic Endovascular Aortic Repair with Retroesophageal Carotid-Carotid Bypass.

PubMed

Yoneyama, Fumiya; Sato, Fujio; Tokunaga, Chiho; Sakamoto, Hiroaki; Enomoto, Yoshiharu; Watanabe, Yutaka; Hiramatsu, Yuji

2017-08-01

A carotid-carotid bypass is commonly used in debranching thoracic endovascular aortic repair. When the bypass graft is placed in the retroesophageal position, the esophagus may be compressed by the graft from behind. Therefore, dysphagia may occur postoperatively as a serious complication. To avoid this issue, we recommend placing the bypass graft below the cricoid cartilage. Copyright © 2017 Elsevier Inc. All rights reserved.

Delayed aneurysm rupture due to residual blood flow at the inflow zone of the intracranial paraclinoid internal carotid aneurysm treated with the Pipeline embolization device: Histopathological investigation

PubMed Central

Ikeda, Hiroyuki; Kikuchi, Takayuki; Ando, Mitsushige; Chihara, Hideo; Arai, Daisuke; Hattori, Etsuko; Miyamoto, Susumu

2015-01-01

Cerebral aneurysm rupture is a serious complication that can occur after flow diverter (FD) placement, but the underlying mechanisms remain unclear. We encountered a case in which direct stress on the aneurysm wall caused by residual blood flow at the inflow zone near the neck during the process of thrombosis after FD placement appeared associated with aneurysm rupture. The patient was a 67-year-old woman with progressive optic nerve compression symptoms caused by a large intracranial paraclinoid internal carotid aneurysm. The patient had undergone treatment with a Pipeline embolization device (PED) with satisfactory adherence between the PED and vessel wall. Surgery was completed without complications, and optic nerve compression symptoms improved immediately after treatment. Postoperative clinical course was satisfactory, but the patient suddenly died 34 days postoperatively. Autopsy confirmed the presence of subarachnoid hemorrhage caused by rupture of the internal carotid aneurysm that had been treated with PED. Although the majority of the aneurysm lumen including the outflow zone was thrombosed, a non-thrombosed area was observed at the inflow zone. Perforation was evident in the aneurysm wall at the inflow zone near the neck, and this particular area of aneurysm wall was not covered in thrombus. Macrophage infiltration was not seen on immunohistochemical studies of the aneurysm wall near the perforation. A hemodynamically unstable period during the process of complete thrombosis of the aneurysm lumen after FD placement may be suggested, and blood pressure management and appropriate management with antiplatelet therapy may be important. PMID:26500232

Risk factors of carotid plaque and carotid common artery intima-media thickening in a high-stroke-risk population.

PubMed

Wang, ChunFang; Lv, GaoPeng; Zang, DaWei

2017-11-01

To analyze the risk factors of carotid plaque (CP) and carotid common artery intima-media thickening (CCAIMT) and the association between the risk factors and CP numbers and the side of the CCAIMT in a high-stroke-risk population. Carotid ultrasonography was conducted in 2025 participants with high stroke risk. Participants were divided into different groups according to the results of the ultrasound. The risk factors and blood biochemical indices were recorded. The presence of CP and CCAIMT were 38.9% and 24.8% respectively. Multivariate logistic regression indicated that the risk factors of CP were age, high LDL-C and FBG levels, male gender, stroke, diabetes, hypertension, and tobacco use. Compared with participants without CPs, the participants who were male, and older in age, with risk factors of tobacco use, diabetes, high LDL-C levels, and a family history of hypertension were likely to have a single CP, whereas the participants with risk factors of tobacco use, diabetes, hypertension, male gender, older age, high LDL-C levels, stroke and AF or valvulopathy were prone to have multiple CPs. The risk factors of CCAIMT were male gender, stroke, hypertension, diabetes, AF or valvulopathy, tobacco use and age. Compared with the N-CCAIMT subgroup, the risk factors of left CCAIMT were tobacco use, diabetes, male gender, and age. The risk factors of right CCAIMT were male gender, high FBG levels, age, AF or valvulopathy. The risk factors of dual CCAIMT were high frequency of drinking milk, tobacco use, male gender, age, stroke, and hypertension. These findings revealed the risk factors of CP and CCAIMT, and an association between the risk factors and the CP numbers and the side of the CCAIMT.

