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Sample records for central artery stiffness

  1. Arterial stiffness, central hemodynamics, and cardiovascular risk in hypertension

    PubMed Central

    Palatini, Paolo; Casiglia, Edoardo; Gąsowski, Jerzy; Głuszek, Jerzy; Jankowski, Piotr; Narkiewicz, Krzysztof; Saladini, Francesca; Stolarz-Skrzypek, Katarzyna; Tikhonoff, Valérie; Van Bortel, Luc; Wojciechowska, Wiktoria; Kawecka-Jaszcz, Kalina

    2011-01-01

    This review summarizes several scientific contributions at the recent Satellite Symposium of the European Society of Hypertension, held in Milan, Italy. Arterial stiffening and its hemodynamic consequences can be easily and reliably measured using a range of noninvasive techniques. However, like blood pressure (BP) measurements, arterial stiffness should be measured carefully under standardized patient conditions. Carotid-femoral pulse wave velocity has been proposed as the gold standard for arterial stiffness measurement and is a well recognized predictor of adverse cardiovascular outcome. Systolic BP and pulse pressure in the ascending aorta may be lower than pressures measured in the upper limb, especially in young individuals. A number of studies suggest closer correlation of end-organ damage with central BP than with peripheral BP, and central BP may provide additional prognostic information regarding cardiovascular risk. Moreover, BP-lowering drugs can have differential effects on central aortic pressures and hemodynamics compared with brachial BP. This may explain the greater beneficial effect provided by newer antihypertensive drugs beyond peripheral BP reduction. Although many methodological problems still hinder the wide clinical application of parameters of arterial stiffness, these will likely contribute to cardiovascular assessment and management in future clinical practice. Each of the abovementioned parameters reflects a different characteristic of the atherosclerotic process, involving functional and/or morphological changes in the vessel wall. Therefore, acquiring simultaneous measurements of different parameters of vascular function and structure could theoretically enhance the power to improve risk stratification. Continuous technological effort is necessary to refine our methods of investigation in order to detect early arterial abnormalities. Arterial stiffness and its consequences represent the great challenge of the twenty-first century for

  2. Central Artery Stiffness in Hypertension and Aging: A Problem with Cause and Consequence

    PubMed Central

    Humphrey, Jay D.; Harrison, David G.; Figueroa, C. Alberto; Lacolley, Patrick; Laurent, Stéphane

    2015-01-01

    Systemic hypertension is a risk factor for many diseases affecting the heart, brain, and kidneys. It has long been thought that hypertension leads to a thickening and stiffening of central arteries (i.e., stiffness is a consequence) while more recent evidence suggests that stiffening precedes hypertension (i.e., stiffness is a cause). We submit, however, that consideration of the wall biomechanics and hemodynamics reveals an insidious positive feedback loop that may render it irrelevant whether hypertension causes or is caused by central arterial stiffening. A progressive worsening can ensue in either case, thus any onset of stiffening merits early intervention. PMID:26846637

  3. Central artery stiffness, baroreflex sensitivity, and brain white matter neuronal fiber integrity in older adults.

    PubMed

    Tarumi, Takashi; de Jong, Daan L K; Zhu, David C; Tseng, Benjamin Y; Liu, Jie; Hill, Candace; Riley, Jonathan; Womack, Kyle B; Kerwin, Diana R; Lu, Hanzhang; Munro Cullum, C; Zhang, Rong

    2015-04-15

    Cerebral hypoperfusion elevates the risk of brain white matter (WM) lesions and cognitive impairment. Central artery stiffness impairs baroreflex, which controls systemic arterial perfusion, and may deteriorate neuronal fiber integrity of brain WM. The purpose of this study was to examine the associations among brain WM neuronal fiber integrity, baroreflex sensitivity (BRS), and central artery stiffness in older adults. Fifty-four adults (65 ± 6 years) with normal cognitive function or mild cognitive impairment (MCI) were tested. The neuronal fiber integrity of brain WM was assessed from diffusion metrics acquired by diffusion tensor imaging. BRS was measured in response to acute changes in blood pressure induced by bolus injections of vasoactive drugs. Central artery stiffness was measured by carotid-femoral pulse wave velocity (cfPWV). The WM diffusion metrics including fractional anisotropy (FA) and radial (RD) and axial (AD) diffusivities, BRS, and cfPWV were not different between the control and MCI groups. Thus, the data from both groups were combined for subsequent analyses. Across WM, fiber tracts with decreased FA and increased RD were associated with lower BRS and higher cfPWV, with many of the areas presenting spatial overlap. In particular, the BRS assessed during hypotension was strongly correlated with FA and RD when compared with hypertension. Executive function performance was associated with FA and RD in the areas that correlated with cfPWV and BRS. These findings suggest that baroreflex-mediated control of systemic arterial perfusion, especially during hypotension, may play a crucial role in maintaining neuronal fiber integrity of brain WM in older adults.

  4. Decreased elastic energy storage, not increased material stiffness, characterizes central artery dysfunction in fibulin-5 deficiency independent of sex.

    PubMed

    Ferruzzi, J; Bersi, M R; Uman, S; Yanagisawa, H; Humphrey, J D

    2015-03-01

    Central artery stiffness has emerged over the past 15 years as a clinically significant indicator of cardiovascular function and initiator of disease. Loss of elastic fiber integrity is one of the primary contributors to increased arterial stiffening in aging, hypertension, and related conditions. Elastic fibers consist of an elastin core and multiple glycoproteins; hence defects in any of these constituents can adversely affect arterial wall mechanics. In this paper, we focus on mechanical consequences of the loss of fibulin-5, an elastin-associated glycoprotein involved in elastogenesis. Specifically, we compared the biaxial mechanical properties of five central arteries-the ascending thoracic aorta, descending thoracic aorta, suprarenal abdominal aorta, infrarenal abdominal aorta, and common carotid artery-from male and female wild-type and fibulin-5 deficient mice. Results revealed that, independent of sex, all five regions in the fibulin-5 deficient mice manifested a marked increase in structural stiffness but also a marked decrease in elastic energy storage and typically an increase in energy dissipation, with all differences being most dramatic in the ascending and abdominal aortas. Given that the primary function of large arteries is to store elastic energy during systole and to use this energy during diastole to work on the blood, fibulin-5 deficiency results in a widespread diminishment of central artery function that can have significant effects on hemodynamics and cardiac function.

  5. Associations and clinical relevance of aortic-brachial artery stiffness mismatch, aortic reservoir function, and central pressure augmentation.

    PubMed

    Schultz, Martin G; Hughes, Alun D; Davies, Justin E; Sharman, James E

    2015-10-01

    Central augmentation pressure (AP) and index (AIx) predict cardiovascular events and mortality, but underlying physiological mechanisms remain disputed. While traditionally believed to relate to wave reflections arising from proximal arterial impedance (and stiffness) mismatching, recent evidence suggests aortic reservoir function may be a more dominant contributor to AP and AIx. Our aim was therefore to determine relationships among aortic-brachial stiffness mismatching, AP, AIx, aortic reservoir function, and end-organ disease. Aortic (aPWV) and brachial (bPWV) pulse wave velocity were measured in 359 individuals (aged 61 ± 9, 49% male). Central AP, AIx, and aortic reservoir indexes were derived from radial tonometry. Participants were stratified by positive (bPWV > aPWV), negligible (bPWV ≈ aPWV), or negative stiffness mismatch (bPWV < aPWV). Left-ventricular mass index (LVMI) was measured by two-dimensional-echocardiography. Central AP and AIx were higher with negative stiffness mismatch vs. negligible or positive stiffness mismatch (11 ± 6 vs. 10 ± 6 vs. 8 ± 6 mmHg, P < 0.001 and 24 ± 10 vs. 24 ± 11 vs. 21 ± 13%, P = 0.042). Stiffness mismatch (bPWV-aPWV) was negatively associated with AP (r = -0.18, P = 0.001) but not AIx (r = -0.06, P = 0.27). Aortic reservoir pressure strongly correlated to AP (r = 0.81, P < 0.001) and AIx (r = 0.62, P < 0.001) independent of age, sex, heart rate, mean arterial pressure, and height (standardized β = 0.61 and 0.12, P ≤ 0.001). Aortic reservoir pressure independently predicted abnormal LVMI (β = 0.13, P = 0.024). Positive aortic-brachial stiffness mismatch does not result in higher AP or AIx. Aortic reservoir function, rather than discrete wave reflection from proximal arterial stiffness mismatching, provides a better model description of AP and AIx and also has clinical relevance as evidenced by an independent association of aortic reservoir pressure with LVMI.

  6. Arterial stiffness in diabetes mellitus.

    PubMed

    Prenner, Stuart B; Chirinos, Julio A

    2015-02-01

    Arterial stiffness is an age-related process that is a shared consequence of numerous diseases including diabetes mellitus (DM), and is an independent predictor of mortality both in this population and in the general population. While much has been published about arterial stiffness in patients with DM, a thorough review of the current literature is lacking. Using a systematic literature search strategy, we aimed to summarize our current understanding related to arterial stiffness in DM. We review key studies demonstrating that, among patients with established DM, arterial stiffness is closely related to the progression of complications of DM, including nephropathy, retinopathy, and neuropathy. It is also becoming clear that arterial stiffness can be increased even in pre-diabetic populations with impaired glucose tolerance, and in those with the metabolic syndrome (METS), well before the onset of overt DM. Some data suggests that arterial stiffness can predict the onset of DM. However, future work is needed to further clarify whether large artery stiffness and the pulsatile hemodynamic changes that accompany it are involved in the pathogenesis of DM, and whether interventions targeting arterial stiffness are associated with improved clinical outcomes in DM. We also review of the potential mechanisms of arterial stiffness in DM, with particular emphasis on the role of advanced glycation endproducts (AGEs) and nitric oxide dysregulation, and address potential future directions for research.

  7. Arterial Stiffness: Recommendations and Standardization

    PubMed Central

    Townsend, Raymond R.

    2017-01-01

    The use of arterial stiffness measurements in longitudinal cohorts of normal populations, hypertensive patients, diabetic patients, healthy elderly, and patients on hemodialysis have confirmed the value of this important measure of arterial health, and established its complementary role to measures of blood pressure. Its contribution to understanding cardiovascular and mortality risk beyond blood pressure measurements has moved measures of arterial stiffness into the ranks of factors such as elevated cholesterol, diabetes, and left ventricular hypertrophy in considering cardiovascular risk. The recent international collaboration's publication of reference ranges for normal people and those with hypertension, along with the American Heart Association's recent scientific statement on standardizing arterial stiffness measurements are important aspects to consider in future studies employing these valuable methods, particularly as interventions that not only lower blood pressure but improve arterial function are tested in the clinical arena. PMID:28275588

  8. Comparison of the effects of antihypertensive agents on central blood pressure and arterial stiffness in isolated systolic hypertension.

    PubMed

    Mackenzie, Isla S; McEniery, Carmel M; Dhakam, Zahid; Brown, Morris J; Cockcroft, John R; Wilkinson, Ian B

    2009-08-01

    Isolated systolic hypertension is an important risk factor for cardiovascular disease and results primarily from elastic artery stiffening. Although various drug therapies are used to lower peripheral blood pressure (BP) in patients with isolated systolic hypertension, the effects of the 4 major classes of antihypertensive agents on central BP, pulse pressure (PP) amplification, and arterial stiffness in this condition are not clear. Fifty-nine patients over the age of 60 years with untreated isolated systolic hypertension (systolic BP > or =140 mm Hg and diastolic BP central PP was only reduced significantly by perindopril, lercanidipine, and bendrofluazide, whereas atenolol had no effect. Lercanidipine reduced the augmentation index, whereas atenolol increased it. Aortic pulse wave velocity was not changed by any of the drugs. In summary, despite similar reductions in peripheral systolic and PPs with the 4 classes of drug, changes in central pressure and augmentation index varied. Because central PP and increased wave reflections are considered important risk factors in patients with isolated systolic hypertension, the choice of therapy may be influenced by these findings in the future.

  9. Arterial Stiffness and Cardiovascular Therapy

    PubMed Central

    Janić, Miodrag; Lunder, Mojca; Šabovič, Mišo

    2014-01-01

    The world population is aging and the number of old people is continuously increasing. Arterial structure and function change with age, progressively leading to arterial stiffening. Arterial stiffness is best characterized by measurement of pulse wave velocity (PWV), which is its surrogate marker. It has been shown that PWV could improve cardiovascular event prediction in models that included standard risk factors. Consequently, it might therefore enable better identification of populations at high-risk of cardiovascular morbidity and mortality. The present review is focused on a survey of different pharmacological therapeutic options for decreasing arterial stiffness. The influence of several groups of drugs is described: antihypertensive drugs (angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, calcium channel blockers, beta-blockers, diuretics, and nitrates), statins, peroral antidiabetics, advanced glycation end-products (AGE) cross-link breakers, anti-inflammatory drugs, endothelin-A receptor antagonists, and vasopeptidase inhibitors. All of these have shown some effect in decreasing arterial stiffness. Nevertheless, further studies are needed which should address the influence of arterial stiffness diminishment on major adverse cardiovascular and cerebrovascular events (MACCE). PMID:25170513

  10. Epidemiology of the arterial stiffness.

    PubMed

    Breithaupt-Grögler, K; Belz, G G

    1999-06-01

    Aortic stiffening is as much an important risk factor in cardiovascular morbidity and mortality, as it serves as reliable surrogate marker for clinical endpoints like myocardial and cerebrovascular incidents. Elevated aortic stiffness induces high systolic blood pressure, augmented pulse pressure with increased ventricular afterload, reduced subendocardial blood flow and augmented pulsatile stress in the peripheral arteries. Factors with relevant impact on the epidemiology of arterial stiffness are widely spread. 3 major groups of parameters influencing the stiffness of the aorta and the large arteries have been studied and described up to now: (i) physiological properties like age, gender, body height, pressure, hormonal state, genetic factors; (ii) environmental factors like nutrition (fish-, salt-, garlic consumption), smoking, performance of sports and aerobic capacity; (iii) diseases like hypertension, hypercholesterolemia, diabetes, coronary heart disease, cerebrovascular disease, renal failure, Marfan-syndrome, growth hormone deficiency. Close association between several of these factors impedes analyzing them independently from each other. Age and blood pressure were found to be the most prominent predictors of arterial stiffness in normal as well as in disease populations. Physiological and environmental factors can modulate these effects of aging, diseases generally seem to amplify them.

  11. Relationships between HDL-C, hs-CRP, with Central Arterial Stiffness in Apparently Healthy People Undergoing a General Health Examination

    PubMed Central

    Fan, Li; Ye, Ping; Yuan, Ying; Lu, XueChun; Wang, Fan; Zeng, Qiang

    2013-01-01

    Background Some cardiovascular risk factors have been confirmed to be positively correlated with arterial stiffness. However, it is unclear whether HDL-C, a well-established anti-risk factor, has an independent association with arterial stiffness. The aim of this study was to evaluate the relationship between HDL-C levels and arterial stiffness and the possible role of high-sensitivity C-reactive protein (hs-CRP) in this potential correlation in apparently healthy adults undergoing a general health examination in China. Materials and Methods This was a cross-sectional survey. In total, 15,302 participants (age range, 18–82 years; mean, 43.88±8.44 years) were recruited during routine health status examinations. A questionnaire was used and we measured the body mass index, systolic and diastolic blood pressure, and fasting glucose, and serum lipid, uric acid, hs-CRP, and serum creatinine levels of each participant. Central arterial stiffness was assessed by carotid–femoral pulse wave velocity (cf-PWV). Results HDL-C levels decreased as cf-PWV increased. Pearson’s correlation analysis revealed that HDL-C levels were associated with cf-PWV (r=−0.18, P<0.001). hs-CRP levels were positively associated with cf-PWV (r=0.13). After adjustment for all confounders, HDL-C was inversely independently associated with all quartiles of cf-PWV. Furthermore, HDL-C was associated with cf-PWV in different quartiles of hs-CRP, and the correlation coefficients (r) gradually decreased with increasing hs-CRP levels (quartiles 1–4). Conclusions HDL-C is inversely independently associated with central arterial stiffness. The anti-inflammatory activity of HDL-C may mediate its relationship with cf-PWV. Further, long-term follow-up studies are needed to evaluate whether high HDL-C levels are protective against central artery stiffening through the anti-inflammatory activity of HDL-C. PMID:24312587

  12. Physical inactivity and arterial stiffness in COPD

    PubMed Central

    Sievi, Noriane A; Franzen, Daniel; Kohler, Malcolm; Clarenbach, Christian F

    2015-01-01

    Background Arterial stiffness is an important predictor of cardiovascular risk besides classic cardiovascular risk factors. Previous studies showed that arterial stiffness is increased in patients with COPD compared to healthy controls and exercise training may reduce arterial stiffness. Since physical inactivity is frequently observed in patients with COPD and exercise training may improve arterial stiffness, we hypothesized that low daily physical activity may be associated with increased arterial stiffness. Methods In 123 patients with COPD (72% men; mean [standard deviation] age: 62 [7.5] years; median [quartile] forced expiratory volume in 1 second 35 [27/65] %predicted), arterial stiffness was assessed by augmentation index (AI). Daily physical activity level (PAL) was measured by an activity monitor (SenseWear Pro™) >1 week. The association between AI and PAL was investigated by univariate and multivariate regression analysis, taking into account disease-specific characteristics and comorbidities. Results Patients suffered from moderate (35%), severe (32%), and very severe (33%) COPD, and 22% were active smokers. Median (quartile) PAL was 1.4 (1.3/1.5) and mean (standard deviation) AI 26% (9.2%). PAL showed a negative association with AI (B=−9.32, P=0.017) independent of age, sex, blood pressure, and airflow limitation. Conclusion In COPD patients, a higher PAL seems to favorably influence arterial stiffness and therefore may reduce cardiovascular risk. Clinical Trial Registration http://www.ClinicalTrials.gov, NCT01527773 PMID:26392763

  13. Large Artery Stiffness Assessment Using SphygmoCor Technology

    PubMed Central

    Butlin, Mark; Qasem, Ahmad

    2017-01-01

    Large artery stiffness assessment has been an integral part of the SphygmoCor technology since 1998. Aortic stiffness is approximated with non-invasive measurement of carotid-femoral pulse wave velocity, with improvements made with time to make the assessment procedure quicker and more user independent. Also standard in the devices is the ability to reliably calculate the central aortic waveform shape from a peripheral pressure waveform from either the brachial or radial artery. This waveform contains much information beyond peak and trough (systolic and diastolic pressure). Relative waveform features such as the augmentation index, wave reflection magnitude, reflection time index, and subendocardial viability ratio are parameters that are influenced by the stiffness of systemic arteries. This article briefly describes these parameters related to large artery stiffness and provides reference to validation and repeatability studies relative to the clinical use of the SphygmoCor devices. It is beyond the scope to review here the 424 original research articles that have employed SphygmoCor devices in measuring arterial stiffness. Instead, the method of measurement across the devices is described, including tonometry, volumetric displacement through cuff placement around limbs, and ambulatory monitoring. Key population and subpopulation studies are cited where the average stiffness parameter progression with age and gender, as measured by SphygmoCor devices, is quantified in the healthy and general population. Finally, with reference to guidelines from working groups on arterial stiffness and hypertension, the clinical utility of large artery stiffness measurement is discussed in the context of the arterial stiffness parameters provided by the SphygmoCor systems. PMID:28229053

  14. Angiotensin Receptor Blockades Effect on Peripheral Muscular and Central Aortic Arterial Stiffness: A Meta-Analysis of Randomized Controlled Trials and Systematic Review

    PubMed Central

    Yen, Chih-Hsuan; Lai, Yau-Huei; Hung, Chung-Lieh; Lee, Ping-Ying; Kuo, Jen-Yuan; Yeh, Hung-I; Hou, Charles Jia-Yin; Chien, Kuo-Liong

    2014-01-01

    Background Previous clinical trials have demonstrated the impact of blocking upstream renin-angiotensin-axis with angiotensin converting enzyme inhibitors (ACEIs) on arterial stiffness as evaluated by pulse-wave velocity (PWV). We ran a meta-analysis to evaluate the anti-stiffness effect of powerful downstream angiotensin receptor blockades (ARBs) on peripheral and central arterial stiffness (brachial to ankle, ba-PWV; carotid to femoral, cf-PWV, respectively), using a systematic review to assess the clinical arterial stiffness issues. Methods For our study, we searched the PubMed and Cochrane Library databases from inception to June 2013, targeting randomized controlled trials. ARBs along with other antihypertensive agents, ACEIs, calcium channel blockers (CCBs), beta-blockers and diuretics were evaluated to ascertain their comparable effect on ba-PWV and cf-PWV, respectively. A meta-analysis was conducted utilizing the fixed or random effect of the weighted mean change difference between the ARB and comparator groups, depending on the I2 statistic heterogeneity measurement. Results In 2 trials treating patients with ARBs (n = 30), the ARBs insignificantly reduced levels of ba-PWV (pooled mean change difference -188, 95% CI -687, 311, p = 0.24 with significant heterogeneity) as compared to other hypertensive agents (ACEIs and CCBs, n = 77). Interestingly, ARBs (n = 20) had a superior capacity to reduce levels of ba-PWV than CCBs (n = 20) in single study results (mean change difference -400, 95% CI -477, -322, p < 0.05). In 7 trials which included a total of 653 patients, treatment with ARBs (n = 308) also insignificantly reduced cf-PWV (pool mean change difference -0.197, 95% CI -0.54, 0.14, p = 0.218) as compared to other anti-hypertensive agents. Conclusions Our data suggested that ARBs had a similar effect as other anti-hypertensive agents in reducing ba-PWV and cf-PWV. Upon systematic review, the renin-angiotensin-axis system mechanism seems more significant

  15. Effect of A Reduction in glomerular filtration rate after NEphrectomy on arterial STiffness and central hemodynamics: Rationale and design of the EARNEST study☆

    PubMed Central

    Moody, William E.; Tomlinson, Laurie A.; Ferro, Charles J.; Steeds, Richard P.; Mark, Patrick B.; Zehnder, Daniel; Tomson, Charles R.; Cockcroft, John R.; Wilkinson, Ian B.; Townend, Jonathan N.

    2014-01-01

    Background There is strong evidence of an association between chronic kidney disease (CKD) and cardiovascular disease. To date, however, proof that a reduction in glomerular filtration rate (GFR) is a causative factor in cardiovascular disease is lacking. Kidney donors comprise a highly screened population without risk factors such as diabetes and inflammation, which invariably confound the association between CKD and cardiovascular disease. There is strong evidence that increased arterial stiffness and left ventricular hypertrophy and fibrosis, rather than atherosclerotic disease, mediate the adverse cardiovascular effects of CKD. The expanding practice of live kidney donation provides a unique opportunity to study the cardiovascular effects of an isolated reduction in GFR in a prospective fashion. At the same time, the proposed study will address ongoing safety concerns that persist because most longitudinal outcome studies have been undertaken at single centers and compared donor cohorts with an inappropriately selected control group. Hypotheses The reduction in GFR accompanying uninephrectomy causes (1) a pressure-independent increase in aortic stiffness (aortic pulse wave velocity) and (2) an increase in peripheral and central blood pressure. Methods This is a prospective, multicenter, longitudinal, parallel group study of 440 living kidney donors and 440 healthy controls. All controls will be eligible for living kidney donation using current UK transplant criteria. Investigations will be performed at baseline and repeated at 12 months in the first instance. These include measurement of arterial stiffness using applanation tonometry to determine pulse wave velocity and pulse wave analysis, office blood pressure, 24-hour ambulatory blood pressure monitoring, and a series of biomarkers for cardiovascular and bone mineral disease. Conclusions These data will prove valuable by characterizing the direction of causality between cardiovascular and renal disease. This

  16. Effect of whole-body mild-cold exposure on arterial stiffness and central haemodynamics: a randomised, cross-over trial in healthy men and women.

    PubMed

    King, Sibella G; Ahuja, Kiran D K; Wass, Jezreel; Shing, Cecilia M; Adams, Murray J; Davies, Justin E; Sharman, James E; Williams, Andrew D

    2013-05-01

    Aortic pulse wave velocity (PWV) and augmentation index (AIx) are independent predictors of cardiovascular risk and mortality, but little is known about the effect of air temperature changes on these variables. Our study investigated the effect of exposure to whole-body mild-cold on measures of arterial stiffness (aortic and brachial PWV), and on central haemodynamics [including augmented pressure (AP), AIx], and aortic reservoir components [including reservoir and excess pressures (P ex)]. Sixteen healthy volunteers (10 men, age 43 ± 19 years; mean ± SD) were randomised to be studied under conditions of 12 °C (mild-cold) and 21 °C (control) on separate days. Supine resting measures were taken at baseline (ambient temperature) and after 10, 30, and 60 min exposure to each experimental condition in a climate chamber. There was no significant change in brachial blood pressure between mild-cold and control conditions. However, compared to control, AP [+2 mmHg, 95 % confidence interval (CI) 0.36-4.36; p = 0.01] and AIx (+6 %, 95 % CI 1.24-10.1; p = 0.02) increased, and time to maximum P ex (a component of reservoir function related to timing of peak aortic in-flow) decreased (-7 ms, 95 % CI -15.4 to 2.03; p = 0.01) compared to control. Yet there was no significant change in aortic PWV (+0.04 m/s, 95 % CI -0.47 to 0.55; p = 0.87) or brachial PWV (+0.36 m/s; -0.41 to 1.12; p = 0.35) between conditions. We conclude that mild-cold exposure increases central haemodynamic stress and alters timing of peak aortic in-flow without differentially affecting arterial stiffness.

  17. Arterial stiffness: pathophysiology and clinical impact.

    PubMed

    London, Gérard M; Marchais, Sylvain J; Guerin, Alain P; Pannier, Bruno

    2004-01-01

    The ill effects of hypertension are usually attributed to a reduction in the caliber or the number of arterioles, resulting in an increase in total peripheral resistance (TPR). This definition does not take into account the fact that BP is a cyclic phenomenon with systolic and diastolic BP being the limits of these oscillations. The appropriate term to define the arterial factor(s) opposing LV ejection is aortic input impedance which depends on TPR, arterial distensibility (D), and wave reflections (WR). D defines the capacitive properties of arterial stiffness, whose role is to dampen pressure and flow oscillations and to transform pulsatile flow and pressure in arteries into a steady flow and pressure in peripheral tissues. Stiffness is the reciprocal value of D. These parameters are BP dependent, and arteries become stiffer at high pressure. In to D which provides information about the of artery as a hollow structure, the elastic incremental modulus (Einc) characterizes the properties of the arterial wall biomaterials, independently of vessel geometry. As an alternative, arterial D can be evaluated by measuring the pulse wave velocity (PWV) which increases with the stiffening of arteries. Arterial stiffening increases left ventricular (LV) afterload and alters the coronary perfusion. With increased PWV, the WR impacts on the aorta during systole, increasing systolic pressures and myocardial oxygen consumption, and decreasing diastolic BP and coronary flow. The arterial stiffness is altered primarily in association with increased collagen content and alterations of extracellular matrix (arteriosclerosis) as classically observed during aging or in arterial hypertension. The arterial stiffening estimated by changes in aortic PWV and intensity of WR are independent predictors of survival in end stage renal disease (ESRD) and general population. Improvement of arterial stiffening could be obtained by antihypertensive treatmen as observed with the calcium

  18. Arterial Stiffness in Nonhypertensive Type 2 Diabetes Patients in Ghana

    PubMed Central

    Antwi, Daniel A.; Gyan, Ben

    2016-01-01

    Background. Increased arterial stiffness is an independent cardiovascular risk factor in diabetes patients and general population. However, the contribution of diabetes to arterial stiffness is often masked by coexistent obesity and hypertension. In this study, we assessed arterial stiffness in nonhypertensive, nonobese type 2 diabetes (T2DM) patients in Ghana. Methods. In case-control design, 166 nonhypertensive, nonobese participants, comprising 96 T2DM patients and 70 nondiabetes controls, were recruited. Peripheral and central blood pressure (BP) indices were measured, and arterial stiffness was assessed as aortic pulse wave velocity (PWVao), augmentation index (AIx), cardioankle vascular index (CAVI), and heart-ankle pulse wave velocity (haPWV). Results. With similar peripheral and central BP indices, T2DM patients had higher PWVao (8.3 ± 1 versus 7.8 ± 1.3, p = 0.044) and CAVI (7.9 ± 1.2 versus 6.9 ± 0.7, p = 0.021) than nondiabetic control. AIx and haPWV were similar between T2DM and nondiabetic controls. Multiple regression models showed that, in the entire study participants, the major determinants of PWVao were diabetes status, age, gender, systolic BP, and previous smoking status (β = 0.22, 0.36, 0.48, 0.21, and 0.25, resp.; all p < 0.05); the determinants of CAVI were diabetes status, age, BMI, heart rate, HbA1c, total cholesterol, HDL cholesterol, and previous smoking status (β = 0.21, 0.38, 0.2, 0.18, 0.24. 0.2, −0.19, and 0.2, resp.; all p < 0.05). Conclusion. Our findings suggest that nonhypertensive, nonobese T2DM patients have increased arterial stiffness without appreciable increase in peripheral and central pressure indices. PMID:27774104

  19. Hypertension and arterial stiffness in heart transplantation patients

    PubMed Central

    de Souza-Neto, João David; de Oliveira, Ítalo Martins; Lima-Rocha, Hermano Alexandre; Oliveira-Lima, José Wellington; Bacal, Fernando

    2016-01-01

    OBJECTIVES: Post-transplantation hypertension is prevalent and is associated with increased cardiovascular morbidity and subsequent graft dysfunction. The present study aimed to identify the factors associated with arterial stiffness as measured by the ambulatory arterial stiffness index. METHODS: The current study used a prospective, observational, analytical design to evaluate a group of adult heart transplantation patients. Arterial stiffness was obtained by monitoring ambulatory blood pressure and using the ambulatory arterial stiffness index as the surrogate outcome. Multivariate logistic regression analyses were performed to control confounding. RESULTS: In a group of 85 adult heart transplantation patients, hypertension was independently associated with arterial stiffness (OR 4.98, CI 95% 1.06-23.4) as well as systolic and diastolic blood pressure averages and nighttime descent. CONCLUSIONS: Measurement of ambulatory arterial stiffness index is a new, non-invasive method that is easy to perform, may contribute to better defining arterial stiffness prognosis and is associated with hypertension. PMID:27652829

  20. Arterial stiffness profiles: investigating various sections of the arterial tree of African and Caucasian people.

    PubMed

    Schutte, Aletta E; Huisman, Hugo W; Schutte, Rudolph; Van Rooyen, Johannes M; Malan, Leoné; Malan, Nicolaas T; Reimann, Manja

    2011-01-01

    In Africans, arterial stiffness progression seems more pronounced compared to Caucasians. We compared the arterial stiffness profiles of different age groups and focused on muscular arteries and two more central arterial segments in African and Caucasian people from South Africa. In African (N = 374) and Caucasian (N = 376) participants (20-70 years), we measured carotid-radial (C-R) and carotid-dorsalis pedis (C-DP) pulse wave velocity (PWV) and aortic characteristic impedance (Zao). Major findings were that normotensive and high-normal/hypertensive (HT) Caucasians indicated increased trends of C-R PWV with aging (P = .029 and P = .067), not seen in the African groups (P = .122 and P = .526). Both ethnic groups showed significant increases of C-DP PWV and Zao with aging. High-normal/hypertensive Africans had significantly stiffer arteries than hypertensive Caucasians for almost all age groups, and for all stiffness measures. African C-R PWV correlated significantly with blood pressure (BP), but not with age. Opposite results were observed for Caucasians. In conclusion, the stiffness of muscular arteries is already elevated in young Africans, in both those with normal or elevated BP. This is possibly due to an earlier deterioration during childhood, or perhaps already present from birth. Also, in Caucasians stiffness seems more age-related, while in Africans it seems to be more pressure-related.

  1. Heart Rate Dependency of Large Artery Stiffness.

    PubMed

    Tan, Isabella; Spronck, Bart; Kiat, Hosen; Barin, Edward; Reesink, Koen D; Delhaas, Tammo; Avolio, Alberto P; Butlin, Mark

    2016-07-01

    Carotid-femoral pulse wave velocity (cfPWV) quantifies large artery stiffness, it is used in hemodynamic research and is considered a useful cardiovascular clinical marker. cfPWV is blood pressure (BP) dependent. Intrinsic heart rate (HR) dependency of cfPWV is unknown because increasing HR is commonly accompanied by increasing BP. This study aims to quantify cfPWV dependency on acute, sympathovagal-independent changes in HR, independent of BP. Individuals (n=52, age 40-93 years, 11 female) with in situ cardiac pacemakers or cardioverter defibrillators were paced at 60, 70, 80, 90, and 100 bpm. BP and cfPWV were measured at each HR. Both cfPWV (mean [95% CI], 0.31 [0.26-0.37] m/s per 10 bpm; P<0.001) and central aortic diastolic pressure (3.78 [3.40-4.17] mm Hg/10 bpm; P<0.001) increased with HR. The HR effect on cfPWV was isolated by correcting the BP effects by 3 different methods: (1) statistically, by a linear mixed model; (2) mathematically, using an exponential relationship between BP and cross-sectional lumen area; and (3) using measured BP dependency of cfPWV derived from changes in BP induced by orthostatic changes (seated and supine) in a subset of subjects (n=17). The BP-independent effects of HR on cfPWV were quantified as 0.20 [0.11-0.28] m/s per 10 bpm (P<0.001, method 1), 0.16 [0.11-0.22] m/s per 10 bpm (P<0.001, method 2), and 0.16 [0.11-0.21] m/s per 10 bpm (P<0.001, method 3). With a mean HR dependency in the range of 0.16 to 0.20 m/s per 10 bpm, cfPWV may be considered to have minimal physiologically relevant changes for small changes in HR, but larger differences in HR must be considered as contributing to significant differences in cfPWV.

  2. Physical exercise improves arterial stiffness after spinal cord injury

    PubMed Central

    Hubli, Michèle; Currie, Katharine D.; West, Christopher R.; Gee, Cameron M.; Krassioukov, Andrei V.

    2014-01-01

    Objective/background Aortic pulse wave velocity (PWV), the gold-standard assessment of central arterial stiffness, has prognostic value for cardiovascular disease risk in able-bodied individuals. The aim of this study was to compare aortic PWV in athletes and non-athletes with spinal cord injury (SCI). Design Cross-sectional comparison. Methods Aortic PWV was assessed in 20 individuals with motor-complete, chronic SCI (C2–T5; 18 ± 8 years post-injury) using applanation tonometry at the carotid and femoral arterial sites. Ten elite hand-cyclists were matched for sex to 10 non-athletes; age and time since injury were comparable between the groups. Heart rate and discrete brachial blood pressure measurements were collected throughout testing. Outcome measures Aortic PWV, blood pressure, heart rate. Results Aortic PWV was significantly lower in athletes vs. non-athletes (6.9 ± 1.0 vs. 8.7 ± 2.5 m/second, P = 0.044). There were no significant between-group differences in resting supine mean arterial blood pressure (91 ± 19 vs. 81 ± 10 mmHg) and heart rate (60 ± 10 vs. 58 ± 6 b.p.m.). Conclusion Athletes with SCI exhibited improved central arterial stiffness compared to non-athletes, which is in agreement with the previous able-bodied literature. This finding implies that chronic exercise training may improve arterial health and potentially lower cardiovascular disease risk in the SCI population. PMID:24976366

  3. Arterial Stiffness and Renal Replacement Therapy: A Controversial Topic

    PubMed Central

    Fischer, Edmundo Cabrera; Zócalo, Yanina; Galli, Cintia; Bia, Daniel

    2015-01-01

    The increase of arterial stiffness has been to have a significant impact on predicting mortality in end-stage renal disease patients. Pulse wave velocity (PWV) is a noninvasive, reliable parameter of regional arterial stiffness that integrates the vascular geometry and arterial wall intrinsic elasticity and is capable of predicting cardiovascular mortality in this patient population. Nevertheless, reports on PWV in dialyzed patients are contradictory and sometimes inconsistent: some reports claim the arterial wall stiffness increases (i.e., PWV increase), others claim that it is reduced, and some even state that it augments in the aorta while it simultaneously decreases in the brachial artery pathway. The purpose of this study was to analyze the literature in which longitudinal or transversal studies were performed in hemodialysis and/or peritoneal dialysis patients, in order to characterize arterial stiffness and the responsiveness to renal replacement therapy. PMID:26064684

  4. Hormones and arterial stiffness in patients with chronic kidney disease.

    PubMed

    Gungor, Ozkan; Kircelli, Fatih; Voroneanu, Luminita; Covic, Adrian; Ok, Ercan

    2013-01-01

    Cardiovascular disease constitutes the major cause of mortality in patients with chronic kidney disease. Arterial stiffness is an important contributor to the occurrence and progression of cardiovascular disease. Various risk factors, including altered hormone levels, have been suggested to be associated with arterial stiffness. Based on the background that chronic kidney disease predisposes individuals to a wide range of hormonal changes, we herein review the available data on the association between arterial stiffness and hormones in patients with chronic kidney disease and summarize the data for the general population.

  5. Estimation of Stiffness Parameter on the Common Carotid Artery

    NASA Astrophysics Data System (ADS)

    Koya, Yoshiharu; Mizoshiri, Isao; Matsui, Kiyoaki; Nakamura, Takashi

    The arteriosclerosis is on the increase with an aging or change of our living environment. For that reason, diagnosis of the common carotid artery using echocardiogram is doing to take precautions carebropathy. Up to the present, several methods to measure stiffness parameter of the carotid artery have been proposed. However, they have analyzed at the only one point of common carotid artery. In this paper, we propose the method of analysis extended over a wide area of common carotid artery. In order to measure stiffness parameter of common carotid artery from echocardiogram, it is required to detect two border curves which are boundaries between vessel wall and blood. The method is composed of two steps. The first step is the detection of border curves, and the second step is the calculation of stiffness parameter using diameter of common carotid artery. Experimental results show the validity of the proposed method.

  6. Gender Difference in Arterial Stiffness in a Multicenter Cross-Sectional Study: The Korean Arterial Aging Study (KAAS)

    PubMed Central

    Kim, Jang-Young; Park, Jeong Bae; Kim, Dong Soo; Kim, Kee Sik; Jeong, Jin Won; Park, Jong Chun; Oh, Byung Hee; Chung, Namsik

    2014-01-01

    Elevated arterial stiffness has emerged as an important risk factor for future cardiovascular (CV) events in men and women. However, gender-related differences in arterial stiffness have not been clearly demonstrated. We thus determine whether gender affects arterial stiffness in subjects with and without CV risk factors. We consecutively enrolled 1,588 subjects aged 17-87 years (mean age: 46.5; 51% women) from the Korean Arterial Aging Study (KAAS), which is a multicenter registry from 13 university hospitals in Korea for the evaluation of arterial stiffness. We compared markers of arterial stiffnesscentral augmentation index (AIx), aortic pulse wave velocity (PWV), and pulse pressure (PP) amplification – in apparently healthy men and women without risk factors with those in high-risk subjects with a smoking habit, hypertension, diabetes, and dyslipidemia but without drug treatment. Aortic PWV and PP amplification were significantly higher in men than in women (7.78 ± 1.16 vs. 7.64 ± 1.15 m/s, p = 0.015, and 1.39 ± 0.22 vs. 1.30 ± 0.18, p < 0.001, respectively). However, women had a significantly higher central AIx than men (23.5 ± 11.9 vs. 16.1 ± 12.6%, p < 0.001). The central AIx and aortic PWV values were significantly higher in the high-risk group than in the healthy group for both men and women. In men, central AIx and aortic PWV were associated positively with age and blood pressure, and negatively with body mass index. In women, central AIx was positively related to age, diastolic blood pressure, and serum cholesterol levels. Aortic PWV was positively related to age, systolic blood pressure, fasting glucose, and heart rate. PP amplification was associated negatively with age and blood pressure and positively with heart rate in both men and women. In conclusion, arterial stiffness is mainly determined by sex, age, and blood pressure. Markers of arterial stiffness differ between men and women. Dyslipidemia and glucose contribute to a modest

  7. Therapeutic modification of arterial stiffness: An update and comprehensive review

    PubMed Central

    Wu, Ching-Fen; Liu, Pang-Yen; Wu, Tsung-Jui; Hung, Yuan; Yang, Shih-Ping; Lin, Gen-Min

    2015-01-01

    Arterial stiffness has been recognized as a marker of cardiovascular disease and associated with long-term worse clinical outcomes in several populations. Age, hypertension, smoking, and dyslipidemia, known as traditional vascular risk factors, as well as diabetes, obesity, and systemic inflammation lead to both atherosclerosis and arterial stiffness. Targeting multiple modifiable risk factors has become the main therapeutic strategy to improve arterial stiffness in patients at high cardiovascular risk. Additionally to life style modifications, long-term ω-3 fatty acids (fish oil) supplementation in diet may improve arterial stiffness in the population with hypertension or metabolic syndrome. Pharmacological treatment such as renin-angiotensin-aldosterone system antagonists, metformin, and 3-hydroxy-3-methyl-glutaryl-CoA reductase inhibitors were useful in individuals with hypertension and diabetes. In obese population with obstructive sleep apnea, weight reduction, aerobic exercise, and continuous positive airway pressure treatment may also improve arterial stiffness. In the populations with chronic inflammatory disease such as rheumatoid arthritis, a use of antibodies against tumor necrosis factor-alpha could work effectively. Other therapeutic options such as renal sympathetic nerve denervation for patients with resistant hypertension are investigated in many ongoing clinical trials. Therefore our comprehensive review provides knowledge in detail regarding many aspects of pathogenesis, measurement, and management of arterial stiffness in several populations, which would be helpful for physicians to make clinical decision. PMID:26635922

  8. Crosstalk between oxidative and nitrosative stress and arterial stiffness.

    PubMed

    Mozos, Ioana; Luca, Constantin Tudor

    2017-02-01

    Arterial stiffness, the expression of reduced arterial elasticity, is an effective predictor of cardiovascular disorders. Oxidative stress is an imbalance between exposure to toxic reactive oxygen species (ROS) and antioxidant systems. The increase in reactive nitrogen species (RNS) is termed nitrosative stress. We review the main mechanisms and products linking arterial stiffness with oxidative and nitrosative stress in several disorders, focusing on recent experimental and clinical data, and the mechanisms explaining benefits of antioxidant therapy. Oxidative and nitrosative stress play important roles in arterial stiffness elevation in several disorders, including diabetes mellitus, hypertension, metabolic syndrome, obesity, peripheral arterial disease, chronic obstructive pulmonary disease, systemic lupus erythematosus, thalassemia, Kawasaki disease and malignant disorders. Oxidative and nitrosative stress are responsible for endothelial dysfunction due to uncoupling of the nitric oxide synthase, oxidative damage to lipids, proteins and DNA in vascular endothelial cells, associated with inflammation, arteriosclerosis and atherosclerosis. Regular physical exercise, caloric restriction, red wine, statins, sartans, metformin, oestradiol, curcumin and combinations of antioxidant vitamins are therapeutic strategies that may decrease arterial stiffness and oxidative stress thus reducing the risk of cardiovascular events. ROS and RNS represent potential therapeutic targets for preventing progression of arterial stiffness.

  9. Arterial Stiffness in the Young: Assessment, Determinants, and Implications

    PubMed Central

    2010-01-01

    Arterial stiffness describes the rigidity of the arterial wall. Its significance owes to its relationship with the pulsatile afterload presented to the left ventricle and its implications on ventricular-arterial coupling. In adults, the contention that arterial stiffness as a marker and risk factor for cardiovascular morbidity and mortality is gaining support. Noninvasive methods have increasingly been adopted in both the research and clinical arena to determine local, segmental, and systemic arterial stiffness in the young. With adoption of these noninvasive techniques for use in children and adolescents, the phenomenon and significance of arterial stiffening in the young is beginning to be unveiled. The list of childhood factors and conditions found to be associated with arterial stiffening has expanded rapidly over the last decade; these include traditional cardiovascular risk factors, prenatal growth restriction, vasculitides, vasculopathies associated with various syndromes, congenital heart disease, and several systemic diseases. The findings of arterial stiffening have functional implications on energetic efficiency, structure, and function of the left ventricle. Early identification of arterial dysfunction in childhood may provide a window for early intervention, although longitudinal studies are required to determine whether improvement of arterial function in normal and at-risk paediatric populations will be translated into clinical benefits. PMID:20421954

  10. Effect of acute aerobic exercise and histamine receptor blockade on arterial stiffness in African Americans and Caucasians.

    PubMed

    Yan, Huimin; Ranadive, Sushant M; Lane-Cordova, Abbi D; Kappus, Rebecca M; Behun, Michael A; Cook, Marc D; Woods, Jeffrey A; Wilund, Kenneth R; Baynard, Tracy; Halliwill, John R; Fernhall, Bo

    2017-02-01

    African Americans (AA) exhibit exaggerated central blood pressure (BP) and arterial stiffness measured by pulse wave velocity (PWV) in response to an acute bout of maximal exercise compared with Caucasians (CA). However, whether potential racial differences exist in central BP, elastic, or muscular arterial distensibility after submaximal aerobic exercise remains unknown. Histamine receptor activation mediates sustained postexercise hyperemia in CA but the effect on arterial stiffness is unknown. This study sought to determine the effects of an acute bout of aerobic exercise on central BP and arterial stiffness and the role of histamine receptors, in AA and CA. Forty-nine (22 AA, 27 CA) young and healthy subjects completed the study. Subjects were randomly assigned to take either histamine receptor antagonist or control placebo. Central blood BP and arterial stiffness measurements were obtained at baseline, and at 30, 60, and 90 min after 45 min of moderate treadmill exercise. AA exhibited greater central diastolic BP, elevated brachial PWV, and local carotid arterial stiffness after an acute bout of submaximal exercise compared with CA, which may contribute to their higher risk of cardiovascular disease. Unexpectedly, histamine receptor blockade did not affect central BP or PWV in AA or CA after exercise, but it may play a role in mediating local carotid arterial stiffness. Furthermore, histamine may mediate postexercise carotid arterial dilation in CA but not in AA. These observations provide evidence that young and healthy AA exhibit an exaggerated hemodynamic response to exercise and attenuated vasodilator response compared with CA.NEW & NOTEWORTHY African Americans are at greater risk for developing cardiovascular disease than Caucasians. We are the first to show that young and healthy African Americans exhibit greater central blood pressure, elevated brachial stiffness, and local carotid arterial stiffness following an acute bout of submaximal exercise

  11. Modifiable risk factors for increased arterial stiffness in outpatient nephrology.

    PubMed

    Elewa, Usama; Fernandez-Fernandez, Beatriz; Alegre, Raquel; Sanchez-Niño, Maria D; Mahillo-Fernández, Ignacio; Perez-Gomez, Maria Vanessa; El-Fishawy, Hussein; Belal, Dawlat; Ortiz, Alberto

    2015-01-01

    Arterial stiffness, as measured by pulse wave velocity (PWV), is an independent predictor of cardiovascular events and mortality. Arterial stiffness increases with age. However, modifiable risk factors such as smoking, BP and salt intake also impact on PWV. The finding of modifiable risk factors may lead to the identification of treatable factors, and, thus, is of interest to practicing nephrologist. We have now studied the prevalence and correlates of arterial stiffness, assessed by PWV, in 191 patients from nephrology outpatient clinics in order to identify modifiable risk factors for arterial stiffness that may in the future guide therapeutic decision-making. PWV was above normal levels for age in 85/191 (44.5%) patients. Multivariate analysis showed that advanced age, systolic BP, diabetes mellitus, serum uric acid and calcium polystyrene sulfonate therapy or calcium-containing medication were independent predictors of PWV. A new parameter, Delta above upper limit of normal PWV (Delta PWV) was defined to decrease the weight of age on PWV values. Delta PWV was calculated as (measured PWV) - (upper limit of the age-adjusted PWV values for the general population). Mean±SD Delta PWV was 0.76±1.60 m/sec. In multivariate analysis, systolic blood pressure, active smoking and calcium polystyrene sulfonate therapy remained independent predictors of higher delta PWV, while age, urinary potassium and beta blocker therapy were independent predictors of lower delta PWV. In conclusion, arterial stiffness was frequent in nephrology outpatients. Systolic blood pressure, smoking, serum uric acid, calcium-containing medications, potassium metabolism and non-use of beta blockers are modifiable factors associated with increased arterial stiffness in Nephrology outpatients.

  12. Children and Adolescent Obesity Associates with Pressure-Dependent and Age-Related Increase in Carotid and Femoral Arteries' Stiffness and Not in Brachial Artery, Indicative of Nonintrinsic Arterial Wall Alteration

    PubMed Central

    García-Espinosa, Victoria; Curcio, Santiago; Castro, Juan Manuel; Arana, Maite; Giachetto, Gustavo; Chiesa, Pedro; Zócalo, Yanina

    2016-01-01

    Aim. To analyze if childhood obesity associates with changes in elastic, transitional, and/or muscular arteries' stiffness. Methods. 221 subjects (4–15 years, 92 females) were assigned to normal weight (NW, n = 137) or obesity (OB, n = 84) groups, considering their body mass index z-score. Age groups were defined: 4–8; 8–12; 12–15 years old. Carotid, femoral, and brachial artery local stiffness was determined through systodiastolic pressure-diameter and stress-strain relationships. To this end, arterial diameter and peripheral and aortic blood pressure (BP) levels and waveforms were recorded. Carotid-femoral, femoropedal, and carotid-radial pulse wave velocities were determined to evaluate aortic, lower-limb, and upper-limb regional arterial stiffness, respectively. Correlation analysis between stiffness parameters and BP was done. Results. Compared to NW, OB subjects showed higher peripheral and central BP and carotid and femoral stiffness, reaching statistical significance in subjects aged 12 and older. Arterial stiffness differences disappeared when levels were normalized for BP. There were no differences in intrinsic arterial wall stiffness (elastic modulus), BP stiffness relationships, and regional stiffness parameters. Conclusion. OB associates with BP-dependent and age-related increase in carotid and femoral (but not brachial) stiffness. Stiffness changes would not be explained by intrinsic arterial wall alterations but could be associated with the higher BP levels observed in obese children. PMID:27066273

  13. A systematic review on the effect of acute aerobic exercise on arterial stiffness reveals a differential response in the upper and lower arterial segments.

    PubMed

    Mutter, Andrew F; Cooke, Alexandra B; Saleh, Olivier; Gomez, Yessica-Haydee; Daskalopoulou, Stella S

    2017-02-01

    The objective of this systematic review was to provide insight into the controversy that still abounds as to the impact of acute aerobic exercise on immediate changes in arterial stiffness. Electronic databases were searched to identify articles assessing the effects of acute aerobic exercise on parameters of arterial stiffness. Eligible studies included arterial stiffness measurements before and after acute aerobic exercise in healthy human subjects. Forty-three studies were included. The effect of acute aerobic exercise on arterial stiffness was found to be dependent on the anatomical segment assessed, and on the timing of the measurement post-exercise. Arterial stiffness of the central and upper body peripheral arterial segments was found to be increased relative to resting values immediately post-exercise (0-5 min), whereas, thereafter (>5 min), decreased to a level at or below resting values. In the lower limbs, proximal to the primary working muscles, arterial stiffness decreased immediately post-exercise (0-5 min), which persisted into the recovery period post-exercise (>5 min). This systematic review reveals a differential response to acute exercise in the lower and upper/central arterial segments in healthy adult subjects. We further showed that the effect of acute aerobic exercise on arterial stiffness is dependent on the timing of the measurements post-exercise. Therefore, when assessing the overall impact of exercise on arterial stiffness, it is important to consider the arterial segment being analyzed and measurement time point, as failure to contextualize the measurement can lead to conflicting results and misleading clinical inferences.

  14. Cardiovascular Health and Arterial Stiffness: The Maine Syracuse Longitudinal Study

    PubMed Central

    Crichton, Georgina E; Elias, Merrill F; Robbins, Michael A

    2014-01-01

    Ideal cardiovascular health is a recently defined construct by the American Heart Association (AHA) to promote cardiovascular disease reduction. Arterial stiffness is a major risk factor for cardiovascular disease. The extent to which the presence of multiple prevalent cardiovascular risk factors and health behaviors is associated with arterial stiffness is unknown. The aim of this study was to examine the association between the AHA construct of cardiovascular health and arterial stiffness, as indexed by pulse wave velocity and pulse pressure. The AHA health metrics, comprising of four health behaviors (smoking, body mass index, physical activity, and diet) and three health factors (total cholesterol, blood pressure, and fasting plasma glucose) were evaluated among 505 participants in the Maine-Syracuse Longitudinal Study. Outcome measures were carotid-femoral pulse wave velocity (PWV) and pulse pressure measured at 4 to 5-year follow-up. Better cardiovascular health, comprising both health factors and behaviors, was associated with lower arterial stiffness, as indexed by pulse wave velocity and pulse pressure. Those with at least five health metrics at ideal levels had significantly lower PWV (9.8 m/s) than those with two or less ideal health metrics (11.7 m/s) (P<0.001). This finding remained with the addition of demographic and PWV-related variables (P=0.004). PMID:24384629

  15. Arterial stiffness and inflammatory response to psychophysiological stress.

    PubMed

    Ellins, Elizabeth; Halcox, Julian; Donald, Ann; Field, Bryony; Brydon, Lena; Deanfield, John; Steptoe, Andrew

    2008-08-01

    The processes through which psychological stress influences cardiovascular disease are poorly understood, but may involve activation of hemodynamic, neuroendocrine and inflammatory responses. We assessed the relationship between carotid arterial stiffness and inflammatory responses to acute psychophysiologic stress. Participants were 155 healthy men and women aged 55.3, SD 2.7 years. Blood samples for the assessment of plasma fibrinogen, tumor necrosis factor (TNF) alpha and interleukin (IL) 6 were drawn at baseline, immediately following standardized behavioral tasks, and 45 min later. Carotid artery stiffness was measured ultrasonically three years later, and blood pressure and heart rate responses were recorded. The tasks induced substantial increases in blood pressure and heart rate, together with increased fibrinogen, TNFalpha and IL-6 concentration. Carotid stiffness was positively associated with body mass, waist/hip ratio, blood pressure, low density lipoprotein cholesterol, and C-reactive protein, and inversely with high density lipoprotein and grade of employment. Baseline levels of inflammatory variables were not related to carotid artery stiffness. But carotid stiffness was greater in participants with larger fibrinogen (p=0.037) and TNFalpha (p=0.036) responses to psychophysiological stress. These effects were independent of age, gender, grade of employment, smoking, body mass, waist/hip ratio, systolic and diastolic pressure, high and low density lipoprotein cholesterol, and C-reactive protein. There were no associations between carotid stiffness and stress responses in IL-6, blood pressure, or heart rate. We conclude that individual differences in inflammatory responses to psychophysiological stress are independently related to structural changes in artery walls that reflect increased cardiovascular disease risk.

  16. Effect of Simvastatin on Arterial Stiffness in Patients with Statin Myalgia

    PubMed Central

    Ballard, Kevin D.; Lorson, Lindsay; White, C. Michael; Thompson, Paul D.; Taylor, Beth A.

    2015-01-01

    Statins reduce arterial stiffness but are also associated with mild muscle complaints. It is unclear whether individuals with muscle symptoms experience the same vascular benefit or whether statins affect striated and smooth muscle cells differently. We examined the effect of simvastatin treatment on arterial stiffness in patients who did versus those who did not exhibit muscle symptoms. Patients with a history of statin-related muscle complaints (n = 115) completed an 8 wk randomized, double-blind, cross-over trial of daily simvastatin 20 mg and placebo. Serum lipids and pulse wave velocity (PWV) were assessed before and after each treatment. Muscle symptoms with daily simvastatin treatment were reported by 38 patients (33%). Compared to baseline, central PWV decreased (P = 0.01) following simvastatin treatment but not placebo (drug ∗ time interaction: P = 0.047). Changes in central PWV with simvastatin treatment were not influenced by myalgia status or time on simvastatin (P ≥ 0.15). Change in central PWV after simvastatin treatment was inversely correlated with age (r = −0.207, P = 0.030), suggesting that advancing age is associated with enhanced statin-mediated arterial destiffening. In patients with a history of statin-related muscle complaints, the development of myalgia with short-term simvastatin treatment did not attenuate the improvement in arterial stiffness. PMID:26257959

  17. Effect of upper body aerobic exercise on arterial stiffness in older adults.

    PubMed

    Aizawa, Kunihiko; Mendelsohn, Marissa E; Overend, Tom J; Petrella, Robert J

    2009-10-01

    The authors evaluated the effects of acute arm-cycling exercise on arterial stiffness of the brachial artery (BA: working limb) and posterior tibial artery (PTA: nonworking limb) in healthy older participants. Eleven participants were tested to evaluate BA and PTA stiffness. Blood pressure (BP), heart rate (HR), and arterial stiffness indices of the BA and PTA measured by Doppler ultrasound were determined before and 10 min after graded arm-cycling exercise to volitional fatigue on 2 separate days. After the exercise, although BA diameter, brachial systolic BP, pulse pressure, and HR increased significantly (all p < .05), arterial stiffness indices of the BA remained unchanged. Similarly, arterial stiffness indices of the PTA remained unchanged after the exercise, whereas HR increased significantly (p < .05). These results show that acute arm-cycling exercise failed to modify arterial stiffness of the BA and PTA, suggesting that it has no systemic effect on arterial stiffness in healthy older adults.

  18. Pulmonary Function and Arterial Stiffness in Chronic Heart Failure

    PubMed Central

    Hu, Bangchuan; Gong, Shijin; Yu, Yihua; Dai, Haiwen

    2016-01-01

    Arterial stiffness contributes to heart failure and is decreased by angiotensin receptor blockers (ARBs). This cross-sectional study aimed to assess associations of lung function and ARB with arterial stiffness in patients with chronic heart failure. 354 outpatients (168 males; 186 females; 68.2 ± 7.2 years old) with chronic heart failure were evaluated. Lung function parameters, including forced vital capacity (FVC), forced expiratory volume in 1 s (FEV1), and FEV1 to FVC ratio (FEV1/FVC), were assessed. The cardio-ankle vascular index (CAVI) was used to estimate arterial stiffness. Unadjusted correlation analyses revealed a positive association of CAVI with ARB but not ACEI, and a negative correlation with FEV1 (r = −0.2987, p < 0.0001). Multiple stepwise regression analyses showed that ARB and FEV1 (p < 0.0001) were independent predicting factors for CAVI. These findings suggest that reduced pulmonary function is associated with increased CAVI. Pulmonary function protection could be used to improve the prognosis in heart failure, but additional studies are necessary. PMID:28097138

  19. Effects of safflower seed extract on arterial stiffness.

    PubMed

    Suzuki, Katsuya; Tsubaki, Shigekazu; Fujita, Masami; Koyama, Naoto; Takahashi, Michio; Takazawa, Kenji

    2010-11-03

    Safflower seed extract (SSE) contains characteristic polyphenols and serotonin derivatives (N-( p-coumaroyl) serotonin and N-feruloylserotonin), which are reported to inhibit oxidation of low-density lipoprotein (LDL), formation of atherosclerotic plaques, and improve arterial stiffness as assessed by pulse wave analysis in animal models. The effects of long-term supplementation with SSE on arterial stiffness in human subjects were evaluated. This doubleblind, placebo-controlled study was conducted in 77 males (35-65 years) and 15 postmenopausal females (55-65 years) with high-normal blood pressure or mild hypertension who were not undergoing treatment. Subjects received SSE (70 mg/day as serotonin derivatives) or placebo for 12 weeks, and pulse wave measurements, ie, second derivative of photoplethysmogram (SDPTG), augmentation index, and brachial-ankle pulse wave velocity (baPWV) were conducted at baseline, and at weeks 4, 8, and 12. Vascular age estimated by SDPTG aging index improved in the SSE-supplemented group when compared with the placebo group at four (P = 0.0368) and 12 weeks (P = 0.0927). The trend of augmentation index reduction (P = 0.072 versus baseline) was observed in the SSE-supplemented group, but reduction of baPWV by SSE supplementation was not observed. The SSE-supplemented group also showed a trend towards a lower malondialdehyde-modified-LDL autoantibody titer at 12 weeks from baseline. These results suggest long-term ingestion of SSE in humans could help to improve arterial stiffness.

  20. Arterial Stiffness, Oxidative Stress, and Smoke Exposure in Wildland Firefighters

    PubMed Central

    Gaughan, Denise M.; Siegel, Paul D.; Hughes, Michael D.; Chang, Chiung-Yu; Law, Brandon F.; Campbell, Corey R.; Richards, Jennifer C.; Kales, Stefanos F.; Chertok, Marcia; Kobzik, Lester; Nguyen, Phuongson; O’Donnell, Carl R.; Kiefer, Max; Wagner, Gregory R.; Christiani, David C.

    2015-01-01

    Objectives To assess the association between exposure, oxidative stress, symptoms, and cardiorespiratory function in wildland firefighters. Methods We studied two Interagency Hotshot Crews with questionnaires, pulse wave analysis for arterial stiffness, spirometry, urinary 8-iso-prostaglandin F2α (8-isoprostane) and 8-hydroxy-2′-deoxyguanosine (8-OHdG), and the smoke exposure marker (urinary levoglucosan). Arterial stiffness was assessed by examining levels of the aortic augmentation index, expressed as a percentage. An oxidative stress score comprising the average of z-scores created for 8-OHdG and 8-isoprostane was calculated. Results Mean augmentation index % was higher for participants with higher oxidative stress scores after adjusting for smoking status. Specifically for every one unit increase in oxidative stress score the augmentation index % increased 10.5% (95% CI: 2.5, 18.5%). Higher mean lower respiratory symptom score was associated with lower percent predicted forced expiratory volume in one second/forced vital capacity. Conclusions Biomarkers of oxidative stress may serve as indicators of arterial stiffness in wildland firefighters. PMID:24909863

  1. Arterial Stiffness is Associated with Increase in Blood Pressure Over Time in Treated Hypertensives

    PubMed Central

    Coutinho, T; Bailey, KR; Turner, ST; Kullo, IJ

    2014-01-01

    Background Arterial stiffness is associated with incident hypertension. We hypothesized that arterial stiffness would predict increases in systolic (SBP), mean (MAP) and pulse pressure (PP) over time in treated hypertensives. Methods Blood pressure (BP) was measured a mean of 8.5±0.9 years apart in 414 non-Hispanic white hypertensives (mean age 60±8 years, 55% women). The average of 3 supine right brachial BPs was recorded. Measures of arterial stiffness including carotid-femoral pulse wave velocity (cfPWV), aortic augmentation index (AIx) and central pulse pressure (CPP) were obtained at baseline by applanation tonometry. We performed stepwise multivariable linear regression analyses adjusting for potential confounders to assess the associations of arterial stiffness parameters with BP changes over time. Results Systolic, mean and pulse pressure increased in 80% of participants. After adjustment for the covariates listed above, cfPWV was significantly associated with increases in SBP (β±SE: 0.71±0.31) and PP (β±SE: 1.09±0.27); AIx was associated with increases in SBP (β±SE: 0.23±0.10) and MAP (β±SE: 0.27±0.07); and CPP was associated with increases in SBP (β±SE: 0.44±0.07), MAP (β±SE: 0.24±0.05) and PP (β±SE: 0.42±0.06) over time (P≤0.02 for all). Conclusions Baseline arterial stiffness measures were associated with longitudinal increases in SBP, MAP and PP in treated hypertensives. PMID:24952654

  2. Aerobic, resistance and combined exercise training on arterial stiffness in normotensive and hypertensive adults: A review.

    PubMed

    Li, Yanlei; Hanssen, Henner; Cordes, Mareike; Rossmeissl, Anja; Endes, Simon; Schmidt-Trucksäss, Arno

    2015-01-01

    Exercise training has different effects on arterial stiffness according to training modalities. The optimal exercise modality for improvement of arterial function in normotensive and hypertensive individuals has not been well established. In this review, we aim to evaluate the effects of aerobic, resistance and combined aerobic and resistance training on arterial stiffness in individuals with and without hypertension. We systematically searched the Pubmed and Web of Science database from 1985 until December 2013 for relevant randomised controlled trials (RCTs). The data were extracted by one investigator and checked by a second investigator. The training effects on arterial stiffness were estimated using weighted mean differences of the relative changes (%) with 95% confidence intervals (CIs). We finally reviewed the results from 17 RCTs. The available evidence indicates that aerobic exercise tends to have a beneficial effect on arterial stiffness in normotensive and hypertensive patients, but does not affect arterial stiffness in patients with isolated systolic hypertension. Resistance exercise has differing effects on arterial stiffness depending on type and intensity. Vigorous resistance training is associated with an increase in arterial stiffness. There seem to be no unfavourable effects on arterial stiffness if the training is of low intensity, in a slow eccentric manner or with lower limb in healthy individuals. Combined training has neutral or even a beneficial effect on arterial stiffness. In conclusion, our review shows that exercise training has varying effects on arterial stiffness depending on the exercise modalities.

  3. Relation of arterial stiffness with gestational age and birth weight

    PubMed Central

    Cheung, Y; Wong, K; Lam, B.; Tsoi, N

    2004-01-01

    Background: The cardiovascular risk of individuals who are born small as a result of prematurity remains controversial. Given the previous findings of stiffer peripheral conduit arteries in growth restricted donor twins in twin–twin transfusion syndrome regardless of gestational age, we hypothesised that among children born preterm, only those with intrauterine growth retardation are predisposed to an increase in cardiovascular risks. Aim: To compare brachioradial arterial stiffness and systemic blood pressure (BP) among children born preterm and small for gestational age (group 1, n = 15), those born preterm but having birth weight appropriate for gestational age (group 2, n = 36), and those born at term with birth weight appropriate for gestational age (group 3, n = 35). Methods: Systemic BP was measured by an automated device (Dinamap), while stiffness of the brachioradial arterial segment was assessed by measuring pulse wave velocity (PWV). The birth weight was adjusted for gestational age and expressed as a z score for analysis. Results: The 86 children were studied at a mean (SD) age of 8.2 (1.7) years. Subjects from group 1, who were born at 32.3 (2.0) weeks' gestation had a significantly lower z score of birth weight (-2.29 (0.63), p<0.001), compared with those from groups 2 and 3. They had a significantly higher mean blood pressure (p<0.001) and their diastolic blood pressure also tended to be higher (p = 0.07). Likewise, their brachioradial PWV, and hence arterial stiffness, was the highest of the three groups (p<0.001). While subjects from group 2 were similarly born preterm, their PWV was not significantly different from that of group 3 subjects (p = 1.00) and likewise their z score of birth weight did not differ (-0.01 (0.71) v -0.04 (1.1), p = 1.00). Brachioradial PWV correlated significantly with systolic (r = 0.31, p = 0.004), diastolic (r = 0.38, p<0.001), and mean (0.47, p<0.001) BP, and with z score of birth weight (r = -0.43, p<0

  4. Increased arterial stiffness in South Dakota American Indian children.

    PubMed

    Litz, Andrew M; Van Guilder, Gary P

    2016-02-01

    Arterial stiffness has been observed in white American obese children, yet there are no data in American Indian youth, who are affected disproportionately by the cardiovascular consequences of childhood obesity and its accompanying risk factors. The purpose of this study was to determine the association of childhood overweight-obesity and cardiometabolic risk factors with arterial stiffness in South Dakota white American and American Indian children. Thirty-six (28 white American and 8 American Indian) children (age, 13 ± 1 years; grades 6-8) from a rural South Dakota elementary and middle school were studied: 18 had a healthy weight (body mass index (BMI), 19.5 ± 1.9 kg/m(2)) and 18 were overweight-obese (BMI, 26.8 ± 3.5 kg/m(2)). Arterial stiffness was assessed using applanation tonometry via pulse wave analysis to determine carotid-radial pulse wave velocity (crPWV) and aortic augmentation index (AIx). There were no differences (P = 0.94) in crPWV between healthy weight (7.1 ± 1.4 m/s) and overweight-obese (7.3 ± 1.0 m/s) children, even after controlling for risk factors. However, crPWV was markedly elevated (P = 0.002) in overweight-obese American Indian children (7.7 ± 1.1 m/s) compared with white American children (6.8 ± 0.5 m/s), and these differences remained after controlling for blood pressure and more severe obesity in the American Indians. An obesity-matched subgroup analysis indicated that crPWV (7.7 ± 1.1 vs 6.8 ± 0.4 m/s) remained significantly greater in the American Indians (P = 0.03). There were no between-group differences in aortic AIx. These findings indicate an adverse influence of American Indian ethnicity on arterial stiffening in children with elevated adiposity. Arterial stiffness in American Indian children may accelerate early adulthood vascular disease.

  5. Effect of passive heat stress on arterial stiffness in smokers versus non-smokers.

    PubMed

    Moyen, N E; Ganio, M S; Burchfield, J M; Tucker, M A; Gonzalez, M A; Dougherty, E K; Robinson, F B; Ridings, C B; Veilleux, J C

    2016-04-01

    In non-smokers, passive heat stress increases shear stress and vasodilation, decreasing arterial stiffness. Smokers, who reportedly have arterial dysfunction, may have similar improvements in arterial stiffness with passive heat stress. Therefore, we examined the effects of an acute bout of whole-body passive heat stress on arterial stiffness in smokers vs. non-smokers. Thirteen smokers (8.8 ± 5.5 [median = 6] cigarettes per day for > 4 years) and 13 non-smokers matched for age, mass, height, and exercise habits (27 ± 8 years; 78.8 ± 15.4 kg; 177.6 ± 6.7 cm) were passively heated to 1.5 °C core temperature (T C) increase. At baseline and each 0.5 °C T C increase, peripheral (pPWV) and central pulse wave velocity (cPWV) were measured via Doppler ultrasound. No differences existed between smokers and non-smokers for any variables (all p >  .05), except cPWV slightly increased from baseline (526.7 ± 81.7 cm · s(-1)) to 1.5 °C ΔT C (579.7 ± 69.8 cm · s(-1); p < 0.005), suggesting heat stress acutely increased central arterial stiffness. pPWV did not change with heating (grand mean: baseline = 691.9 ± 92.9 cm · s(-1); 1.5 °C ΔT C = 691.9 ± 79.5 cm · s(-1); p > 0.05). Changes in cPWV and pPWV during heating correlated (p < 0.05) with baseline PWV in smokers (cPWV: r = -0.59; pPWV: r = -0.62) and non-smokers (cPWV: r = -0.45; pPWV: r = -0.77). Independent of smoking status, baseline stiffness appears to mediate the magnitude of heating-induced changes in arterial stiffness.

  6. Effect of passive heat stress on arterial stiffness in smokers versus non-smokers

    NASA Astrophysics Data System (ADS)

    Moyen, N. E.; Ganio, M. S.; Burchfield, J. M.; Tucker, M. A.; Gonzalez, M. A.; Dougherty, E. K.; Robinson, F. B.; Ridings, C. B.; Veilleux, J. C.

    2016-04-01

    In non-smokers, passive heat stress increases shear stress and vasodilation, decreasing arterial stiffness. Smokers, who reportedly have arterial dysfunction, may have similar improvements in arterial stiffness with passive heat stress. Therefore, we examined the effects of an acute bout of whole-body passive heat stress on arterial stiffness in smokers vs. non-smokers. Thirteen smokers (8.8 ± 5.5 [median = 6] cigarettes per day for >4 years) and 13 non-smokers matched for age, mass, height, and exercise habits (27 ± 8 years; 78.8 ± 15.4 kg; 177.6 ± 6.7 cm) were passively heated to 1.5 °C core temperature ( T C) increase. At baseline and each 0.5 °C T C increase, peripheral (pPWV) and central pulse wave velocity (cPWV) were measured via Doppler ultrasound. No differences existed between smokers and non-smokers for any variables (all p > 0.05), except cPWV slightly increased from baseline (526.7 ± 81.7 cm · s-1) to 1.5 °C Δ T C (579.7 ± 69.8 cm · s-1; p < 0.005), suggesting heat stress acutely increased central arterial stiffness. pPWV did not change with heating (grand mean: baseline = 691.9 ± 92.9 cm · s-1; 1.5 °C Δ T C = 691.9 ± 79.5 cm · s-1; p > 0.05). Changes in cPWV and pPWV during heating correlated ( p < 0.05) with baseline PWV in smokers (cPWV: r = -0.59; pPWV: r = -0.62) and non-smokers (cPWV: r = -0.45; pPWV: r = -0.77). Independent of smoking status, baseline stiffness appears to mediate the magnitude of heating-induced changes in arterial stiffness.

  7. Arterial Stiffness in Patients Taking Second-generation Antipsychotics

    PubMed Central

    Fındıklı, Ebru; Gökçe, Mustafa; Nacitarhan, Vedat; Camkurt, Mehmet Akif; Fındıklı, Hüseyin Avni; Kardaş, Selçuk; Şahin, Merve Coşgun; Karaaslan, Mehmet Fatih

    2016-01-01

    Objective That treatment with second-generation antipsychotics (SGAs) causes metabolic side effects and atherosclerosis in patients with schizophrenia and bipolar disorder (BD) is well-known. Increased arterial stiffness is an important marker of arteriosclerosis and has been identified as an independent risk factor for cardiovascular diseases. We measured pulse wave velocity (PWV) as a marker of arteriosclerosis in patients with schizophrenia and BD who use SGAs. Methods Patients and controls were collected from our psychiatry outpatient clinics or family medicine. Mental illness was diagnosed according to the Diagnostic and Statistical Manual of Mental Disorders, 4th edition. Mean age, gender, systolic and diastolic blood pressure, body mass index, Framingham risk score (FRS), etc. were determined. Simultaneous electrocardiography and pulse wave were recorded with an electromyography device. The photo-plethysmographic method was used to record the pulse wave. Inclusion criteria included use of SGAs for at least the last six months. Patients with diseases that are known to cause stiffness and the use of typical antipsychotics were excluded. Results Ninety-six subject (56 patients, 40 controls) were included in our study. There were 49 females, 47 males. Patients had schizophrenia (n=17) and BD (n=39). Their treatments were quetiapine (n=15), risperidone (n=13), olanzapine (n=15), and aripiprazole (n=13). Although differences in mean age, gender, and FRS in the patient and control groups were not statistically significant (p=1), PWV was greater in patients in the antipsychotic group (p=0.048). Conclusion This study supported the liability to stiffness in patients with schizophrenia and BD. Using SGAs may contribute to arterial stiffness in these patients. PMID:27776389

  8. Habitual cocoa intake reduces arterial stiffness in postmenopausal women regardless of intake frequency: a randomized parallel-group study

    PubMed Central

    Okamoto, Takanobu; Kobayashi, Ryota; Natsume, Midori; Nakazato, Koichi

    2016-01-01

    Arterial stiffness is substantially higher in postmenopausal than in premenopausal women. Daily cocoa intake has been shown to reduce central arterial stiffness in health adults, regardless of age; however, the effect of cocoa-intake frequency on arterial stiffness in postmenopausal women remains unclear. Therefore, the purpose of this study was to investigate the effects of cocoa-intake frequency on arterial stiffness in postmenopausal women. A total of 26 postmenopausal women (mean age ± standard deviation 64±12 years) were randomly assigned to two groups with different cocoa-intake frequencies: one group ingested 17 g of cocoa once daily except on Sundays (every-day group, n=13), and the other ingested 17 g of cocoa twice daily every other day (every-other-day group, n=13). These intake regimens were maintained in both groups for 12 weeks. Carotid–femoral pulse-wave velocity and femoral–ankle pulse-wave velocity were measured in both groups at baseline and again at the end of the 12-week study period. Compared to baseline, both pulse-wave velocities had significantly decreased after the 12-week study period in both groups (P<0.05). However, no significant difference in degree of change was observed between the two groups. Although this study did not include a sedentary control group, these results suggest that regardless of frequency, habitual cocoa intake reduces central and peripheral arterial stiffness in postmenopausal women. PMID:27881914

  9. Habitual cocoa intake reduces arterial stiffness in postmenopausal women regardless of intake frequency: a randomized parallel-group study.

    PubMed

    Okamoto, Takanobu; Kobayashi, Ryota; Natsume, Midori; Nakazato, Koichi

    2016-01-01

    Arterial stiffness is substantially higher in postmenopausal than in premenopausal women. Daily cocoa intake has been shown to reduce central arterial stiffness in health adults, regardless of age; however, the effect of cocoa-intake frequency on arterial stiffness in postmenopausal women remains unclear. Therefore, the purpose of this study was to investigate the effects of cocoa-intake frequency on arterial stiffness in postmenopausal women. A total of 26 postmenopausal women (mean age ± standard deviation 64±12 years) were randomly assigned to two groups with different cocoa-intake frequencies: one group ingested 17 g of cocoa once daily except on Sundays (every-day group, n=13), and the other ingested 17 g of cocoa twice daily every other day (every-other-day group, n=13). These intake regimens were maintained in both groups for 12 weeks. Carotid-femoral pulse-wave velocity and femoral-ankle pulse-wave velocity were measured in both groups at baseline and again at the end of the 12-week study period. Compared to baseline, both pulse-wave velocities had significantly decreased after the 12-week study period in both groups (P<0.05). However, no significant difference in degree of change was observed between the two groups. Although this study did not include a sedentary control group, these results suggest that regardless of frequency, habitual cocoa intake reduces central and peripheral arterial stiffness in postmenopausal women.

  10. The effects of single hemodialysis session on arterial stiffness in hemodialysis patients.

    PubMed

    Öğünç, Handan; Akdam, Hakan; Alp, Alper; Gencer, Fatih; Akar, Harun; Yeniçerioğlu, Yavuz

    2015-07-01

    Increased arterial stiffness in hemodialysis patients is a strong predictor of cardiovascular morbidity and mortality. Pulse wave velocity (PWV) and augmentation index (AIx), which are markers of arterial stiffness, were used to determine the severity of vascular damage noninvasively. This study aimed to investigate the effects of solute volume removal and hemodynamic changes on PWV and AIx of a single hemodialysis session. Thirty hemodialysis patients were enrolled in the study. Before initiation of hemodialysis, every 15 minutes during hemodialysis, and 30 minutes after the completion of the session, measurements of PWV and AIx@75 (normalized with heart rate 75 bpm) were obtained from each patient. Body composition was analyzed by bioimpedance spectroscopy device before and 30 minutes after completion of the hemodialysis session. During the hemodialysis, no significant change was observed in AIx@75. However, PWV decreased steadily during the session reaching statistically significant level at 135th minute (P = 0.026), with a maximal drop at 210th minute (P < 0.001). At 210th minute, decrease in PWV correlated positively with the decrease in central systolic blood pressure, central diastolic blood pressure, central pulse pressure, augmentation pressure, and AIx@75. Multiple regression analysis showed that decrease in PWV at 210th minute was associated with decrease in central systolic blood pressure and central pulse pressure. Ultrafiltration during hemodialysis had no significant effect on PWV and AIx@75. Delta urea correlated positively with delta PWV at 240th minute. A significant decrease in PWV was observed during hemodialysis and correlated with urea reduction; however, we were unable to document any effect of volume removal on arterial stiffness.

  11. Blood pressure and arterial stiffness in obese children and adolescents.

    PubMed

    Hvidt, Kristian Nebelin

    2015-03-01

    Obesity, elevated blood pressure (BP) and arterial stiffness are risk factors for cardiovascular disease. A strong relationship exists between obesity and elevated BP in both children and adults. Obesity and elevated BP in childhood track into adult life increasing the risk of cardiovascular disease in adulthood. Ambulatory BP is the most precise measure to evaluate the BP burden, whereas carotid-femoral pulse wave velocity (cfPWV) is regarded as the gold standard for evaluating arterial (i.e. aortic) stiffness. These measures might contribute to a better understanding of obesity's adverse impact on the cardiovascular system, and ultimately a better prevention and treatment of childhood obesity. The overall aim of the present PhD thesis is to investigate arterial stiffness and 24-hour BP in obese children and adolescents, and evaluate whether these measures are influenced by weight reduction. The present PhD thesis is based on four scientific papers.  In a cross-sectional design, 104 severe obese children and adolescents with an age of 10-18 years were recruited when newly referred to the Children's Obesity Clinic, Holbæk University Hospital, and compared to 50 normal weighted age and gender matched control individuals. Ambulatory BP was measured, and cfPWV was investigated in two ways in respect to the distance measure of aorta; the previously recommended length - the so called subtracted distance, and the currently recommended length - the direct distance. In a longitudinal design, the obese patients were re-investigated after one-year of lifestyle intervention at the Children's Obesity Clinic in purpose of reducing the degree of obesity. In the cross-sectional design, the obese group had higher measures of obesity, while matched for age, gender and height, when compared to the control group. In the longitudinal design, 74% of the 72 followed up obese patients experienced a significant weight reduction. CfPWV was dependent on the method used to measure the

  12. Aerobic exercise training increases plasma Klotho levels and reduces arterial stiffness in postmenopausal women.

    PubMed

    Matsubara, Tomoko; Miyaki, Asako; Akazawa, Nobuhiko; Choi, Youngju; Ra, Song-Gyu; Tanahashi, Koichiro; Kumagai, Hiroshi; Oikawa, Satoshi; Maeda, Seiji

    2014-02-01

    The Klotho gene is a suppressor of the aging phenomena, and the secretion as well as the circulation of Klotho proteins decrease with aging. Although habitual exercise has antiaging effects (e.g., a decrease in arterial stiffness), the relationship between Klotho and habitual exercise remains unclear. In the present study, we investigated the effect of habitual exercise on Klotho, with a particular focus on arterial stiffness. First, we examined the correlation between plasma Klotho concentration and arterial stiffness (carotid artery compliance and β-stiffness index) or aerobic exercise capacity [oxygen uptake at ventilatory threshold (VT)] in 69 healthy, postmenopausal women (50-76 years old) by conducting a cross-sectional study. Second, we tested the effects of aerobic exercise training on plasma Klotho concentrations and arterial stiffness. A total of 19 healthy, postmenopausal women (50-76 years old) were divided into two groups: control group and exercise group. The exercise group completed 12 wk of moderate aerobic exercise training. In the cross-sectional study, plasma Klotho concentrations positively correlated with carotid artery compliance and VT and negatively correlated with the β-stiffness index. In the interventional study, aerobic exercise training increased plasma Klotho concentrations and carotid artery compliance and decreased the β-stiffness index. Moreover, the changes in plasma Klotho concentration and arterial stiffness were found to be correlated. These results suggest a possible role for secreted Klotho in the exercise-induced modulation of arterial stiffness.

  13. Acute effects of submaximal endurance training on arterial stiffness in healthy middle- and long-distance runners.

    PubMed

    Müller, Jan; Wilms, Michael; Oberhoffer, Renate

    2015-05-01

    Measures of arterial stiffness are indicators for cardiovascular health and predictors of cardiovascular events. Arterial stiffness is responsive to acute physiologic stressors such as exercise. However, the acute effects of intensive exercise and recovery on arterial stiffness are controversial. Thirty-seven healthy middle- and long-distance runners (33 men, mean age 26.5±6.6 years) underwent evaluation of their cardiovascular stiffness at rest, after a 15-minute warm-up, immediately after vigorous running 3 km at the pace of their 10-km personal best, and finally 30 minutes after terminating their workout. Peripheral and central systolic blood pressure, as well as augmentation index and pulse wave velocity (PWV), increased during exercise in comparison to baseline (P<.001, general linear model). Thirty minutes after terminating the workout, a drop in peripheral blood pressure (P<.001), central blood pressure (P<.001), and PWV (P=.001) below baseline was observed. Therefore, the authors found that exercise of either moderate or vigorous intensity causes a temporary increase in arterial stiffness in middle- and long-distance runners.