Three-dimensional color Doppler imaging of the carotid artery

NASA Astrophysics Data System (ADS)

Picot, Paul A.; Rickey, Daniel W.; Mitchell, Ross; Rankin, Richard N.; Fenster, Aaron

1991-05-01

Stroke is the third leading cause of death in the United States. It is caused by ischemic injury to the brain, usually resulting from emboli from atherosclerotic plaques. The carotid bifurcation in humans is prone to atherosclerotic disease and is a site where emboli may originate. Currently, carotid stenoses are evaluated by non-invasive duplex Doppler ultrasound, with preoperative verification by intra-arterial angiography. We have developed a system that uses a color Doppler ultrasound imaging system to acquire in-vivo 3-D color Doppler images of the human carotid artery, with the aim of increasing the diagnostic accuracy of ultrasound and decreasing the use of angiography for verification. A clinical TL Ultramark 9 color Doppler ultrasound system was modified by mounting the hand-held ultrasound scan head on a motor-driven translation stage. The stage allows planar ultrasound images to be acquired over 45 mm along the neck between the clavicle and the mandible. A 3- D image is acquired by digitizing, in synchrony with the cardiac cycle, successive color ultrasound video images as the scan head is stepped along the neck. A complete volume set of 64 frames, comprising some 15 megabytes of data, requires approximately 2 minutes to acquire. The volume image is reformatted and displayed on a Sun 4/360 workstation equipped with a TAAC-1 graphics accelerator. The 3-D image may be manipulated in real time to yield the best view of blood flow in the bifurcation.

Histological and Morphometric Analyses for Rat Carotid Artery Balloon Injury Studies

PubMed Central

Tulis, David Anthony

2010-01-01

i. Summary Experiments aimed at analyzing the response of blood vessels to mechanical injury and ensuing remodeling responses often employ the highly characterized carotid artery balloon injury model in laboratory rats. This approach utilizes luminal insertion of a balloon embolectomy catheter into the common carotid artery with inflation and withdrawal resulting in an injury characterized by vascular endothelial cell (EC) denudation and medial wall distension. The adaptive response to this injury is typified by robust vascular smooth muscle cell (SMC) replication and migration, SMC apoptosis and necrosis, enhanced synthesis and deposition of extracellular matrix (ECM) components, partial vascular EC regeneration from the border zones, luminal narrowing and establishment of a neointima in time-dependent fashion. Evaluation of these adaptive responses to blood vessel injury can include acute and longer-term qualitative and quantitative measures including expression analyses, activity assays, immunostaining for a plethora of factors and signals, and morphometry of neointima formation and gross mural remodeling. This chapter presents a logical continuation of Chapter    in this series that offers details for performing the rat carotid artery balloon injury model in a standard laboratory setting by providing commonly used protocols for performing histological and morphometric analyses in such studies. Moreover, procedures, caveats, and considerations included in this chapter are highly relevant for alternative animal vascular physiology/pathophysiology studies and in particular those related to mechanisms of vascular injury and repair. Included in this chapter are specifics for in situ perfusion-fixation, tissue harvesting and processing for both snap-frozen and paraffin-embedded protocols, specimen embedding and sectioning, slide preparation, several standard histological staining steps, and routine morphological assessment. Included in Notes are important caveats

Treatment of Carotid Artery Disease: Endarterectomy or Angioplasty?

PubMed Central

Marchidann, Adrian; Marshall, Randolph S.

2011-01-01

The management of carotid stenosis has enjoyed renewed interest in the neurological community in recent years due to the advent of endovascular approaches. In concert, progress in medical treatment of these patients has rekindled the debate regarding the best management of carotid stenosis overall, both for symptomatic and asymptomatic disease. For symptomatic carotid stenosis, the major decision required is choosing the type of intervention best suited for individual patients — carotid endarterectomy (CEA) versus carotid artery stenting (CAS). For patients with asymptomatic carotid stenosis, intensive medical management has evolved significantly over the past decade to decrease the risk of ischemic stroke to match surgical intervention under most circumstances. This review will examine the supporting evidence for each intervention, and discuss the recent advances in medical and endovascular therapy that provide the data for a new era in clinical decision making. PMID:20960240

Advances in atheroma imaging in the carotid.

PubMed

Gillard, Jonathan H

2007-01-01

Atherosclerosis affects all vascular beds, including the coronary, carotid, intracerebral, peripheral and aortic vascular beds, and is responsible for tremendous morbidity and mortality, with the most serious outcomes being myocardial infarction, stroke and death. Historically the effects of vascular narrowing and associated thrombosis have been key indicators of disease in the coronary and carotid territories, with degrees of vascular stenosis being of profound importance in carotid surgery trials. Our improving understanding of the biology of atheromatous lesions and the development of alternative therapeutic agents which can initiate actual plaque regression have created a need to attempt to image plaque itself, with the carotid artery being an achievable target. This article reviews current strategies for assessing carotid atherosclerotic disease, particularly with reference to identifying plaque components and risk of rupture, the so-called vulnerable plaque. Copyright 2007 S. Karger AG, Basel.

Selected heavy metals and selenium in the blood of black sea turtle (Chelonia mydas agasiizzi) from Sonora, Mexico.

PubMed

Ley-Quiñónez, C P; Zavala-Norzagaray, A A; Réndon-Maldonado, J G; Espinosa-Carreón, T L; Canizales-Román, A; Escobedo-Urías, D C; Leal-Acosta, M L; Hart, C E; Aguirre, A A

2013-12-01

The concentration of heavy metals (Zn, Cd, Ni, Cu, Mn) and selenium (Se) was analyzed in blood collected from 12 black turtles (Chelonia mydas agasiizzi) captured in Canal del Infiernillo, Punta Chueca, Mexico. The most abundant metals were Zn (63.58 μg g(-1)) and Se (7.66 μg g(-1)), and Cd was the lower (0.99 μg g(-1)). The sequential concentrations of trace metals were Zn > Se > Cu > Mn > Ni > Cd. In conclusion, this information is important as a baseline when using blood as tissue analysis of heavy metals; however, these levels could represent recent exposure in foraging grounds of black turtles in the Sea of Cortez.

Salivary inflammatory cytokines may be novel markers of carotid atherosclerosis in a Japanese general population: the Suita study.

PubMed

Kosaka, Takayuki; Kokubo, Yoshihiro; Ono, Takahiro; Sekine, Shinichi; Kida, Momoyo; Kikui, Miki; Yamamoto, Masaaki; Watanabe, Makoto; Amano, Atsuo; Maeda, Yoshinobu; Miyamoto, Yoshihiro