  14. The role of pulmonary arterial stiffness in COPD

    PubMed Central

    Weir-McCall, Jonathan R.; Struthers, Allan D.; Lipworth, Brian J.; Houston, J. Graeme

    2015-01-01

    COPD is the second most common cause of pulmonary hypertension, and is a common complication of severe COPD with significant implications for both quality of life and mortality. However, the use of a rigid diagnostic threshold of a mean pulmonary arterial pressure (mPAP) of ≥25mHg when considering the impact of the pulmonary vasculature on symptoms and disease is misleading. Even minimal exertion causes oxygen desaturation and elevations in mPAP, with right ventricular hypertrophy and dilatation present in patients with mild to moderate COPD with pressures below the threshold for diagnosis of pulmonary hypertension. This has significant implications, with right ventricular dysfunction associated with poorer exercise capability and increased mortality independent of pulmonary function tests. The compliance of the pulmonary artery (PA) is a key component in decoupling the right ventricle from the pulmonary bed, allowing the right ventricle to work at maximum efficiency and protecting the microcirculation from large pressure gradients. PA stiffness increases with the severity of COPD, and correlates well with the presence of exercise induced pulmonary hypertension. A curvilinear relationship exists between PA distensibility and mPAP and pulmonary vascular resistance (PVR) with marked loss of distensibility before a rapid rise in mPAP and PVR occurs with resultant right ventricular failure. This combination of features suggests PA stiffness as a promising biomarker for early detection of pulmonary vascular disease, and to play a role in right ventricular failure in COPD. Early detection would open this up as a potential therapeutic target before end stage arterial remodelling occurs. PMID:26095859

  15. Cardiac Organ Damage and Arterial Stiffness in Autonomic Failure: Comparison With Essential Hypertension.

    PubMed

    Milazzo, Valeria; Maule, Simona; Di Stefano, Cristina; Tosello, Francesco; Totaro, Silvia; Veglio, Franco; Milan, Alberto

    2015-12-01

    Autonomic failure (AF) is characterized by orthostatic hypotension, supine hypertension, and increased blood pressure (BP) variability. AF patients develop cardiac organ damage, similarly to essential hypertension (EH), and have higher arterial stiffness than healthy controls. Determinants of cardiovascular organ damage in AF are not well known: both BP variability and mean BP values may be involved. The aim of the study was to evaluate cardiac organ damage, arterial stiffness, and central hemodynamics in AF, compared with EH subjects with similar 24-hour BP and a group of healthy controls, and to evaluate determinants of target organ damage in patients with AF. Twenty-seven patients with primary AF were studied (mean age, 65.7±11.2 years) using transthoracic echocardiography, carotid-femoral pulse wave velocity, central hemodynamics, and 24-hour ambulatory BP monitoring. They were compared with 27 EH subjects matched for age, sex, and 24-hour mean BP and with 27 healthy controls. AF and EH had similar left ventricular mass (101.6±33.3 versus 97.7±28.1 g/m(2), P=0.59) and carotid-femoral pulse wave velocity (9.3±1.8 versus 9.2±3.0 m/s, P=0.93); both parameters were significantly lower in healthy controls (P<0.01). Compared with EH, AF patients had higher augmentation index (31.0±7.6% versus 26.1±9.2%, P=0.04) and central BP values. Nighttime systolic BP and 24-hour systolic BP predicted organ damage, independent of BP variability. AF patients develop hypertensive heart disease and increased arterial stiffness, similar to EH with comparable mean BP values. Twenty-four-hour and nighttime systolic BP were determinants of cardiovascular damage, independent of BP variability.

  16. A Review of Genetics, Arterial Stiffness, and Blood Pressure in African Americans

    PubMed Central

    Hall, Jennifer L.; Duprez, Daniel A.; Barac, Ana; Rich, Stephen S.

    2012-01-01

    The prevalence of hypertension in African Americans in the United States is amongst the highest in the world and increasing. The identification of genes and pathways regulating blood pressure in African Americans has been challenging. An early predictor of hypertension is arterial stiffness. The prevalence of arterial stiffness is significantly higher in African Americans compared to Caucasians. Approximately 20% of the variance in arterial stiffness is estimated to be heritable. Identifying genes and biological pathways regulating arterial stiffness may provide insight into the genetics underlying the increased risk of hypertension in African Americans. This paper reviews the genetic findings to date in the area of arterial stiffness and blood pressure in African Americans with an emphasis on the current limitations and new efforts to move the field forward. PMID:22492025

  17. Torque-stiffness-controlled dynamic walking with central pattern generators.

    PubMed

    Huang, Yan; Vanderborght, Bram; Van Ham, Ronald; Wang, Qining

    2014-12-01

    Walking behavior is modulated by controlling joint torques in most existing passivity-based bipeds. Controlled Passive Walking with adaptable stiffness exhibits controllable natural motions and energy efficient gaits. In this paper, we propose torque-stiffness-controlled dynamic bipedal walking, which extends the concept of Controlled Passive Walking by introducing structured control parameters and a bio-inspired control method with central pattern generators. The proposed walking paradigm is beneficial in clarifying the respective effects of the external actuation and the internal natural dynamics. We present a seven-link biped model to validate the presented walking. Effects of joint torque and joint stiffness on gait selection, walking performance and walking pattern transitions are studied in simulations. The work in this paper develops a new solution of motion control of bipedal robots with adaptable stiffness and provides insights of efficient and sophisticated walking gaits of humans.

  18. Add-on therapy with doxazosin in patients with hypertension influences arterial stiffness and albuterol-mediated arterial vasodilation

    PubMed Central

    Wykretowicz, Andrzej; Guzik, Przemyslaw; Krauze, Tomasz; Adamska, Karolina; Milewska, Agata; Wysocki, Henryk

    2007-01-01

    What is already known about this subject Hypertension is associated with increased arterial stiffness and impaired endothelial function. Arterial vasodilation depends on endothelial function and can be regulated by β2-adrenergic stimulation. Doxazosin is a known and potent antihypertensive agent. However, its effects on arterial stiffness and vasodilation have not been fully established. What this study adds Sixteen-week add-on antihypertensive therapy with 4 mg of doxazosin extended release daily: Reduces arterial stiffness. Improves albuterol-mediated, i.e. endothelium-dependent, arterial vasodilation. Does not influence nitroglycerin-mediated, i.e. endothelium-independent, arterial vasodilation. Aims Doxazosin is an antihypertensive agent with largely unknown effects on arterial stiffness and vasodilation. The aim of this study was to determine the effect of the addition of doxazosin extended-release (ER) to the standard management of hypertension in patients with inadequately controlled blood pressure (BP) on arterial stiffness and arterial vasodilation. Methods Twenty patients with inadequately controlled hypertension were treated with 4 mg doxazosin ER daily for 16 weeks as an adjunct to their existing antihypertensive regimen. Results Doxazosin ER add-on therapy was associated with significantly reduced systolic (P < 0.0001) and diastolic (P = 0.0003) BP, improved arterial stiffness (determined by digital volume pulse analysis (P = 0.048) and albuterol-mediated arterial vasodilation (P = 0.030). Conclusions Add-on therapy with 4 mg of doxazosin ER daily reduces BP and arterial stiffness and improves arterial vasodilation in response to adrenergic stimulation. PMID:17635498

  19. Cerebral Small Vessel Disease and Arterial Stiffness: Tsunami Effect in the Brain?

    PubMed Central

    Saji, Naoki; Toba, Kenji; Sakurai, Takashi

    2016-01-01

    Background Cerebral small vessel diseases, including silent lacunar infarcts, white matter hyperintensities, and microbleeds, pose a risk for cerebrovascular disease, cognitive impairment, and the geriatric syndrome via effects on arterial stiffness. However, the vascular, physiological, and metabolic roles of arterial stiffness in cerebral small vessel diseases remain unclear. Summary Arterial stiffness can be assessed using various indicators such as the ankle-brachial index, pulse wave velocity, cardio-ankle vascular index, and augmentation index. Arterial stiffness is independently associated with all components of cerebral small vessel disease including silent lacunar infarcts, white matter hyperintensities, and microbleeds, although there are some methodological differences between the various surrogate markers. Evidence of arterial stiffness indicates microvessel arteriosclerosis presenting with vascular endothelial dysfunction. Further, vascular narrowing due to atherosclerosis and vascular stiffness due to lipohyalinosis can accelerate the pulse waves. This hemodynamic stress, pulsatile pressure, or blood pressure variability can cause a ‘tsunami effect’ towards the cerebral parenchyma and lead to cerebral small vessel disease. Previous studies have shown that silent lacunar infarcts and white matter hyperintensities are strongly associated with arterial stiffness. However, the association between microbleeds and arterial stiffness remains controversial, as there are two vessel mechanisms related to microbleeds: cerebral amyloid angiopathy and hypertensive small vessel disease. Key Messages Cerebral small vessel disease with associated arterial stiffness is a risk factor for silent cerebral lesions, stroke, and cognitive impairment. Improvement of the living environment, management of risk factors, and innovation and development of novel drugs that improve arterial stiffness may suppress the progression of cerebral small vessel disease, and may reduce

  20. Arterial pressure measurement: Is the envelope curve of the oscillometric method influenced by arterial stiffness?

    NASA Astrophysics Data System (ADS)

    Gelido, G.; Angiletta, S.; Pujalte, A.; Quiroga, P.; Cornes, P.; Craiem, D.

    2007-11-01

    Measurement of peripheral arterial pressure using the oscillometric method is commonly used by professionals as well as by patients in their homes. This non invasive automatic method is fast, efficient and the required equipment is affordable with a low cost. The measurement method consists of obtaining parameters from a calibrated decreasing curve that is modulated by heart beats witch appear when arterial pressure reaches the cuff pressure. Diastolic, mean and systolic pressures are obtained calculating particular instants from the heart beats envelope curve. In this article we analyze the envelope of this amplified curve to find out if its morphology is related to arterial stiffness in patients. We found, in 33 volunteers, that the envelope waveform width correlates to systolic pressure (r=0.4, p<0.05), to pulse pressure (r=0.6, p<0.05) and to pulse pressure normalized to systolic pressure (r=0.6, p<0.05). We believe that the morphology of the heart beats envelope curve obtained with the oscillometric method for peripheral pressure measurement depends on arterial stiffness and can be used to enhance pressure measurements.

  1. Surrogates of Large Artery versus Small Artery Stiffness and Ankle-Brachial Index

    PubMed Central

    Korhonen, Päivi; Syvänen, Kari; Aarnio, Pertti

    2011-01-01

    Peripheral artery tonometry (PAT) is a novel method for assessing arterial stiffness of small digital arteries. Pulse pressure can be regarded as a surrogate of large artery stiffness. When ankle-brachial index (ABI) is calculated using the higher of the two ankle systolic pressures as denominator (ABI-higher), leg perfusion can be reliably estimated. However, using the lower of the ankle pressures to calculate ABI (ABI-lower) identifies more patients with isolated peripheral arterial disease (PAD) in ankle arteries. We aimed to compare the ability of PAT, pulse pressure, and different calculations of ABI to detect atherosclerotic disease in lower extremities. We examined PAT, pulse pressure, and ABI in 66 cardiovascular risk subjects in whom borderline PAD (ABI 0.91 to 1.00) was diagnosed 4 years earlier. Using ABI-lower to diagnose PAD yielded 2-fold higher prevalence of PAD than using ABI-higher. Endothelial dysfunction was diagnosed in 15/66 subjects (23%). In a bivariate correlation analysis, pulse pressure was negatively correlated with ABI-higher (r = −0.347, p = 0.004) and with ABI-lower (r = −0.424, p < 0.001). PAT hyperemic response was not significantly correlated with either ABI-higher (r = −0.148, p = 0.24) or with ABI-lower (r = −0.208, p = 0.095). Measurement of ABI using the lower of the two ankle pressures is an efficient method to identify patients with clinical or subclinical atherosclerosis and worth performing on subjects with pulse pressure above 65 mm Hg. The usefulness of PAT measurement in detecting PAD is vague. PMID:22942632

  2. Arterial stiffness and sedentary lifestyle: Role of oxidative stress.

    PubMed

    Lessiani, Gianfranco; Santilli, Francesca; Boccatonda, Andrea; Iodice, Pierpaolo; Liani, Rossella; Tripaldi, Romina; Saggini, Raoul; Davì, Giovanni

    2016-04-01

    Sedentary lifestyle is a risk factor for the development of cardiovascular disease, and leads to a quantifiable impairment in vascular function and arterial wall stiffening. We tested the hypothesis of oxidative stress as a determinant of arterial stiffness (AS) in physically inactive subjects, and challenged the reversibility of these processes after the completion of an eight-week, high-intensity exercise training (ET). AS was assessed before and after ET, measuring carotid to femoral pulse wave velocity (PWV) with a Vicorder device. At baseline and after ET, participants performed urine collection and underwent fasting blood sampling. Urinary 8-iso-PGF2α, an in vivo marker of lipid peroxidation, total, HDL and LDL cholesterol, and triglyceride concentrations were measured. ET was associated with significantly reduced urinary 8-iso-PGF2α(p<0.0001) levels. PWV was significantly reduced after ET completion (p<0.0001), and was directly related to urinary 8-iso-PGF2α(Rho=0.383, p=0.021). After ET, cardiovascular fitness improved [peak oxygen consumption (p<0.0001), peak heart rate (p<0.0001)]. However, no improvement in lipid profile was observed, apart from a significant reduction of triglycerides (p=0.022). PWV and triglycerides were significantly related (Rho=0.466, p=0.005) throughout the study period. PWV levels were also related to urinary 8-iso-PGF2α in our previously sedentary subjects. We conclude that regular physical exercise may be a natural antioxidant strategy, lowering oxidant stress and thereby the AS degree.

  3. Stiffness Indices and Fractal Dimension relationship in Arterial Pressure and Diameter Time Series in-Vitro

    NASA Astrophysics Data System (ADS)

    Cymberknop, L.; Legnani, W.; Pessana, F.; Bia, D.; Zócalo, Y.; Armentano, R. L.

    2011-12-01

    The advent of vascular diseases, such as hypertension and atherosclerosis, is associated to significant alterations in the physical properties of arterial vessels. Evaluation of arterial biomechanical behaviour is related to the assessment of three representative indices: arterial compliance, arterial distensibility and arterial stiffness index. Elasticity is the most important mechanical property of the arterial wall, whose natures is strictly non-linear. Intervention of elastin and collagen fibres, passive constituent elements of the arterial wall, is related to the applied wall stress level. Concerning this, appropriate tools are required to analyse the temporal dynamics of the signals involved, in order to characterize the whole phenomenon. Fractal geometry can be mentioned as one of those techniques. The aim of this study consisted on arterial pressure and diameter signals processing, by means of nonlinear techniques based on fractal geometry. Time series morphology was related to different arterial stiffness states, generated by means of blood flow variations, during experiences performed in vitro.

  4. Acute effects of firefighting on arterial stiffness and blood flow.

    PubMed

    Fahs, Christopher A; Yan, Huimin; Ranadive, Sushant; Rossow, Lindy M; Agiovlasitis, Stamatis; Echols, George; Smith, Denise; Horn, Gavin P; Rowland, Thomas; Lane, Abbi; Fernhall, Bo

    2011-04-01

    Sudden cardiac events are responsible for 40-50% of line-of-duty firefighter fatalities, yet the exact cause of these events is unknown. Likely, combinations of thermal, physical, and mental factors impair cardiovascular function and trigger such events. Therefore, the purpose of this study was to examine the impact of firefighting activities on vascular function. Sixty-nine young (28 ± 1 years) male firefighters underwent 3 hours of firefighting activities. Carotid, aortic, and brachial blood pressures (BP), heart rate (HR), augmentation index (AIx), wave reflection timing (TR), aortic pulse wave velocity (PWV), forearm blood flow (FBF), and forearm reactive hyperemia (RH) were measured before and after firefighting activities. Paired samples t-tests revealed significant (p < 0.05) increases in aortic diastolic BP, HR, AIx, PWV, RH, and FBF, and significant decreases in brachial and aortic pulse pressure and TR following firefighting activities. In conclusion, these results suggest that 3 hours of firefighting activities increase both arterial stiffness and vasodilation.

  5. Pulmonary Arterial Stiffness: Toward a New Paradigm in Pulmonary Arterial Hypertension Pathophysiology and Assessment.

    PubMed

    Schäfer, Michal; Myers, Cynthia; Brown, R Dale; Frid, Maria G; Tan, Wei; Hunter, Kendall; Stenmark, Kurt R

    2016-01-01

    Stiffening of the pulmonary arterial bed with the subsequent increased load on the right ventricle is a paramount feature of pulmonary hypertension (PH). The pathophysiology of vascular stiffening is a complex and self-reinforcing function of extracellular matrix remodeling, driven by recruitment of circulating inflammatory cells and their interactions with resident vascular cells, and mechanotransduction of altered hemodynamic forces throughout the ventricular-vascular axis. New approaches to understanding the cell and molecular determinants of the pathophysiology combine novel biopolymer substrates, controlled flow conditions, and defined cell types to recapitulate the biomechanical environment in vitro. Simultaneously, advances are occurring to assess novel parameters of stiffness in vivo. In this comprehensive state-of-art review, we describe clinical hemodynamic markers, together with the newest translational echocardiographic and cardiac magnetic resonance imaging methods, to assess vascular stiffness and ventricular-vascular coupling. Finally, fluid-tissue interactions appear to offer a novel route of investigating the mechanotransduction processes and disease progression.

  6. Assessment of Arterial Stiffness, Volume, and Nutritional Status in Stable Renal Transplant Recipients

    PubMed Central

    Czyzewski, Lukasz; Wyzgal, Janusz; Czyzewska, Emilia; Kurowski, Andrzej; Sierdzinski, Janusz; Truszewski, Zenon; Szarpak, Lukasz

    2016-01-01

    Abstract Reduction of cardiovascular death might have a significant effect on the long-term survival rates of renal transplant recipients (RTRs). The aim of the study was to assess the relation between arterial stiffness and graft function, adipose tissue content, and hydration status in patients after kidney transplantation (KTx). The study included 83 RTR patients (mean age: 55 ± 13 years) who had been admitted to a nephrology-transplantation outpatient clinic 0.5 to 24 years after KTx. Clinical and laboratory data were analyzed and eGFR was calculated with the CKD-EPI formula. Arterial stiffness was assessed in all RTRs with pulse wave propagation velocity (PWV) with the use of a complior device. In addition, fluid and nutritional status was assessed with a Tanita BC 418 body composition analyzer. The control group consisted of 31 hospital workers who received no medication and had no history of cardiovascular disease. Multivariable linear regression analysis, with PWV as a dependent variable, retained the following independent predictors in the final regression model: red blood cell distribution width (RDW) (B = 0.323; P = 0.004), age (B = 0.297; P = 0.005), tacrolimus therapy (B = −0.286; P = 0.004), and central DBP (B = 0.185; P = 0.041). Multivariable linear regression analysis with eGFR as a dependent variable retained the following independent predictors in the final regression model; creatinine concentration (B = −0.632; P = 0.000), hemoglobin (B = 0.280; P = 0.000), CRP (B = −0.172; P = 0.011), tacrolimus therapy (B = 0.142; P = 0.039), and triglycerides (B = −0.142; P = 0.035). Our data indicates that: kidney transplant recipients can present modifiable CVD risk factors linked to increased arterial stiffness, DBP, waist circumference, SCr, time on dialysis, CyA therapy, and visceral fat mass; RDW is a parameter associated with arterial stiffness; and parameters such as

  7. A knowledge-based approach to arterial stiffness estimation using the digital volume pulse.

    PubMed

    Jang, Dae-Geun; Farooq, Umar; Park, Seung-Hun; Goh, Choong-Won; Hahn, Minsoo

    2012-08-01

    We have developed a knowledge based approach for arterial stiffness estimation. The proposed new approach reliably estimates arterial stiffness based on the analysis of age and heart rate normalized reflected wave arrival time. The proposed new approach reduces cost, space, technical expertise, specialized equipment, complexity, and increases the usability compared to recently researched noninvasive arterial stiffness estimators. The proposed method consists of two main stages: pulse feature extraction and linear regression analysis. The new approach extracts the pulse features and establishes a linear prediction equation. On evaluating proposed methodology with pulse wave velocity (PWV) based arterial stiffness estimators, the proposed methodology offered the error rate of 8.36% for men and 9.52% for women, respectively. With such low error rates and increased benefits, the proposed approach could be usefully applied as low cost and effective solution for ubiquitous and home healthcare environments.

  8. Clinical appraisal of arterial stiffness: the Argonauts in front of the Golden Fleece

    PubMed Central

    Vlachopoulos, C; Aznaouridis, K; Stefanadis, C

    2006-01-01

    Interest in evaluating arterial elastic properties has grown in parallel with the widespread availability of non‐invasive methods for assessing arterial stiffness. A clinically useful diagnostic index must be pathophysiologically relevant, must be readily measurable, and must indicate the severity of the disease and predict the corresponding risk. Interventional modification of this index must parallel disease regression and benefit prognosis. The current evidence for the clinical value of estimating arterial stiffness (mainly of large, elastic‐type arteries, such as the aorta and the carotids) in the contemporary era of cardiovascular medicine is reviewed. PMID:16339817

  9. Clinical appraisal of arterial stiffness: the Argonauts in front of the Golden Fleece.

    PubMed

    Vlachopoulos, C; Aznaouridis, K; Stefanadis, C

    2006-11-01

    Interest in evaluating arterial elastic properties has grown in parallel with the widespread availability of non-invasive methods for assessing arterial stiffness. A clinically useful diagnostic index must be pathophysiologically relevant, must be readily measurable, and must indicate the severity of the disease and predict the corresponding risk. Interventional modification of this index must parallel disease regression and benefit prognosis. The current evidence for the clinical value of estimating arterial stiffness (mainly of large, elastic-type arteries, such as the aorta and the carotids) in the contemporary era of cardiovascular medicine is reviewed.

  10. Arterial Stiffness and Trace Elements in Apparently Healthy Population- A Cross-sectional Study

    PubMed Central

    Subrahmanyam, Gangapatnam; Ramalingam, Krishnan; Indira, Selvam Armugam; Kantha, Katari; Soren, Bhemasen

    2016-01-01

    Introduction Stiffening of arteries is a natural ageing process. Any diseases/disorders or risk factors that escalate oxidative stress, microvascular inflammation and endothelial damage may promote to premature vascular stiffening. Any imbalance in these trace element levels may independently contribute to the changes in the components in the arterial wall and thus, arterial stiffness via one or more mechanisms. Aim To evaluate the severity of arterial stiffness in apparently healthy population and also to evaluate role of various risk factors and trace elements in the severity of arterial stiffness Materials and Methods Male and female subjects living in urban and rural areas of Nellore district, Andhra Pradesh, India, between 20-60 years, apparently normal as judged by the clinician basing on clinical and laboratory findings, were studied. Carotid-Femoral Pulse Wave Velocity (cf-PWV) a marker of arterial stiffness was assessed using non-invasive blood pressure curve monitoring (periscope). Furthermore, we also estimated serum levels of Copper (Cu), Zinc (Zn), Selenium (Se), chromium (Cr), Aluminium (Al), silicon (Si), Manganese (Mn), Molybdenum (Mb), Vanadium (Vn) and lead (Pb) using atomic absorption spectrophotometer. ANOVA and Chi-Square test were used to study the clinical correlations between severity of arterial stiffness, risk factors and trace elements. Results A total of 737 apparently healthy subjects participated in this cross-sectional study. Of the total 542 (73.5%) were from rural and the remaining 195 (26.5%) were living in urban areas, 328 (44.5%) were males, and 409 (55.5%) were females. A 63.5% (468/737) had normal arterial stiffness followed by 14.5% (107/737) with mild stiffness, 7% (57/737) had moderate stiffness and 14.2% (105/737) had severe arterial stiffness. Smoking, alcohol, blood pressures, fasting blood sugar, and total cholesterol, Cu, Al and Vn correlated (p<0.05) with different grades of arterial stiffness. Conclusion A 36.5% had

  11. A higher baseline plasma uric acid level is an independent predictor of arterial stiffness

    PubMed Central

    Ding, Xiao-Han; Wang, Xiaona; Cao, Ruihua; Yang, Xu; Xiao, Wenkai; Zhang, Yun; Bai, Yongyi; Wu, Hongmei; Ye, Ping

    2017-01-01

    Abstract Hyperuricemia has been demonstrated to be a risk factor for cardiovascular diseases. Though the association between uric acid (UA) and arterial stiffness has been investigated previously in patients with basic diseases, the predictive value of baseline UA level for arterial stiffness has not been conducted. We aimed at identifying the predictive role of UA for arterial stiffness prospectively. A longitudinal follow-up study in a routine health check-up population was performed with an average follow-up of 4.8 years. The demographic information, baseline and follow-up anthropometric parameters, arterial stiffness (pulse-wave velocity, PWV), and biomarker variables including UA have been measured and analyzed. A total of 1447 valid follow-ups were available for the final analysis. Both of the baseline and follow-up UA levels were significantly higher in the arterial stiffness groups than that in the nonarterial stiffness groups (all P values <0.001). The follow-up carotid-femoral PWV [(cf-PWV), r = 0.161, P < 0.001] was strongly correlated with baseline UA. At the follow-up cross-section, cf-PWV was also closely associated with UA (r = 0.101, P < 0.001). Logistic regressions revealed that a higher baseline UA level was an independent predictor of follow-up arterial stiffness assessed by cf-PWV [odds ratio (OR): 1.824; P = 0.046]. A higher baseline level of UA is closely related to arterial stiffness and is an independent predictor of arterial stiffening. PMID:28178136

  12. Arterial stiffness and hand osteoarthritis: a novel relationship?

    PubMed Central

    Saleh, A. S.; Najjar, S. S.; Muller, D. C.; Shetty, V.; Ferrucci, L.; Gelber, A. C.; Ling, S. M.

    2009-01-01

    Summary Objective Osteoarthritis (OA) and vascular stiffening may share elements of common pathogenesis, but their potential relatedness has been the focus of little prior inquiry. We tested the hypothesis that these two aging-associated conditions are related to each other. Method We analyzed cross-sectional data from 256 participants of the Baltimore Longitudinal Study of Aging (BLSA), a study of normative aging. All underwent measurement of arterial pulse wave velocity (PWV), an index of vascular stiffness, as well as hand radiographs that were graded for evidence of OA. Twenty total joints across three joint groups (distal interphalangeal [DIP], proximal interphalangeal [PIP], carpal-metacarpal [CMC]) were each assigned a Kellgren–Lawrence grade (K–L) of 0 (normal) through 4 (severe), with K–L grades ≥2 considered evidence of definite OA. Radiographic hand OA was defined as definite OA changes in at least two of the three anatomic hand sites (DIP, PIP, CMC). OA burden was represented by the total number of affected OA joints, and a cumulative K–L grade was aggregated across all hand joint groups. The relationship of PWV with these three measures of hand OA was assessed by linear regression. Results Upon univariate analysis, the presence of radiographic hand OA (β = 218.1, P < 0.01), the total number of OA joints (β = 32.9, P < 0.01), and the cumulative K–L grade across all joint groups (β = 12.2, P < 0.01) were each associated with increased PWV. These associations, however, were no longer significant in age-adjusted models. Conclusion Although significant individual relationships between PWV and several measures of hand OA were observed, these associations were largely attributable to the confounding effect of age. PMID:17097316

  13. Relationship between sympathetic baroreflex sensitivity and arterial stiffness in elderly men and women.

    PubMed

    Okada, Yoshiyuki; Galbreath, M Melyn; Shibata, Shigeki; Jarvis, Sara S; VanGundy, Tiffany B; Meier, Rhonda L; Vongpatanasin, Wanpen; Levine, Benjamin D; Fu, Qi

    2012-01-01

    Previous human studies have shown that large-artery stiffness contributes to an age-related decrease in cardiovagal baroreflex sensitivity. Whether this is also true with sympathetic baroreflex sensitivity is unknown. We tested the hypothesis that sympathetic baroreflex sensitivity is associated with the stiffness of baroreceptor segments (the carotid artery and the aorta) in elderly individuals and that sex affects this relationship. Sympathetic baroreflex sensitivity was assessed from the spontaneous changes in beat-by-beat diastolic pressure and corresponding muscle sympathetic nerve activity (microneurography) during supine rest in 30 men (mean±SEM: 69±1 years) and 31 women (68±1 years). Carotid artery stiffness (B-mode ultrasonography) and aortic stiffness (MRI) were also determined. We found that elderly women had lower sympathetic baroreflex sensitivity than elderly men (-2.33±0.25 versus -3.32±0.25 bursts · 100 beats(-1) · mm Hg(-1); P=0.007). β-Stiffness indices of the carotid artery and the aorta were greater in elderly women than in men (6.68±0.48 versus 5.10±0.50 and 4.03±0.47 versus 2.68±0.42; both P<0.050). Sympathetic baroreflex sensitivity was inversely correlated with carotid artery stiffness in both men and women (r=0.49 and 0.50; both P<0.05), whereas this relation was shifted in parallel upward (toward a reduced sensitivity) in women with no changes in the slope (0.26 versus 0.24 arbitrary units). Sympathetic baroreflex sensitivity and aortic stiffness showed similar trends. Thus, barosensory artery stiffness seems to be one independent determinant of sympathetic baroreflex sensitivity in elderly men and women. The lower sympathetic baroreflex sensitivity in elderly women may predispose them to an increased prevalence of hypertension.

  14. Arterial stiffness is not increased in patients with short duration rheumatoid arthritis and ankylosing spondylitis.

    PubMed

    Dzieża-Grudnik, Anna; Sulicka, Joanna; Strach, Magdalena; Siga, Olga; Klimek, Ewa; Korkosz, Mariusz; Grodzicki, Tomasz

    2017-04-01

    Patients with rheumatoid arthritis (RA) and ankylosing spondylitis (AS) have increased cardiovascular (CV) morbidity and mortality. Arterial stiffness is an independent predictor of CV events. The aim of the study was to assess arterial stiffness and inflammatory markers in patients with short duration chronic arthritis. We assessed carotid-femoral pulse wave velocity (PWV), augmentation index (AIx), traditional CV risk factors and inflammatory and endothelial markers in 71 chronic arthritis patients (RA and AS) and in 29 healthy controls. We did not find differences in PWV (for RA, AS and controls, respectively: 10 [8.8-10.9] versus 10.7 [9.1-11.8] versus 9.2 [8.3-11.4] m/s; p = .14) and AIx (for RA, AS and controls, respectively: 24.3 ± 11.5 versus 5.7 ± 12.4 versus 10 ± 12.8%; p = .22). Both groups of arthritis patients had active disease with significantly elevated inflammatory markers compared to controls. There were no correlations between endothelial and inflammatory markers and parameters of arterial stiffness in arthritis patients. When analyzing arthritis patients according to median of PVW, there were no significant differences in inflammatory and endothelial markers. We found that in patients with short duration active RA and AS arterial stiffness was not increased and furthermore, there was no association between markers of systemic inflammation and arterial stiffness.

  15. Hypertension, Diabetes Type II, and Their Association: Role of Arterial Stiffness.

    PubMed

    Smulyan, Harold; Lieber, Ari; Safar, Michel E

    2016-01-01

    In patients with both hypertension and type II diabetes, the systolic blood pressure (SBP) increases linearly with age, while that of diastolic blood pressure (DBP) declines curvilinearly as early as age 45, all suggesting the development of increased arterial stiffness. Increased stiffness is an important, independent, and significant risk predictor in subjects with hypertension and diabetes. In patients with both diseases, stiffness assessed at the same mean arterial pressure (MAP) was significantly higher in diabetic patients. Arterial stiffness is related to age, heart rate (HR), and MAP, but in diabetic patients, it also related to diabetes duration and insulin treatment (IT). In the metabolic syndrome (MetSyn), diabetes also acts on the small arteries through capillary rarefaction to reduce the effective length of the arterial tree, increases the reflected pulse wave and thus the pulse pressure (PP). These studies indicate that diabetes and hypertension additively contribute to increased pulsatility and suggest that any means to reduce stiffness would be beneficial in these conditions.

  16. Relationship between occupational exposure to lead and local arterial stiffness and left ventricular diastolic function in individuals with arterial hypertension

    SciTech Connect

    Poreba, Rafal; Gac, Pawel; Poreba, Malgorzata; Antonowicz-Juchniewicz, Jolanta; Andrzejak, Ryszard

    2011-08-01

    Relationship between occupational exposure to lead and frequency of complications in persons with arterial hypertension has been poorly investigated. This study aimed at evaluation of the relationship between occupational exposure to lead and manifestation of an increased local arterial stiffness and left ventricular diastolic dysfunction. The studies included 105 men (mean age: 44.47 {+-} 9.12 years) with arterial hypertension, treated with hypotensive drugs: group I - men occupationally exposed to lead (n = 53), and group II - men not exposed to lead (n = 52). In echocardiographic examination, the left ventricular diastolic dysfunction was diagnosed significantly more frequently in group I than in group II. In eTracking examination mean values of stiffness parameter ({beta}), augmentation index (AI) and one-point pulse wave velocity (PWV-{beta}) were significantly higher and mean values of arterial compliance (AC) were significantly lower in group I than in group II. The logistic regression showed that in the group of persons with arterial hypertension occupationally exposed to lead a more advanced age, higher blood lead concentration and higher mean values of augmentation index represent independent risk factors of left ventricular diastolic dysfunction. The multifactorial regression showed that amongst persons with arterial hypertension occupationally exposed to lead higher blood zinc protoporphyrin concentration, a more advanced age and higher value of body mass index (BMI) represent independent risk factors of an increased local arterial stiffness. In summary, we should note that in the group of persons with arterial hypertension occupationally exposed to lead the study has demonstrated a significantly more frequent manifestation of left ventricular diastolic dysfunction and an increase in local arterial stiffness. - Highlights: > Amongst persons with AH exposed to Pb higher ZnPP represent independent risk factor of increased local arterial stiffness

  17. The Impact of Remote Ischemic Preconditioning on Arterial Stiffness and Heart Rate Variability in Patients with Angina Pectoris

    PubMed Central

    Zagidullin, Naufal; Scherbakova, Elena; Safina, Yuliana; Zulkarneev, Rustem; Zagidullin, Shamil

    2016-01-01

    Remote ischemic preconditioning (RIPC) is the set of ischemia episodes that protects against subsequent periods of prolonged ischemia through the cascade of adaptive responses; however, the mechanisms of RIPC are not entirely clear. Here, we aimed to study the impact of RIPC in patients with stable angina pectoris and compare it with healthy individuals with respect to arterial stiffness and heart rate variability. In the randomized, sham-controlled, crossover blind design study, a group of 30 coronary heart disease (CHD) patients (63.9 ± 1.6 years) with stable angina pectoris NYHA II-III and a control group of 20 healthy individuals (58.2 ± 2.49) were both randomly allocated for remote RIPC or sham RIPC. Arterial stiffness, pulse wave velocity (Spygmacor, Australia), and heart rate variability (HRV) were recorded before and after the procedure followed by the crossover examination. In the group of healthy individuals, RIPC showed virtually no impact on the cardiovascular parameters, while, in the CHD group, the systolic and central systolic blood pressure, central pulse pressure, and augmentation decreased, and total power of HRV improved. We conclude that ischemic preconditioning reduces not only systolic blood pressure, but also reduces central systolic blood pressure and improves arterial compliance and heart rate modulation reserve, which may be associated with the antianginal effect of preconditioning. PMID:27348009

  18. Relation between coronary artery disease, risk factors and intima-media thickness of carotid artery, arterial distensibility, and stiffness index.

    PubMed

    Alan, Sait; Ulgen, Mehmet S; Ozturk, Onder; Alan, Bircan; Ozdemir, Levent; Toprak, Nizamettin

    2003-01-01

    Atherosclerosis is a diffuse process that involves vessel structures. In recent years, the relation of noninvasive parameters such as intima-media thickening (IMT), arterial distensibility (AD), and stiffness index (SI) to cardiovascular diseases has been researched. However, we have not found any study that has included all these parameters. The aim of this study is to examine the relation between the presence of coronary artery disease (CAD) and its risk factors to AD, SI, and IMT, which are the noninvasive predictors of atherosclerotic process in the carotid artery. Included in the study were 180 patients who were diagnosed as having CAD by coronary angiography (those with at least > or = 30% stenosis in the coronary arteries) and, as a control group, 53 persons who had normal appearing coronary angiographies. IMT, AD, and SI values of all the patients in the study were measured by echo-Doppler imaging (AD formula = 2 x (AoS - AoD)/PP x AoD, SI formula = (SBP/DBP)/([AoS - AoD]/AoD). Significantly increased IMT (0.82 +/- 0.1, 0.57 +/- 0.1, p<0.05), decreased AD (0.25 +/- 0.9, 0.37 +/- 0.1, p<0.05), and increased SI (13 +/- 4, 8 +/- 3, p<0.05) values were detected in the CAD group compared to the control group. A significant correlation was found between IMT and presence of diabetes mellitus (DM), systolic blood pressure, total cholesterol, and presence of plaque in carotids, and age. In the coronary artery disease group there was a significant correlation between AD and age, systolic blood pressure, and HDL cholesterol levels, while there was no significant correlation with plaque development. A significant correlation was also found between stiffness index and systolic blood pressure and age; however, there was no relation between number of involved vessels and IMT, AD, and SI. We found sensitivity, specificity, and positive predictive and negative predictive values for CAD diagnosis to be 70%, 75%, 77%, and 66%, respectively. In CAD cases, according to data in

  19. HIV infection and arterial stiffness among older-adults taking antiretroviral therapy in rural Uganda

    PubMed Central

    Siedner, Mark J.; Kim, June-Ho; Nakku, Ruth Sentongo; Hemphill, Linda; Triant, Virginia A.; Haberer, Jessica E.; Martin, Jeffrey N.; Boum, Yap; Kwon, Douglas S.; Tsai, Alexander C.; Hunt, Peter W.; Okello, Samson; Bangsberg, David R.

    2015-01-01

    HIV infection is associated with arterial stiffness, but no studies have assessed this relationship in sub-Saharan Africa. We enrolled 205 participants over 40 years old in Uganda: 105 on antiretroviral therapy for a median of 7 years, and a random sample of 100 age and gender-matched HIV-uninfected controls from the clinic catchment area. The prevalence of arterial stiffness (ABI>1.2) was 33%, 18%, 19% and 2% in HIV+ men, HIV- men, HIV+ women, and HIV- women. In multivariable models adjusted for cardiovascular risk factors, HIV+ individuals had over double the prevalence of arterial stiffness (APR 2.86, 95%CI 1.41–5.79, P=0.003). PMID:26636926

  20. Development of easy operating arterial stiffness assessment instrument for home care.

    PubMed

    Wu, Hsien-Tsai; Yao, Cheng-Tso; Wu, Tsang-Chih; Liu, An-Bang

    2007-01-01

    In this study, 41 asymptomatic subjects (22 men and 19 women, 20 to 60 years of age) were enrolled. The PWV was measured both by dual-channel PPG (PWV-DVP) and by the proposed PWV instrument, Pulse Wave Velocity by Digital Volume Pulse Easy (PWV-DVPE). The developed system recorded digital volume pulse simultaneously from both the finger and ear. Time of pulse transition was measured on the time delay difference between two digital volume pulses. The PWV was calculated by dividing the distance between finger and ear by that of transit time. PWV-DVPE's capability of precise self-monitoring arterial stiffness is being proven in this study. In home care area, only few minutes is needed for self arterial stiffness assessment. Therefore, early self-monitoring of cardio-vascular dys-function and arterial stiffness is easily and effectively achieved.

  1. Reduction in arterial stiffness and vascular age by naltrexone-induced interruption of opiate agonism: a cohort study

    PubMed Central

    Reece, Albert Stuart; Hulse, Gary Kenneth

    2013-01-01

    Objective To prospectively assess if opiate antagonist treatment or the opiate-free status could reverse opiate-related vasculopathy. Design Longitudinal Open Observational, Serial ‘N of One’, over 6.5 years under various treatment conditions: opiate dependence, naltrexone and opiate-free. Setting Primary care, Australia. Participants 20 opiate-dependent patients (16 males: 16 cases of buprenorphine 4.11±1.17 mg, two of methadone 57.5±12.5 mg and two of heroin 0.75±0.25 g). Intervention Studies of central arterial stiffness and vascular reference age (RA) were performed longitudinally by SphygmoCor Pulse Wave Analysis (AtCor, Sydney). Primary outcomes Primary outcome was vascular age and arterial stiffness accrual under different treatment conditions. Results The mean chronological age (CA) was 33.62±2.03 years. The opiate-free condition was associated with a lower apparent vascular age both in itself (males: p=0.0402 and females: p=0.0360) and in interaction with time (males: p=0.0001 and females: p=0.0004), and confirmed with other measures of arterial stiffness. The mean modelled RA was 38.82, 37.73 and 35.05 years in the opiate, naltrexone and opiate-free conditions, respectively. The opiate-free condition was superior to opiate agonism after full multivariate adjustment (p=0.0131), with modelled RA/CA of 1.0173, 0.9563 and 0.8985 (reductions of 6.1% and 11.9%, respectively). Conclusions Data demonstrate that opiate-free status improves vascular age and arterial stiffness in previous chronic opiate users. The role of opiate antagonist treatment in achieving these outcomes requires future clarification and offers hope of novel therapeutic remediation. PMID:23524044

  2. Reciprocal relationship between plasma ghrelin level and arterial stiffness in hypertensive subjects.

    PubMed

    Zhao, Yin-Tao; Yang, Hai-Bo; Li, Ling; Gao, Ke; Li, Peng-Fei; Xie, Wei-Wei

    2013-11-01

    Arterial stiffness, considered an independent predictor of cardiovascular morbidity and mortality, is closely associated with hypertension. Futhermore, the role of ghrelin in the development of hypertension has been widely recognized. The purpose of the present study was to explore the potential relationship between circulating ghrelin and arterial stiffness in hypertensive subjects. A total of 192 patients with primary hypertension and 107 normotensive (NT) control subjects were enrolled in the present cross-sectional study. Plasma ghrelin was determined by ELISA. Arterial stiffness was assessed by brachial-ankle pulse wave velocity (baPWV) and the augmentation index (AIx). Both baPWV and AIx values were markedly higher in the hypertensive compared with NT group (P < 0.01). In contrast, plasma ghrelin concentrations were significantly lower in hypertensive patients compared with NT subjects (P < 0.01). Plasma ghrelin concentrations were negatively correlated with age (odds ratio (OR) -1.836; P < 0.001), smoking (OR -1.347; P = 0.042), baPWV (OR -1.762; P < 0.001) and AIx (OR -1.516; P = 0.005), but positively associated with fasting plasma glucose (OR 1.293; P = 0.047) and HbA1c (OR 1.413; P = 0.025). The inverse correlation between circulating ghrelin and the extent of arterial stiffness suggests that ghrelin is an independent determinant of arterial stiffness, even after adjustment for confounding cardiovascular risk factors, and it actively participates in the pathophysiology of arterial stiffness in hypertensive subjects.

  3. Relationship between sleep duration and arterial stiffness in a multi-ethnic population: The HELIUS study

    PubMed Central

    Anujuo, Kenneth; Stronks, Karien; Snijder, Marieke B.; Jean-Louis, Girardin; van den Born, Bert-Jan; Peters, Ron J.; Agyemang, Charles

    2017-01-01

    We examined the relationship between sleep duration and arterial stiffness among a multi-ethnic cohort, and whether the associations differed among ethnic minority groups in the Netherlands. Data were derived from 10 994 participants (aged 18–71 years) of the Healthy Life in an Urban Setting (HELIUS) study. Self-reported sleep duration was categorized into: short (<7 h/night), healthy (7–8 h/night) and long (≥9 h/night). Arterial stiffness was assessed by duplicate pulse-wave velocity (PWV in m/s) measurements using the Arteriograph system. The association of sleep duration with PWV was analysed using linear regression (β) with 95% confidence interval (CI). Results showed that neither short nor long sleep was related to PWV in all ethnic groups, except for long sleep in Dutch men which was associated with higher PWV (indicating stiffer arteries) after adjustment for potential confounders (β = 0.67, 95%CI, 0.23–1.11). Our study showed no convincing evidence that sleep duration was related to arterial stiffness among various ethnic groups. The link between sleep duration and cardiovascular outcomes does not seem to operate through arterial stiffness. Further research is needed to consolidate these findings. PMID:27058653

  4. Assessment of Arterial Stiffness Using the Cardio-Ankle Vascular Index

    PubMed Central

    Miyoshi, Toru; Ito, Hiroshi

    2016-01-01

    Background Arterial stiffness is an independent predictor of outcomes for patients with cardiovascular disease. Although measurement of pulse wave velocity is a widely accepted, noninvasive approach for the assessment of arterial stiffness, its accuracy is affected by changes in blood pressure. Summary The cardio-ankle vascular index (CAVI) is an index of the overall stiffness of the artery from the origin of the aorta to the ankle and is theoretically independent of blood pressure at the time of measurement. CAVI increases linearly with age and is elevated even in mild arteriosclerotic disease. It can identify differences in the degree of arteriosclerosis among patients with severe arteriosclerotic disease and better reflects the severity of disease of the coronary artery than does brachial-ankle pulse wave velocity. Patients with higher CAVI values show a poor prognosis compared with those with lower CAVI values. Furthermore, CAVI can be lowered by controlling diabetes mellitus and hypertension. Key Messages The primary aims of assessing arterial stiffness using CAVI are to assist in the early detection of arteriosclerosis, allowing timely treatment and lifestyle modification, and to quantitatively evaluate the progression of disease and the effectiveness of treatment. Whether CAVI-guided therapy can improve prognosis in high-risk patients needs to be further examined to confirm the clinical usefulness of this measure. PMID:27493899

  5. Association between arterial stiffness and peritoneal small solute transport rate.

    PubMed

    Zhe, Xing-wei; Tian, Xin-kui; Chen, Wei; Guo, Li-juan; Gu, Yue; Chen, Hui-min; Tang, Li-jun; Wang, Tao

    2008-05-01

    While cardiovascular disease accounts for 40-50% of the mortality in dialysis patients, and while a high peritoneal transport in continuous ambulatory peritoneal dialysis (CAPD) is an independent predictor of outcome, it is unclear if there are any links. Aortic stiffness has become established as a cardiovascular risk factor. We thus studied pulse wave velocity (PWV) in CAPD patients to explore the possible link between peritoneal small solute transport and aortic stiffness. CAPD patients (n = 76, 27 M/49 F) in our center were included in the present study. Aortic stiffness was assessed by brachial pulse pressure (PP) and carotid-femoral PWV. Patients' peritoneal small solute transport rate was assessed by D/P(cr) at 4 h. Extracellular water over total body water (E/T ratio) was assessed by means of bioimpedance analysis. C-reactive protein was also measured. Carotid-femoral PWV was positively associated with patients' age (r = 0.555; P < 0.01), time on peritoneal dialysis (r = 0.332; P < 0.01), diabetic status (r = 0.319; P < 0.01), D/P(cr) (r = 0.241; P < 0.05), PP (r = 0.475; P < 0.01), and E/T (r = 0.606; P < 0.01). In a multivariate regression analysis, carotid-femoral PWV was independently determined by E/T (P < 0.01), PP (P < 0.01), age (P < 0.01), and D/P(cr) (P < 0.05). D/P(cr), in addition to E/T, age, and PP, was an independent predictor of elevated carotid-femoral PWV in CAPD patients, suggesting that there might be a link between high aortic stiffness and increased peritoneal small solute transport rate.

  6. Long-term pioglitazone therapy improves arterial stiffness in patients with type 2 diabetes mellitus.

    PubMed

    Harashima, Keiichiro; Hayashi, Junichi; Miwa, Takashi; Tsunoda, Tooru

    2009-06-01

    Pioglitazone, a peroxisome proliferator-activated receptor gamma agonist, not only improves insulin resistance and glycemic control, but may also have additional beneficial vascular effects in patients with type 2 diabetes mellitus. We investigated whether pioglitazone had an influence on arterial stiffness, which is an independent predictor of cardiovascular events, in 204 patients with type 2 diabetes mellitus. A prospective, nonrandomized, open-label trial was performed that involved 41 patients treated with pioglitazone, 46 patients receiving sulfonylureas, 67 patients on insulin, and 50 patients on diet/exercise only. The follow-up period was 56 +/- 3 months. Arterial stiffness was evaluated by using the arterial stiffness index (ASI), which was based on analysis of the pulse wave amplitude pattern obtained during automated blood pressure measurement in the upper limb. The 4 groups had a similar baseline ASI, which was greater than the reference range in each group. Although antidiabetic therapies improved hemoglobin A(1c) and low-density lipoprotein cholesterol, ASI only decreased significantly in the pioglitazone group. Thus, pioglitazone improved abnormal arterial stiffness in patients with type 2 diabetes mellitus via a mechanism beyond the metabolic improvement. These findings may have important clinical implications in the use of pioglitazone in patients with type 2 diabetes mellitus.

  7. Is arterial stiffness predicted by continuous metabolic syndrome score in obese children?

    PubMed

    Prochotska, Katarina; Kovacs, Laszlo; Vitariusova, Eva; Feber, Janusz

    2016-01-01

    The aim of the article was to evaluate arterial stiffness, an early marker of increased cardiovascular risk, in relation to obesity. The continuous metabolic syndrome (cMetS) score was calculated as sum of Z score of mean arterial pressure, body mass index, serum glucose, triglyceride, and high-density lipoprotein cholesterol in 144 obese patients and 66 nonobese controls. Ambulatory arterial stiffness index (AASI) was calculated as 1 minus regression slope of diastolic on systolic blood pressure from ambulatory blood pressure measurements. The mean AASI increased progressively with severity of obesity. The receiver operator curve analysis of body mass index and AASI showed area under the curve of 0.64 ± 0.06; cMetS area under the curve was 0.72 ± 0.05 suggesting a better predictive power of the cMetS for an increased AASI (>0.3). Patients with obesity have significantly higher arterial stiffness. A composite score such as cMetS seems to be better predictor of an increased stiffness than individual risk factors.

  8. Moderate and heavy metabolic stress interval training improve arterial stiffness and heart rate dynamics in humans.

    PubMed

    Rakobowchuk, Mark; Harris, Emma; Taylor, Annabelle; Cubbon, Richard M; Birch, Karen M

    2013-04-01

    Traditional continuous aerobic exercise training attenuates age-related increases of arterial stiffness, however, training studies have not determined whether metabolic stress impacts these favourable effects. Twenty untrained healthy participants (n = 11 heavy metabolic stress interval training, n = 9 moderate metabolic stress interval training) completed 6 weeks of moderate or heavy intensity interval training matched for total work and exercise duration. Carotid artery stiffness, blood pressure contour analysis, and linear and non-linear heart rate variability were assessed before and following training. Overall, carotid arterial stiffness was reduced (p < 0.01), but metabolic stress-specific alterations were not apparent. There was a trend for increased absolute high-frequency (HF) power (p = 0.10) whereas both absolute low-frequency (LF) power (p = 0.05) and overall power (p = 0.02) were increased to a similar degree following both training programmes. Non-linear heart rate dynamics such as detrended fluctuation analysis [Formula: see text] also improved (p > 0.05). This study demonstrates the effectiveness of interval training at improving arterial stiffness and autonomic function, however, the metabolic stress was not a mediator of this effect. In addition, these changes were also independent of improvements in aerobic capacity, which were only induced by training that involved a high metabolic stress.

  9. Etiology of End-Stage Renal Disease and Arterial Stiffness among Hemodialysis Patients

    PubMed Central

    El Ghoul, Balsam; Korjian, Serge; El Alam, Andrew; Samad, Salam; Dahdah, Georges; Blacher, Jacques; Safar, Michel E.

    2017-01-01

    Background. Prior studies have demonstrated that conventional and emerging CV risk factors are associated with worsening arterial stiffness among end-stage renal disease (ESRD) patients on hemodialysis. The present cross-sectional study evaluates the association between the etiology of ESRD and arterial stiffness among a cohort of hemodialysis patients. Methods. Etiology of ESRD was identified from patients' medical records and classified as either vascular renal disease, diabetic nephropathy, nondiabetic glomerulopathy, tubular interstitial nephropathy, hereditary nephropathy, or ESRD of unconfirmed etiology. Results. A total of 82 subjects were enrolled. cfPWV was independently associated with the composite of either diabetic nephropathy or vascular renal disease (p = 0.022), pulse pressure (p = 0.001), and a history of CV events (p = 0.025), but not history of hypertension or diabetes mellitus alone. The median cfPWVs in diabetic nephropathy and vascular renal disease were comparable and significantly higher than median cfPWVs in other etiologies of ESRD. Conclusion. The study suggests that the etiology of ESRD is independently associated with arterial stiffness among hemodialysis patients. Furthermore, arterial stiffness was higher among patients who developed renal sequelae of either diabetes mellitus or hypertension as compared with those who have a history of either diabetes mellitus or hypertension alone. PMID:28299320

  10. Acute effects of aerobic exercise intensity on arterial stiffness after glucose ingestion in young men.

    PubMed

    Kobayashi, Ryota; Hashimoto, Yuto; Hatakeyama, Hiroyuki; Okamoto, Takanobu

    2016-10-18

    Arterial stiffness increases after glucose ingestion. Acute low- and moderate-intensity aerobic exercise decreases arterial stiffness. However, the acute effects of 30 min of cycling at low- and moderate-intensity [25% (LE trial) and 65% (ME trial) peak oxygen uptake, respectively] on arterial stiffness at 30, 60 and 120 min of a postexercise glucose ingestion. Ten healthy young men (age, 22·4 ± 0·5 years) performed LE and ME trials on separate days in a randomized controlled crossover fashion. Carotid-femoral (aortic) pulse wave velocity (PWV), femoral-ankle (leg) PWV, carotid augmentation index (AIx) and carotid blood pressure (BP) (applanation tonometry), brachial and ankle BP (oscillometric device), heart rate (HR) (electrocardiography), blood glucose (UV-hexokinase method) and blood insulin (CLEIA method) levels were measured at before (baseline) and at 30, 60 and 120 min after the 75-g OGTT. Leg PWV, ankle pulse pressure and BG levels significantly increased from baseline after the 75-g OGTT in the LE trial (P<0·05), but not in the ME trial. Insulin levels and HR significantly increased from baseline after the 75-g OGTT in both trials (P<0·05). Aortic PWV, carotid AIx, brachial BP and carotid BP did not change from baseline after the 75-g OGTT in both trials. The present findings indicate that aerobic exercise at moderate intensity before glucose ingestion suppresses increases leg arterial stiffness after glucose ingestion.

  11. Optical imaging of resting-state functional connectivity in a novel arterial stiffness model.

    PubMed

    Guevara, Edgar; Sadekova, Nataliya; Girouard, Hélène; Lesage, Frédéric

    2013-01-01

    This study aims to assess the impact of unilateral increases in carotid stiffness on cortical functional connectivity measures in the resting state. Using a novel animal model of induced arterial stiffness combined with optical intrinsic signals and laser speckle imaging, resting state functional networks derived from hemodynamic signals are investigated for their modulation by isolated changes in stiffness of the right common carotid artery. By means of seed-based analysis, results showed a decreasing trend of homologous correlation in the motor and cingulate cortices. Furthermore, a graph analysis indicated a randomization of the cortex functional networks, suggesting a loss of connectivity, more specifically in the motor cortex lateral to the treated carotid, which however did not translate in differentiated metabolic activity.

  12. Roles of Arterial Stiffness and Blood Pressure in Hypertension-Associated Cognitive Decline in Healthy Adults.

    PubMed

    Hajjar, Ihab; Goldstein, Felicia C; Martin, Greg S; Quyyumi, Arshed A

    2016-01-01

    Although there is strong evidence that hypertension leads to cognitive decline, especially in the executive domain, the relationship between blood pressure and cognition has been conflicted. Hypertension is characterized by blood pressure elevation and increased arterial stiffness. We aimed at investigating whether arterial stiffness would be superior to blood pressure in predicting cognitive decline and explaining the hypertension-executive decline association. A randomly selected asymptomatic population (n=591, age=49.2 years, 70% women, 27% black, and education=18 years) underwent annual vascular and cognitive assessments. Cognition was assessed using computerized versions commonly used cognitive tests, and principal component analysis was used for deriving cognitive scores for executive function, memory, and working memory. Arterial stiffness was measured by carotid-femoral pulse wave velocity (PWV). Higher PWV, but not blood pressure, was associated with a steeper decline in executive (P=0.0002), memory (P=0.05), and working memory (P=0.02) scores after adjusting for demographics, education, and baseline cognitive performance. This remained true after adjusting for hypertension. Hypertension was associated with greater decline in executive score (P=0.0029) and those with combined hypertension and elevated PWV (>7 m/s) had the greatest decline in executive score (P value hypertension×PWV=0.02). PWV explained the association between hypertension and executive function (P value for hypertension=0.0029 versus 0.24 when adjusting for PWV). In healthy adults, increased arterial stiffness is superior to blood pressure in predicting cognitive decline in all domains and in explaining the hypertension-executive function association. Arterial stiffness, especially in hypertension, may be a target in the prevention of cognitive decline.

  13. Arterial stiffness is not associated with bone parameters in an elderly hyperhomocysteinemic population.

    PubMed

    van Dijk, S C; de Jongh, R T; Enneman, A W; Ham, A C; Swart, K M A; van Wijngaarden, J P; van der Zwaluw, N L; Brouwer-Brolsma, E M; van Schoor, N M; Dhonukshe-Rutten, R A M; Lips, P; de Groot, C P G M; Smulders, Y M; Blom, H J; Feskens, E J; Geleijnse, J M; van den Meiracker, A H; Mattace Raso, F U S; Uitterlinden, A G; Zillikens, M C; van der Velde, N

    2016-01-01

    Several studies have observed positive associations between bone disease and cardiovascular disease. A potential common pathway is hyperhomocysteinemia; however, to date, there is a lack of data regarding hyperhomocysteinemic populations. Therefore, we examined both cross-sectionally and longitudinally, whether there is an association between bone parameters and arterial stiffness in a hyperhomocysteinemic population, and investigated the potential common role of homocysteine (hcy) level on these associations. Cross-sectional and longitudinal data of the B-PROOF study were used (n = 519). At both baseline and 2-year follow-up we determined bone measures-incident fractures and history of fractures, bone-mineral density (BMD) and quantitative ultrasound (QUS) measurement. We also measured arterial stiffness parameters at baseline-pulse wave velocity, augmentation index and aortic pulse pressure levels with applanation tonometry. Linear regression analysis was used to examine these associations and we tested for potential interaction of hcy level. The mean age of the study population was 72.3 years and 44.3 % were female. Both cross-sectionally and longitudinally there was no association between arterial stiffness measures and BMD or QUS measurements or with incident fractures (n = 16) within the 2-3 years of follow-up. Hcy level did not modify the associations and adjustment for hcy did not change the results. Arterial stiffness was not associated with bone parameters and fractures, and hcy neither acted as a pleiotropic factor nor as a mediator. The potential association between bone and arterial stiffness is therefore not likely to be driven by hyperhomocysteinemia.

  14. Assessments of endothelial function and arterial stiffness are reproducible in patients with COPD

    PubMed Central

    Rodriguez-Miguelez, Paula; Seigler, Nichole; Bass, Leon; Dillard, Thomas A; Harris, Ryan A

    2015-01-01

    Background Elevated cardiovascular disease risk is observed in patients with COPD. Non-invasive assessments of endothelial dysfunction and arterial stiffness have recently emerged to provide mechanistic insight into cardiovascular disease risk in COPD; however, the reproducibility of endothelial function and arterial stiffness has yet to be investigated in this patient population. Objectives This study sought to examine the within-day and between-day reproducibility of endothelial function and arterial stiffness in patients with COPD. Methods Baseline diameter, peak diameter, flow-mediated dilation, augmentation index, augmentation index at 75 beats per minute, and pulse wave velocity were assessed three times in 17 patients with COPD (six males, eleven females, age range 47–75 years old; forced expiratory volume in 1 second =51.5% predicted). Session A and B were separated by 3 hours (within-day), whereas session C was conducted at least 7 days following session B (between-day). Reproducibility was assessed by: 1) paired t-tests, 2) coefficients of variation, 3) coefficients of variation prime, 4) intra-class correlation coefficient, 5) Pearson’s correlations (r), and 6) Bland–Altman plots. Five acceptable assessments were required to confirm reproducibility. Results Six out of six within-day criteria were met for endothelial function and arterial stiffness outcomes. Six out of six between-day criteria were met for baseline and peak diameter, augmentation index and pulse wave velocity, whereas five out of six criteria were met for flow-mediated dilation. Conclusion The present study provides evidence for within-day and between-day reproducibility of endothelial function and arterial stiffness in patients with COPD. PMID:26396509

  15. Physical Activity Correlates with Arterial Stiffness in Community-dwelling Individuals with Stroke

    PubMed Central

    Tang, Ada; Eng, Janice J.; Brasher, Penelope M.; Madden, Kenneth M.; Mohammadi, Azam; Krassioukov, Andrei V.; Tsang, Teresa S. M.

    2013-01-01

    Background Physical inactivity contributes to atherosclerotic processes, which manifest as increased arterial stiffness. Arterial stiffness is associated with myocardial demand and coronary perfusion and is a risk factor for stroke and other adverse cardiac outcomes. Poststroke mobility limitations often lead to physical inactivity and sedentary behaviors. This exploratory study aimed to identify functional correlates, reflective of daily physical activity levels, with arterial stiffness in community-dwelling individuals >1 year poststroke. Methods Carotid–femoral pulse wave velocity (cfPWV) was measured in 35 participants (65% men; mean ± SD age 66.9 ± 6.9 years; median time poststroke 3.7 years). Multivariable regression analyses examined the relationships between cfPWV and factors associated with daily physical activity: aerobic capacity (VO2 peak), gait speed, and balance ability (Berg Balance Scale). Age and the use of antihypertensive medications, known to be associated with pulse wave velocity, were also included in the model. Results Mean cfPWV was 11.2 ± 2.4 m/s. VO2 peak and age were correlated with cfPWV (r = −0.45 [P = .006] and r = 0.46 [P = .004], respectively). In the multivariable regression analyses, age and the use of antihypertensive medication accounted for 20.4% of the variance of cfPWV, and the addition of VO2 peak explained an additional 4.5% of the variance (R2 = 0.249). Conclusions We found that arterial stiffness is elevated in community-dwelling, ambulatory individuals with stroke relative to healthy people. Multivariable regression analysis suggests that aerobic capacity (VO2 peak) may contribute to the variance of cfPWV after accounting for the effects of age and medication use. Whether intense risk modification and augmented physical activity will improve arterial stiffness in this population remains to be determined. PMID:23473623

  16. Effects of sodium and potassium supplementation on blood pressure and arterial stiffness: a fully controlled dietary intervention study.

    PubMed

    Gijsbers, L; Dower, J I; Mensink, M; Siebelink, E; Bakker, S J L; Geleijnse, J M

    2015-10-01

    We performed a randomised, placebo-controlled, crossover study to examine the effects of sodium and potassium supplementation on blood pressure (BP) and arterial stiffness in untreated (pre)hypertensive individuals. During the study, subjects were on a fully controlled diet that was relatively low in sodium and potassium. After a 1-week run-in period, subjects received capsules with supplemental sodium (3 g d(-1), equals 7.6 g d(-1) of salt), supplemental potassium (3 g d(-1)) or placebo, for 4 weeks each, in random order. Fasting office BP, 24-h ambulatory BP and measures of arterial stiffness were assessed at baseline and every 4 weeks. Of 37 randomized subjects, 36 completed the study. They had a mean pre-treatment BP of 145/81 mm Hg and 69% had systolic BP ⩾140 mm Hg. Sodium excretion was increased by 98 mmol per 24 h and potassium excretion by 63 mmol per 24 h during active interventions, compared with placebo. During sodium supplementation, office BP was significantly increased by 7.5/3.3 mm Hg, 24-h BP by 7.5/2.7 mm Hg and central BP by 8.5/3.6 mm Hg. During potassium supplementation, 24-h BP was significantly reduced by 3.9/1.6 mm Hg and central pulse pressure by 2.9 mm Hg. Pulse wave velocity and augmentation index were not significantly affected by sodium or potassium supplementation. In conclusion, increasing the intake of sodium caused a substantial increase in BP in subjects with untreated elevated BP. Increased potassium intake, on top of a relatively low-sodium diet, had a beneficial effect on BP. Arterial stiffness did not materially change during 4-week interventions with sodium or potassium.

  17. Mean Platelet Volume and Arterial Stiffness – Clinical Relationship and Common Genetic Variability

    PubMed Central

    Panova-Noeva, Marina; Arnold, Natalie; Hermanns, M. Iris; Prochaska, Jürgen H.; Schulz, Andreas; Spronk, Henri M.; Binder, Harald; Pfeiffer, Norbert; Beutel, Manfred; Blankenberg, Stefan; Zeller, Tanja; Lotz, Johannes; Münzel, Thomas; Lackner, Karl J.; ten Cate, Hugo; Wild, Philipp S.

    2017-01-01

    Vessel wall stiffening is an important clinical parameter, but it is unknown whether platelets, key elements in the pathogenesis of arterial thrombosis, are associated with arterial stiffness. The present studies sought to determine whether mean platelet volume (MPV), a potential marker of platelet activation, is linked to vascular elasticity as assessed by the augmentation index (AIx), in 15,010 individuals from the population-based Gutenberg Health Study. Multivariable analysis showed that MPV in both males (β 0.776; 95thCI [0.250;1.16]; p = 0.0024) and females (β 0.881[0.328;1.43]; p = 0.0018) is strongly associated with AIx. Individuals with MPV and AIx above the sex-specific medians had worse survival. Association analysis between MPV-related genetic variants and arterial stiffness identified four genetic variants in males and one in females related with AIx. Cox regression analysis for mortality identified one of these joint genetic variants close to ring finger protein 145 gene (RNF145, rs10076782) linked with increased mortality (hazard ratio 2.02; 95thCI [1.35;3.02]; p = 0.00061). Thus, these population-based data demonstrate a close relation between platelet volume as a potential marker of platelet activation and arterial stiffness in both sexes. Further research is warranted to further elucidate the mechanisms underlying larger platelets‘ role in arterial stiffening including the role of shared common genetics. PMID:28059166

  18. Manipulation of arterial stiffness, wave reflections, and retrograde shear rate in the femoral artery using lower limb external compression.

    PubMed

    Heffernan, Kevin S; Lefferts, Wesley K; Kasprowicz, Ari G; Tarzia, Brendan J; Thijssen, Dick H; Brutsaert, Tom D

    2013-07-01

    Exposure of the arterial wall to retrograde shear acutely leads to endothelial dysfunction and chronically contributes to a proatherogenic vascular phenotype. Arterial stiffness and increased pressure from wave reflections are known arbiters of blood flow in the systemic circulation and each related to atherosclerosis. Using distal external compression of the calf to increase upstream retrograde shear in the superficial femoral artery (SFA), we examined the hypothesis that changes in retrograde shear are correlated with changes in SFA stiffness and pressure from wave reflections. For this purpose, a pneumatic cuff was applied to the calf and inflated to 0, 35, and 70 mmHg (5 min compression, randomized order, separated by 5 min) in 16 healthy young men (23 ± 1 years of age). Doppler ultrasound and wave intensity analysis was used to measure SFA retrograde shear rate, reflected pressure wave intensity (negative area [NA]), elastic modulus (Ep), and a single-point pulse wave velocity (PWV) during acute cuff inflation. Cuff inflation resulted in stepwise increases in retrograde shear rate (P < 0.05 for main effect). There were also significant cuff pressure-dependent increases in NA, Ep, and PWV across conditions (P < 0.05 for main effects). Change in NA, but not Ep or PWV, was associated with change in retrograde shear rate across conditions (P < 0.05). In conclusion, external compression of the calf increases retrograde shear, arterial stiffness, and pressure from wave reflection in the upstream SFA in a dose-dependent manner. Wave reflection intensity, but not arterial stiffness, is correlated with changes in peripheral retrograde shear with this hemodynamic manipulation.

  19. Uteroplacental insufficiency and lactational environment separately influence arterial stiffness and vascular function in adult male rats.

    PubMed

    Tare, Marianne; Parkington, Helena C; Bubb, Kristen J; Wlodek, Mary E

    2012-08-01

    Early life environmental influences can have lifelong consequences for health, including the risk of cardiovascular disease. Uteroplacental insufficiency causes fetal undernutrition and impairs fetal growth. Previously we have shown that uteroplacental insufficiency is associated with impaired maternal mammary development, compromising postnatal growth leading to hypertension in male rat offspring. In this study we investigated the roles of prenatal and postnatal nutritional environments on endothelial and smooth muscle reactivity and passive wall stiffness of resistance arteries of male rat offspring. Fetal growth restriction was induced by maternal bilateral uterine vessel ligation (restricted) on day 18 of pregnancy. Control offspring were from mothers that had sham surgery (control) and another group from mothers with their litter size reduced (reduced; litter size reduced to 5 at birth, equivalent to the restricted group). On postnatal day 1, offspring (control, restricted, and reduced) were cross-fostered onto control or restricted mothers. At 6 months, mesenteric and femoral arteries were studied using wire and pressure myography. In restricted-on-restricted rats, wall stiffness was increased, and sensitivity to phenylephrine and relaxation evoked by endothelium-derived hyperpolarizing factor and sodium nitroprusside were impaired in mesenteric arteries. In femoral arteries, relaxation to sodium nitroprusside was reduced, whereas wall stiffness was unaltered. Cross-fostering restricted offspring onto control mothers alleviated deficits in vascular stiffness and reactivity. Control or reduced offspring who suckled a restricted mother had marked vascular stiffening. In conclusion, prenatal and early postnatal environments separately influence vascular function and stiffness. Furthermore, the early postnatal lactational environment is a determinant of later cardiovascular function.

  20. Relationship between carotid intima‐media thickness and arterial stiffness in children after Kawasaki disease

    PubMed Central

    Cheung, Y‐f; Wong, S J; Ho, M H K

    2007-01-01

    Background Evidence of premature atherosclerosis and systemic arterial stiffening in patients after Kawasaki disease is accumulating. Aim To test the hypothesis that carotid intima‐media thickness (IMT), a surrogate marker of atherosclerosis, is associated with systemic arterial stiffness in children after Kawasaki disease. Methods A cohort of 72 patients was studied, comprising 26 patients with Kawasaki disease and coronary aneurysms (group I), 24 patients with Kawasaki disease and normal coronary arteries (group II) and 22 healthy age‐matched children (group III). The carotid IMT, carotid artery stiffness index, brachioradial pulse wave velocity (PWV), fasting total cholesterol, high‐density lipoprotein (HDL) cholesterol and low‐density lipoprotein (LDL) cholesterol were determined and compared among the three groups. Results The carotid IMT was related to indices of arterial stiffness, and significant determinants of carotid IMT were identified by multivariate analysis. The mean (standard deviation (SD)) carotid IMT of both group I (0.41 (0.04) mm) and group II (0.39 (0.04) mm) was significantly greater than that of group III (0.36 (0.04) mm; p<0.001 and p = 0.008, respectively). For the entire cohort, carotid IMT correlated positively with LDL cholesterol (r = 0.31, p = 0.009), carotid artery stiffness index (r = 0.40, p = 0.001) and brachioradial PWV (r = 0.28, p = 0.016), but not with age, body mass index, systemic blood pressure, and HDL and total cholesterol. Multiple linear regression analysis identified carotid artery stiffness index (β = 0.25, p = 0.028) and subject grouping (β = −0.39, p = 0.001; model R2 = 0.29) as significant correlates of carotid IMT. Conclusion The increased carotid IMT in children after Kawasaki disease is associated with systemic arterial stiffening. PMID:16820386

  1. Arterial stiffness is increased in Hodgkin lymphoma survivors treated with radiotherapy.

    PubMed

    van Leeuwen-Segarceanu, Elena M; Dorresteijn, Lucille D A; Vogels, Oscar J M; Biesma, Douwe H; Bos, Willem-Jan W

    2013-08-01

    Radiotherapy has been associated with an increased risk for cardiovascular disease (CVD) in Hodgkin lymphoma survivors (HLS). Identifying subjects most likely to develop these complications is challenging. Arterial stiffness has been frequently used as an early marker of CVD, but has never previously been investigated in patients treated with radiotherapy. The carotid-femoral pulse wave velocity (PWV) and the distensibility coefficient (DC) of the common carotid artery were used as markers of arterial stiffness. Eighty-two HLS and 40 age- and gender-matched control subjects were studied. The aorta and the carotid arteries were situated within the radiation field in 50 and 39 patients. Mean PWV was not significantly different in HLS treated with radiotherapy on the mediastinum when compared to HLS treated without mediastinal radiotherapy and to controls. If HLS were 40 years or older at radiotherapy their PWV was significantly higher (8.54 m/s) than patients irradiated at a younger age (7.14 m/s, p = 0.004) and controls (6.91 m/s, p < 0.001), after adjusting for current age and other CVD risk factors. Mean DC was lower, indicative of stiffer arteries, in HLS treated with radiotherapy on the common carotid artery (2.79) than in HLS without radiotherapy (3.35, p = 0.029) and versus controls (3.60, p = 0.001). DC was lowest in HLS treated at 35 years of age or later (2.05), compared to HLS irradiated at a younger age (2.98, p = 0.046). In HLS, radiotherapy is associated with increased arterial stiffness. The effect of radiotherapy seems most evident when radiotherapy is administered at ages above 35-40 years.

  2. Influence of Postprandial Hyperglycemic Conditions on Arterial Stiffness in Patients With Type 2 Diabetes

    PubMed Central

    Gordin, Daniel; Saraheimo, Markku; Tuomikangas, Jaana; Soro-Paavonen, Aino; Forsblom, Carol; Paavonen, Karri; Steckel-Hamann, Birgit; Vandenhende, Francois; Nicolaou, Loizos; Pavo, Imre; Koivisto, Veikko

    2016-01-01

    Context: Patients with type 2 diabetes (T2D) are at an increased risk of cardiovascular disease. Objective: The objective of the study was to determine whether postprandial hyperglycemia affects arterial function in T2D. Design: A single-center, open-label study of three groups of men were studied: 1) T2D patients with albuminuria (n = 22), 2) T2D patients without albuminuria (n = 24), and 3) nondiabetic controls (n = 25). Patients were randomized to a two-period crossover study schedule, ingesting breakfast, with or without insulin lispro (to induce low or high postprandial glycemia). Main Outcome Measures: Arterial stiffness was assessed by calculating pulse wave velocity (PWV) and augmentation index using applanation tonometry, and endothelial dysfunction was assessed using peripheral arterial tonometry, 30 minutes before breakfast and up to 240 minutes after breakfast. Results: At baseline, arterial stiffness was increased in patients. When adjusted for age and body mass index, in a combined group of patients with and without albuminuria, brachial PWV was higher during low (P = .032) and high (P = .038) postprandial glycemia vs controls. These differences were driven by the albuminuria group vs controls during low (P = .014) and high (P = .018) postprandial glycemia. No differences were observed in aortic PWV, augmentation index, or peripheral arterial tonometry ratio between patients and controls. Endothelin-1 and IL-6 were higher, and superoxide dismutase was lower, during postprandial hyperglycemia in T2D patients vs controls. Conclusions: In patients with T2D and albuminuria, brachial PWV was higher under postprandial hyperglycemic conditions, relative to controls. These data suggest that hyperglycemia induces an increase in stiffness of intermediate-sized arteries. We found no changes in other parts of the arterial bed. PMID:26731258

  3. Serum Phospholipid Docosahexaenoic Acid Is Inversely Associated with Arterial Stiffness in Metabolically Healthy Men

    PubMed Central

    Lee, Mi-Hyang; Kwon, Nayeon; Yoon, So Ra

    2016-01-01

    We hypothesized that lower proportion of serum phospholipid docosahexaenoic acid (DHA) is inversely associated with increased cardiovascular risk and vascular function in metabolically healthy men. To elucidate it, we first compared serum phospholipid free fatty acid (FA) compositions and cardiovascular risk parameters between healthy men (n = 499) and male patients with coronary artery disease (CAD, n = 111) (30-69 years) without metabolic syndrome, and then further-analyzed the association of serum phospholipid DHA composition with arterial stiffness expressed by brachial-ankle pulse wave velocity (ba-PWV) in metabolically healthy men. Basic parameters, lipid profiles, fasting glycemic status, adiponectin, high sensitivity C-reactive protein (hs-CRP) and LDL particle size, and serum phospholipid FA compositions were significantly different between the two subject groups. Serum phospholipid DHA was highly correlated with most of long-chain FAs. Metabolically healthy men were subdivided into tertile groups according to serum phospholipid DHA proportion: lower (< 2.061%), middle (2.061%-3.235%) and higher (> 3.235%). Fasting glucose, insulin resistance, hs-CRP and ba-PWVs were significantly higher and adiponectin and LDL particle size were significantly lower in the lower-DHA group than the higher-DHA group after adjusted for confounding factors. In metabolically healthy men, multiple stepwise regression analysis revealed that serum phospholipid DHA mainly contributed to arterial stiffness (β′-coefficients = -0.127, p = 0.006) together with age, systolic blood pressure, triglyceride (r = 0.548, p = 0.023). Lower proportion of serum phospholipid DHA was associated with increased cardiovascular risk and arterial stiffness in metabolically healthy men. It suggests that maintaining higher proportion of serum phospholipid DHA may be beneficial for reducing cardiovascular risk including arterial stiffness in metabolically healthy men. PMID:27482523

  4. Deterioration in Renal Function Is Associated With Increased Arterial Stiffness

    PubMed Central

    2014-01-01

    BACKGROUND Higher levels of baseline pulse wave velocity (PWV) have been associated with longitudinal decline in renal function in patients with kidney disease. We examined longitudinal decline in renal function in relation to levels of PWV. We hypothesized that longitudinal decline in renal function in a community-based, nonclinic sample would be associated with higher levels of PWV. METHODS We conducted a 4–5 year longitudinal study with 482 community-living individuals free from acute stroke, dementia, and end-stage renal disease (mean age = 60.9 years; 59% women; 93.2% white; 10% with diabetes mellitus; mean estimated glomerular filtration rate (eGFR) = 79.2ml/min/1.73 m2). Multiple linear regression analyses were used to examine the association between changes in renal function (eGFR and serum creatinine) from baseline to follow-up and PWV levels at follow-up, the outcome measure. Regression coefficients were adjusted for age, sex, education, race/ethnicity, weight, activity level, mean arterial pressure, treatment of hypertension, and cardiovascular risk factors. RESULTS With adjustment for covariables, decline in renal function was associated with higher levels of PWV over a mean follow-up of 4.68 years. CONCLUSIONS Decline in renal functioning from baseline levels measured 4–5 years before measurement of PWV is related to higher levels of PWV in a community sample. PMID:24080989

  5. Application of a four-channel vibrometer system for detection of arterial stiffness

    NASA Astrophysics Data System (ADS)

    Campo, Adriaan; Waz, Adam; Dudzik, Grzegorz; Dirckx, Joris; Abramski, Krzysztof

    2016-06-01

    Cardiovascular diseases (CD) are the most important cause of death in the world and their prevalence is only rising. A significant aspect in the etiology of CD is the stiffening of the large arteries (arteriosclerosis) and plaque formation (atherosclerosis) in the common carotid artery (CCA) in the neck. As shown by increasing evidence, both conditions can be detected by assessing pulse wave velocity (PWV) in the CCA, and several approaches allow local detection of PWV, including ultrasound (US) and magnetic resonance imaging (MRI). In previous studies, laser Doppler vibrometry (LDV) was introduced as an approach to assess arterial stiffness. In the present work, a new, compact four-channel LDV system is used for PWV detection in four phantom arteries mimicking real life CCA conditions. The high sensitivity of the LDV system allowed PWV to be assessed, and even local changes in phantom architecture could be detected. This method has potential for cardiovascular screening, as it allows arteriosclerosis assessment and plaque detection.

  6. Taurine supplementation attenuates delayed increase in exercise-induced arterial stiffness.

    PubMed

    Ra, Song-Gyu; Choi, Youngju; Akazawa, Nobuhiko; Ohmori, Hajime; Maeda, Seiji

    2016-06-01

    There is a delayed increase in arterial stiffness after eccentric exercise that is possibly mediated by the concurrent delayed increase in circulating oxidative stress. Taurine has anti-oxidant action, and taurine supplementation may be able to attenuate the increase in oxidative stress after exercise. The purpose of the present study was to investigate whether taurine supplementation attenuates the delayed increase in arterial stiffness after eccentric exercise. In the present double-blind, randomized, and placebo-controlled trial, we divided 29 young, healthy men into 2 groups. Subjects received either 2.0 g of placebo (n = 14) or taurine (n = 15) 3 times per day for 14 days prior to the exercise, on the day of exercise, and the following 3 days. The exercise consisted of 2 sets of 20 maximal-effort eccentric repetitions with the nondominant arm only. On the morning of exercise and for 4 days thereafter, we measured serum malondialdehyde (MDA) and carotid-femoral pulse wave velocity (cfPWV) as indices of oxidative stress and arterial stiffness, respectively. On the third and fourth days after exercise, both MDA and cfPWV significantly increased in the placebo group. However, these elevations were significantly attenuated in the taurine group. The increase in MDA was associated with an increase in cfPWV from before exercise to 4 days after exercise (r = 0.597, p < 0.05) in the placebo group, but not in the taurine group. Our results suggest that delayed increase in arterial stiffness after eccentric exercise was probably affected by the exercise-induced oxidative stress and was attenuated by the taurine supplementation.

  7. Relation of Habitual Chocolate Consumption to Arterial Stiffness in a Community-Based Sample: Preliminary Findings

    PubMed Central

    Crichton, Georgina E.; Elias, Merrill F.; Alkerwi, Ala'a; Stranges, Saverio; Abhayaratna, Walter P.

    2016-01-01

    Background The consumption of chocolate and cocoa has established cardiovascular benefits. Less is known about the effects of chocolate on arterial stiffness, a marker of subclinical cardiovascular disease. The aim of this study was to investigate whether chocolate intakes are independently associated with pulse wave velocity (PWV), after adjustment for cardiovascular, lifestyle and dietary factors. Methods Prospective analyses were undertaken on 508 community-dwelling participants (mean age 61 years, 60% women) from the Maine-Syracuse Longitudinal Study (MSLS). Habitual chocolate intakes, measured using a food frequency questionnaire, were related to PWV, measured approximately 5 years later. Results Chocolate intake was significantly associated with PWV in a non-linear fashion with the highest levels of PWV in those who never or rarely ate chocolate and lowest levels in those who consumed chocolate once a week. This pattern of results remained and was not attenuated after multivariate adjustment for diabetes, cardiovascular risk factors and dietary variables (p = 0.002). Conclusions Weekly chocolate intake may be of benefit to arterial stiffness. Further studies are needed to explore the underlying mechanisms that may mediate the observed effects of habitual chocolate consumption on arterial stiffness. PMID:27493901

  8. Arterial stiffness is inversely associated with a better running record in a full course marathon race

    PubMed Central

    Jung, Su-Jeen; Park, Jae-Hyoung; Lee, Sewon

    2014-01-01

    [Purpose] Arterial stiffness is an independent predictor of cardiovascular risk and may contribute to reduced running capacity in humans. This study investigated the relationship between course record and arterial stiffness in marathoners who participated in the Seoul International Marathon in 2012. [Methods] A total of 30 amateur marathoners (Males n = 28, Females n = 2, mean age = 51.6 ± 8.3 years) were assessed before and after the marathon race. Brachial-ankle pulse wave velocity (ba-PWV) was assessed by VP-1000 plus (Omron Healthcare Co., Ltd., Kyoto, Japan) before and immediately after the marathon race. Pearson's correlation coefficient was used to determine the relationship between race record and ba-PWV. In addition, Wilcoxon signed rank test was used to determine the difference in ba-PWV between before and after the race. [Results] There was no significant change in the ba-PWV of marathoners before and after the race (1271.1 ± 185 vs. 1268.8 ± 200 cm/s, P=0.579). Both the full course record (Pearson's correlation coefficient = 0.416, P = 0.022) and the record of half line (Pearson's correlation coefficient = 0.482, P = 0.007) were positively related with the difference in ba-PWV, suggesting that reduced arterial stiffness is associated with a better running record in the marathon. [Conclusion] These results may suggest that good vascular function contributes to a better running record in the marathon race. PMID:25671202

  9. Genetic variation in CYP17A1 is associated with arterial stiffness in diabetic subjects.

    PubMed

    Yang, Soo Jin; Lee, Seung-Tae; Kim, Won Jun; Park, Se Eun; Park, Sung Woo; Kim, Jong-Won; Park, Cheol-Young

    2012-01-01

    Hypertension and arterial stiffness are associated with an increasing risk of diabetes and cardiovascular diseases. This study aimed to identify genetic variants affecting hypertension and arterial stiffness in diabetic subjects and to compare genetic associations with hypertension between prediabetic and diabetic subjects. A total of 1,069 participants (326 prediabetic and 743 diabetic subjects) were assessed to determine the genetic variants affecting hypertension by analyzing 52 SNPs previously reported to be associated with hypertension. Moreover, the SNPs were tested for association with hemodynamic parameters related to hypertension. Out of the 52 SNPs analyzed, four SNPs including rs5326 (DRD1), rs1004467 (CYP17A1), rs2960306 (GRK4), and rs11191548 (near NT5C2) in diabetic subjects and rs1530440 (C10orf107) in prediabetic subjects showed a modest association with hypertension (P = 0.0265, 0.0020, 0.0066, 0.0078, and 0.0015, resp; all were insignificant after Bonferroni correction). Of these SNPs, rs1004467 in CYP17A1 was significantly associated with augmentation index in diabetic subjects who were not taking antihypertensive medication (P = 0.0001; corrected P = 0.006) but not in diabetic subjects receiving antihypertensive medication. This finding suggests that certain genetic variations found in diabetic subjects may confer arterial stiffness and the development of hypertension and also be affected by antihypertensive medication.