2014-11-01

Salivary biomarkers have been recently useful of periodontal disease, which is also risk factor of atherosclerosis. However, there are few studies of the association between salivary inflammatory cytokines and carotid atherosclerosis. We aimed to clarify the association between salivary inflammatory cytokines and periodontal disease and carotid atherosclerosis in a general urban population. We studied 608 Japanese men and women (mean age: 65.4 years) in the Suita study. Carotid atherosclerosis was evaluated by high-resolution ultrasonography with atherosclerotic indexes of intima-media thickness (IMT). Periodontal status was evaluated by the Community Periodontal Index (CPI). Salivary levels of interleukin-1β, interleukin-6, tumor necrosis factor-α (TNF-α), and prostaglandin E2 (PGE2) were measured by enzyme linked immunosorbent assay. The risks of carotid atherosclerosis (≥75th percentiles of mean- [0.88 mm] and Max-IMT [1.50 mm]) according to the quartiles of salivary inflammatory cytokines were compared using of adjusted-logistic regression models. All salivary inflammatory cytokines were positively associated with CPI. The adjusted odds ratios for carotid atherosclerosis of mean-IMT in the highest quartile of interleukin-6 and TNF-α were higher than those in the lowest quartiles (OR = 2.32 and 2.88; 95% confidence intervals = 1.19-4.51 and 1.51-5.49, respectively). The adjusted odds ratio for carotid atherosclerosis of mean-IMT in the highest quartile of PGE2 was greater than those in the lowest quartile in women (OR = 2.78; 95% confidence intervals = 1.11-6.95). In conclusion, higher levels of salivary inflammatory cytokines were associated with both periodontal disease and carotid atherosclerosis. Selected salivary inflammatory cytokines may be useful screening markers for periodontal disease and carotid atherosclerosis. Copyright © 2014. Published by Elsevier Ireland Ltd.

Clinical and electroencephalographic features of carotid sinus syncope induced by internal carotid artery angioplasty.

PubMed

Martinez-Fernandez, E; García, F Boza; Gonzalez-Marcos, J R; Peralta, A Gil; Garcia, A Gonzalez; Deya, A Mayol

2008-02-01

Carotid sinus syncope may occur acutely during internal carotid artery angioplasty (CA). We performed this study to investigate the clinical, electroencephalographic (EEG), and hemodynamic features of carotid sinus syncope induced by CA. Between 1992 and 2003, clinical, EEG, and cardiovascular monitoring was performed in 359 consecutive patients undergoing CA. Carotid sinus reaction (CSR) and syncope occurred in 62.7% and 18.6% of the procedures, respectively. CSR and syncopal spells were classified into cardioinhibitory, vasodepressor, and mixed type. Syncope occurred more frequently in patients with cardioinhibitory CSR (P < .001). The odds ratios for the risk of syncope in patients with cardioinhibitory CSR and vasodepressor/mixed CSR were 6.9 and 1.4, respectively. Sixty-one patients had cardioinhibitory syncope; 7 had the vasodepressor/mixed type. Thirteen spells were not related to cardiovascular disturbances. This last syncope subtype was significantly associated with brain hemodynamic disturbances, including a decrease in cerebral vasoreactivity (P = .04) and the absence of function of both communicating arteries (P = .03). Convulsive movements resembling supplementary sensorimotor seizures occurred in 79% of patients who experienced syncopal spells. EEG changes were more prominent in patients with cardioinhibitory syncope. Syncope occurs frequently in patients undergoing CA and can be misdiagnosed as seizures. The most frequent mechanism was a cardioinhibitory response. Cerebral hemodynamic disturbances may play a crucial role in the pathophysiology of syncope with normal sinus rhythm and normotension. Moreover, direct depression of the CNS following carotid sinus distension is likely to be involved.

Breath-hold black-blood T1rho mapping improves liver T1rho quantification in healthy volunteers.

PubMed

Wáng, Yì Xiáng J; Deng, Min; Lo, Gladys G; Liang, Dong; Yuan, Jing; Chen, Weitian