  10. Influence of detraining on temporal changes in arterial stiffness in endurance athletes: a prospective study

    PubMed Central

    Koshiba, Hiroya; Maeshima, Etsuko

    2015-01-01

    [Purpose] We examined the effects of detraining on temporal changes in arterial stiffness in endurance athletes. [Subjects] Eighteen female university athletes requiring high endurance exercise capabilities were classified into 2 groups: 10 retired players (detraining group) and 8 active players (training group). [Methods] Brachial-ankle pulse wave velocity, an index of arterial stiffness, was measured a total of 6 times: immediately before retirement of the detraining group and at 1, 2, 3, 6, and 12 months after retirement. [Results] Brachial-ankle pulse wave velocity was measured in the training group at the same 6 points to allow comparison with the detraining group. The brachial-ankle pulse wave velocity in the detraining group increased significantly at 3 and 12 months as compared with that at 0 months and showed a significant increase at 12 months compared with that at 1 month. Moreover, the brachial-ankle pulse wave velocity in the detraining group was significantly higher at 3, 6, and 12 months than in the training group. [Conclusion] These results revealed that detraining may result in increased arterial stiffness from 3 months onward in endurance athletes. PMID:26834331

  11. The Use of the Ambulatory Arterial Stiffness Index in Patients Suspected of Secondary Hypertension

    PubMed Central

    Verbakel, Joshua R. A.; Adiyaman, Ahmet; Kraayvanger, Nicole; Dechering, Dirk G.; Postma, Cornelis T.

    2016-01-01

    The ambulatory arterial stiffness index (AASI) is a marker of arterial stiffness and is derived from ambulatory 24-h blood pressure registration. We studied whether the AASI could be used as a predictive factor for the presence of renal artery stenosis (RAS) in patients with a suspicion of secondary hypertension and as such as a diagnostic tool for RAS. We included 169 patients with difficult-to-treat hypertension. They all underwent 24-h ambulatory blood pressure monitoring registration, imaging of the renal arteries, and cardiovascular risk measurement, including smoking, history, biometrics, blood pressure, renal function, lipids, and glucose metabolism. Performing univariate and multivariate analyses, we investigated if AASI and the other cardiovascular risk factors were related to the presence of RAS. Of the 169 patients (49% women), 31% had RAS. The mean AASI was 0.44 (0.16). The presence of RAS showed no significant correlation with AASI (r = 0.14, P = 0.06). Age (r = 0.19, P = 0.01), hypercholesterolemia (r = 0.26, P = 0.001), history of CVD (r = 0.22, P = 0.004), and creatinine clearance (r = −0.34, P < 0.001) all demonstrated a correlation with RAS. Although AASI is higher in patients with RAS, AASI does not independently predict the presence of RAS in hypertensive subjects. PMID:28018907

  12. Increased Pulse Wave Velocity Reflecting Arterial Stiffness in Patients with Colorectal Adenomas

    PubMed Central

    Lim, Yun Jeong; Kwack, Won Gun; Lee, Youg-Sup; Hahm, Ki Baik; Kim, Young-Kwon

    2010-01-01

    The obese patients with diabetes or cardiovascular risk factors are associated with increased risk of colorectal cancer as well as adenomas under the shared pathogenesis related to atherosclerosis. Here we determined the association between increased arterial stiffness and colorectal adenomas incorporating parameters including age, gender, waist circumference, body mass index, lipid profiles, fasting glucose, and blood pressure. Subjects who simultaneously underwent colonoscopies and pulse wave velocity (PWV) determinations between July 2005 and September 2006 were analyzed, based on which the subjects were classified into two groups as patients group with colorectal adenomas (n = 49) and control group (n = 200) with normal, non-polypoid benign lesions or hyperplastic polyps. Uni- and multi-variate analyses were performed to calculate the odd ratio for colon adenomas. Based on uni-variate analysis, age, waist circumference, body mass index, heart-femoral PWV (hfPWV), and brachial-ankle PWV were significantly associated with adenomas (p<0.05) and multiple logistic regression analysis showed that the heart-femoral PWV, waist circumference, and the levels of LDL-C were significant risk factor for colorectal adenoma. However, arterial stiffness did not affect the progression of colon adenoma. The finding that hfPWV, reflecting aortic stiffness, was increased in patients with colorectal adenomas lead to conclusion that patients who have prominently increased arterial stiffness can be recommended to undergo colonoscopic examinations and at the same time we also recommend counseling about the risk for atherosclerosis in those who have colorectal adenomas. PMID:21103036

  13. Prevalence of arterial stiffness and the risk of myocardial diastolic dysfunction in women

    PubMed Central

    Seeland, Ute; Brecht, Anna; Nauman, Ahmad T.; Oertelt-Prigione, Sabine; Ruecke, Mirjam; Knebel, Fabian; Stangl, Verena; Regitz-Zagrosek, Vera

    2016-01-01

    The present study determines the prevalence of vascular dysfunction and arterial stiffness (ASt) in a female urban population by measuring the brachial augmentation index (AIx) and aortic pulse wave velocity (PWV). The study tests the hypothesis that the measurement of AIx and PWV is useful in addition to that of traditional cardiovascular risk factors when assessing the risk for left ventricular diastolic dysfunction (LVDD). This cross-sectional study recruited 965 women aged 25–75 years from 12 districts of Berlin. The ASt indices, brachial AIx, aortic PWV and the central blood pressure were measured by an oscillometric method. A randomly selected subgroup (n=343) was examined by echocardiography. Trans-mitral inflow E/A ratio and diastolic mitral annulus velocity (é) were assessed. Questionnaires, medical history and blood sampling were used for the evaluation of individual risk factors. Normal vascular function was found in 55% of the women included. The prevalence of women with pathological AIx only (AIx ⩾ −10%, PWV normal) was 21.5%, whereas 17.9% were affected by increased AIx and PWV (AIx ⩾ −10%, PWV ⩾9.7 m/s), and 6% with only pathological PWV values. The prevalence of LVDD was 31.7%. LVDD was significantly associated with pathological PWV ⩾ 9.7 m/s [OR: 1.27, 95%CI: 1.02–1.57], age [OR: 4.17, 95%CI: 2.87–6.07] and a waist circumference >80 cm [OR: 3.61, 95%CI: 1.85–7.04] in multiple regression analysis. The high prevalence of markers for vascular dysfunction and ASt in a general female population and their importance as a mediator of diastolic dysfunction should encourage implementation of aortic PWV measurement to improve cardiovascular-risk assessment in particular to identify subclinical myocardial diastolic dysfunction. PMID:27653526

  14. Effects of dark chocolate and cocoa consumption on endothelial function and arterial stiffness in overweight adults.

    PubMed

    West, Sheila G; McIntyre, Molly D; Piotrowski, Matthew J; Poupin, Nathalie; Miller, Debra L; Preston, Amy G; Wagner, Paul; Groves, Lisa F; Skulas-Ray, Ann C

    2014-02-01

    The consumption of cocoa and dark chocolate is associated with a lower risk of CVD, and improvements in endothelial function may mediate this relationship. Less is known about the effects of cocoa/chocolate on the augmentation index (AI), a measure of vascular stiffness and vascular tone in the peripheral arterioles. We enrolled thirty middle-aged, overweight adults in a randomised, placebo-controlled, 4-week, cross-over study. During the active treatment (cocoa) period, the participants consumed 37 g/d of dark chocolate and a sugar-free cocoa beverage (total cocoa = 22 g/d, total flavanols (TF) = 814 mg/d). Colour-matched controls included a low-flavanol chocolate bar and a cocoa-free beverage with no added sugar (TF = 3 mg/d). Treatments were matched for total fat, saturated fat, carbohydrates and protein. The cocoa treatment significantly increased the basal diameter and peak diameter of the brachial artery by 6% (+2 mm) and basal blood flow volume by 22%. Substantial decreases in the AI, a measure of arterial stiffness, were observed in only women. Flow-mediated dilation and the reactive hyperaemia index remained unchanged. The consumption of cocoa had no effect on fasting blood measures, while the control treatment increased fasting insulin concentration and insulin resistance (P= 0·01). Fasting blood pressure (BP) remained unchanged, although the acute consumption of cocoa increased resting BP by 4 mmHg. In summary, the high-flavanol cocoa and dark chocolate treatment was associated with enhanced vasodilation in both conduit and resistance arteries and was accompanied by significant reductions in arterial stiffness in women.

  15. Arterial Stiffness Is Significantly Associated With Left Ventricular Diastolic Dysfunction in Patients With Cardiovascular Disease.

    PubMed

    Namba, Takayuki; Masaki, Nobuyuki; Matsuo, Yuki; Sato, Atsushi; Kimura, Toyokazu; Horii, Shunpei; Yasuda, Risako; Yada, Hirotaka; Kawamura, Akio; Takase, Bonpei; Adachi, Takeshi

    2016-12-02

    Left ventricular (LV) diastolic dysfunction is considered the main cause of heart failure with preserved ejection fraction (HFpEF). There have been few reports on the correlation between LV diastolic dysfunction and arterial stiffness in patients with clinical cardiovascular disease.This cross-sectional study enrolled 100 patients (67 men, 33 women; mean age, 70 years). All participants were diagnosed with cardiovascular disease. A total of 89 (89%) patients had coronary artery disease or HF. Patients with reduced EF and valvular disease were excluded. Arterial stiffness was assessed by the cardio-ankle vascular index (CAVI), and LV diastolic dysfunction was estimated using echocardiography. The patients were divided into two groups based on the median value of CAVI. In all patients the ratio of early diastolic transmitral flow velocity to early diastolic mitral annular velocity (E/e') was significantly higher in the high CAVI group than in the low CAVI group (15.5 ± 6.4 versus 12.5 ± 2.9, P = 0.003). In the HF subgroup, E/e' was also significantly higher in the high CAVI group than in the low CAVI group (17.2 ± 5.9 versus 13.0 ± 3.1, P = 0.026). In univariate regression analysis, CAVI was significantly associated with E/e' in all patients (β = 0.28, P = 0.004) and in HF patients (β = 0.4, P = 0.028). Also in multivariate analysis, CAVI remained as an independent predictive factor of E/e' (β = 0.252, P = 0.037).A high CAVI was independently associated with LV diastolic dysfunction in patients with clinical cardiovascular disease. These results suggested that arterial stiffness contributed to the development of LV diastolic dysfunction.

  16. Opiate Dependence as an Independent and Interactive Risk Factor for Arterial Stiffness and Cardiovascular Ageing - A Longitudinal Study in Females

    PubMed Central

    Reece, Albert Stuart; Hulse, Gary Kenneth

    2013-01-01

    Background Despite intriguing observational cross-sectional data there are no longitudinal studies of opiate related arterial disease. As opiates act via P16INK4A/CDKN2A, and vascular ageing has been thought to be a surrogate for organismal ageing, the subject has far-reaching implications. Methods Pulse Wave Analysis (PWA) by radial arterial tonometry (SphygmoCor) was performed on control and opiate dependent patients. Results A total of 37 controls were compared with 93 opiate dependents. They were studied on 117 and 275 occasions respectively up to 1,797 days. The mean (± S.E.M.) ages were 38.72 ± 2.64 and 33.78 ± 0.90 years (P = 0.0260), 91.4% and 10.8% smoked (P < 0.0001). Body mass index rose more in controls (P = 0.0185) and in interaction with time (P = 0.0025). When controlled for time and BMI, opiate dependency status was shown to be associated with vascular age and central arterial stiffness and pressure indices (all P < 0.05). When repeated measures multiple regression was performed on all traditional cardiovascular risk factors, the opiate dose-duration interaction was significant and appeared in 12 terms in the final model. It was also independently significant (P = 0.0153). Opiate dose or duration appeared in a further 15 terms. The model was shown to be significantly improved by the inclusion of terms for opiate dependency (A.I.C. 71.10 v 54.31, P < 0.0001). Conclusion These data confirm increased vascular stiffness and ageing in a longitudinal study, and thereby imply advanced organismal ageing. These multivariate studies are consistent with opiate dependency as an interactive and multivariate cardiovascular risk factor and emphasize the role of treatment duration. PMID:23976908

  17. Crosstalk between Vitamins A, B12, D, K, C, and E Status and Arterial Stiffness.

    PubMed

    Mozos, Ioana; Stoian, Dana; Luca, Constantin Tudor

    2017-01-01

    Arterial stiffness is associated with cardiovascular risk, morbidity, and mortality. The present paper reviews the main vitamins related to arterial stiffness and enabling destiffening, their mechanisms of action, providing a brief description of the latest studies in the area, and their implications for primary cardiovascular prevention, clinical practice, and therapy. Despite inconsistent evidence for destiffening induced by vitamin supplementation in several randomized clinical trials, positive results were obtained in specific populations. The main mechanisms are related to antiatherogenic effects, improvement of endothelial function (vitamins A, C, D, and E) and metabolic profile (vitamins A, B12, C, D, and K), inhibition of the renin-angiotensin-aldosterone system (vitamin D), anti-inflammatory (vitamins A, D, E, and K) and antioxidant effects (vitamins A, C, and E), decrease of homocysteine level (vitamin B12), and reversing calcification of arteries (vitamin K). Vitamins A, B12, C, D, E, and K status is important in evaluating cardiovascular risk, and vitamin supplementation may be an effective, individualized, and inexpensive destiffening therapy.

  18. Crosstalk between Vitamins A, B12, D, K, C, and E Status and Arterial Stiffness

    PubMed Central

    Luca, Constantin Tudor

    2017-01-01

    Arterial stiffness is associated with cardiovascular risk, morbidity, and mortality. The present paper reviews the main vitamins related to arterial stiffness and enabling destiffening, their mechanisms of action, providing a brief description of the latest studies in the area, and their implications for primary cardiovascular prevention, clinical practice, and therapy. Despite inconsistent evidence for destiffening induced by vitamin supplementation in several randomized clinical trials, positive results were obtained in specific populations. The main mechanisms are related to antiatherogenic effects, improvement of endothelial function (vitamins A, C, D, and E) and metabolic profile (vitamins A, B12, C, D, and K), inhibition of the renin-angiotensin-aldosterone system (vitamin D), anti-inflammatory (vitamins A, D, E, and K) and antioxidant effects (vitamins A, C, and E), decrease of homocysteine level (vitamin B12), and reversing calcification of arteries (vitamin K). Vitamins A, B12, C, D, E, and K status is important in evaluating cardiovascular risk, and vitamin supplementation may be an effective, individualized, and inexpensive destiffening therapy. PMID:28167849

  19. Arterial stiffness and influences of the metabolic syndrome: a cross-countries study.

    PubMed

    Scuteri, Angelo; Cunha, Pedro G; Rosei, E Agabiti; Badariere, Jolita; Bekaert, Sofie; Cockcroft, John R; Cotter, Jorge; Cucca, Francesco; De Buyzere, Marc L; De Meyer, Tim; Ferrucci, Luigi; Franco, Osca; Gale, Nichols; Gillebert, Thierry C; Hofman, A; Langlois, Michel; Laucevicius, Aleksandras; Laurent, Stephane; Mattace Raso, Francesco U S; Morrell, Cristopher H; Muiesan, Maria Lorenza; Munnery, Margaret M; Navickas, Rokas; Oliveira, Pedro; Orru', Marco; Pilia, Maria Grazia; Rietzschel, Ernst R; Ryliskyte, Ligita; Salvetti, Massimo; Schlessinger, David; Sousa, Nuno; Stefanadis, Christodoulos; Strait, James; Van daele, Caroline; Villa, Isabel; Vlachopoulos, Charalambos; Witteman, Jacqueline; Xaplanteris, Panagiotis; Nilsson, Peter; Lakatta, Edward G

    2014-04-01

    Specific clusters of metabolic syndrome (MetS) components impact differentially on arterial stiffness, indexed as pulse wave velocity (PWV). Of note, in several population-based studies participating in the MARE (Metabolic syndrome and Arteries REsearch) Consortium the occurrence of specific clusters of MetS differed markedly across Europe and the US. The aim of the present study was to investigate whether specific clusters of MetS are consistently associated with stiffer arteries in different populations. We studied 20,570 subjects from 9 cohorts representing 8 different European countries and the US participating in the MARE Consortium. MetS was defined in accordance with NCEP ATPIII criteria as the simultaneous alteration in ≥3 of the 5 components: abdominal obesity (W), high triglycerides (T), low HDL cholesterol (H), elevated blood pressure (B), and elevated fasting glucose (G). PWV measured in each cohort was "normalized" to account for different acquisition methods. MetS had an overall prevalence of 24.2% (4985 subjects). MetS accelerated the age-associated increase in PWV levels at any age, and similarly in men and women. MetS clusters TBW, GBW, and GTBW are consistently associated with significantly stiffer arteries to an extent similar or greater than observed in subjects with alteration in all the five MetS components--even after controlling for age, sex, smoking, cholesterol levels, and diabetes mellitus--in all the MARE cohorts. In conclusion, different component clusters of MetS showed varying associations with arterial stiffness (PWV).

  20. Arterial stiffness and enlargement in mild-to-moderate chronic kidney disease.

    PubMed

    Briet, M; Bozec, E; Laurent, S; Fassot, C; London, G M; Jacquot, C; Froissart, M; Houillier, P; Boutouyrie, P

    2006-01-01

    Chronic kidney disease (CKD) is associated with an increased risk of cardiovascular morbidity and mortality. Arterial stiffness and remodeling have been well documented in patients with end-stage renal disease, but little is known about arterial phenotype in CKD patients with moderate reduction in glomerular filtration rate (GFR). In total, 95 patients (58+/-15 years, mean+/-s.d.) with CKD and GFR measured by renal clearance of (51)Cr-ethylenediaminetetraacetate were compared to 121 hypertensive patients without CKD (59+/-11 years), and 57 normotensive subjects (56+/-6 years). Common carotid artery diameter, intima-media thickness (IMT), distensibility, and Young's elastic modulus were noninvasively determined with a high-definition echotracking system. Patients with CKD had a significantly larger carotid internal diameter than in hypertensives and normotensives (6.32+/-1.05, 5.84+/-0.74, and 5.50+/-0.64 m x 10(-3), respectively; P<0.001), resulting in 25% and 11% increases in circumferential wall stress, respectively, since no significant difference in IMT was observed. Carotid distensibility and elastic modulus did not significantly differ between CKD and hypertensives; normotensives had significantly higher distensibility and lower elastic modulus than CKD and hypertensive patients. Carotid-femoral pulse wave velocity was significantly higher in CKD patients than in hypertensives and normotensives. In multivariate analyses either involving the entire population or restricted to CKD patients, GFR was independently and strongly related to carotid diameter and elastic modulus. Arterial enlargement and increased arterial stiffness occur in parallel with the decline in renal function in patients with mild-to-moderate CKD.

  1. Main pulmonary arterial wall shear stress correlates with invasive hemodynamics and stiffness in pulmonary hypertension

    PubMed Central

    Kheyfets, Vitaly O.; Schroeder, Joyce D.; Dunning, Jamie; Shandas, Robin; Buckner, J. Kern; Browning, James; Hertzberg, Jean; Hunter, Kendall S.; Fenster, Brett E.

    2016-01-01

    Abstract Pulmonary hypertension (PH) is associated with proximal pulmonary arterial remodeling characterized by increased vessel diameter, wall thickening, and stiffness. In vivo assessment of wall shear stress (WSS) may provide insights into the relationships between pulmonary hemodynamics and vascular remodeling. We investigated the relationship between main pulmonary artery (MPA) WSS and pulmonary hemodynamics as well as markers of stiffness. As part of a prospective study, 17 PH patients and 5 controls underwent same-day four-dimensional flow cardiac magnetic resonance imaging (4-D CMR) and right heart catheterization. Streamwise velocity profiles were generated in the cross-sectional MPA in 45° increments from velocity vector fields determined by 4-D CMR. WSS was calculated as the product of hematocrit-dependent viscosity and shear rate generated from the spatial gradient of the velocity profiles. In-plane average MPA WSS was significantly decreased in the PH cohort compared with that in controls (0.18 ± 0.07 vs. 0.32 ± 0.08 N/m2; P = 0.01). In-plane MPA WSS showed strong inverse correlations with multiple hemodynamic indices, including pulmonary resistance (ρ = −0.74, P < 0.001), mean pulmonary pressure (ρ = −0.64, P = 0.006), and elastance (ρ = −0.70, P < 0.001). In addition, MPA WSS had significant associations with markers of stiffness, including capacitance (ρ = 0.67, P < 0.001), distensibility (ρ = 0.52, P = 0.013), and elastic modulus (ρ = −0.54, P = 0.01). In conclusion, MPA WSS is decreased in PH and is significantly associated with invasive hemodynamic indices and markers of stiffness. 4-D CMR–based assessment of WSS may represent a novel methodology to study blood-vessel wall interactions in PH. PMID:27076906

  2. Aerobic training-induced improvements in arterial stiffness are not sustained in older adults with multiple cardiovascular risk factors

    PubMed Central

    Madden, K M; Lockhart, C; Cuff, D; Potter, T F; Meneilly, G S

    2013-01-01

    There is a well-established relationship between increased arterial stiffness and cardiovascular mortality. We examined whether a long-term aerobic exercise intervention (6 months) would increase arterial compliance in older adults with hypertension complicated by Type 2 diabetes (T2DM) and hyperlipidemia. A total of 52 older adults (mean age 69.3±0.6 years, 30 males and 22 females) with diet/oral hypoglycemic-controlled T2DM, hypertension and hypercholesterolemia were recruited. Subjects were randomly assigned to one of two groups: an aerobic group (6 months vigorous aerobic exercise, AT group) and a non-aerobic group (6 months of no aerobic exercise, NA group). Arterial stiffness was measured as pulse-wave velocity (PWV) using the Complior device. Aerobic training decreased arterial stiffness as measured by both radial (P=0.001, 2-way analysis of variance with repeated measures) and femoral (P=0.002) PWV. This was due to a decrease in arterial stiffness in the AT group after 3 months of training, which was not maintained after 6-month training for either radial (P=0.707) or femoral (P=0.680) PWV. Our findings indicate that in older adults with multiple cardiovascular risk factors, short-term improvements in arterial stiffness became attenuated over the long term. PMID:22951625

  3. Arterial Stiffness and Carotid Intima-Media Thickness in Diabetic Peripheral Neuropathy

    PubMed Central

    Avci, Ahmet; Demir, Kenan; Kaya, Zeynettin; Marakoglu, Kamile; Ceylan, Esra; Ekmekci, Ahmet Hakan; Yilmaz, Ahmet; Demir, Aysegul; Altunkeser, Bulent Behlul

    2014-01-01

    Background We investigated the relationship between peripheral neuropathy and parameters of arterial stiffness and carotid intima media thickness (CIMT) in patients with type 2 diabetes mellitus (T2DM). Material/Methods The study included 161 patients (80 females and 81 males), 69 of whom had peripheral neuropathy. All patients underwent 24-h blood pressure monitoring, and arterial stiffness parameters were measured. The CIMT was measured using B-mode ultrasonography and patients also underwent transthoracic echocardiographic examination. Results Patients with peripheral neuropathy, compared with those without it, were older (54.68±8.35 years vs. 51.04±7.89 years; p=0.005) and had T2DM for longer periods (60 vs. 36 months; p=0.004). Glycated hemoglobin (HbA1c) values (8.55±1.85 mg/dL vs. 7.30±1.51 mg/dL; p<0.001), pulse wave velocity (PWV) (7.74±1.14 m/s vs. 7.15±1.10 m/s; p=0.001), CIMT (anterior 0.74±0.15 mm vs. 0.67±0.13 mm; p=0.01), and left ventricular mass (LVM) index (98.68±26.28 g/m2 vs. 89.71±19.70 g/m2; p=0.02) were all significantly increased in the group with peripheral neuropathy compared to the group without peripheral neuropathy. We determined that duration of diabetes, HbA1c, and LVM index were predictors of peripheral neuropathy. Conclusions A significant relationship was found between diabetic neuropathy and increased PWV, a parameter of arterial stiffness, as well as CIMT, a marker of systemic atherosclerosis. Diabetic peripheral neuropathy may be a determinant of subclinical atherosclerosis in T2DM. PMID:25351260

  4. Bone Strength and Arterial Stiffness Impact on Cardiovascular Mortality in a General Population

    PubMed Central

    Avramovska, Maja; Sikole, Aleksandar

    2016-01-01

    Osteoporosis and increased arterial stiffness independently have been found to be associated with higher cardiovascular events rates in the general population (GP). We examined 558 patients from GP by dual-energy X-ray absorptiometry (DXA) and pulse wave velocity (PWV) measurements at baseline, with 36-month follow-up period. DXA assessed bone mineral density of femoral neck (BMD FN) and lumbar spine (BMD LS). Carotid-femoral PWV was assessed by pulsed-Doppler. The aim of our study is to find correlation between bone strength and arterial stiffness and their impact on cardiovascular mortality in GP. The mean ± SD of BMD FN, BMD LS, and PWV was 0.852 ± 0.1432 g/cm2, 0.934 ± 0.1546 g/cm2, and 9.209 ± 1.9815 m/s. In multiple regression analysis we found BMD FN (βst = −6.0094, p < 0.0001), hypertension (βst = 1.7340, p < 0.0091), and diabetes (βst = 0.4595, p < 0.0046). With Cox-regression analysis, after 17 cardiovascular events, the significant covariates retained by the backward model were BMD FN (b = −2.4129, p = 0.015) and PWV (b = 0.2606, p = 0.0318). The cut-off values were PWV = 9.4 m/s, BMD FN = 0.783 g/cm2, and BMD LS = 0.992 g/cm2. The results for BMD FN and PWV hazard ratio risk were 1.116 and 1.297, respectively. BMD FN as a measure of bone strength and PWV as a measure of arterial stiffness are strong independent predictors of cardiovascular mortality in GP. PMID:27047700

  5. Developing an effective arterial stiffness monitoring system using the spring constant method and photoplethysmography.

    PubMed

    Wei, Ching-Chuan

    2013-01-01

    This study aimed to develop a fast and effective arterial stiffness monitoring system for diabetic patients using the spring constant method and photoplethysmography (PPG). The experimental group comprised 70 patients (4 type 1 diabetes mellitus patients and 66 type 2 diabetes mellitus patients); 23 participants suffered from atherosclerosis. All were subjected to the measurements of both the carotid-femoral pulse wave velocity (cfPWV) and the spring constants evaluated using the PPG pulse as well as the radial pulse. The control group comprised 70 normal participants (39 men and 31 women) who did not have diabetes mellitus, with an age range of 40-84 years. All control group members were only subjected to the measurement by the spring constant method. For the experimental group, statistical analysis indicated a significantly high correlation between the spring constants computed using PPG and the radial pulse (p < 0.001, correlation coefficient =0.89). The result also showed a significant negative correlation between the cfPWV and the spring constant of PPG (p < 0.001, correlation coefficient = - 0.72); multivariate analysis similarly indicated a close relationship. In addition, we used Student's t test to examine the difference between the experimental and control groups for the spring constant of PPG. A P value less than 0.05 confirmed that the difference between the two groups was statistically significant. In the receiver operating characteristic curve, area under curve (=0.82) indicates a good discrimination, and a spring constant of PPG below 516 (g/s (2)) may imply a risk of arterial stiffness for diabetic patients. These findings imply that the spring constant of PPG could effectively identify normal versus abnormal characteristics of elasticity in normal and diabetic participants. As a result of some excellent characteristics in clinical monitoring, the spring constant computed using PPG shows the effectiveness and feasibility in the monitoring system of

  6. Effect of Lysyl Oxidase Inhibition on Angiotensin II-Induced Arterial Hypertension, Remodeling, and Stiffness

    PubMed Central

    Eberson, Lance S.; Sanchez, Pablo A.; Majeed, Beenish A.; Tawinwung, Supannikar; Secomb, Timothy W.; Larson, Douglas F.

    2015-01-01

    It is well accepted that angiotensin II (Ang II) induces altered vascular stiffness through responses including both structural and material remodeling. Concurrent with remodeling is the induction of the enzyme lysyl oxidase (LOX) through which ECM proteins are cross-linked. The study objective was to determine the effect of LOX mediated cross-linking on vascular mechanical properties. Three-month old mice were chronically treated with Ang II with or without the LOX blocker, β -aminopropionitrile (BAPN), for 14 days. Pulse wave velocity (PWV) from Doppler measurements of the aortic flow wave was used to quantify in vivo vascular stiffness in terms of an effective Young’s modulus. The increase in effective Young’s modulus with Ang II administration was abolished with the addition of BAPN, suggesting that the material properties are a major controlling element in vascular stiffness. BAPN inhibited the Ang II induced collagen cross-link formation by 2-fold and PWV by 44% (P<0.05). Consistent with this observation, morphometric analysis showed that BAPN did not affect the Ang II mediated increase in medial thickness but significantly reduced the adventitial thickness. Since the hypertensive state contributes to the measured in vivo PWV stiffness, we removed the Ang II infusion pumps on Day 14 and achieved normal arterial blood pressures. With pump removal we observed a decrease of the PWV in the Ang II group to 25% above that of the control values (P=0.002), with a complete return to control values in the Ang II plus BAPN group. In conclusion, we have shown that the increase in vascular stiffness with 14 day Ang II administration results from a combination of hypertension-induced wall strain, adventitial wall thickening and Ang II mediated LOX ECM cross-linking, which is a major material source of vascular stiffening, and that the increased PWV was significantly inhibited with co-administration of BAPN. PMID:25875748

  7. The predictive value of arterial stiffness on major adverse cardiovascular events in individuals with mildly impaired renal function

    PubMed Central

    Han, Jie; Wang, Xiaona; Ye, Ping; Cao, Ruihua; Yang, Xu; Xiao, Wenkai; Zhang, Yun; Bai, Yongyi; Wu, Hongmei

    2016-01-01

    Objectives Despite growing evidence that arterial stiffness has important predictive value for cardiovascular disease in patients with advanced stages of chronic kidney disease, the predictive significance of arterial stiffness in individuals with mildly impaired renal function has not been established. The aim of this study was to evaluate the predictive value of arterial stiffness on cardiovascular disease in this specific population. Materials and methods We analyzed measurements of arterial stiffness (carotid–femoral pulse-wave velocity [cf-PWV]) and the incidence of major adverse cardiovascular events (MACEs) in 1,499 subjects from a 4.8-year longitudinal study. Results A multivariate Cox proportional-hazard regression analysis showed that in individuals with normal renal function (estimated glomerular filtration rate [eGFR] ≥90 mL/min/1.73 m2), the baseline cf-PWV was not associated with occurrence of MACEs (hazard ratio 1.398, 95% confidence interval 0.748–2.613; P=0.293). In individuals with mildly impaired renal function (eGFR <90 mL/min/1.73 m2), a higher baseline cf-PWV level was associated with a higher risk of MACEs (hazard ratio 2.334, 95% confidence interval 1.082–5.036; P=0.031). Conclusion Arterial stiffness is a moderate and independent predictive factor for MACEs in individuals with mildly impaired renal function (eGFR <90 mL/min/1.73 m2). PMID:27621605

  8. Relation of epicardial adipose tissue with arterial compliance and stiffness in patients with hypertension.

    PubMed

    Korkmaz, Levent; Cirakoglu, Omer Faruk; Ağaç, Mustafa Tarik; Erkan, Hakan; Korkmaz, Ayca Ata; Acar, Zeydin; Kul, Selim; Hatem, Engin; Çelik, Şükrü

    2014-09-01

    The main aim of the present study was to investigate the association between epicardial adipose tissue (EAT) and arterial function in patients with asymptomatic hypertension. Patients with hypertension (n = 155) were enrolled consecutively. Patients with decreased arterial compliance (AC) and increased cardioankle vascular index (CAVI) had higher EAT values compared with those with normal AC and CAVI (6.23 ± 1.67 vs 4.91 ± 1.40, P < .001 and 6.02 ± 1.61 vs 4.96 ± 1.46, P = .01, respectively). Analysis using the receiver-operating characteristics curve demonstrated that EAT 5.5 mm constitutes the cutoff value for the presence of increased CAVI with 67% sensitivity and 62% specificity (area under the curve [AUC]: 0.702, 95% confidence interval [CI] 0.590-0.814) and decreased AC with 77% sensitivity and 65% specificity (AUC: 0.756, 95% CI 0.645-0.867). Assessment of EAT during echocardiography examination may provide information on arterial function in patients with asymptomatic hypertension. The link between EAT and arterial stiffness deserves further investigation.

  9. Differential effects of nebivolol and metoprolol on arterial stiffness, circulating progenitor cells, and oxidative stress.

    PubMed

    Hayek, Salim S; Poole, Joseph C; Neuman, Robert; Morris, Alanna A; Khayata, Mohamed; Kavtaradze, Nino; Topel, Matthew L; Binongo, Jose G; Li, Qunna; Jones, Dean P; Waller, Edmund K; Quyyumi, Arshed A

    2015-03-01

    Unlike traditional beta receptor antagonists, nebivolol activates nitric oxide. We hypothesized that therapy with nebivolol compared with metoprolol would improve arterial stiffness, increase levels of circulating progenitor cells (PC), and decrease oxidative stress (OS). In a randomized, double-blind, cross-over study, 30 hypertensive subjects received either once daily nebivolol or metoprolol succinate for 3 months each. Pulse wave velocity and augmentation index were measured using tonometry. Flow cytometry was used to measure circulating PC. OS was measured as plasma aminothiols. Measurements were performed at baseline, and repeated at 3 and 6 months. No significant differences were present between the levels of OS, arterial stiffness, and PC numbers during treatment with metoprolol compared with nebivolol. In subgroup analyses of beta-blocker naïve subjects (n = 19), nebivolol reduced pulse wave velocity significantly compared with metoprolol (-1.4 ± 1.9 vs. -0.1 ± 2.2; P = .005). Both nebivolol and metoprolol increased circulating levels of CD34+/CD133 + PC similarly (P = .05), suggesting improved regenerative capacity.

  10. Arterial stiffness evaluated by cardio-ankle vascular index (CAVI) in adolescent hypertension.

    PubMed

    Mestanik, Michal; Jurko, Alexander; Mestanikova, Andrea; Jurko, Tomas; Tonhajzerova, Ingrid

    2016-01-01

    Elevated blood pressure (BP) is a major risk factor for atherosclerosis. As the studies concerning vascular alterations in pediatric patients are rare, we aimed to study the relationship between hypertension and arterial stiffness in adolescence by novel method independent from BP during examination. Twenty nonobese adolescent boys (16.5 ± 0.4 years) with newly diagnosed essential hypertension, 20 adolescent boys (16.7 ± 0.4 years) with newly diagnosed white-coat hypertension, and 20 healthy controls matched to age and body mass index were examined. Cardio-ankle vascular index (CAVI), brachial-ankle pulse wave velocity (baPWV), pre-ejection period (PEP), and ejection time (ET) were evaluated. CAVI was significantly increased in essential hypertension patients compared with controls (p < 0.05) with no significant difference in white-coat hypertension patients. Significantly higher baPWV was found in essential and white-coat hypertension patients compared with controls (both p < 0.001). White-coat hypertension patients showed significantly shortened PEP and ET compared with controls (p < 0.01 and p < 0.001, respectively) and essential hypertension patients (both p < 0.05). For the first time, the arterial stiffness in adolescents with newly diagnosed essential and white-coat hypertension was studied using BP-independent index CAVI combined with conventional baPWV. Our study revealed significantly increased CAVI in adolescents with newly diagnosed essential hypertension compared with controls. Our findings could help to understand hypertension-atherosclerosis interaction.

  11. Factors associated with arterial stiffness in children aged 9-10 years

    PubMed Central

    Batista, Milena Santos; Mill, José Geraldo; Pereira, Taisa Sabrina Silva; Fernandes, Carolina Dadalto Rocha; Molina, Maria del Carmen Bisi

    2015-01-01

    OBJECTIVE To analyze the factors associated with stiffness of the great arteries in prepubertal children. METHODS This study with convenience sample of 231 schoolchildren aged 9-10 years enrolled in public and private schools in Vitória, ES, Southeastern Brazil, in 2010-2011. Anthropometric and hemodynamic data, blood pressure, and pulse wave velocity in the carotid-femoral segment were obtained. Data on current and previous health conditions were obtained by questionnaire and notes on the child’s health card. Multiple linear regression was applied to identify the partial and total contribution of the factors in determining the pulse wave velocity values. RESULTS Among the students, 50.2% were female and 55.4% were 10 years old. Among those classified in the last tertile of pulse wave velocity, 60.0% were overweight, with higher mean blood pressure, waist circumference, and waist-to-height ratio. Birth weight was not associated with pulse wave velocity. After multiple linear regression analysis, body mass index (BMI) and diastolic blood pressure remained in the model. CONCLUSIONS BMI was the most important factor in determining arterial stiffness in children aged 9-10 years. PMID:25902563

  12. High-Dose versus Low-Dose Vitamin D Supplementation and Arterial Stiffness among Individuals with Prehypertension and Vitamin D Deficiency

    PubMed Central

    Zaleski, Amanda; Panza, Gregory; Swales, Heather; Arora, Pankaj; Newton-Cheh, Christopher; Wang, Thomas; Thompson, Paul D.; Taylor, Beth

    2015-01-01

    Introduction. Vitamin D deficiency is associated with the onset and progression of hypertension and cardiovascular disease (CVD). However, mechanisms underlying vitamin D deficiency-mediated increased risk of CVD remain unknown. We sought to examine the differential effect of high-dose versus low-dose vitamin D supplementation on markers of arterial stiffness among ~40 vitamin D deficient adults with prehypertension. Methods. Participants were randomized to high-dose (4000 IU/d) versus low-dose (400 IU/d) oral vitamin D3 for 6 months. 24 hr ambulatory blood pressure (BP), carotid-femoral pulse wave velocity, and pulse wave analyses were obtained at baseline and after 6 months of vitamin D supplementation. Results. There were no changes in resting BP or pulse wave velocity over 6 mo regardless of vitamin D dose (all p > 0.202). High-dose vitamin D decreased augmentation index and pressure by 12.3 ± 5.3% (p = 0.047) and 4.0 ± 1.5 mmHg (p = 0.02), respectively. However, these decreases in arterial stiffness were not associated with increases in serum 25-hydroxyvitamin D over 6 mo (p = 0.425). Conclusion. High-dose vitamin D supplementation appears to lower surrogate measures of arterial stiffness but not indices of central pulse wave velocity. Clinical Trial Registration. This trial is registered with www.clinicaltrials.gov (Unique Identifier: NCT01240512). PMID:26451070

  13. Impaired renal function impacts negatively on vascular stiffness in patients with coronary artery disease

    PubMed Central

    2013-01-01

    Background Chronic kidney disease (CKD) and coronary artery disease (CAD) are independently associated with increased vascular stiffness. We examined whether renal function contributes to vascular stiffness independently of CAD status. Methods We studied 160 patients with CAD and 169 subjects without CAD. The 4-variable MDRD formula was used to estimate glomerular filtration rate (eGFR); impaired renal function was defined as eGFR <60 mL/min. Carotid-femoral pulse wave velocity (PWV) was measured with the SphygmoCor® device. Circulating biomarkers were assessed in plasma using xMAP® multiplexing technology. Results Patients with CAD and impaired renal function had greater PWV compared to those with CAD and normal renal function (10.2 [9.1;11.2] vs 7.3 [6.9;7.7] m/s; P < 0.001). In all patients, PWV was a function of eGFR (β = −0.293; P < 0.001) even after adjustment for age, sex, systolic blood pressure, body mass index and presence or absence of CAD. Patients with CAD and impaired renal function had higher levels of adhesion and inflammatory molecules including E-selectin and osteopontin (all P < 0.05) compared to those with CAD alone, but had similar levels of markers of oxidative stress. Conclusions Renal function is a determinant of vascular stiffness even in patients with severe atherosclerotic disease. This was paralleled by differences in markers of cell adhesion and inflammation. Increased vascular stiffness may therefore be linked to inflammatory remodeling of the vasculature in people with impaired renal function, irrespective of concomitant atherosclerotic disease. PMID:23937620

  14. Aortic stiffness and blood pressure variability in young people: a multimodality investigation of central and peripheral vasculature

    PubMed Central

    Boardman, Henry; Lewandowski, Adam J.; Lazdam, Merzaka; Kenworthy, Yvonne; Whitworth, Polly; Zwager, Charlotte L.; Francis, Jane M.; Aye, Christina Y.L.; Williamson, Wilby; Neubauer, Stefan; Leeson, Paul

    2017-01-01

    Introduction: Increased blood pressure (BP) variability is a cardiovascular risk marker for young individuals and may relate to the ability of their aorta to buffer cardiac output. We used a multimodality approach to determine relations between central and peripheral arterial stiffness and BP variability. Methods: We studied 152 adults (mean age of 31 years) who had BP variability measures based on SD of awake ambulatory BPs, 24-h weighted SD and average real variability (ARV). Global and regional aortic distensibility was measured by cardiovascular magnetic resonance, arterial stiffness by cardio-ankle vascular index (CAVI) and pulse wave velocity (PWV) by SphygmoCor (carotid–femoral) and Vicorder (brachial–femoral). Results: In young people, free from overt cardiovascular disease, all indices of SBP and DBP variability correlated with aortic distensibility (global aortic distensibility versus awake SBP SD: r = −0.39, P < 0.001; SBP ARV: r = −0.34, P < 0.001; weighted 24-h SBP SD: r = −0.42, P < 0.001). CAVI, which closely associated with aortic distensibility, also related to DBP variability, as well as awake SBP SD (r = 0.19, P < 0.05) and weighted 24-h SBP SD (r = 0.24, P < 0.01), with a trend for SBP ARV (r = 0.17, P = 0.06). In contrast, associations with PWV were only between carotid–femoral PWV and weighted SD of SBP (r = 0.20, P = 0.03) as well as weighted and ARV of DBP. Conclusion: Greater BP variability in young people relates to increases in central aortic stiffness, strategies to measure and protect aortic function from a young age may be important to reduce cardiovascular risk. PMID:27846043

  15. Association between arterial stiffness, cerebral small vessel disease and cognitive impairment: a systematic review and meta-analysis

    PubMed Central

    van Sloten, Thomas T; Protogerou, Athanase D; Henry, Ronald MA; Schram, Miranda T; Launer, Lenore J; Stehouwer, Coen DA

    2017-01-01

    Arterial stiffness may be a cause of cerebral small vessel disease and cognitive impairment. We therefore performed a systematic review and meta-analysis of studies on the association between stiffness, cerebral small vessel disease and cognitive impairment. For the associations between stiffness (i.e. carotid-femoral pulse wave velocity (cfPWV), brachial-ankle PWV (baPWV), carotid stiffness and pulse pressure) on the one hand and cerebral small vessel disease and cognitive impairment on the other, we identified 23 (n=15,666/22 cross-sectional/3 longitudinal) and 41 studies (n=57,671/30 cross-sectional/15 longitudinal), respectively. Pooled analyses of cross-sectional studies showed that greater stiffness was associated with markers of cerebral small vessel disease with odds ratios, per +1 SD, of 1.29 to 1.32 (P<.001). Studies on cognitive impairment could not be pooled due to large heterogeneity. Some (but not all) studies showed an association between greater stiffness and cognitive impairment, and the strength of this association was relatively weak. The present study supports the hypothesis that greater arterial stiffness is a contributor to microvascular brain disease. PMID:25827412

  16. Increased postflight carotid artery stiffness and inflight insulin resistance resulting from 6-mo spaceflight in male and female astronauts.