2018-03-01

Background Recent researches suggest that T1rho may be a non-invasive and quantitative technique for detecting and grading liver fibrosis. Purpose To compare a multi-breath-hold bright-blood fast gradient echo (GRE) imaging and a single breath-hold single-shot fast spin echo (FSE) imaging with black-blood effect for liver parenchyma T1rho measurement and to study liver physiological T1rho value in healthy volunteers. Material and Methods The institutional Ethics Committee approved this study. 28 healthy participants (18 men, 10 women; age = 29.6 ± 5.1 years) underwent GRE liver T1rho imaging, and 20 healthy participants (10 men, 10 women; age = 36.9 ± 10.3 years) underwent novel black-blood FSE liver T1rho imaging, both at 3T with spin-lock frequency of 500 Hz. The FSE technique allows simultaneous acquisition of four spin lock times (TSLs; 1 ms, 10 ms, 30 ms, 50msec) in 10 s. Results For FSE technique the intra-scan repeatability intraclass correlation coefficient (ICC) was 0.98; while the inter-scan reproducibility ICC was 0.82 which is better than GRE technique's 0.76. Liver T1rho value in women tended to have a higher value than T1rho values in men (FSE: 42.28 ± 4.06 ms for women and 39.13 ± 2.12 ms for men; GRE: 44.44 ± 1.62 ms for women and 42.36 ± 2.00 ms for men) and FSE technique showed liver T1rho value decreased slightly as age increased. Conclusion Single breath-hold black-blood FSE sequence has better scan-rescan reproducibility than multi-breath-hold bright-blood GRE sequence. Gender and age dependence of liver T1rho in healthy participants is observed, with young women tending to have a higher T1rho measurement.

Quantification of the Interrelationship between Brachial-Ankle and Carotid-Femoral Pulse Wave Velocity in a Workplace Population

PubMed Central

Cheng, Yi-Bang; Li, Yan; Sheng, Chang-Sheng; Huang, Qi-Fang; Wang, Ji-Guang

2016-01-01

Background Brachial-ankle pulse wave velocity (PWV) is increasingly used for the measurement of arterial stiffness. In the present study, we quantified the interrelationship between brachial-ankle and carotid-femoral PWV in a workplace population, and investigated the associations with cardiovascular risk factors and carotid intima-media thickness (IMT). Methods Brachial-ankle and carotid-femoral PWV were measured using the Omron-Colin VP1000 and SphygmoCor devices, respectively. We investigated the interrelationship by the Pearson's correlation analysis and Bland-Altman plot, and performed sensitivity and specificity analyses. Results The 954 participants (mean ± standard deviation age 42.6 ± 14.2 years) included 630 (66.0%) men and 203 (21.3%) hypertensive patients. Brachial-ankle (13.4 ± 2.7 m/s) and carotid-femoral PWV (7.3 ± 1.6 m/s) were significantly correlated in all subjects (r = 0.75) as well as in men (r = 0.72) and women (r = 0.80) separately. For arterial stiffness defined as a carotid-femoral PWV of 10 m/s or higher, the sensitivity and specificity of brachial-ankle PWV of 16.7 m/s or higher were 72 and 94%, respectively. The area under the receiver operating characteristic curve was 0.953. In multiple stepwise regression, brachial-ankle and carotid-femoral PWV were significantly (p < 0.001) associated with age (partial r = 0.33 and 0.34, respectively) and systolic blood pressure (partial r = 0.71 and 0.66, respectively). In addition, brachial-ankle and carotid-femoral PWV were significantly (p < 0.001) associated with carotid IMT (r = 0.57 and 0.55, respectively) in unadjusted analysis, but not in analysis adjusted for cardiovascular risk factors (p ≥ 0.08). Conclusions Brachial-ankle and carotid-femoral PWV were closely correlated, and had similar determinants. Brachial-ankle PWV can behave as an ease-of-use alternative measure of arterial stiffness for assessing cardiovascular risk. PMID:27195246

Effects of the consumption of fish meals on the carotid IntimaMedia thickness in patients with hypertension: a prospective study.

PubMed

Colussi, GianLuca; Catena, Cristiana; Dialti, Valeria; Mos, Lucio; Sechi, Leonardo A

2014-01-01

The composition of dietary fat affects various modifiable cardiovascular risk factors and cardiovascular outcomes in the general population. We investigated the effects of the regular consumption of fish meals on the fatty acid composition of red blood cell (RBC) membranes and the relationship of this parameter with the carotid intima-media thickness (IMT), an early marker of atherosclerosis. In 56 hypertensive patients, we measured the carotid IMT using ultrasound imaging and the RBC membrane fatty acid composition using gas-chromatography and calculated the polyunsaturated to saturated fatty acid (PUFA/SFA) ratio. The patients received intensive nutritional counseling and three weekly meals of fish containing elevated amounts of PUFA, in order to increase the membrane PUFA content. The RBC membrane fatty acid composition and IMT were reassessed after one year. At baseline, the membrane PUFA/SFA ratio was inversely related to the carotid IMT, and the relationship was independent of all major cardiovascular risk factors. At follow-up, the PUFA/SFA ratio increased in the RBC membranes of 25 (45%) of 56 patients. The regular consumption of fish meals resulted in a decreased carotid IMT only in the patients with an increased membrane PUFA/SFA ratio. Changes in the PUFA/SFA ratio induced by the dietary intervention were inversely related to the changes in the IMT, independent of variations in body mass, blood pressure and plasma lipids. In hypertensive patients, a low RBC membrane PUFA/SFA ratio is associated with more prominent vascular damage, and the regular consumption of fish reduces the carotid IMT in patients in whom dietary intervention affects the membrane fatty acid composition.

Changes in arterial stiffness, carotid intima-media thickness, and epicardial fat after L-thyroxine replacement therapy in hypothyroidism.

PubMed

del Busto-Mesa, Abdel; Cabrera-Rego, Julio Oscar; Carrero-Fernández, Lisván; Hernández-Roca, Cristina Victoria; González-Valdés, Jorge Luis; de la Rosa-Pazos, José Eduardo

2015-01-01

To assess the relationship between primary hypothyroidism and subclinical atherosclerosis and its potential changes with L-thyroxine replacement therapy. A prospective cohort study including 101 patients with primary hypothyroidism and 101 euthyroid patients as controls was conducted from July 2011 to December 2013. Clinical, anthropometrical, biochemical, and ultrasonographic parameters were assessed at baseline and after one year of L-thyroxine replacement therapy. At baseline, hypothyroid patients had significantly greater values of blood pressure, total cholesterol, VLDL cholesterol, left ventricular mass, epicardial fat, and carotid intima-media thickness as compared to controls. Total cholesterol, VLDL cholesterol, ventricular diastolic function, epicardial fat, carotid intima-media thickness, carotid local pulse wave velocity, pressure strain elastic modulus, and β arterial stiffness index showed a significant and positive correlation with TSH levels. After one year of replacement therapy, patients with hypothyroidism showed changes in total cholesterol, VLDL cholesterol, TSH, carotid intima-media thickness, and arterial stiffness parameters. Primary hypothyroidism is characterized by an increased cardiovascular risk. In these patients, L-thyroxine replacement therapy for one year is related to decreased dyslipidemia and improvement in markers of subclinical carotid atherosclerosis. Copyright © 2014 SEEN. Published by Elsevier España, S.L.U. All rights reserved.

Adrenaline release evokes hyperpnoea and an increase in ventilatory CO2 sensitivity during hypoglycaemia: a role for the carotid body

PubMed Central

Thompson, Emma L.; Ray, Clare J.; Holmes, Andrew P.; Pye, Richard L.; Wyatt, Christopher N.; Kumar, Prem