    PubMed

    Hughson, Richard L; Robertson, Andrew D; Arbeille, Philippe; Shoemaker, J Kevin; Rush, James W E; Fraser, Katelyn S; Greaves, Danielle K

    2016-03-01

    Removal of the normal head-to-foot gravity vector and chronic weightlessness during spaceflight might induce cardiovascular and metabolic adaptations related to changes in arterial pressure and reduction in physical activity. We tested hypotheses that stiffness of arteries located above the heart would be increased postflight, and that blood biomarkers inflight would be consistent with changes in vascular function. Possible sex differences in responses were explored in four male and four female astronauts who lived on the International Space Station for 6 mo. Carotid artery distensibility coefficient (P = 0.005) and β-stiffness index (P = 0.006) reflected 17-30% increases in arterial stiffness when measured within 38 h of return to Earth compared with preflight. Spaceflight-by-sex interaction effects were found with greater changes in β-stiffness index in women (P = 0.017), but greater changes in pulse wave transit time in men (P = 0.006). Several blood biomarkers were changed from preflight to inflight, including an increase in an index of insulin resistance (P < 0.001) with a spaceflight-by-sex term suggesting greater change in men (P = 0.034). Spaceflight-by-sex interactions for renin (P = 0.016) and aldosterone (P = 0.010) indicated greater increases in women than men. Six-month spaceflight caused increased arterial stiffness. Altered hydrostatic arterial pressure gradients as well as changes in insulin resistance and other biomarkers might have contributed to alterations in arterial properties, including sex differences between male and female astronauts.

  17. Association between arterial stiffness and left ventricular diastolic function in relation to gender and age

    PubMed Central

    Kim, Hack-Lyoung; Lim, Woo-Hyun; Seo, Jae-Bin; Chung, Woo-Young; Kim, Sang-Hyun; Kim, Myung-A.; Zo, Joo-Hee

    2017-01-01

    Abstract Left ventricular (LV) diastolic dysfunction and subsequent overt heart failure are more prevalent in elderly women. Close interaction between arterial stiffness and LV morphology/function has been reported. The aim of this study was to investigate whether there is an age- and gender-dependent relationship between arterial stiffness and LV diastolic function. A total of 819 subjects (58.6 ± 13.3 years, 50.2% men) without structural heart disease (LV ejection fraction ≥50%) were retrospectively analyzed. All participants underwent transthoracic echocardiography and brachial-ankle pulse wave velocity (baPWV) measurement on the same day. The association of baPWV with septal e′ velocity and average E/e′ was assessed. In the total study subjects, baPWV was negatively correlated with septal e′ velocity (r = 0.383, P < 0.001), and positively correlated with E/e′ (r = −0.266, P < 0.001). These linear correlations remained significant even after stratificaion of the study subjects by age (<65 years vs ≥65 years) and genders (P < 0.05 for each). There were obvious differences in baPWV according to groups with normal LV diastolic function, intermediate profile and LV diastolic dysfunction in young (P = 0.010) and elderly (≥65 years) women (P < 0.001) and eldery men (P = 0.012) but not in elderly men (P = 0.270). There was a significant association of baPWV with septal e′ velocity (β = −0.258, P = 0.020) and E/e′ (β = 0.122, P = 0.030) in elderly women even after controlling for multiple clinical covariates. This independent association was not seen in younger women and men (P > 0.05 for each). In conclusion, baPWV was independently associated with septal e′ velocity and E/e′ in elderly women but not in younger women or men. The results of this study provide additional evidence that increased arterial stiffness plays an important role in the development of heart failure with

  18. Hemi-central retinal artery occlusion in young adults.

    PubMed

    Rishi, Pukhraj; Rishi, Ekta; Sharma, Tarun; Mahajan, Sheshadri

    2010-01-01

    Amongst the clinical presentations of retinal artery occlusion, hemi-central retinal artery occlusion (Hemi-CRAO) is rarely described. This case series of four adults aged between 22 and 36 years attempts to describe the clinical profile, etiology and management of Hemi-CRAO. Case 1 had an artificial mitral valve implant. Polycythemia and malignant hypertension were noted in Case 2. The third patient had Leiden mutation while the fourth patient had Eisenmenger's syndrome. Clinical examination and fundus fluorescein angiography revealed a bifurcated central retinal artery at emergence from the optic nerve head, in all cases. Color Doppler examination of the central retinal artery confirmed branching of the artery behind the lamina cribrosa. It is hypothesized that bifurcation of central retinal artery behind the lamina cribrosa may predispose these hemi-trunks to develop an acute occlusion if associated with underlying risk factors. The prognosis depends upon arterial recanalisation and etiology of the thromboembolic event.

  19. Association between aerobic exercise training effects of serum adropin level, arterial stiffness, and adiposity in obese elderly adults.

    PubMed

    Fujie, Shumpei; Hasegawa, Natsuki; Kurihara, Toshiyuki; Sanada, Kiyoshi; Hamaoka, Takafumi; Iemitsu, Motoyuki

    2017-01-01

    Serum levels of adropin, which enhances endothelial cell release of nitric oxide (NO), are lower in obese patients. Although habitual aerobic exercise reduces arterial stiffness and adiposity, the relationship between these effects and circulating levels of adropin remains unclear. The purpose of this study was to determine if serum adropin level is associated with the effects of aerobic exercise training on arterial stiffness and adiposity in obese adults. In Experiment 1, we examined whether serum adropin levels are associated with cardiorespiratory fitness, carotid β-stiffness, plasma nitrite/nitrate (NOx) level, and abdominal visceral fat in 27 normal, 20 overweight, and 25 obese adults (age, 41-79 years). In Experiment 2, we examined the effects of an 8-week aerobic exercise training program on the relationship between serum adropin level and arterial stiffness or adiposity in 13 obese adults (age, 54-76 years). Serum adropin levels in normal, overweight, and obese adults negatively correlated with carotid β-stiffness and abdominal visceral fat, and positively correlated with plasma NOx level and cardiorespiratory fitness. After the 8-week exercise program, serum adropin levels in obese adults were elevated, and correlated with training-induced changes in carotid β-stiffness (r = -0.573, P < 0.05), plasma NOx level (r = 0.671, P < 0.05), and abdominal visceral fat (r = -0.585, P < 0.05). These findings suggest that the exercise training-induced increase in serum adropin may be related to the training effects of arterial stiffness and adiposity in obese adults.

  20. Effects of a nitrate-rich meal on arterial stiffness and blood pressure in healthy volunteers.

    PubMed

    Liu, Alex H; Bondonno, Catherine P; Croft, Kevin D; Puddey, Ian B; Woodman, Richard J; Rich, Lisa; Ward, Natalie C; Vita, Joseph A; Hodgson, Jonathan M

    2013-11-30

    An increase in nitrate intake can augment circulating nitrite and nitric oxide. This may lead to lower blood pressure and improved vascular function. Green leafy vegetables, such as spinach, are rich sources of nitrate. We aimed to assess the acute effects of a nitrate-rich meal containing spinach on arterial stiffness and blood pressure in healthy men and women. Twenty-six participants aged 38-69years were recruited to a randomized controlled cross-over trial. The acute effects of two energy-matched (2000kJ) meals, administered in random order, were compared. The meals were either high nitrate (220mg of nitrate derived from spinach [spinach]) or low nitrate [control]. Outcome measurements were performed pre-meal and at specific time points up to 210min post meal. Spinach resulted in an eightfold increase in salivary nitrite and a sevenfold increase in salivary nitrate concentrations from pre-meal (P<0.001) to 120min post meal. Spinach compared with control resulted in higher large artery elasticity index (P<0.001), and lower pulse pressure (P<0.001) and systolic blood pressure (P<0.001). Post meal carotid-femoral pulse wave velocity (P=0.07), augmentation index (P=0.63), small artery elasticity index (P=0.98) and diastolic blood pressure (P=0.13) were not significantly altered by spinach relative to control. Therefore, consumption of a nitrate-rich meal can lower systolic blood pressure and pulse pressure and increase large artery compliance acutely in healthy men and women. If sustained, these effects could contribute to better cardiovascular health.

  1. Long-term anti-hypertensive therapy with benidipine improves arterial stiffness over blood pressure lowering.

    PubMed

    Kita, Toshihiro; Suzuki, Yoshihiko; Eto, Tanenao; Kitamura, Kazuo

    2005-12-01

    Pulse wave velocity (PWV) reflects arterial stiffness and is an independent predictor of cardiovascular mortality and morbidity. However, because it is closely related to blood pressure (BP), PWV is an imperfect measure for evaluating the effects of anti-hypertensive drugs on arterial wall properties. To clarify the effect of benidipine on arterial properties, we first derived the regression line between BP and PWV changes in a short-term experiment. Using this line, we evaluated the long-term effect of benidipine on PWV changes. In the short-term experiment, 29 participants were intravenously administered nicardipine for 90 min. Maximum decreases of brachial-ankle PWV (baPWV) were plotted against the corresponding decreases in BP. In the long-term experiment, 9 hypertensive patients were treated with benidipine for 1 year, during which BP and baPWV were monitored. After 1 year, benidipine was suspended for 2 weeks, and BP and baPWV were reevaluated. In the short-term experiment, PWV was dependent on BP only, and the equation of the regression line was deltaPWV (cm/s) =10.114 x deltaMBP (mmHg) (r=0.913) or deltaPWV (%) =0.719 x deltaMBP (%) (r=0.926). In the long-term therapy, benidipine treatment achieved stable BP control within 3 months; the real PWV decreases (r-PWV) were almost identical to the PWV decrease estimated (e-PWV) from BP lowering at 3 months. However, r-PWV exceeded e-PWV after 6 months. Relative BP and PWV improvements compared to the control were maintained 2 weeks after suspension of benidipine. In conclusion, long-term benidipine administration improves arterial wall properties beyond what can be accounted for by changes in BP.

  2. Infant Arterial Stiffness and Maternal Iron Status in Pregnancy: A UK Birth Cohort (Baby VIP Study)

    PubMed Central

    Alwan, Nisreen A.; Cade, Janet E.; McArdle, Harry J.; Greenwood, Darren C.; Hayes, Helen E.; Ciantar, Etienne; Simpson, Nigel A.B.

    2015-01-01

    Background In animal studies, iron deficiency during pregnancy has been linked to increased offspring cardiovascular risk. No previous population studies have measured arterial stiffness early in life to examine its association with maternal iron status. Objective This study aimed to examine the association between maternal iron status in early pregnancy with infant brachio-femoral pulse wave velocity (PWV). Methods The Baby VIP (Baby's Vascular Health and Iron in Pregnancy) study is a UK-based birth cohort which recruited 362 women after delivery from the Leeds Teaching Hospitals postnatal wards. Ferritin and transferrin receptor levels were measured in maternal serum samples previously obtained in the first trimester. Infant brachio-femoral PWV was measured during a home visit at 2–6 weeks. Results Iron depletion (ferritin <15 µg/l) was detected in 79 (23%) women in early pregnancy. Infant PWV (mean = 6.7 m/s, SD = 1.3, n = 284) was neither associated with maternal ferritin (adjusted change per 10 µg/l = 0.02, 95% CI: −0.01, 0.1), nor with iron depletion (adjusted change = −0.2, 95% CI: −0.6, 0.2). No evidence of association was observed between maternal serum transferrin receptor level and its ratio to ferritin with infant PWV. Maternal anaemia (<11 g/dl) at <20 weeks’ gestation was associated with a 1.0-m/s increase in infant PWV (adjusted 95% CI: 0.1, 1.9). Conclusion This is the largest study to date which has assessed peripheral PWV as a measure of arterial stiffness in infants. There was no evidence of an association between markers of maternal iron status early in pregnancy and infant PWV. PMID:25790854

  3. Racial and socioeconomic disparities in arterial stiffness and intima media thickness among adolescents

    PubMed Central

    Thurston, Rebecca C.; Matthews, Karen A.

    2010-01-01

    Racial and socioeconomic status (SES) disparities in cardiovascular disease (CVD) risk are well established among adults. However, little is known about disparities in CVD risk among adolescents, particularly considering indices of subclinical CVD. Our aim was to examine socioeconomic and racial disparities in subclinical CVD indices among adolescents. We hypothesized that African American and lower SES adolescents would show greater arterial stiffness and intima media thickness compared to Caucasian and higher SES adolescents, respectively. Participants were 81 African American and 78 Caucasian adolescents (mean age = 17.8) from two schools in Pittsburgh, PA, USA. Measures of subclinical CVD were pulse wave velocity and intima media thickness, as assessed by Doppler and B-mode ultrasound, respectively. SES indices included parental education, family income, family assets, subjective social status, and census-derived neighborhood SES. Hypotheses were evaluated in multiple linear regression models with the covariates age, gender, body mass index, and systolic blood pressure. Results indicated that African American adolescents were more often in low SES positions than Caucasians. When considered individually, racial and SES disparities in pulse wave velocity, and to a lesser extent, intima media thickness, were evident. When race and SES were considered together, high school education, low or medium income, and low neighborhood SES were associated with higher pulse wave velocity. Fewer assets were associated with higher intima media thickness. In conclusion, racial and SES disparities in indices of subclinical CVD were observed, with findings most pronounced for SES disparities in pulse wave velocity. This study extends previous findings in adults to adolescents, indicating that disparities in arterial stiffness and intima media thickness occur as early as adolescence. Efforts to reduce socioeconomic and racial disparities in CVD should target disparities early in

  4. Arterial stiffness is associated with left ventricular dysfunction in patients with rheumatoid arthritis.

    PubMed

    Ilter, Abdulselam; Kiris, Abdulkadir; Karkucak, Murat; Sahin, Mursel; Serdar, Omer Faruk; Ugan, Yunus

    2016-11-01

    Arterial stiffness (AS) has a detrimental effect on cardiovascular system particularly on left ventricle (LV). The aim of the study was to evaluate the impact of AS on LV functions in patients with rheumatoid arthritis (RA). Forty patients with RA and 25 age-sex matched control subjects (mean age 48.5 ± 6.3 vs. 45.1 ± 6.9 years, respectively, p = 0.06) were enrolled in study. AS was assessed by carotid-femoral pulse wave velocity (CF-PWV) and heart rate corrected augmentation index (AIx@75) measured by applanation tonometry (SphygmoCor). LV function was evaluated using tissue Doppler-derived myocardial performance index (MPI) from lateral mitral annulus. CF-PWV (28.3 ± 10.3 vs. 21.8 ± 9.3 m/s, p = 0.03), AIx@75 (10.2 ± 2.3 vs. 9.2 ± 1, %, p = 0.01) and MPI (0.46 ± 0.12 vs. 0.36 ± 0.1, p < 0.001) were significantly higher in patients with RA than in controls. LV MPI was found to be significantly positive correlated with CF-PWV, AIx@75, and ESR (r = 0.360, p = 0.005; r = 0.334, p = 0.009; r = 0.293, p = 0.023, respectively). Arterial stiffness parameters including CF-PWV and AIx@75 are associated with subclinical left ventricular dysfunction in patients with RA.

  5. Circulating concentrations of vitamin E isomers: Association with bone turnover and arterial stiffness in post-menopausal women.

    PubMed

    Hampson, G; Edwards, S; Sankaralingam, A; Harrington, D J; Voong, K; Fogelman, I; Frost, M L

    2015-12-01

    The effects of vitamin E on cardiovascular and bone health are conflicting with beneficial and detrimental findings reported. To investigate this further, we carried out a cross-sectional study to determine the relationship between circulating concentrations of the 2 vitamin E isomers, α- and γ-tocopherol (TP) with bone turnover and arterial stiffness. Two hundred and seventy eight post-menopausal women with mean age [SD] 60.9 [6.0] years were studied. Fasting serum α-TP and γ-TP, bone turnover markers; procollagen type 1 amino-terminal propeptide (P1NP) and C-terminal telopeptide of type 1 collagen (CTX), parathyroid hormone (PTH), total cholesterol (TC) and triglycerides (TG) were measured. Pulse wave velocity (PWV) and central augmentation index (AI) as markers of arterial stiffness were also determined. A positive correlation was observed between α-TP and γ-TP (r=0.14, p=0.022). A significant negative association between α-TP and P1NP only was seen in multiple linear regression analysis following adjustment for serum TC and TG (p=0.016). In a full multi-linear regression model, following correction for age, years since menopause, smoking habits, alcohol intake, use of calcium supplements, BMI, PTH, serum calcium, and estimated glomerular filtration rate (eGFR), the association between α-TP and P1NP remained significant (p=0.011). We did not observe any significant association between γ-TP or α-TP/γ-TP ratio with P1NP or CTX. P1NP was significantly lower in subjects with α-TP concentrations of >30 μmol/L (α-TP >30 μmol/L; P1NP: 57.5 [20.7], α-TP<30 μmol/L; P1NP: 65.7 [24.9] μg/L, p=0.005). PWV was significantly associated with α-TP/γ-TP ratio (p=0.04) but not with serum α-TP or γ-TP in a full multi-linear regression model adjusting for serum lipids, age, and blood pressure. The data suggest that high serum concentrations of α-TP may have a negative effect on bone formation. The balance of α-TP and γ-TP may be important in maintaining

  6. Stiffness of the large arteries in individuals with and without Down syndrome

    PubMed Central

    Rodrigues, Anabel N; Coelho, Luan Cesar; Goncalves, Washington LS; Gouvea, Sonia Alves; Vasconcellos, Maria José Rossi; Cunha, Roberto S; Abreu, Glaucia R

    2011-01-01

    Background: Down syndrome is known to cause premature aging in several organ systems. However, it remains unclear whether this aging effect also affects the structure and function of the large arterial trunks. In this controlled study, the possibility of changes in the large arteries due to aging was evaluated in patients with Down syndrome. Methods: Eighty-two subjects of both genders were selected. The Down syndrome group had 41 active subjects consisting of 19 males and 22 females (mean age 21 ± 1, range 13–42 years) without cardiovascular complications and who did not use vasoactive drugs. The control group consisted of 41 healthy individuals without trisomy 21 of the same gender and age as the Down syndrome group and who did not use vasoactive medication. Carotid–femoral pulse wave velocity was obtained as an index of aortic stiffness using an automatic noninvasive method. Results: Individuals with Down syndrome had significantly lower blood pressure than those in the control group. Systolic blood pressure for the Down syndrome group and control group was 106 ± 2 mmHg vs 117 ± 2 mmHg (P < 0.001), respectively; diastolic blood pressure was 66 ± 2 mmHg vs 77 ± 2 mmHg (P < 0.001); and mean arterial pressure was 80 ± 1 mmHg vs 90 ± 1 mmHg (P < 0.001). Only age and systolic blood pressure were shown to correlate significantly with pulse wave velocity, but the slopes of the linear regression curves of these two variables showed no significant difference between the two study groups. Pulse wave velocity, which was initially significantly lower in the Down syndrome group (7.51 ± 0.14 m/s vs 7.84 ± 0.12 m/s; P <0.05), was similar between the groups after systolic blood pressure adjustment (7.62 ± 0.13 m/s vs 7.73 ± 0.13 m/s). Conclusion: Despite evidence in the literature that patients with Down syndrome undergo early aging, this process does not seem to affect the large arterial trunks, given that values of carotid-femoral pulse wave velocity were

  7. Effects of aerobic exercise on the resting heart rate, physical fitness, and arterial stiffness of female patients with metabolic syndrome

    PubMed Central

    Kang, Seol-Jung; Kim,, Eon-ho; Ko, Kwang-Jun

    2016-01-01

    [Purpose] The purpose of this study was to investigate the effects of aerobic exercise on the resting heart rate, physical fitness, and arterial stiffness or female patients with metabolic syndrome. [Subjects and Methods] Subjects were randomly assigned to an exercise group (n=12) or a control group (n=11). Subjects in the exercise group performed aerobic exercise at 60–80% of maximum heart rate for 40 min 5 times a week for 12 weeks. The changes in metabolic syndrome risk factors, resting heart rate, physical fitness, and arterial stiffness were measured and analyzed before and after initiation of the exercise program to determine the effect of exercise. Arterial stiffness was assessed based on brachial-ankle pulse wave velocity (ba-PWV). [Results] Compared to the control group; The metabolic syndrome risk factors (weight, % body fat, waist circumference, systolic blood pressure, diastolic blood pressure, and HDL-Cholesterol) were significantly improved in the exercise: resting heart rate was significantly decreased; VO2max, muscle strength and muscle endurance were significantly increased; and ba-PWV was significantly decreased. [Conclusion] Aerobic exercise had beneficial effects on the resting heart rate, physical fitness, and arterial stiffness of patients with metabolic syndrome. PMID:27390411

  8. Effects of aerobic exercise on the resting heart rate, physical fitness, and arterial stiffness of female patients with metabolic syndrome.

    PubMed

    Kang, Seol-Jung; Kim, Eon-Ho; Ko, Kwang-Jun

    2016-06-01

    [Purpose] The purpose of this study was to investigate the effects of aerobic exercise on the resting heart rate, physical fitness, and arterial stiffness or female patients with metabolic syndrome. [Subjects and Methods] Subjects were randomly assigned to an exercise group (n=12) or a control group (n=11). Subjects in the exercise group performed aerobic exercise at 60-80% of maximum heart rate for 40 min 5 times a week for 12 weeks. The changes in metabolic syndrome risk factors, resting heart rate, physical fitness, and arterial stiffness were measured and analyzed before and after initiation of the exercise program to determine the effect of exercise. Arterial stiffness was assessed based on brachial-ankle pulse wave velocity (ba-PWV). [Results] Compared to the control group; The metabolic syndrome risk factors (weight, % body fat, waist circumference, systolic blood pressure, diastolic blood pressure, and HDL-Cholesterol) were significantly improved in the exercise: resting heart rate was significantly decreased; VO2max, muscle strength and muscle endurance were significantly increased; and ba-PWV was significantly decreased. [Conclusion] Aerobic exercise had beneficial effects on the resting heart rate, physical fitness, and arterial stiffness of patients with metabolic syndrome.

  9. Effect of a tart cherry juice supplement on arterial stiffness and inflammation in healthy adults: a randomised controlled trial.

    PubMed

    Lynn, Anthony; Mathew, Shilpa; Moore, Chris T; Russell, Jean; Robinson, Emma; Soumpasi, Vithleem; Barker, Margo E

    2014-06-01

    Tart cherries are a particularly rich source of anthocyanins. Evidence indicates that dietary intake of anthocyanins is inversely associated with arterial stiffness. We conducted an open-label randomised placebo controlled study to determine whether a tart cherry juice concentrate (Cherry Active) reduced arterial stiffness, inflammation and risk markers for cardiovascular disease in 47 healthy adults (30-50 years). Participants consumed 30 ml of cherry concentrate diluted to a volume of 250 ml with water or the same volume of an energy matched control drink daily for six weeks. Measurements were taken at baseline and at the end of the intervention. There was no effect of the intervention on arterial stiffness (P = 0.218), c-reactive protein (P = 0.220), systolic blood pressure (P = 0.163), diastolic blood pressure (P = 0.121), total cholesterol (P = 0.342) and high density lipoprotein cholesterol (P = 0.127). At the end of the intervention, plasma antioxidant capacity (measured as the ferric reducing ability of plasma (FRAP)) was significantly higher in the intervention group than the control group (P = 0.012). We conclude that a tart cherry juice concentrate rich in anthocyanins has no effect on arterial stiffness, c-reactive protein and risk markers for cardiovascular disease, but evokes a minor increase in antioxidant status in healthy adults.

  10. Menaquinone-7 supplementation improves arterial stiffness in healthy postmenopausal women. A double-blind randomised clinical trial.

    PubMed

    Knapen, Marjo H J; Braam, Lavienja A J L M; Drummen, Nadja E; Bekers, Otto; Hoeks, Arnold P G; Vermeer, Cees

    2015-05-01

    Observational data suggest a link between menaquinone (MK, vitamin K2) intake and cardiovascular (CV) health. However, MK intervention trials with vascular endpoints are lacking. We investigated long-term effects of MK-7 (180 µg MenaQ7/day) supplementation on arterial stiffness in a double-blind, placebo-controlled trial. Healthy postmenopausal women (n=244) received either placebo (n=124) or MK-7 (n=120) for three years. Indices of local carotid stiffness (intima-media thickness IMT, Diameter end-diastole and Distension) were measured by echotracking. Regional aortic stiffness (carotid-femoral and carotid-radial Pulse Wave Velocity, cfPWV and crPWV, respectively) was measured using mechanotransducers. Circulating desphospho-uncarboxylated matrix Gla-protein (dp-ucMGP) as well as acute phase markers Interleukin-6 (IL-6), high-sensitive C-reactive protein (hsCRP), tumour necrosis factor-α (TNF-α) and markers for endothelial dysfunction Vascular Cell Adhesion Molecule (VCAM), E-selectin, and Advanced Glycation Endproducts (AGEs) were measured. At baseline dp-ucMGP was associated with IMT, Diameter, cfPWV and with the mean z-scores of acute phase markers (APMscore) and of markers for endothelial dysfunction (EDFscore). After three year MK-7 supplementation cfPWV and the Stiffness Index βsignificantly decreased in the total group, whereas distension, compliance, distensibility, Young's Modulus, and the local carotid PWV (cPWV) improved in women having a baseline Stiffness Index β above the median of 10.8. MK-7 decreased dp-ucMGP by 50 % compared to placebo, but did not influence the markers for acute phase and endothelial dysfunction. In conclusion, long-term use of MK-7 supplements improves arterial stiffness in healthy postmenopausal women, especially in women having a high arterial stiffness.

  11. Cullin-3 mutation causes arterial stiffness and hypertension through a vascular smooth muscle mechanism

    PubMed Central

    Agbor, Larry N.; Ibeawuchi, Stella-Rita C.; Hu, Chunyan; Davis, Deborah R.; Keen, Henry L.; Quelle, Frederick W.; Sigmund, Curt D.

    2016-01-01

    Cullin-3 (CUL3) mutations (CUL3Δ9) were previously identified in hypertensive patients with pseudohypoaldosteronism type-II (PHAII), but the mechanism causing hypertension and whether this is driven by renal tubular or extratubular mechanisms remains unknown. We report that selective expression of CUL3Δ9 in smooth muscle acts by interfering with expression and function of endogenous CUL3, resulting in impaired turnover of the CUL3 substrate RhoA, increased RhoA activity, and augmented RhoA/Rho kinase signaling. This caused vascular dysfunction and increased arterial pressure under baseline conditions and a marked increase in arterial pressure, collagen deposition, and vascular stiffness in response to a subpressor dose of angiotensin II, which did not cause hypertension in control mice. Inhibition of total cullin activity increased the level of CUL3 substrates cyclin E and RhoA, and expression of CUL3Δ9 decreased the level of the active form of endogenous CUL3 in human aortic smooth muscle cells. These data indicate that selective expression of the Cul3Δ9 mutation in vascular smooth muscle phenocopies the hypertension observed in Cul3Δ9 human subjects and suggest that mutations in CUL3 cause human hypertension in part through a mechanism involving smooth muscle dysfunction initiated by a loss of CUL3-mediated degradation of RhoA. PMID:27882355

  12. Ambulatory Arterial Stiffness Index Is Higher in Hypertensive Patients with Chronic Kidney Disease

    PubMed Central

    Gismondi, Ronaldo Altenburg; Neves, Mario Fritsch; Oigman, Wille; Bregman, Rachel

    2012-01-01

    Ambulatory arterial stiffness index (AASI) is a parameter obtained from ambulatory blood pressure monitoring (ABPM) that correlates with clinical endpoints. The aim of this study was to compare AASI in nondiabetic hypertensive patients with and without chronic kidney disease (CKD). Subjects with systemic arterial hypertension (SAH, n = 30) with normal renal function, aged 40 to 75 years, were compared to hypertensive patients with CKD (n = 30) presenting estimated glomerular filtration rate (eGFR) <60 mL/min by MDRD formula. ABPM was carried out in all patients. In CKD group, eGFR was 35.3 ± 2.8 ml/min. The mean 24-hour systolic and diastolic blood pressure (BP) was similar in both groups. AASI was significantly higher in CKD group (0.45 ± 0.03 versus 0.37 ± 0.02, P < 0.05), positively correlated to age (r = 0.38, P < 0.01) and pulse pressure (r = 0.43, P < 0.01) and negatively correlated to nocturnal BP fall (r = -0.28, P = 0.03). These findings indicate the presence of stiffer vessels in CKD hypertensive patients. PMID:22675608

  13. Peripheral Augmentation Index is Associated With the Ambulatory Arterial Stiffness Index in Patients With Hypertension

    PubMed Central

    Heffernan, Kevin S.; Patvardhan, Eshan A.; Karas, Richard H.; Kuvin, Jeffrey T.

    2011-01-01

    Background Vascular dysfunction is highly prevalent if not ubiquitous in patients with hypertension. We compared two different measures of vascular function obtained from digital volume waveforms with measures of ventricular-vascular load derived from 24-hour blood pressure (BP) recordings in patients with hypertension. Methods Digital pulsatile volume waveforms were captured via plethysmography (peripheral arterial tone, PAT) and used to derive augmentation index (a measure of ventricular-vascular coupling) and the pulse wave amplitude-reactive hyperemia index (a measure of microvascular reactivity). Ambulatory arterial stiffness index (AASI) and the BP variability ratio (BPVR) were derived from 24-hour ambulatory BP recordings. Results There was a positive association between PAT-AIx and AASI (r = 0.52, P < 0.05). There was also a positive association between PAT-AIx and BPVR (r = 0.37, P < 0.05). PAT-AIx was not associated with PWA-RHI (r = -0.14, P > 0.05). PWA-RHI was not associated with AASI or BPVR (P > 0.05). Conclusions PAT-AIx is associated with ambulatory measures of vascular function and may offer clinical insight into vascular burden and cardiovascular disease risk in patients with hypertension independent of information obtained from PWA-RHI.

  14. Noninvasive pulse transit time measurement for arterial stiffness monitoring in microgravity.

    PubMed

    McCall, Corey; Rostosky, Rea; Wiard, Richard M; Inan, Omer T; Giovangrandi, Laurent; Cuttino, Charles Marsh; Kovacs, Gregory T A

    2015-01-01

    The use of a noninvasive hemodynamic monitor to estimate arterial stiffness, by measurement of pulse transit time (PTT), was demonstrated in microgravity. The monitor's utility for space applications was shown by establishing the correlation between ground-based and microgravity-based measurements. The system consists of a scale-based ballistocardiogram (BCG) and a toe-mounted photoplethysmogram (PPG). PTT was measured from the BCG I-wave to the intersecting tangents of the first trough and maximum first derivative of the PPG waveforms of each subject. The system was tested on a recent series of parabolic flights in which the PTT of nine subjects was measured on the ground and in microgravity. An average of 60.2 ms PTT increase from ground to microgravity environments was shown, and was consistent across all test subjects (standard deviation = 32.9 ms). This increase in PTT could be explained by a number of factors associated with microgravity and reported in previous research, including elimination of hydrostatic pressure, reduction of intrathoracic pressure, and reduction of mean arterial pressure induced by vasodilation.

  15. Arterial aging and arterial disease: interplay between central hemodynamics, cardiac work, and organ flow—implications for CKD and cardiovascular disease

    PubMed Central

    London, Gerard; Covic, Adrian; Goldsmith, David; Wiecek, Andrzej; Suleymanlar, Gultekin; Ortiz, Alberto; Massy, Ziad; Lindholm, Bengt; Martinez-Castelao, Alberto; Fliser, Danilo; Agarwal, Rajiv; Jager, Kitty J; Dekker, Friedo W; Blankestijn, Peter J; Zoccali, Carmine

    2011-01-01

    Cardiovascular disease is an important cause of morbidity and mortality in patients with chronic kidney disease (CKD) and end-stage renal disease (ESRD). All epidemiological studies have clearly shown that accelerated arterial and cardiac aging is characteristic of these populations. Arterial premature aging is heterogeneous. It principally involves the aorta and central capacitive arteries, and is characterized by preferential aortic stiffening and disappearance of stiffness/impedance gradients between the central and peripheral arteries. These changes have a double impact: on the heart, upstream, with left ventricular hypertrophy and decreased coronary perfusion; and, downstream, on renal and brain microcirculation (decrease in glomerular filtration and cognitive functions). Multifactorial at origin, the pathophysiology of aortic ‘progeria' and microvascular disorders in CKD/ESRD is not well understood and should be the focus of interest in future studies. PMID:25018896

  16. Assessment of Pulmonary Artery Stiffness of Repaired Congenital Heart Disease Patients

    NASA Astrophysics Data System (ADS)

    Lee, Namheon; Banerjee, Rajit; Taylor, Michael; Hor, Kan

    2012-10-01

    Surgical correction or palliation of congenital heart disease (CHD) often requires augmenting the main pulmonary artery (MPA) with non-native material or placing a cylindrical graft. The degree to which this intervention affects PA compliance is largely unknown. In this study, the MPA stiffness characteristics were assessed by its compliance, distensibility, and pressure-strain modulus. Coregistered velocity encoded phase-contrast MRI and cardiac catheterization data were available for a cohort of repaired CHD patients (n=8) and controls (n=3). All patients were repaired with either an RV-PA conduit or a RV outflow tract patch. We measured the MPA area change by MRI and MPA pressure during the cath. The measurements were taken through or just distal to the conduit. The MPA compliance and distensibility for the patients were significantly lower than the controls: compliance (9.8±10.8 vs 28.3±7.7mm^2/mmHg, p<0.05), distensibility (2.2±1.5 vs 6.6±2.1%Area change/mmHg, p=0.05). The patients had a significantly higher pressure-strain modulus (152.3±116.4mmHg, p<0.05) than the controls (35.8±10.6mmHg). The abnormally elevated PA stiffness due to the rigidity of the conduit or patch material may cause a compliance mismatch resulting in high stress levels contributing to the observed progressive PA dilatation. This may be a factor in the progressive RV dilatation seen in this cohort of repaired CHD patients.

  17. Cilio-retinal arterial circulation in central retinal vein occlusion.

    PubMed Central

    McLeod, D

    1975-01-01

    The hypothesis that an occlusion of the central retinal artery is an essential prerequisite for haemorrhage formation after central retinal vein obstruction has been investigated by examining the fundus changes in patients with a cilio-retinal arterial circulation; the findings are at variance with the 'combined occlusion hypothesis'. Comparisons were made between the pathological features in two retinal capillary beds with independent sources of arterial supply--namely, the central retinal and cilio-retinal arteries--but with an obstructed venous drainage channel common to both--namely, the central retinal vein. The importance of intraluminal pressure changes (as distinct from perfusion changes) in the causation of haemorrhages and oedema after venous occlusion is stressed, and the role of arterial disease in the pathogenesis of venous occlusions is distinguished from its role in determining the sequelae of such occlusions. Images PMID:1203235

  18. Creatine supplementation attenuates hemodynamic and arterial stiffness responses following an acute bout of isokinetic exercise.

    PubMed

    Sanchez-Gonzalez, Marcos A; Wieder, Ralph; Kim, Jeong-Su; Vicil, Florence; Figueroa, Arturo

    2011-09-01

    Arterial stiffness and hemodynamics may be increased following a bout of resistance exercise. Oral creatine supplementation (Cr) may attenuate cardiovascular responses after exercise via improved anaerobic metabolism. This study was aimed to determine the effect of Cr on hemodynamic and arterial stiffness responses after acute isokinetic exercise. Sixteen healthy males (22.6 ± 0.6 year) were randomly assigned to either placebo (Pl, n = 8) or Cr (n = 8) (2 × 5 g/day) for 3 weeks. Brachial systolic blood pressure (SBP), heart rate (HR), brachial-ankle pulse wave velocity (baPWV), and leg PWV were measured in the supine position at rest before and after the interventions. After the supplementation period, parameters were also measured 5 min (PE5) and 15 min (PE15) after two sets of leg isokinetic exercise. There was no difference between the groups in resting measurements before and after the supplementation. Compared with the Pl group, the Cr group had attenuated (P < 0.05) increases in SBP at PE5 (Pl 14.0 ± 2.5, Cr 5.6 ± 2.3 mmHg), HR at both P5 (Pl 28 ± 4 vs. Cr 16 ± 2 beats/min) and PE15 (Pl 21 ± 3, Cr 11 ± 2 beats/min) and rate pressure product at P5 (Pl 45.8 ± 6.4, Cr 24.8 ± 2.2) and P15 (Pl 34.2 ± 5.0, Cr 15.9 ± 6.0). Compared with the Pl group, the Cr group had suppressed increases in baPWV at PE5 (Pl 1.5 ± 0.4, Cr -0.1 ± 0.4 m/s) and PE15 (Pl 1.1 ± 0.2, Cr -0.3 ± 0.3 m/s) and returned SBP to pre-exercise values at PE15 (Pl 10.6 ± 2.8, Cr 2.1 ± 2.6 mmHg). PWV in the exercised leg decreased at PE5 in both groups. These findings suggest that Cr supplementation attenuates the hemodynamic and baPWV responses after acute isokinetic exercise.

  19. Stress phase angle depicts differences in arterial stiffness: phantom and in vivo study

    NASA Astrophysics Data System (ADS)

    Niu, Lili; Meng, Long; Xu, Lisheng; Liu, Jia; Wang, Qiwen; Xiao, Yang; Qian, Ming; Zheng, Hairong

    2015-06-01

    The endothelial cells (ECs) lining of a blood vessel wall are exposed to both the wall shear stress (WSS) of blood flow and the circumferential strain (CS) of pulsing artery wall motion. Both WSS and CS keep involved in the modulation of ECs’ biochemical response and function and the temporal phase angle between the two is called stress phase angle (SPA). Previous studies at the cellular level have indicated that SPA is highly negative at sites that are prone to atherosclerosis, and hypothesized that large SPA may contribute to atherogenesis. Till now, there is no experimental data to support this hypothesis, probably due to the lack of a proper tool for measuring WSS and CS simultaneously and real time. In this study, a non-invasive ultrasonic biomechanics method was utilized to quantitatively calculate the SPA and experimentally evaluate the role of SPA in predicting early atherosclerosis. Three silicon tubes with a stiffness of 1.15, 3.62, 9.38 MPa were assembled in a pulsatile flow circuit and the values of SPA were measured to be -101.86 ± 3.65°,-170.19 ± 17.77° and -260.63 ± 18.62°, respectively. For the PVA-c phantoms, stiffness was 162.45, 235.68 and 374.24 kPa, the SPA corresponding to -170.32 ± 17.55°,-207.56 ± 10.78° and -261.08 ± 10.90°, respectively. Both phantom studies results demonstrated that SPA was highly negative in stiffer arteries. Further, experiments were taken in healthy living rats as control group (n = 3), atherosclerotic model group (n = 3), and drug treated group (n = 3), and the results showed that SPA was most negative in the model group, and SPA was least negative in the control group. Together, this study suggested that highly negative SPA appeared to be a prominent mechanical feature of vessels prone to atherosclerotic disease.