2016-01-01

Key points Hypoglycaemia is counteracted by release of hormones and an increase in ventilation and CO2 sensitivity to restore blood glucose levels and prevent a fall in blood pH.The full counter‐regulatory response and an appropriate increase in ventilation is dependent on carotid body stimulation.We show that the hypoglycaemia‐induced increase in ventilation and CO2 sensitivity is abolished by preventing adrenaline release or blocking its receptors.Physiological levels of adrenaline mimicked the effect of hypoglycaemia on ventilation and CO2 sensitivity.These results suggest that adrenaline, rather than low glucose, is an adequate stimulus for the carotid body‐mediated changes in ventilation and CO2 sensitivity during hypoglycaemia to prevent a serious acidosis in poorly controlled diabetes. Abstract Hypoglycaemia in vivo induces a counter‐regulatory response that involves the release of hormones to restore blood glucose levels. Concomitantly, hypoglycaemia evokes a carotid body‐mediated hyperpnoea that maintains arterial CO2 levels and prevents respiratory acidosis in the face of increased metabolism. It is unclear whether the carotid body is directly stimulated by low glucose or by a counter‐regulatory hormone such as adrenaline. Minute ventilation was recorded during infusion of insulin‐induced hypoglycaemia (8–17 mIU kg−1 min−1) in Alfaxan‐anaesthetised male Wistar rats. Hypoglycaemia significantly augmented minute ventilation (123 ± 4 to 143 ± 7 ml min−1) and CO2 sensitivity (3.3 ± 0.3 to 4.4 ± 0.4 ml min−1 mmHg−1). These effects were abolished by either β‐adrenoreceptor blockade with propranolol or adrenalectomy. In this hypermetabolic, hypoglycaemic state, propranolol stimulated a rise in P aC O2, suggestive of a ventilation–metabolism mismatch. Infusion of adrenaline (1 μg kg−1 min−1) increased minute ventilation (145 ± 4 to 173 ± 5 ml min−1) without altering P aC O2 or pH and enhanced

Adrenaline release evokes hyperpnoea and an increase in ventilatory CO2 sensitivity during hypoglycaemia: a role for the carotid body.

PubMed

Thompson, Emma L; Ray, Clare J; Holmes, Andrew P; Pye, Richard L; Wyatt, Christopher N; Coney, Andrew M; Kumar, Prem

2016-08-01

Hypoglycaemia is counteracted by release of hormones and an increase in ventilation and CO2 sensitivity to restore blood glucose levels and prevent a fall in blood pH. The full counter-regulatory response and an appropriate increase in ventilation is dependent on carotid body stimulation. We show that the hypoglycaemia-induced increase in ventilation and CO2 sensitivity is abolished by preventing adrenaline release or blocking its receptors. Physiological levels of adrenaline mimicked the effect of hypoglycaemia on ventilation and CO2 sensitivity. These results suggest that adrenaline, rather than low glucose, is an adequate stimulus for the carotid body-mediated changes in ventilation and CO2 sensitivity during hypoglycaemia to prevent a serious acidosis in poorly controlled diabetes. Hypoglycaemia in vivo induces a counter-regulatory response that involves the release of hormones to restore blood glucose levels. Concomitantly, hypoglycaemia evokes a carotid body-mediated hyperpnoea that maintains arterial CO2 levels and prevents respiratory acidosis in the face of increased metabolism. It is unclear whether the carotid body is directly stimulated by low glucose or by a counter-regulatory hormone such as adrenaline. Minute ventilation was recorded during infusion of insulin-induced hypoglycaemia (8-17 mIU kg(-1)  min(-1) ) in Alfaxan-anaesthetised male Wistar rats. Hypoglycaemia significantly augmented minute ventilation (123 ± 4 to 143 ± 7 ml min(-1) ) and CO2 sensitivity (3.3 ± 0.3 to 4.4 ± 0.4 ml min(-1)  mmHg(-1) ). These effects were abolished by either β-adrenoreceptor blockade with propranolol or adrenalectomy. In this hypermetabolic, hypoglycaemic state, propranolol stimulated a rise in P aC O2, suggestive of a ventilation-metabolism mismatch. Infusion of adrenaline (1 μg kg(-1)  min(-1) ) increased minute ventilation (145 ± 4 to 173 ± 5 ml min(-1) ) without altering P aC O2 or pH and enhanced ventilatory CO2 sensitivity (3

Hybrid treatment of tandem, common carotid/innominate artery and ipsilateral carotid bifurcation stenoses by simultaneous, retrograde proximal stenting and eversion carotid endarterectomy: Preliminary results of a case series.

PubMed

Illuminati, Giulio; Pizzardi, Giulia; Pasqua, Rocco; Frezzotti, Francesca; Palumbo, Piergaspare; Macrina, Francesco; Calio', Francesco

2018-04-01

Tandem stenoses of the internal carotid artery (ICA) and proximal, ipsilateral common carotid artery (CCA) or innominate artery can be treated with a hybrid approach, combining conventional carotid endarterectomy (CEA) and retrograde stenting of the proximal stenosis, through surgical exposure of the carotid bifurcation. The purpose of this study was to evaluate the results of combining eversion CEA with retrograde CCA/innominate artery stenting. From January 2015 to July 2017, 7 patients, 6 men of a mean age of 72 years (range 59-83 years) underwent simultaneous, retrograde stenting of the proximal CCA/innominate artery and an eversion CEA of the ipsilateral ICA, through surgical exposure of the carotid bifurcation, for severe tandem stenoses. The proximal stenosis involved the left proximal CCA in 4 patients, the proximal innominate artery in 2 patients and the right CCA in one patient. The procedure was performed under general anesthesia in a conventional operating room equipped with a mobile C-arm. A covered, balloon expandable stent was deployed over the proximal stenosis via a 6-F sheath directly introduced into the proximal CCA through the obliquely transected carotid bulb. After removing the sheath, debris were flushed through the carotid bulb and eversion CEA completed the procedure. Study endpoints were: postoperative stroke/mortality rate, cardiac mortality and morbidity, peripheral nerve injury, cervical hematoma, overall late survival, freedom from ipsilateral stroke and patency of arterial reconstruction. No postoperative mortality or neurologic morbidity was observed in any patient. Cervical hematomas and peripheral nerve injuries were likewise absent. At a mean follow-up of 18 months, all the patients were alive, free from neurologic events of new onset and free from restenosis. Combined proximal stenting and eversion CEA for tandem lesions seems a valid treatment, with the advantages of eversion CEA over other techniques of carotid bifurcation

Modified criteria for carotid sinus hypersensitivity are associated with increased mortality in a population-based study

PubMed Central

McDonald, Claire; Pearce, Mark S.; Newton, Julia L.; Kerr, Simon R.J.

2016-01-01

Abstract Aims Carotid sinus hypersensitivity (CSH) is arbitrarily defined as ≥3 s asystole or vasodepression of ≥50 mmHg in response to carotid sinus massage (CSM). Using this definition, 39% of older people meet the criteria for CSH. It has been suggested that current criteria are too sensitive. Krediet et al. [The history of diagnosing carotid sinus hypersensitivity: why are the current criteria too sensitive? Europace 2011;13:14–22] and Kerr et al. [Carotid sinus hypersensitivity in asymptomatic older persons: implications for diagnosis of syncope and falls. Arch Intern Med 2006;166:515–20] have proposed modified criteria. This population-based study aimed to compare the prevalence of CSH defined according to standard, Krediet and Kerr criteria, and to establish if CSH defined according these criteria is associated with all-cause mortality. Methods and results A total of 272 community-dwelling people aged ≥65 were recruited at random. Carotid sinus massage was performed for 5 s in supine and head-up positions. Heart rate and blood pressure response were recorded using an electrocardiogram and photoplethysmography. Cox regression analysis was used to examine the association between each definition of CSH and all-cause mortality. The prevalence of CSH defined according to standard, Krediet, and Kerr criteria was 39, 52, and 10%, respectively. Seventy-one participants died over a mean follow-up of 8.6 years (SD 2.1). Carotid sinus hypersensitivity defined according to standard and Krediet criteria was not associated with survival. Carotid sinus hypersensitivity defined according to Kerr criteria was associated with all-cause mortality independent of age and sex [hazard ratio (HR) 2.023 (95% confidence interval (95% CI) 1.131–3.618) P = 0.018)]. This remained significant after adjusting for cardiovascular risk factors [HR 2.174 (1.075–3.900) P = 0.009]. Conclusion Carotid sinus hypersensitivity defined according to Kerr criteria is associated with

The carotid baroreflex modifies the pressor threshold of the muscle metaboreflex in humans.

PubMed