  20. Effect of continuous positive airway pressure on arterial stiffness in patients with obstructive sleep apnea and hypertension: a meta-analysis.

    PubMed

    Lin, Xin; Chen, Gongping; Qi, Jiachao; Chen, Xiaofang; Zhao, Jiangming; Lin, Qichang

    2016-12-01

    Arterial stiffness has been recognized as a predictor of cardiovascular and all-cause mortality in hypertensive patients. However, the impact of continuous positive airway pressure (CPAP) on arterial stiffness in patients with OSA and hypertension remains inconclusive. We performed a meta-analysis to determine whether effective CPAP therapy could decrease arterial stiffness. Two reviewers independently searched PubMed, Embase, Web of Science and Cochrane Library prior to March 5, 2015. Information on characteristics of subjects, study design and pre- and post-CPAP treatment of arterial stiffness was extracted for analysis. Standardized mean difference (SMD) was used to analyze the summary estimates for CPAP therapy. Three articles with 186 patients were included in this meta-analysis, including two observational studies and one randomized controlled study. The meta-analysis showed that CPAP was associated with a statistically significant decrease in arterial stiffness in patients with OSA and hypertension (SMD = -0.65, 95 % confidence interval (CI) = -1.14 to -0.16, z = 2.60, p = 0.009). Our meta-analysis suggested that CPAP among OSA and hypertensive patients was significantly associated with a decrease in arterial stiffness. Further prospective large-scale multicenter RCTs are needed to explore the precise impact of CPAP therapy on arterial stiffness in patients with OSA and hypertension.

  1. Effect of angiotensin-converting enzyme inhibitors on arterial stiffness in hypertension: systematic review and meta-analysis.

    PubMed

    Mallareddy, Madhavi; Parikh, Chirag R; Peixoto, Aldo J

    2006-06-01

    Arterial stiffness is an independent cardiovascular prognostic factor and is modulated by angiotensin-converting enzyme inhibitors (ACEIs). The authors performed a meta-analysis of clinical trials investigating the effects of ACEIs on pulse wave velocity (PWV) or augmentation index. The search included randomized clinical trials as well as uncontrolled studies that measured in-treatment changes in arterial stiffness. The authors performed separate analyses for carotid-femoral PWV, brachioradial PWV, and augmentation index. Average absolute and relative reduction in mean arterial pressure and PWV were -15.4 mm Hg and -13.04% and -1.15 m/s and -9.74% for carotid-femoral PWV studies; and -11.2 mm Hg and -9.3% and -1.9 m/s and -16.7% for brachioradial PWV studies. There was a greater reduction in augmentation index by ACEIs when compared with controls (-1.0% to -5.3%). The authors conclude that ACEIs have modest beneficial effects on arterial stiffness measured as PWV and augmentation index, and this effect is at least partly independent of changes in blood pressure.

  2. Arterial stiffness in periodontitis patients and controls. A case–control and pilot intervention study.

    PubMed

    Houcken, W; Teeuw, W J; Bizzarro, S; Alvarez Rodriguez, E; Mulders, T A; van den Born, B-Jh; Loos, B G

    2016-01-01

    Increased arterial stiffness (AS) is an important indicator for atherosclerotic cardiovascular disease (ACVD). Epidemiologically, periodontitis and ACVD are associated. Therefore, we aimed to investigate AS in periodontitis patients and controls. In addition, we explored the effect of periodontal therapy on AS in a sub-group of cases. Pulse-wave velocity (PWV), a non-invasive chair-side function test for AS, was measured in periodontitis patients (n=57; mean age 46.6 years) and compared with a reference group (n=48; mean age 45.5 years). In addition, 45 cases (mean age 46.9 years) were 6 months followed after periodontal treatment, to explore a possible effect on arterial function. Periodontitis patients showed a significantly increased PWV compared with the reference group (8.01±0.20 vs. 7.36±0.22 m s(-1) respectively; P=0.029) and this remained significant after adjustments for ACVD risk factors (P=0.019). After periodontal therapy, no significant reduction in PWV was seen (8.00±1.8 to 7.82±1.6 m s(-1); P=0.13), but systolic blood pressure (SBP) was significantly reduced (119.8±14.6 to 116.9±15.1 mm Hg; P=0.040). It can be concluded that periodontitis is associated with increased AS. This confirms with a new parameter the association of periodontitis with ACVD. Although periodontal treatment did not lower AS significantly, a modest reduction of SBP after 6 months was observed.

  3. Intra-arterial Thrombolysis for Central Retinal Artery Occlusion after the Coil Embolization of Paraclinoid Aneurysm

    PubMed Central

    Yoo, Minwook; Kim, Hae Yu; Choi, Byeong-Sam

    2016-01-01

    The most common complication of coil embolization for cerebral aneurysms is thrombo-embolic stroke; in rare cases, these strokes, can present with central retinal artery occlusion. At our institution, a 53-year-old woman underwent stent-assisted coiling of the aneurysm. The patient's vision was improved immediately after intra-arterial thrombolysis and had further improved 8 months later. This report describes our experience of a rare case of central retinal artery occlusion after coil embolization that was successfully treated by intra-arterial thrombolysis. PMID:28184347

  4. Fatty acids impair endothelium-dependent vasorelaxation: a link between obesity and arterial stiffness in very old Zucker rats.

    PubMed

    Sloboda, Natacha; Fève, Bruno; Thornton, Simon N; Nzietchueng, Rosine; Regnault, Véronique; Simon, Ginny; Labat, Carlos; Louis, Huguette; Max, Jean-Pierre; Muscat, Adeline; Osborne-Pellegrin, Mary; Lacolley, Patrick; Benetos, Athanase

    2012-09-01

    To analyze age-related interactions between obesity, its associated metabolic disorders, and macrocirculation, we studied large artery stiffness and fatty acid responsiveness in lean and obese Zucker rats, aged 25 (adult) and 80 weeks (very old). Systolic arterial pressure was higher in old obese than in old lean rats (178 ± 10 vs 134 ± 8 mmHg, respectively). Carotid elastic modulus-wall stress curves showed increased age-dependent arterial stiffening, which was greater in obese animals. Old obese exhibited endothelial dysfunction with increased systemic oxidative stress. Adult obese had elevated plasma free fatty acid levels (1,866 ± 177 vs 310 ± 34 μg/μL in lean animals). In old obese, linoleate and palmitate increased contractility to phenylephrine and reduced relaxation to acetylcholine. Thus, obesity at 25 weeks appears to trigger accelerated arterial aging observed at 80 weeks. The early increase in free fatty acids may be a key effector in the severe arterial stiffness of the aged obese Zucker model.

  5. Endothelial function, arterial stiffness, and adherence to the 2010 Dietary Guidelines for Americans: a cross-sectional analysis

    PubMed Central

    Sauder, Katherine A.; Proctor, David N.; Chow, Mosuk; Troy, Lisa M.; Wang, Na; Vita, Joseph A.; Vasan, Ramachandran S.; Mitchell, Gary F.; Jacques, Paul F.; Hamburg, Naomi M.; West, Sheila G.

    2015-01-01

    Endothelial dysfunction and arterial stiffness are early predictors of cardiovascular disease. Intervention studies suggest that diet is related to vascular health, but most prior studies tested individual foods or nutrients and relied on small samples of younger adults. The purpose of this study was to examine relations between adherence to the 2010 Dietary Guidelines for Americans and vascular health in a large, cross-sectional analysis. In 5887 adults in the Framingham Heart Study Offspring and Third Generation cohorts, diet quality was quantified with the 2010 Dietary Guidelines for Americans Index (DGAI-2010). Endothelial function was assessed via brachial artery ultrasound and arterial stiffness via arterial tonometry. In age-, sex-, and cohort-adjusted analyses, higher DGAI-2010 score (greater adherence) was modestly associated with lower resting flow velocity, hyperemic response, mean arterial pressure, carotid-femoral pulse wave velocity, and augmentation index, but not associated with resting arterial diameter or flow-mediated dilation. In multivariable models adjusting for cardiovascular risk factors, only the association of higher DGAI-2010 with lower baseline flow and augmentation index persisted (β=−0.002, P=0.003 and β=−0.05 ± 0.02, P<0.001, respectively). Age-stratified multivariate-adjusted analyses suggested that the relation of higher DGAI-2010 scores with lower mean arterial pressure, pulse wave velocity, and augmentation index was more pronounced among adults younger than 50 years. Better adherence to the 2010 Dietary Guidelines for Americans, particularly in younger adults, is associated with lower peripheral blood flow velocity and arterial wave reflection but not flow-mediated dilation. Our results suggest a link between adherence to the Dietary Guidelines and favorable vascular health. PMID:25885520

  6. Anti-Platelet Factor 4/Heparin Antibody Plays a Significant Role in Progression of Arterial Stiffness among Hemodialysis Patients

    PubMed Central

    Kuo, Chieh; Tsai, Chiang-Chin; Chen, Chien-An; Tsai, Yueh-Feng; Chen, Yen-Hsun

    2017-01-01

    Background Arterial stiffness is a determinant of cardiovascular disease in end stage renal disease. Hemodialysis patients may develop anti-platelet factor 4/heparin antibody (PF4-H Ab) because of heparin treatment in dialysis. We tested whether PF4-H Ab was associated with progression of arterial stiffness in a 3-year follow-up. Methods We enrolled 74 hemodialysis patients and studied their clinical, biochemical and arterial stiffness measurement with brachial-ankle pulse wave velocity (baPWV) over 3 years. Baseline and changes in baPWV after 3 years (ΔbaPWV) were collected and compared with related clinical and biochemical parameters. PF4-H Ab was evaluated by the enzyme-linked immunosorbent assay and titer ≥ 0.4 was defined to have PF4-H Ab. Results We found a positive PF4-H Ab status in 25 of 74 patients. Mean baPWV was 16.1 ± 3.8 (m/s) at baseline and 17.6 ± 4.0 (m/s) after 3 years. Mean ΔbaPWV was 3.4 ± 2.2 (m/s) in the PF4-H Ab positive group, and 0.6 ± 1.2 (m/s) in the PF4-H Ab negative group. Baseline baPWV was only significantly associated with age (β = 0.49, p < 0.01). ΔbaPWV was significantly different between the PF4-H Ab positive and negative groups (p < 0.01). In multivariate regression analysis, only PF4-H Ab was positively associated with ΔbaPWV (β = 0.71, p < 0.01). Conclusions Our study concluded that PF4-H Ab was associated with progression of arterial stiffness in hemodialysis patients. PMID:28344423

  7. Relationship between Arterial Stiffness and Blood Pressure Drop During the Sit-to-stand Test in Patients with Diabetes Mellitus

    PubMed Central

    Kobayashi, Yusuke; Kobayashi, Hideo; Sumida, Koichiro; Suzuki, Shota; Kagimoto, Minako; Okuyama, Yuki; Ehara, Yosuke; Katsumata, Mari; Fujita, Megumi; Fujiwara, Akira; Saka, Sanae; Yatsu, Keisuke; Hashimoto, Tatsuo; Kuji, Tadashi; Hirawa, Nobuhito; Toya, Yoshiyuki; Yasuda, Gen; Umemura, Satoshi

    2017-01-01

    Aim: Patients with orthostatic hypotension (OH) have high arterial stiffness. Patients with diabetes mellitus (DM) often have cardiac autonomic neuropathy that leads to OH; however, whether OH is an indicator of arterial stiffness progression is unclear. We aimed to investigate whether the cardioankle vascular index (CAVI) varies between DM patients with and without OH using the sit-to-stand test (STST). Methods: One hundred and fifty-nine patients with DM underwent CAVI assessment and blood pressure (BP) and heart rate change evaluation during the STST. OH was defined as a decline in systolic BP (SBP) and/or diastolic BP of at least 20 mmHg or 10 mmHg, respectively, in the initial and late upright positions compared with that in the sitting position. Results: OH was diagnosed in 42 patients (26.4%). DM patients with OH had significantly higher CAVI (9.36 ± 1.15 versus 8.89 ± 1.18, p = 0.026) than those without OH. CAVI was significantly inversely correlated with systolic and diastolic BP changes (R = −0.347, p <0.001 and R = −0.314, p <0.001, respectively) in the initial upright position. Multivariate regression analysis revealed that age, SBP changes, and low frequency component in the initial upright position were independent determinants of CAVI. Conclusion: Patients with DM having large BP drops occurring when moving from sitting to standing have high arterial stiffness. A significant BP drop during the STST necessitates careful evaluation of advanced arterial stiffness in patient with DM. PMID:27453255

  8. Plasma homocysteine levels are independently associated with alterations of large artery stiffness in men but not in women

    PubMed Central

    Sheng, Li; Wu, Cai; Bai, Yong-Yi; Xiao, Wen-Kai; Feng, Dan; Ye, Ping

    2015-01-01

    Objectives To investigate the associations of the plasma homocysteine levels with the alterations in arterial stiffness in a community-based cohort. The gender differences in these associations were examined. Methods We evaluated the relationship between plasma homocysteine levels to three measures of vascular function [carotid-femoral pulse wave velocity (CF-PWV), carotid-ankle PWV (CA-PWV) and heart rate corrected augmentation index (AI)] in 1680 participants (mean age: 61.5 years; 709 men, 971 women) from communities of Beijing, China. Results In univariate analysis, plasma homocysteine levels was positively related to the CF-PWV (r = 0.211, P < 0.0001) and CA-PWV (r = 0.148, P < 0.0001), whereas inversely associated with AI (r = −0.052, P = 0.016). In multiple linear regression models adjusting for covariants, plasma homocysteine remained positively related to the CF-PWV (standardized β = 0.065, P = 0.007) in total cases. When the groups of men and women were examined separately, plasma homocysteine remained positively associated with the CF-PWV (standardized β = 0.082, P = 0.023) in men, whereas the relations between homocysteine and any of the arterial stiffness indices were not further present in women. Conclusions In Chinese population, plasma homocysteine levels are independently associated with alterations of large artery stiffness in men but not in women. PMID:26089849

  9. Identification of artery wall stiffness: in vitro validation and in vivo results of a data assimilation procedure applied to a 3D fluid-structure interaction model.

    PubMed

    Bertoglio, Cristóbal; Barber, David; Gaddum, Nicholas; Valverde, Israel; Rutten, Marcel; Beerbaum, Philipp; Moireau, Philippe; Hose, Rodney; Gerbeau, Jean-Frédéric

    2014-03-21

    We consider the problem of estimating the stiffness of an artery wall using a data assimilation method applied to a 3D fluid-structure interaction (FSI) model. Recalling previous works, we briefly present the FSI model, the data assimilation procedure and the segmentation algorithm. We present then two examples of the procedure using real data. First, we estimate the stiffness distribution of a silicon rubber tube from image data. Second, we present the estimation of aortic wall stiffness from real clinical data.

  10. Adiposity, obesity, and arterial aging: longitudinal study of aortic stiffness in the Whitehall II cohort.

    PubMed

    Brunner, Eric J; Shipley, Martin J; Ahmadi-Abhari, Sara; Tabak, Adam G; McEniery, Carmel M; Wilkinson, Ian B; Marmot, Michael G; Singh-Manoux, Archana; Kivimaki, Mika

    2015-08-01

    We sought to determine whether adiposity in later midlife is an independent predictor of accelerated stiffening of the aorta. Whitehall II study participants (3789 men; 1383 women) underwent carotid-femoral applanation tonometry at the mean age of 66 and again 4 years later. General adiposity by body mass index, central adiposity by waist circumference and waist:hip ratio, and fat mass percent by body impedance were assessed 5 years before and at baseline. In linear mixed models adjusted for age, sex, ethnicity, and mean arterial pressure, all adiposity measures were associated with aortic stiffening measured as increase in pulse wave velocity (PWV) between baseline and follow-up. The associations were similar in the metabolically healthy and unhealthy, according to Adult Treatment Panel-III criteria excluding waist circumference. C-reactive protein and interleukin-6 levels accounted for part of the longitudinal association between adiposity and PWV change. Adjusting for chronic disease, antihypertensive medication and risk factors, standardized effects of general and central adiposity and fat mass percent on PWV increase (m/s) were similar (0.14, 95% confidence interval: 0.05-0.24, P=0.003; 0.17, 0.08-0.27, P<0.001; 0.14, 0.05-0.22, P=0.002, respectively). Previous adiposity was associated with aortic stiffening independent of change in adiposity, glycaemia, and lipid levels across PWV assessments. We estimated that the body mass index-linked PWV increase will account for 12% of the projected increase in cardiovascular risk because of high body mass index. General and central adiposity in later midlife were strong independent predictors of aortic stiffening. Our findings suggest that adiposity is an important and potentially modifiable determinant of arterial aging.

  11. Association of fibroblast growth factor-23 with arterial stiffness in the Multi-Ethnic Study of Atherosclerosis

    PubMed Central

    Hsu, Jeffrey J.; Katz, Ronit; Ix, Joachim H.; de Boer, Ian H.; Kestenbaum, Bryan; Shlipak, Michael G.

    2014-01-01

    Background Serum fibroblast growth factor-23 (FGF-23) is associated with cardiovascular disease (CVD), yet the mechanisms remain uncertain. Our objective was to determine whether higher FGF-23 concentrations are associated with arterial stiffness. Methods In this cross-sectional study, serum FGF-23 concentrations were measured in 5977 participants without known CVD in the Multi-Ethnic Study of Atherosclerosis. The primary outcomes of interest were large (LAE) and small artery elasticity (SAE), pulse pressure and ankle-brachial index (ABI) > 1.30. LAE and SAE were measured by pulse contour analysis of the radial artery. Pulse pressure was measured with an automated sphygmomanometer using the average of two resting blood pressure measurements. ABI was calculated as the ratio of the ankle and brachial systolic blood pressures. Results Serum FGF-23 concentrations were not significantly associated with LAE [relative difference (RD) per doubling: 0%; 95% confidence interval (CI): −2–1%], SAE (RD per doubling: 0%; 95% CI: −3–2%), pulse pressure (β per doubling: 0.44; 95% CI: −0.31–1.19), or a high ABI (odds ratio per doubling: 1.14; 95% CI: 0.84–1.55). Findings were similar irrespective of chronic kidney disease status. Conclusions Higher serum FGF-23 concentrations are not associated with arterial stiffness, as measured by pulse pressure, LAE, SAE or high ABI, in a community-based population without CVD. PMID:24782533

  12. Reduction of plasma aldosterone and arterial stiffness in obese pre- and stage1 hypertensive subjects after aerobic exercise

    PubMed Central

    Collier, SR; Sandberg, K; Moody, AM; Frechette, V; Curry, CD; Ji, H; Gowdar, R; Chaudhuri, D; Meucci, M

    2017-01-01

    Obesity-related hypertension is associated with increased activity of the renin-angiotensin-aldosterone system (RAAS), increasing arterial stiffness. Aerobic exercise decreases pulse wave velocity (PWV), therefore a treatment option for hypertension and obesity. Assess RAAS activity and PWV before and after 4 weeks of aerobic training in unmedicated, pre-to-stage-1 hypertensives. Ten obese subjects (52±3.2 years, body mass index=33.5±1.4) performed 30 min of aerobic exercise on a treadmill 3 days per week at 65% of peak oxygen consumption (VO2peak). Descriptive characteristics, systolic and diastolic blood pressure (SBP and DBP), PWV, and a blood draw was performed at baseline, following the 4-week control and training interventions. No differences in descriptive characteristics during the control period were observed, however, a significant decrease in plasma aldosterone (ALDO) (255.4±75 to 215.8±66 pg ml−1, P=0.001), SBP (140±12 to 136±10.4 mm Hg; P=0.02), DBP (89±4.2 to 85±6.3 mm Hg; P =0.03) and central PWV (11.2±0.6 to 9.8±0.8 m s−1; P=0.04) was shown pre-to-post exercise training. Four weeks of moderate-intensity aerobic training in obese, hypertensives decreases plasma ALDO independently of body weight and is significantly correlated to decreases in PWV reductions. PMID:24785976

  13. Activation of SIRT1 Attenuates Klotho Deficiency-Induced Arterial Stiffness and Hypertension by Enhancing AMP-Activated Protein Kinase Activity.

    PubMed

    Gao, Diansa; Zuo, Zhong; Tian, Jing; Ali, Quaisar; Lin, Yi; Lei, Han; Sun, Zhongjie

    2016-11-01

    Arterial stiffness is an independent risk factor for stroke and myocardial infarction. This study was designed to investigate the role of SIRT1, an important deacetylase, and its relationship with Klotho, a kidney-derived aging-suppressor protein, in the pathogenesis of arterial stiffness and hypertension. We found that the serum level of Klotho was decreased by ≈45% in patients with arterial stiffness and hypertension. Interestingly, Klotho haplodeficiency caused arterial stiffening and hypertension, as evidenced by significant increases in pulse wave velocity and blood pressure in Klotho-haplodeficient (KL(+/-)) mice. Notably, the expression and activity of SIRT1 were decreased significantly in aortic endothelial and smooth muscle cells in KL(+/-) mice, suggesting that Klotho deficiency downregulates SIRT1. Treatment with SRT1720 (15 mg/kg/d, IP), a specific SIRT1 activator, abolished Klotho deficiency-induced arterial stiffness and hypertension in KL(+/-) mice. Klotho deficiency was associated with significant decreases in activities of AMP-activated protein kinase α (AMPKα) and endothelial NO synthase (eNOS) in aortas, which were abolished by SRT1720. Furthermore, Klotho deficiency upregulated NADPH oxidase activity and superoxide production, increased collagen expression, and enhanced elastin fragmentation in the media of aortas. These Klotho deficiency-associated changes were blocked by SRT1720. In conclusion, this study provides the first evidence that Klotho deficiency downregulates SIRT1 activity in arterial endothelial and smooth muscle cells. Pharmacological activation of SIRT1 may be an effective therapeutic strategy for arterial stiffness and hypertension.

  14. Stabilizing the Central Part of Tropomyosin Increases the Bending Stiffness of the Thin Filament

    PubMed Central

    Nabiev, Salavat R.; Ovsyannikov, Denis A.; Kopylova, Galina V.; Shchepkin, Daniil V.; Matyushenko, Alexander M.; Koubassova, Natalia A.; Levitsky, Dmitrii I.; Tsaturyan, Andrey K.; Bershitsky, Sergey Y.

    2015-01-01

    A two-beam optical trap was used to measure the bending stiffness of F-actin and reconstructed thin filaments. A dumbbell was formed by a filament segment attached to two beads that were held in the two optical traps. One trap was static and held a bead used as a force transducer, whereas an acoustooptical deflector moved the beam holding the second bead, causing stretch of the dumbbell. The distance between the beads was measured using image analysis of micrographs. An exact solution to the problem of bending of an elastic filament attached to two beads and subjected to a stretch was used for data analysis. Substitution of noncanonical residues in the central part of tropomyosin with canonical ones, G126R and D137L, and especially their combination, caused an increase in the bending stiffness of the thin filaments. The data confirm that the effect of these mutations on the regulation of actin-myosin interactions may be caused by an increase in tropomyosin stiffness. PMID:26200873

  15. Associations of atherosclerosis in the descending thoracic aorta on CTA with arterial stiffness and chronic kidney disease in asymptomatic patients with diabetes mellitus.

    PubMed

    Roos, Cornelis J; Delgado, V; de Koning, Eelco J; Rabelink, Ton J; Jukema, J Wouter; Bax, Jeroen J; Scholte, Arthur J

    2014-08-01

    The relation between atherosclerosis in the descending thoracic aortic (DTA), arterial stiffness and chronic kidney disease (CKD) in patients with diabetes mellitus (DM) remains unclear. The current aim was to evaluate associations of DTA atherosclerosis with arterial stiffness and parameters of CKD in asymptomatic patients with DM. A total of 213 asymptomatic patients with diabetes (mean age 52 years, 56% men) underwent cardiovascular risk assessment including multi-slice computed tomography (for non-invasive coronary angiography, from which DTA atherosclerosis can be derived), non-invasive assessment of arterial stiffness with applanation tonometry and assessment of renal function. Measurements of DTA atherosclerosis included assessment of DTA thickening and calcium score. Arterial stiffness was determined by the carotid-femoral pulse wave velocity (PWV), parameters of CKD included estimated glomerular filtration rate (eGFR) and urinary albumin-creatinine ratio (UACR). DTA atherosclerosis was present in 180 (84%) patients. Patients with DTA atherosclerosis had increased arterial stiffness, lower eGFR and higher UACR values. After multivariate correction, DTA calcium score was independently associated with PWV (β = 0.18, p = 0.04). Furthermore, both DTA maximal wall thickness and DTA calcium score were independently associated with eGFR (β = -7.37, p < 0.001 and β = -1.99, p < 0.003, respectively), but not with UACR. The increase in arterial stiffness by atherosclerosis seemed to be mediated by arterial calcification, while the DTA calcium score was independently associated with arterial stiffness, but not DTA maximal wall thickness. Furthermore, parameters of CKD in patients with DM had a distinct relationship with DTA atherosclerosis: DTA atherosclerosis was associated with eGFR but not with UACR.

  16. The shear-stress intensity factor for a centrally cracked stiff-flanged shear web

    NASA Technical Reports Server (NTRS)

    Fichter, W. B.

    1976-01-01

    By use of the principle of superposition the stiff-flanged shear web is modeled mathematically by an infinite elastic strip with fixed longitudinal edges. The shear-stress intensity factor for a central longitudinal crack is calculated for various values of the ratio of strip width to crack length, h/a, in the range 0.1-10. The interaction of the crack with the boundaries is illustrated by boundary shear-stress distributions for three values of h/a. Some implications of the results for the design of damage-tolerant shear webs are discussed briefly.

  17. Central arterial pressure assessment with intensity POF sensor

    NASA Astrophysics Data System (ADS)

    Leitão, Cátia; Gonçalves, Steve; Antunes, Paulo; Bastos, José M.; Pinto, João. L.; André, Paulo

    2015-09-01

    The central pressure monitoring is considered a new key factor in hypertension assessment and cardiovascular prevention. In this work, it is presented the central arterial systolic pressure assessment with an intensity based POF sensor. The device was tested in four subjects, and stable pulse waves were obtained, allowing the calculation of the central pressure for all the subjects. The results shown that the sensor performs reliably, being a simple and low-cost solution to the intended application.

  18. Vascular Health Assessment of The Hypertensive Patients (VASOTENS) Registry: Study Protocol of an International, Web-Based Telemonitoring Registry for Ambulatory Blood Pressure and Arterial Stiffness

    PubMed Central

    Parati, Gianfranco; Avolio, Alberto; Rogoza, Anatoly N; Kotovskaya, Yulia V; Mulè, Giuseppe; Muiesan, Maria Lorenza; Orlova, Iana A; Grigoricheva, Elena A; Cardona Muñoz, Ernesto; Zelveian, Parounak H; Pereira, Telmo; Peixoto Maldonado, João Manuel

    2016-01-01

    Background Hypertension guidelines recommend ambulatory blood pressure (ABP), central aortic pressure (CAP), and pulse wave velocity (PWV) as parameters for estimating blood pressure (BP) control and vascular impairment. Recent advances in technology have enabled devices to combine non-invasive estimation of these parameters over the 24-hour ABP monitoring. However, currently there is limited evidence on the usefulness of such an approach for routine hypertension management. Objective We recently launched an investigator-initiated, international, multicenter, observational, prospective study, the Vascular health Assessment Of The Hypertensive patients (VASOTENS) Registry, aimed at (1) evaluating non-invasive 24-hour ABP and arterial stiffness estimates (through 24-hour pulse wave analysis, PWA) in hypertensive subjects undergoing ambulatory blood pressure monitoring (ABPM) for clinical reasons; (2) assessing the changes in estimates following treatment; (3) weighing the impact of 24-hour PWA on target organ damage and cardiovascular prognosis; (4) assessing the relationship between arterial stiffness, BP absolute mean level and variability, and prognosis; and (5) validating the use of a 24-hour PWA electronic health (e-health) solution for hypertension screening. Methods Approximately 2000 subjects, referred to 20 hypertension clinics for routine diagnostic evaluation and follow-up of hypertension of any severity or stage, will be recruited. Data collection will include ABPM, performed with a device allowing simultaneous non-invasive assessment of 24-hour CAP and arterial stiffness (BPLab), and clinical data (including cardiovascular outcomes). As recommended by current guidelines, each patient will be followed-up with visits occurring at regular intervals (ideally every 6 months, and not less than once a year depending on disease severity). A Web-based telemedicine platform (THOLOMEUS) will be used for data collection. The use of the telemedicine system will allow

  19. Left Ventricular Mass and Intrarenal Arterial Stiffness as Early Diagnostic Markers in Cardiorenal Syndrome Type 5 due to Systemic Sclerosis

    PubMed Central

    Gigante, Antonietta; Barilaro, Giuseppe; Barbano, Biagio; Romaniello, Antonella; Di Mario, Francesca; Quarta, Silvia; Gasperini, Maria Ludovica; Di Lazzaro Giraldi, Gianluca; Laviano, Alessandro; Amoroso, Antonio; Cianci, Rosario; Rosato, Edoardo

    2016-01-01

    Background Cardiorenal syndrome type 5 (CRS-5) includes a group of conditions characterized by a simultaneous involvement of the heart and kidney in the course of a systemic disease. Systemic sclerosis (SSc) is frequently involved in the etiology of acute and chronic CRS-5 among connective tissue diseases. In SSc patients, left ventricular mass (LVM) can be used as a marker of nutritional status and fibrosis, while altered intrarenal hemodynamic parameters are suggestive of early kidney involvement. Methods Forty-two consecutive patients with a diagnosis of SSc without cardiac and/or renal impairment were enrolled to assess whether cardiac muscle mass can be related to arterial stiffness. Thirty subjects matched for age and sex were also enrolled as healthy controls (HC). All patients performed echocardiography and renal ultrasound. Results Doppler indices of intrarenal stiffness and echocardiographic indices of LVM were significantly increased in SSc patients compared to HC. A positive correlation exists between LVM/body surface area and pulsatile index (p < 0.05, r = 0.36), resistive index (p < 0.05, r = 0.33) and systolic/diastolic ratio (p < 0.05, r = 0.38). Doppler indices of intrarenal stiffness and LVM indices were significantly higher in SSc patients with digital ulcers than in SSc patients without a digital ulcer history. Conclusions SSc is characterized by the presence of microvascular and multiorgan injury. An early cardiac and renal impairment is very common. LVM and intrarenal arterial stiffness can be considered as early markers of CRS onset. The clinical use of these markers permits a prompt identification of organ damage. An early diagnosis allows the appropriate setting of pharmacological management, by slowing disease progression. © 2016 S. Karger AG, Basel PMID:27022332

  20. Non-HDL cholesterol is a good predictor of the risk of increased arterial stiffness in postmenopausal women in an urban Brazilian population

    PubMed Central

    de Oliveira Alvim, Rafael; Mourao, Carlos Alberto; Magalhães, Géssica Lopes; de Oliveira, Camila Maciel; Krieger, José Eduardo; Mill, José Geraldo; Pereira, Alexandre Costa

    2017-01-01

    OBJECTIVES: Increased arterial stiffness is an important determinant of the risk of cardiovascular disease. Lipid profile impairment, especially hypercholesterolemia, is associated with stiffer blood vessels. Thus, the aim of this study was to determine which of the five circulating lipid components (high-density lipoprotein cholesterol (HDL-C), non-high-density lipoprotein cholesterol (non-HDL-C), low-density lipoprotein cholesterol (LDL), total cholesterol (TC) and triglycerides) is the best predictor of increased arterial stiffness in an urban Brazilian population. METHODS: A random sample of 1,662 individuals from the general population of Vitoria, Brazil (25-64 years), was selected, and lipid components were measured using standard methods. Pulse wave velocity was measured using a non-invasive automatic device, and increased arterial stiffness was defined as a pulse wave velocity ≥10 m/s. RESULTS: In men, only total cholesterol (OR=1.59; CI=1.02 to 2.48, p=0.04) was associated with the risk of increased arterial stiffness. In women, HDL-C (OR=1.99; CI=1.18 to 3.35, p=0.01) and non-HDL-C (OR=1.61; CI=1.01 to 2.56, p=0.04) were good predictors of the risk of increased arterial stiffness. However, these associations were only found in postmenopausal women (OR=2.06; CI=1.00 to 4.26, p=0.05 for HDL-C and OR=1.83; CI=1.01 to 3.33, p=0.04 for non-HDL-C). CONCLUSION: Our findings indicate that both HDL-C and non-HDL-C are good predictors of the risk of increased arterial stiffness in postmenopausal women in an urban Brazilian population and may be useful tools for assessing the risk of arterial stiffness. PMID:28273234

  1. A constitutive modeling interpretation of the relationship among carotid artery stiffness, blood pressure, and age in hypertensive subjects.

    PubMed

    Spronck, Bart; Heusinkveld, Maarten H G; Donders, Wouter P; de Lepper, Anouk G W; Op't Roodt, Jos; Kroon, Abraham A; Delhaas, Tammo; Reesink, Koen D

    2015-03-15

    Aging has a profound influence on arterial wall structure and function. We have previously reported the relationship among pulse wave velocity, age, and blood pressure in hypertensive subjects. In the present study, we aimed for a quantitative interpretation of the observed changes in wall behavior with age using a constitutive modeling approach. We implemented a model of arterial wall biomechanics and fitted this to the group-averaged pressure-area (P-A) relationship of the "young" subgroup of our study population. Using this model as our take-off point, we assessed which parameters had to be changed to let the model describe the "old" subgroup's P-A relationship. We allowed elastin stiffness and collagen recruitment parameters to vary and adjusted residual stress parameters according to published age-related changes. We required wall stress to be homogeneously distributed over the arterial wall and assumed wall stress normalization with age by keeping average "old" wall stress at the "young" level. Additionally, we required axial force to remain constant over the cardiac cycle. Our simulations showed an age-related shift in pressure-load bearing from elastin to collagen, caused by a decrease in elastin stiffness and a considerable increase in collagen recruitment. Correspondingly, simulated diameter and wall thickness increased by about 20 and 17%, respectively. The latter compared well with a measured thickness increase of 21%. We conclude that the physiologically realistic changes in constitutive properties we found under physiological constraints with respect to wall stress could well explain the influence of aging in the stiffness-pressure-age pattern observed.

  2. Dilated Basilar Arteries in Patients with Congenital Central Hypoventilation Syndrome

    PubMed Central

    Kumar, Rajesh; Nguyen, Haidang D.; Macey, Paul M.; Woo, Mary A.; Harper, Ronald M.

    2009-01-01

    Congenital central hypoventilation syndrome (CCHS) patients show hypoventilation during sleep and severe autonomic impairments, including aberrant cardiovascular regulation. Abnormal sympathetic patterns, together with increased and variable CO2 levels, lead to the potential for sustained cerebral vasculature changes. We performed high-resolution T1-weighted imaging in 13 CCHS and 31 control subjects using a 3.0-Tesla magnetic resonance imaging scanner, and evaluated resting basilar and bilateral middle cerebral artery cross-sections. Two T1-weighted image series were acquired; images were averaged and reoriented to common space, and regions containing basilar and both middle cerebral arteries were oversampled. Cross-sections of the basilar and middle cerebral arteries were manually outlined to calculate cross-sectional areas, and differences between and within groups were evaluated. Basilar arteries in CCHS were significantly dilated over control subjects, but both middle cerebral artery cross-sections were similar between groups. No significant differences appeared between left and right middle cerebral arteries within either group. Basilar artery dilation may result from differential sensitivity to high CO2 over other vascular beds, damage to serotonergic or other chemosensitive cells accompanying the artery, or enhanced microvascular resistance, and that dilation may impair tissue perfusion, leading to further neural injury in CCHS. PMID:19822189

  3. Central retinal artery occlusion (reversible in sickle trait with glaucoma.

    PubMed Central

    Radius, R L; Finkelstein, D

    1976-01-01

    We report a case of central retinal artery occlusion in an 18-year-old black woman with sickle-trait haemoglobinopathy and acute glaucoma after hyphaema. The central retinal artery occlusion occurred immediately after treatment of the glaucoma with osmotic agents, raising the possibility that they played a precipitating role. We suggest that osmotic agents be used with extreme caution in sickle patients with glaucoma. The occlusion was treated by anterior chamber paracentesis with eventual return of good vision. The reversibility of retinal and optic nerve function after total ischaemia is discussed. PMID:952815

  4. Selective thrombolysis performed through meningo-ophthalmic artery in central retinal artery occlusion.

    PubMed

    Cohen, José E; Moscovici, Samuel; Halpert, Michael; Itshayek, Eyal

    2012-03-01

    The poor natural history of central retinal artery occlusion (CRAO) is usually not modified with conventional, conservative management techniques. Guidelines for selective intraarterial ophthalmic thrombolysis are still lacking. While many centers continue to perform this procedure with promising results, others are reluctant due to conflicting findings in recent studies. We present our experience in a 36-year-old male with CRAO. Based on the patient's clinical presentation, we planned to perform selective intraarterial ophthalmic thrombolysis via the ophthalmic artery. When angiography demonstrated that the retina was not supplied by the ophthalmic artery, but by a meningo-ophthalmic artery branching from the internal maxillary artery, we instead administered thrombolytic agents via the meningo-ophthalmic artery. The patient's vision recovered completely, with visual acuity and visual field examination at 30 day follow up comparable to his pre-treatment status. This case emphasizes the need for external carotid artery examination in cases of nonvisualization of the ophthalmic artery. In addition, it illustrates the successful use of the meningo-ophthalmic artery to perform selective intraarterial thrombolysis for CRAO.

  5. Visit-to-visit blood pressure variability, average BP level and carotid arterial stiffness in the elderly: a prospective study.

    PubMed

    Nagai, M; Dote, K; Kato, M; Sasaki, S; Oda, N; Kagawa, E; Nakano, Y; Yamane, A; Kubo, Y; Higashihara, T; Miyauchi, S; Harada, W; Masuda, H

    2016-10-20

    In a cross-sectional study, visit-to-visit blood pressure (BP) variability was shown to be associated with artery remodelling. Here, we investigated the impact of visit-to-visit BP variability and average BP on the carotid artery remodelling progression in high-risk elderly according to different classes of antihypertension medication use/non-use. BP measurements and carotid ultrasound were performed in the common carotid artery in 164 subjects (mean age 79.7 years at baseline, 74.7% females) with one or more cardiovascular risk factors. Based on 12 visits (1 × /month for 1 year), we calculated visit-to-visit BP variability expressed as the standard deviation (s.d.), coefficient of variation (CV), maximum BP, minimum BP and delta (maximum-minimum) BP. We measured mean intima-media thickness (IMT) as well as stiffness parameter β were measured at baseline and at the mean 4.2-year follow-up. In a multiple regression analysis, the maximum, minimum, s.d. and average of systolic BP (SBP) were significantly associated with a change in β-values between the baseline and follow-up after adjustment for age, smoking, lower high-density lipoprotein level, baseline β-value and follow-up period. There were no significant associations between the visit-to-visit BP variability measures and the change in mean IMT. Significant associations of maximum, minimum, s.d. and average SBP were found with increased β-values in the subjects without calcium channel blocker (CCB) use and in the subjects using renin-angiotensin system inhibitors (RASIs). Thus, exaggerated visit-to-visit SBP variability and a high average SBP level were significant predictors of progression in carotid arterial stiffness in high-risk elderly without CCBs use and in those using a RASI.Journal of Human Hypertension advance online publication, 20 October 2016; doi:10.1038/jhh.2016.77.

  6. Tau leaping of stiff stochastic chemical systems via local central limit approximation

    NASA Astrophysics Data System (ADS)

    Yang, Yushu; Rathinam, Muruhan

    2013-06-01

    Stiffness manifests in stochastic dynamic systems in a more complex manner than in deterministic systems; it is not only important for a time-stepping method to remain stable but it is also important for the method to capture the asymptotic variances accurately. In the context of stochastic chemical systems, time stepping methods are known as tau leaping. Well known existing tau leaping methods have shortcomings in this regard. The implicit tau method is far more stable than the trapezoidal tau method but underestimates the asymptotic variance. On the other hand, the trapezoidal tau method which estimates the asymptotic variance exactly for linear systems suffers from the fact that the transients of the method do not decay fast enough in the context of very stiff systems. We propose a tau leaping method that possesses the same stability properties as the implicit method while it also captures the asymptotic variance with reasonable accuracy at least for the test system S1↔S2. The proposed method uses a central limit approximation (CLA) locally over the tau leaping interval and is referred to as the LCLA-τ. The CLA predicts the mean and covariance as solutions of certain differential equations (ODEs) and for efficiency we solve these using a single time step of a suitable low order method. We perform a mean/covariance stability analysis of various possible low order schemes to determine the best scheme. Numerical experiments presented show that LCLA-τ performs favorably for stiff systems and that the LCLA-τ is also able to capture bimodal distributions unlike the CLA itself. The proposed LCLA-τ method uses a split implicit step to compute the mean update. We also prove that any tau leaping method employing a split implicit step converges in the fluid limit to the implicit Euler method as applied to the fluid limit differential equation.

  7. The effects of acute hypobaric hypoxia on arterial stiffness and endothelial function and its relationship to changes in pulmonary artery pressure and left ventricular diastolic function.

    PubMed

    Boos, C J; Hodkinson, P; Mellor, A; Green, N P; Woods, D R

    2012-06-01

    This study investigated, for the first time, the effects of simulated high altitude, following acute hypobaric hypoxia (HH), on simultaneous assessment of large artery stiffness and endothelial function and its inter-relationship to left ventricular (LV) diastolic function, pulmonary artery systolic pressure (PASP), and estimated PA vascular resistance (PVR). Ten healthy subjects were studied at baseline pre and following acute HH to 4800 m for a total of 180 minutes. Assessments of LV diastolic function, mitral inflow, estimated LV filling pressure (E/e'), PVR, and PASP were undertaken using transthoracic echocardiography. Simultaneous assessments of arterial stiffness index (SI), systemic vascular resistance (SVR), vascular tone, and endothelial function (reflective index [RI]) were performed using pulse contour analysis of the digital arterial waveform. Acute hypoxia led to a fall in SpO₂ (98.1±0.7 vs. 71.8±7.1%; p=0.0002), SVR (1589.1±191.2 vs. 1187.8±248.7; p=0.004), and RI (50.8±10.3 vs. 33.0±6.5%; p=0.0008) with an increase in PASP (24.3±2.2 to 35.0±5.3 mmHg; p=0.0001) and estimated PVR (116.40±19.0 vs. 144.6±21.5; p<0.001). There was no rise in either SI (p=0.13), mitral early annular early e' filling velocity or E/e'. There was a significant inverse correlation between SpO₂ and PASP (r=-0.77; p<0.0001), PVR (r=-0.57; p=0.008) and between the fall in SpO₂ and change (Δ) in RI (baseline vs. 150 min, r=-0.52; p<0.001). There was a modest inverse correlation between ΔRI (lower ΔRI=worsening endothelial function) and ΔPAP (r=-0.55; p=0.10) and a strong inverse correlation between ΔRI and ΔPVR (r=-0.89; p=0.0007). Acute hypobaric hypoxia does not significantly alter large artery stiffness or cause overt LV diastolic function. However, the degree of hypoxia influences both the systemic endothelial and pulmonary vascular responses. This noted association is intriguing and requires further investigation.

  8. Association of Serum 25-hydroxy-vitamin D Concentration and Arterial Stiffness among Korean Adults in Single Center

    PubMed Central

    Lee, Jung Hae

    2017-01-01

    Background There are growing concerns about the role of vitamin D deficiency in cardiovascular diseases. Therefore, we investigated the correlation between serum 25-hydroxy-vitamin D (25[OH]D) and arterial stiffness among Korean adults. Methods We retrospectively reviewed the medical charts of 302 people (115 women and 187 men) who visited a tertiary hospital from January 2015 to December 2016. Serum 25(OH)D was measured using the radioimmunoassay technique, and brachial-ankle pulse wave velocity (baPWV) was measured using an automatic wave analyzer. We obtained the doctor's report on the medical history of the participants, their alcohol consumption and smoking habits, and their exercise status. Metabolic syndrome was diagnosed based on guidelines from the National Cholesterol Education Program (NCEP)-Adult Treatment Panel (ATP III) and the International Diabetes Federation (IDF). Results of basic blood tests and physical assessment were also collected. Results In the Pearson correlation analysis, serum 25(OH)D and baPWV showed a statistically significant inverse relationship (r=-0.279, P<0.001). Using multiple regression analysis, and after adjusting for possible confounders, serum 25(OH)D concentration was found to be significantly associated with baPWV (β=-0.121, P=0.011). Conclusions We observed an association between serum 25(OH)D concentration and arterial stiffness. Further studies involving larger sample sizes will be needed to confirm this associations. PMID:28326301

  9. Visual prognosis following treatment of acute central retinal artery obstruction.

    PubMed Central

    Augsburger, J J; Magargal, L E

    1980-01-01

    The authors report the visual outcome in 34 consecutive cases of treated acute central retinal artery obstruction. Visual acuity equal to or better than 6/30 was recovered in 35% of the cases. The presenting visual acuity and duration of visual impairment appear to correlate with visual prognosis. PMID:7448144

  10. Beat-to-Beat Blood Pressure and Two-dimensional (axial and radial) Motion of the Carotid Artery Wall: Physiological Evaluation of Arterial Stiffness

    PubMed Central

    Xu, Chenchu; Xiong, Huahua; Gao, Zhifan; Liu, Xin; Zhang, Heye; Zhang, Yanping; Du, Xiuquan; Wu, Wanqing; Liu, Guotao; Li, Shuo

    2017-01-01

    The physiological relationship between local arterial displacement and blood pressure (BP) plays an integral role in assess- ment of the mechanical properties of arteries. In this study, we used more advanced methods to obtain reliable continuous BP and the displacement of the common carotid artery (CCA) simultaneously. We propose a novel evaluation method for arterial stiffness that relies on determining the physiological relationship between the axial and radial displacements of the CCA wall and beat-to-beat BP. Patients (total of 138) were divided into groups according to the following three criteria: essential hyper- tension (EH) and normotension, male and female, elderly and younger. The Pearson correlation test and canonical correlation analysis showed that the CCA indices were significantly correlated with BP indices (r = 0:787; p < 0:05). The slope of the CCA displacement/pressure curve showed a progressive reduction with increasing age and EH disease occurrence (EH: 0.496 vs. normotension: 0.822; age <= 60:0.585 vs. age > 60:0.783). Our method provides an explicit reference value and relationship for the manner in which the CCA wall responds to changes in BP. Short-term and continuous BP were significantly correlated with CCA displacement and exhibited a close inverse relationship with each subject’s BP and EH, age, and systolic blood pressure. PMID:28198819

  11. Cardiovascular design in fin whales: high-stiffness arteries protect against adverse pressure gradients at depth.

    PubMed

    Lillie, M A; Piscitelli, M A; Vogl, A W; Gosline, J M; Shadwick, R E

    2013-07-15

    Fin whales have an incompliant aorta, which, we hypothesize, represents an adaptation to large, depth-induced variations in arterial transmural pressures. We hypothesize these variations arise from a limited ability of tissues to respond to rapid changes in ambient ocean pressures during a dive. We tested this hypothesis by measuring arterial mechanics experimentally and modelling arterial transmural pressures mathematically. The mechanical properties of mammalian arteries reflect the physiological loads they experience, so we examined a wide range of fin whale arteries. All arteries had abundant adventitial collagen that was usually recruited at very low stretches and inflation pressures (2-3 kPa), making arterial diameter largely independent of transmural pressure. Arteries withstood significant negative transmural pressures (-7 to -50 kPa) before collapsing. Collapse was resisted by recruitment of adventitial collagen at very low stretches. These findings are compatible with the hypothesis of depth-induced variation of arterial transmural pressure. Because transmural pressures depend on thoracic pressures, we modelled the thorax of a diving fin whale to assess the likelihood of significant variation in transmural pressures. The model predicted that deformation of the thorax body wall and diaphragm could not always equalize thoracic and ambient pressures because of asymmetrical conditions on dive descent and ascent. Redistribution of blood could partially compensate for asymmetrical conditions, but inertial and viscoelastic lag necessarily limits tissue response rates. Without pressure equilibrium, particularly when ambient pressures change rapidly, internal pressure gradients will develop and expose arteries to transient pressure fluctuations, but with minimal hemodynamic consequence due to their low compliance.

  12. Tributyltin chloride increases phenylephrine-induced contraction and vascular stiffness in mesenteric resistance arteries from female rats.

    PubMed

    Ribeiro Júnior, Rogério Faustino; Marques, Vinicius Bermond; Nunes, Dieli Oliveira; Ronconi, Karoline de Sousa; de Araújo, Julia F P; Rodrigues, Paula Lopes; Padilha, Alessandra Simão; Vassallo, Dalton Valentim; Graceli, Jones B; Stefanon, Ivanita

    2016-03-15

    Tributyltin chloride (TBT) is an organotin compound that reduces estrogen levels in female rats. We aimed to investigate the effects of TBT exposure on vascular tonus and vascular remodelling in the resistance arteries of female rats. Rats were treated daily with TBT (500 ng/kg) for 15 days. TBT did not change arterial blood pressure but did modify some morpho-physiological parameters of third-order mesenteric resistance arteries in the following ways: (1) decreased lumen and external diameters; (2) increased wall/lm ratio and wall thickness; (3) decreased distensibility and increased stiffness; (4) increased collagen deposition; and (5) increased pulse wave velocity. TBT exposure increased the phenylephrine-induced contractile response in mesenteric resistance arteries. However, vasodilatation responses induced by acetylcholine and sodium nitroprusside were not modified by TBT. It is suggested that TBT exposure reduces vascular nitric oxide (NO) production, because:(1) L-NAME incubation did not cause a leftward shift in the concentration-response curve for phenylephrine; (2) both eNOS protein expression; (3) in situ NO production were reduced. Incubation with L-NAME; and (4) SOD shifted the phenylephrine response curve to the left in TBT rats. Tiron, catalase, ML-171 and VAS2870 decreased vascular reactivity to phenylephrine only in TBT rats. Moreover, increased superoxide anion production was observed in the mesenteric resistance arteries of TBT rats accompanied by an increase in gp91phox, catalase, AT1 receptor and total ERK1/2 protein expression. In conclusion, these findings show that TBT induced alterations are most likely due to a reduction of NO production combined with increased O2(-) production derived from NADPH oxidase and ERK1/2 activation. These findings offer further evidence that TBT is an environmental risk factor for cardiovascular disease.

  13. Age and cigarette smoking modulate the relationship between pulmonary function and arterial stiffness in heart failure patients

    PubMed Central

    Li, Li; Hu, Bangchuan; Gong, Shijin; Yu, Yihua; Yan, Jing

    2017-01-01

    Abstract The aim of this study was to assess the relationship between arterial stiffness and pulmonary function in chronic heart failure (CHF). Outpatients previously diagnosed as CHF were enrolled between April 2008 and March 2010, and submitted to arterial stiffness measurement and lung function assessment. Spirometry was performed by measuring forced vital capacity (FVC), the fraction of predicted FVC, forced expiratory volume in 1 second (FEV1), the percentage of predicted FEV1 in 1 second, FEV1 to FVC ratio, and the percentage of predicted FEV1/FVC. Cardio-ankle vascular index (CAVI) was considered for the estimation of arterial stiffness. The 354 patients assessed included 315 nonsmokers, and were 68.2 ± 7.2 years’ old. Unadjusted correlation analyses demonstrated CAVI was positively related to age (r = 0.3664, P < 0.0001), and negatively related to body mass index (BMI, r = −0.2040, P = 0.0001), E/A ratio (r = −0.1759, P = 0.0010), and FEV1 (r = −0.2987, P < 0.0001). Stepwise multivariate regression analyses showed age (r2 = 0.2391, P < 0.0001), BMI (r2 = −0.2139, P < 0.0001), smoking (r2 = 0.1211, P = 0.0130), E/A ratio (r2 = −0.1082, P = 0.0386), and FEV1 (r2 = −0.2550, P < 0.0001) were independent determinants of CAVI. In addition, there is a significant interaction between CAVI and forced expiratory volume in 1 second (FEV1) in relation to age (Pint < 0.0001) and smoking (Pint = 0.0001). Meanwhile, pulmonary function was not associated with BMI or E/A ratio. These findings demonstrated that reduced pulmonary function is associated with the increased CAVI, and had an interactive effect with age and smoking on CAVI in patients with CHF. PMID:28272233

  14. A Comparative Study on Skin and Plasma Advanced Glycation End Products and Their Associations with Arterial Stiffness

    PubMed Central

    Liu, Chang-Yuan; Huang, Qi-Fang; Cheng, Yi-Bang; Guo, Qian-Hui; Chen, Qi; Li, Yan; Wang, Ji-Guang

    2017-01-01

    Background We compared skin and plasma measurements of advanced glycation end products (AGEs), with particular focus on their levels in the presence of hypertension or diabetes and prediabetes and their associations with arterial stiffness in outpatients with suspected or diagnosed hypertension. Methods Skin AGE accumulation was measured as autofluorescence on the left forearm using the skin autofluorescence Reader and expressed in arbitrary units in the range from 0 to 25. Plasma AGE concentration was measured by the enzyme-linked immunosorbent assay method and logarithmically transformed for statistical analysis. Arterial stiffness was assessed by carotid-femoral pulse wave velocity (cfPWV) using the SphygmoCor system (Sydney, Australia). Results The 218 participants (96 [44.0%] men, mean age 51.9 years) had a mean skin autofluorescence of 1.89 arbitrary units, plasma AGE concentration of 4.47 μg/ml, and cfPWV of 8.0 m/s. Skin autofluorescence was significantly correlated with plasma AGEs in diabetic or prediabetic patients (n = 31, r = 0.37, p = 0.04) but not in subjects with normoglycemia (n = 187, r = −0.05, p = 0.48). Nonetheless, both measurements were significantly (p ≤ 0.001) higher in men (2.00 arbitrary units and 6.73 μg/ml, respectively) than women (1.81 arbitrary units and 3.60 μg/ml, respectively) and in diabetic or prediabetic (2.03 arbitrary units and 6.61 μg/ml, respectively) than normoglycemia subjects (1.87 arbitrary units and 4.17 μg/ml, respectively), but similar in hypertensive (n = 105) and normotensive subjects (n = 113, p ≥ 0.35). In adjusted multiple regression analyses, plasma AGE concentration, but not skin autofluorescence (p ≥ 0.37), was significantly associated with cfPWV in all subjects (β 0.44 m/s for each 10-fold increase; p = 0.04) and in subgroups of men and diabetes and prediabetes (β 0.12-0.55 m/s for each 10-fold increase; p ≤ 0.02). Conclusions Although skin and plasma AGEs were similarly associated with

  15. Comparison of central artery elasticity in swimmers, runners, and the sedentary.

    PubMed

    Nualnim, Nantinee; Barnes, Jill N; Tarumi, Takashi; Renzi, Christopher P; Tanaka, Hirofumi

    2011-03-01

    Although swimming is one of the most popular, most practiced, and most recommended forms of physical activity, little information is available regarding the influence of regular swimming on vascular disease risks. Using a cross-sectional study design, key measurements of vascular function were performed in middle-aged and older swimmers, runners, and sedentary controls. There were no group differences in age, height, dietary intake, and fasting plasma concentrations of glucose, total cholesterol, and low-density lipoprotein cholesterol. Runners and swimmers were not different in their weekly training volume. Brachial systolic blood pressure and pulse pressure were higher (p <0.05) in swimmers than in sedentary controls and runners. Runners and swimmers had lower (p <0.05) carotid systolic blood pressure and carotid pulse pressure than sedentary controls. Carotid arterial compliance was higher (p <0.05) and β-stiffness index was lower (p <0.05) in runners and swimmers than in sedentary controls. There were no significant group differences between runners and swimmers. Cardiovagal baroreflex sensitivity was greater (p <0.05) in runners than in sedentary controls and swimmers and baroreflex sensitivity tended to be higher in swimmers than in sedentary controls (p = 0.07). Brachial artery flow-mediated dilation was significant greater (p <0.05) in runners compared with sedentary controls and swimmers. In conclusion, our present findings are consistent with the notion that habitual swimming exercise may be an effective endurance exercise for preventing loss in central arterial compliance.

  16. Carotid and femoral artery stiffness in relation to three candidate genes in a white population.

    PubMed

    Balkestein, E J; Staessen, J A; Wang, J G; van Der Heijden-Spek, J J; Van Bortel, L M; Barlassina, C; Bianchi, G; Brand, E; Herrmann, S M; Struijker-Boudier, H A

    2001-11-01

    Different genetic polymorphisms influence cardiovascular disease. We recently discovered a relationship between the intima-media thickness of the muscular femoral artery, but not the elastic common carotid artery, and the combined ACE (ACE, I/D), alpha-adducin (Gly460Trp),and aldosterone synthase (AS, C-344T) gene polymorphisms. To investigate the relationship between these polymorphisms and functional properties of the carotid artery and femoral artery, a sample of 756 subjects enrolled in a population study were genotyped for the presence of the ACE D, alpha-adducin 460Trp, and aldosterone synthase -344T alleles. Vessel wall properties were assessed using a vessel wall movement detector system in combination with applanation tonometry. Statistical analysis allowed for confounders and interaction among genes. Cross-sectional compliance of the common carotid artery was negatively associated with the ACE D allele. ACE II versus ACE DD homozygotes differed, expressed as a percentage of the population mean (7.0%; 95% confidence interval [CI], 1.6% to 12.4%; P=0.02). In multigene analysis, ACE DD subjects also deviated significantly from the population mean for the distensibility coefficient of the common carotid artery when carrying the AS/T allele (-5.5%; 95% CI, -9.3% to -1.7%; P<0.01), without a change in cross-sectional compliance. ACE DD subjects, when homozygote for alpha-adducin Gly460, had a lower femoral cross-sectional compliance (-10.4%; 95% CI, -1.9% to -18.9%; P<0.03) and a lower distensibility (-9.7%; 95% CI, -2.1% to -17.3%; P<0.02) compared with the population mean. These data show that functional large artery properties are influenced by the ACE I/D polymorphism. Cross-sectional compliance and distensibility coefficients are influenced by the ACE I/D genotype, but this influence depends on the vascular territory and genetic background.

  17. Aerobic exercise training-induced changes in serum adropin level are associated with reduced arterial stiffness in middle-aged and older adults.

    PubMed

    Fujie, Shumpei; Hasegawa, Natsuki; Sato, Koji; Fujita, Satoshi; Sanada, Kiyoshi; Hamaoka, Takafumi; Iemitsu, Motoyuki

    2015-11-15

    Aging-induced arterial stiffening is reduced by aerobic exercise training, and elevated production of nitric oxide (NO) participates in this effect. Adropin is a regulator of endothelial NO synthase and NO release, and circulating adropin level decreases with age. However, the effect of habitual aerobic exercise on circulating adropin levels in healthy middle-aged and older adults remains unclear. We sought to determine whether serum adropin level is associated with exercise training-induced changes in arterial stiffness. First, in a cross-sectional study, we investigated the association between serum adropin level and both arterial stiffness and cardiorespiratory fitness in 80 healthy middle-aged and older subjects (65.6 ± 0.9 yr). Second, in an intervention study, we examined the effects of 8-wk aerobic exercise training on serum adropin level and arterial stiffness in 40 healthy middle-aged and older subjects (67.3 ± 1.0 yr) divided into two groups: aerobic exercise training and sedentary controls. In the cross-sectional study, serum adropin level was negatively correlated with carotid β-stiffness (r = -0.437, P < 0.001) and positively correlated with plasma NOx level (r = 0.493, P < 0.001) and cardiorespiratory fitness (r = 0.457, P < 0.001). Serum adropin levels were elevated after the 8-wk aerobic exercise training intervention, and training-induced changes in serum adropin level were correlated with training-induced changes in carotid β-stiffness (r = -0.399, P < 0.05) and plasma NOx level (r = 0.623, P < 0.001). Thus the increase in adropin may participate in the exercise-induced reduction of arterial stiffness.

  18. Age, hypertension and arterial function.

    PubMed

    McEniery, Carmel M; Wilkinson, Ian B; Avolio, Albert P

    2007-07-01

    1. Ageing exerts a marked effect on the cardiovascular system and, in particular, the large arteries. Using a variety of techniques to assess arterial stiffness, many cross-sectional studies have demonstrated a significant relationship between age and aortic stiffness, although the age-related changes observed in peripheral arteries appear to be less marked. 2. The relationship between arterial stiffness and hypertension is more complex. The distending, or mean arterial, pressure is an important confounder of measurements of arterial stiffness and, therefore, must be taken into consideration when assessing arterial stiffness in hypertensive subjects or investigating the effect of antihypertensive agents. Current methods for correcting for differences in distending pressure involve pharmacological manipulation, statistical correction or mathematical manipulation of stiffness indices. 3. Many studies have provided evidence that both peripheral (muscular) and central (elastic) arteries are stiffer in subjects with mixed (systolic/diastolic) hypertension compared with normotensive subjects. However, it is unclear to what extent differences in mean arterial pressure explain the observed differences in hypertensive subjects. In contrast, isolated systolic hypertension is associated with increased aortic, but not peripheral artery, stiffness, although the underlying mechanisms are somewhat unclear. 4. Traditional antihypertensive agents appear to reduce arterial stiffness, but mostly via an indirect effect of lowering mean pressure. Therefore, therapies that target the large arteries to reduce stiffness directly are urgently required. Agents such as nitric oxide donors and phosphodiesterase inhibitors may be useful in reducing stiffness via functional mechanisms. In addition, inhibitors or breakers of advanced glycation end-product cross-links between proteins, such as collagen and elastin, hold substantial promise.

  19. Evaluation of Ophthalmic Artery Branch Retrograde Intervention in the Treatment of Central Retinal Artery Occlusion (CRAO)

    PubMed Central

    Wang, Runsheng; Qian, Lu; Wang, Yi; Zheng, Yi; Du, Shanshuang; Lei, Tao; Lv, Peilin; Long, Tan; Wang, Wenjun

    2017-01-01

    Background Central retinal artery occlusion (CRAO) is the occlusion of the central retinal artery resulting in retinal infarction and acute vision loss. Digital subtraction angiography (DSA)–guided superselective ophthalmic artery or selective carotid thrombolysis remains the preferred treatment method for CRAO. This study aimed to evaluate the safety and clinical efficacy of the novel ophthalmic artery branch retrograde thrombolytic intervention for CRAO. Material/Methods Fifty patients with monocular CRAO were enrolled, including 28 males and 22 females (mean age: 55.7±2.3 years). The patients were randomly divided into two groups for thrombolysis with urokinase (400,000 U) and papaverine (30 mg) by either ophthalmic artery branch retrograde intervention (group A, n=26) or superselective ophthalmic artery/selective carotid intervention (group B, n=24). There was no significant difference in age (P=0.58), gender ratio (P=0.49), and time to onset (P=1.00) between the two groups. The adverse reactions and clinical efficacy were evaluated by postoperative DSA, fundus fluorescein angiography (FFA), and visual acuity tests. Results No serious complications, abnormal eye movement, or vitreous hemorrhage occurred in either group. DSA showed that group A had an effective rate (92.30%) comparable to that of group B (100%, χ2=2.08, P=0.25). FFA suggested that both groups had similar treatment efficacy (χ2=3.09, P=0.21). Visual acuity tests also confirmed a similar efficacy of the two intervention approaches (χ2=0.25, P=0.88). Conclusions The developed novel ophthalmic artery branch retrograde intervention is highly effective and safe for CRAO, and may be a superior method compared with the conventional approach. PMID:28064304

  20. Large artery stiffness and carotid intima-media thickness in relation to markers of calcium and bone mineral metabolism in African women older than 46 years.

    PubMed

    Gafane, L F; Schutte, R; Kruger, I M; Schutte, A E

    2015-03-01

    Vascular calcification and cardiovascular diseases have been associated with altered bone metabolism. We explored the relationships of arterial pressures and carotid intima-media thickness (CIMT) with parathyroid hormone, 25-hydroxycholecalciferol and their ratio (PTH:25(OH)D3) as well as a marker of bone resorption (CTX) in lean and overweight/obese African women. A population of 434 African women older than 46 years was divided into lean and overweight/obese groups. We assessed brachial blood pressure, central pulse pressure (cPP) and CIMT, and determined PTH, 25(OH)D3 and CTX concentrations. Overweight/obese women had elevated PTH and PTH:25(OH)D3 compared with lean women (both P<0.001), whereas lean women had higher CTX (P<0.001). Single, partial and multiple regression analyses indicated that, in lean women CIMT was independently associated with PTH:25(OH)D3 (R(2)=0.22; β=0.26; P=0.003), whereas in obese women cPP was associated with both PTH:25(OH)D3 (R2=0.20; β=0.17; P=0.017) and CTX (R2=0.20; β=0.17; P=0.025). In conclusion, we found that in African women with increased adiposity, cPP (as a surrogate measure of arterial stiffness), was positively associated with alterations in bone metabolism and calciotropic hormones, whereas CIMT of lean women was positively associated with PTH:25(OH)D3. Our results suggest that alterations in bone and calcium metabolism may contribute to arterial calcification in older African women.

  1. Arterial Stiffness, Lifestyle Intervention and a Low-Calorie Diet in Morbidly Obese Patients—A Nonrandomized Clinical Trial

    PubMed Central

    Nordstrand, N; Gjevestad, E; Hertel, JK; Johnson, LK; Saltvedt, E; Røislien, J; Hjelmesæth, J

    2013-01-01

    Objective Arterial stiffness is an independent predictor of cardiovascular morbidity and mortality. This study aimed to compare the 7-week effect of a low-calorie diet (LCD) and an intensive lifestyle intervention program (ILI) on arterial stiffness in morbidly obese individuals. Design and Methods Nonrandomized clinical trial. The LCD provided 900 kcal/day, and participants in the LCD group were instructed to maintain their habitual physical activity level. The ILI included two 90-min supervised training sessions 3 days a week at moderate to high intensity (4-8 METs) and a caloric restriction of 1000 kcal/day. Results A total of 179 individuals completed the study, 88 (56 women) in the ILI group and 91 (57 women) in the LCD group. High-fidelity applanation tonometry (Millar®, Sphygmocor®) was used to measure carotid-femoral pulse wave velocity (PWV). After adjustment for relevant confounders, the ILI group had a significantly greater reduction in PWV than the LCD group; −0.4 (−0.6, −0.1) m/s, P = 0.004. When compared to the LCD group, the ILI group showed a larger reduction in systolic and diastolic blood pressure −5 (−9, −1) and −5 (−7, −2) mmHg, P = 0.038 and P ≤ 0.001 respectively, whereas no difference was observed regarding pulse pressure, P = 0.661. No significant differences between groups were found regarding the loss of fat mass, P = 0.259, but the loss of muscle mass was larger in the LCD group, 0.8 (0.5, 1.1) kg, P ≤ 0.001. Conclusion Despite the limitations of a nonrandomized design, our findings indicate that for morbidly obese individuals a moderate caloric restriction combined with aerobic physical exercise is associated with a greater decline in PWV than a LCD alone. PMID:23712971

  2. Circulating sclerostin and Dickkopf-1 (DKK1) in predialysis chronic kidney disease (CKD): relationship with bone density and arterial stiffness.

    PubMed

    Thambiah, S; Roplekar, R; Manghat, P; Fogelman, I; Fraser, W D; Goldsmith, D; Hampson, Geeta

    2012-06-01

    Abnormalities of bone metabolism and increased vascular calcification are common in chronic kidney disease (CKD) and important causes of morbidity and mortality. The Wnt signaling pathway may play a role in the bone and vascular disturbances seen in CKD, termed collectively "CKD-MBD." The aim of the study was to investigate the possible association of circulating concentrations of the secreted Wnt signaling inhibitors DKK1 and sclerostin with BMD and arterial stiffness in predialysis CKD. Seventy-seven patients (48 M, 29 F), mean age 57 (SD = 14) years with CKD stages 3B (n = 32) and 4 (n = 45) were studied. Sclerostin, DKK1, PTH, and 1,25(OH)(2)D were analyzed. BMD was measured at the lumbar spine (LS), femoral neck (FN), total hip (TH), and forearm (FARM). Arterial stiffness index was determined by contour analysis of digital volume pulse (SI(DVP)). There was a positive correlation between sclerostin and age (r = 0.47, p < 0.000). Sclerostin was higher in men than women (p = 0.013). Following correction for age and gender, there was a negative association between GFR and sclerostin (p = 0.002). We observed a positive association between sclerostin and BMD at the LS (p = 0.0001), FN (p = 0.004), and TH (p = 0.002). In contrast, DKK1 was negatively associated with BMD at the FN (p = 0.038). A negative association was seen between DKK1 and SI(DVP) (p = 0.027). Our data suggest that the Wnt pathway may play a role in CKD-MBD. Prospective studies are required to establish the clinical relevance of sclerostin and DKK1 as serological markers in CKD.

  3. Inactive Matrix Gla-Protein Is Associated With Arterial Stiffness in an Adult Population-Based Study.

    PubMed

    Pivin, Edward; Ponte, Belen; Pruijm, Menno; Ackermann, Daniel; Guessous, Idris; Ehret, Georg; Liu, Yan-Ping; Drummen, Nadja E A; Knapen, Marjo H J; Pechere-Bertschi, Antoinette; Paccaud, Fred; Mohaupt, Markus; Vermeer, Cees; Staessen, Jan A; Vogt, Bruno; Martin, Pierre-Yves; Burnier, Michel; Bochud, Murielle

    2015-07-01

    Increased pulse wave velocity (PWV) is a marker of aortic stiffness and an independent predictor of mortality. Matrix Gla-protein (MGP) is a vascular calcification inhibitor that needs vitamin K to be activated. Inactive MGP, known as desphospho-uncarboxylated MGP (dp-ucMGP), can be measured in plasma and has been associated with various cardiovascular markers, cardiovascular outcomes, and mortality. In this study, we hypothesized that high levels of dp-ucMGP are associated with increased PWV. We recruited participants via a multicenter family-based cross-sectional study in Switzerland. Dp-ucMGP was quantified in plasma by sandwich ELISA. Aortic PWV was determined by applanation tonometry using carotid and femoral pulse waveforms. Multiple regression analysis was performed to estimate associations between PWV and dp-ucMGP adjusting for age, renal function, and other cardiovascular risk factors. We included 1001 participants in our analyses (475 men and 526 women). Mean values were 7.87±2.10 m/s for PWV and 0.43±0.20 nmol/L for dp-ucMGP. PWV was positively associated with dp-ucMGP both before and after adjustment for sex, age, body mass index, height, systolic and diastolic blood pressure (BP), heart rate, renal function, low- and high-density lipoprotein, glucose, smoking status, diabetes mellitus, BP and cholesterol lowering drugs, and history of cardiovascular disease (P≤0.01). In conclusion, high levels of dp-ucMGP are independently and positively associated with arterial stiffness after adjustment for common cardiovascular risk factors, renal function, and age. Experimental studies are needed to determine whether vitamin K supplementation slows arterial stiffening by increasing MGP carboxylation.

  4. Relationship of socioeconomic status to C-reactive protein and arterial stiffness in urban Japanese civil servants.

    PubMed

    Saijo, Yasuaki; Yoshioka, Eiji; Fukui, Tomonori; Kawaharada, Mariko; Kishi, Reiko

    2008-09-01

    This study investigates whether the two socioeconomic status indicators, educational level and employment grade, are associated with C-reactive protein (CRP) levels and arterial stiffness among Japanese urban civil servants. Brachial-ankle pulse-wave velocity (baPWV) as an indicator of arterial stiffness, CRP, occupational stress and conventional risk factors were evaluated in 3412 men and 854 women. Although the socioeconomic gradient showed a significant association with the CRP levels in men after adjustment for age, the significance disappeared after multivariate adjustment, whereas in women, the socioeconomic gradient showed no significant association with the CRP levels. In men, educational level was significantly associated with the baPWV value after adjustment for conventional risk factors, CRP and occupational stress (P for trend <0.0001). With regards to employment grade, only low-level non-manual workers had a significantly lower baPWV value as compared to manual workers at a fully adjusted model, and trend significance disappeared. However, in women, neither educational level nor employment grade was associated with the baPWV value. In summary, the socioeconomic gradient, especially the educational level, was significantly inversely related to the baPWV value in men. In women, the socioeconomic gradient was not related to the baPWV value. An inverse relationship between the socioeconomic gradient and CRP levels was found in men only after age adjustment. We suggest that because the educational level is an important aspect in the adolescent environment and hence might influence the future lifestyle, early health education should be provided to prevent an unfavourable lifestyle and atherosclerotic diseases in later life.

  5. Longitudinal trajectories of arterial stiffness and the role of blood pressure: the Baltimore Longitudinal Study of Aging.

    PubMed

    AlGhatrif, Majd; Strait, James B; Morrell, Chris H; Canepa, Marco; Wright, Jeanette; Elango, Palchamy; Scuteri, Angelo; Najjar, Samer S; Ferrucci, Luigi; Lakatta, Edward G

    2013-11-01

    Carotid-femoral pulse wave velocity (PWV), a marker of arterial stiffness, is an established independent cardiovascular risk factor. Little information is available on the pattern and determinants of the longitudinal change in PWV with aging. Such information is crucial to elucidating mechanisms underlying arterial stiffness and the design of interventions to retard it. Between 1988 and 2013, we collected 2 to 9 serial measures of PWV in 354 men and 423 women of the Baltimore Longitudinal Study of Aging, who were 21 to 94 years of age and free of clinically significant cardiovascular disease. Rates of PWV increase accelerated with advancing age in men more than women, leading to sex differences in PWV after the age of 50 years. In both sexes, not only systolic blood pressure (SBP) ≥140 mm Hg but also SBP of 120 to 139 mm Hg was associated with steeper rates of PWV increase compared with SBP<120 mm Hg. Furthermore, there was a dose-dependent effect of SBP in men with marked acceleration in PWV rate of increase with age at SBP ≥140 mm Hg compared with SBP of 120 to 139 mm Hg. Except for waist circumference in women, no other traditional cardiovascular risk factors predicted longitudinal PWV increase. In conclusion, the steeper longitudinal increase of PWV in men than women led to the sex difference that expanded with advancing age. Age and SBP are the main longitudinal determinants of PWV, and the effect of SBP on PWV trajectories exists even in the prehypertensive range.

  6. Relationships Among Conventional Cardiovascular Risk Factors and Lifestyle Habits With Arterial Stiffness in Type 2 Diabetic Patients

    PubMed Central

    Hamamura, Misako; Mita, Tomoya; Osonoi, Yusuke; Osonoi, Takeshi; Saito, Miyoko; Tamasawa, Atsuko; Nakayama, Shiho; Someya, Yuki; Ishida, Hidenori; Gosho, Masahiko; Kanazawa, Akio; Watada, Hirotaka

    2017-01-01

    Background While conventional cardiovascular risk factors and certain lifestyle habits are associated with arterial stiffness in patients with type 2 diabetes mellitus (T2DM), it is still unknown whether they are actually associated with arterial stiffness even after adjustment for conventional cardiovascular risk factors and lifestyle habits. The aim of this study was to identify variables that are associated with brachial-ankle pulse wave velocity (baPWV). Methods The study participants comprised 724 Japanese T2DM outpatients free of history of cardiovascular diseases. Lifestyle habits were analyzed using self-reported questionnaires. The associations among conventional cardiovascular risk factors and lifestyle habits with baPWV were investigated by multivariable linear regression analysis. Results The mean age of the study subjects was 57.8 ± 8.6 years, and 62.8% of those were males. The mean HbA1c was 7.0±1.0%, and the estimated duration of T2DM was 9.9 ± 7.2 years. Multiple linear regression analysis that included age and gender demonstrated that age and male sex were positively associated with baPWV. In a model adjusted for numerous conventional cardiovascular risk factors and lifestyle habits, age, duration of T2DM, systolic blood pressure, serum uric acid, urinary albumin excretion and poor sleep quality were positively associated with baPWV, while body mass index was negatively associated with baPWV. Conclusions In Japanese T2DM, in addition to several conventional cardiovascular risk factors, poor sleep quality was associated with baPWV even after adjustment for numerous conventional cardiovascular risk factors and lifestyle habits. PMID:28270889

  7. The age-related increase in arterial stiffness is augmented in phases according to the severity of hypertension.

    PubMed

    Tomiyama, Hirofumi; Arai, Tomio; Koji, Yutaka; Yambe, Minoru; Motobe, Kohki; Zaydun, Glunisa; Yamamoto, Yoshio; Hori, Saburoh; Yamashina, Akira

    2004-07-01

    Although blood pressure and age are major determinants of arterial stiffness, it is still unclear whether age-related changes in arterial stiffness are similar among subjects with different degrees of severity of hypertension. The present study examined the association between age and pulse wave velocity in subjects with different degrees of hypertension stratified according to the JNC-7 classification (Normal, Prehypertensive, and Stage I or II Hypertensive subjects). A number of 5,312 subjects (age range, 30-79 years) with no atherosclerotic risk factors other than high blood pressure were selected from two cohorts who regularly underwent annual health checkups, including the measurement of brachial-ankle pulse wave velocity (baPWV). baPWV was increased according to the severity of hypertension in all age groups. The association between age and baPWV formed a quadratic curve in each stage in both genders. The steepness of the slope of the quadratic curve increased according to the severity of hypertension. In each stage of hypertension, age and the baPWV were divided into tertiles. After adjustment for systolic and diastolic blood pressure, the odds ratio of having an increased baPWV in the 3rd age tertile (the highest-age group) was found to increase according to the severity of hypertension. In conclusion, the age-related increase of baPWV was shown to be augmented in phases according to the severity of hypertension, and this augmentation occurred even between the Normal and Prehypertensive stages. These results support the JNC-7 recommendations for a strict control of blood pressure even in the elderly.

  8. Nettleship collaterals: circumpapillary cilioretinal anastomoses after occlusion of the central retinal artery.

    PubMed

    Ragge, N K; Hoyt, W F

    1992-03-01

    In extremely rare cases, after occlusion of the central retinal artery, a complete ring of peripapillary anastomotic channels develops. One such case is described and a proposed term given to these channels--'Nettleship collaterals'--after the man who first described them. These collaterals are dilated pathways within the terminal capillary networks of the posterior ciliary arteries and the branches of the central retinal artery. Formation of the channels is believed to be promoted by prelaminar obstruction of the central retinal artery.

  9. Relationship between radial and central arterial pulse wave and evaluation of central aortic pressure using the radial arterial pulse wave.

    PubMed

    Takazawa, Kenji; Kobayashi, Hideyuki; Shindo, Naohisa; Tanaka, Nobuhiro; Yamashina, Akira

    2007-03-01

    Since a decrease of central aortic pressure contributes to the prevention of cardiovascular events, simple measurement of not only brachial blood pressure but also central aortic pressure may be useful in the prevention and treatment of cardiovascular diseases. In this study, we simultaneously measured radial artery pulse waves non-invasively and ascending aortic pressure invasively, before and after the administration of nicorandil. We then compared changes in central aortic pressure and radial arterial blood pressure calibrated with brachial blood pressure in addition to calculating the augmentation index (AI) at the aorta and radial artery. After nicorandil administration, the reduction in maximal systolic blood pressure in the aorta (Deltaa-SBP) was -14+/-15 mmHg, significantly larger than that in early systolic pressure in the radial artery (Deltar-SBP) (-9+/-12 mmHg). The reduction in late systolic blood pressure in the radial artery (Deltar-SBP2) was -15+/-14 mmHg, significantly larger than Deltar-SBP, but not significantly different from Deltaa-SBP. There were significant relationships between Deltaa-SBP and Deltar-SBP (r=0.81, p<0.001), and between Deltaa-SBP and Deltar-SBP2 (r=0.91, p<0.001). The slope of the correlation regression line with Deltar-SBP2 (0.83) was larger and closer to 1 than that with Deltar-SBP (0.63), showing that the relationship was close to 1:1. Significant correlations were obtained between aortic AI (a-AI) and radial AI (r-AI) (before nicorandil administration: r=0.91, p<0.001; after administration: r=0.70, p<0.001). These data suggest that the measurement of radial artery pulse wave and observation of changes in the late systolic blood pressure in the radial artery (r-SBP2) in addition to the ordinary measurement of brachial blood pressure may enable a more accurate evaluation of changes in maximal systolic blood pressure in the aorta (a-SBP).

  10. Estimation of Arterial Stiffness by Time-Frequency Analysis of Pulse Wave

    NASA Astrophysics Data System (ADS)

    Saito, Masashi; Yamamoto, Yuya; Shibayama, Yuka; Matsukawa, Mami; Watanabe, Yoshiaki; Furuya, Mio; Asada, Takaaki

    2011-07-01

    Evaluation of a pulse wave is effective for the early diagnosis of arteriosclerosis because the pulse wave contains the reflected wave that is the age- and stiffness-dependent component. In this study, we attempted to extract the parameter reflecting the component by pulse wave analysis using continuous wavelet transform. The Morlet wavelet was used as the mother wavelet. We then investigated the relationship between the parameter and the reflected wave that was extracted from the pulse wave by our previously reported separation technique. Consequently, the result of wavelet transform of the differentiated pulse waveform changed markedly owing to age and had medium correlation with the peak of the reflected wave (R=0.68).

  11. Non-contact measurement of carotid arterial stiffness by two-point heart-pulse laser detection

    NASA Astrophysics Data System (ADS)

    Benedetti, M.; Favalli, V.; Mariano, A.; Rebrova, N.; Consoli, A.; Ayadi, J.; Gilardi, L.; Perna, M.; Minzioni, P.; Arbustini, E.; Giuliani, G.

    2016-02-01

    Arterial stiffness (AS) is a recognized predictor of cardiovascular risk and mortality, and a potential marker for monitoring the beneficial effects of medical treatments for arterial diseases. AS is typically evaluated indirectly, by assessing the so called pulse wave velocity (PWV), i.e. the speed at which the pressure wave created by the heart contraction travels along the aorta and other arteries. PWV is generally measured using piezoelectric transducers, or via a complex ultrasound technique, but in both cases it requires a direct contact with the patient, which could also modify the measured parameters. In the EU project "NISTAS" (Non-invasive screening of the status of the vascular system) [1], we develop a contactless system allowing to measure the PWV thanks to a technology derived from laser triangulation devices. The measurement principle consists in the detection of the small (around 100μm) displacement of the neck skin, induced by the transit of the pressure wave in the carotid. By simultaneously measuring the displacement caused by the pulse wave in two distinct points along the carotid, the time required by the pressure wave to travel a certain distance can be measured, and the PWV can then be easily calculated. The chosen technique for the skin displacement measurement is laser triangulation in its 2D variant (i.e. "laser profilometry"), which is robust to slight movements of the target, it does not suffer from speckle-pattern signal fading, and it can be conveniently implemented using low-cost optical components. Two light lines, emitted by two blue LEDs are projected on the target (the patient's neck skin), and the skin displacement versus time is measured using a high-frame-rate CMOS camera. In this manuscript we present the results obtained by measuring the PWV of 10 volunteers. It is foreseen that this technique can become a simple and widespread point-of-care method for large-scale cardiovascular system screening over large populations.

  12. Assessment of proximal pulmonary arterial stiffness using magnetic resonance imaging: effects of technique, age and exercise

    PubMed Central

    Kamalasanan, Anu; Cassidy, Deidre B; Struthers, Allan D; Lipworth, Brian J; Houston, J Graeme

    2016-01-01

    Introduction To compare the reproducibility of pulmonary pulse wave velocity (PWV) techniques, and the effects of age and exercise on these. Methods 10 young healthy volunteers (YHV) and 20 older healthy volunteers (OHV) with no cardiac or lung condition were recruited. High temporal resolution phase contrast sequences were performed through the main pulmonary arteries (MPAs), right pulmonary arteries (RPAs) and left pulmonary arteries (LPAs), while high spatial resolution sequences were obtained through the MPA. YHV underwent 2 MRIs 6 months apart with the sequences repeated during exercise. OHV underwent an MRI scan with on-table repetition. PWV was calculated using the transit time (TT) and flow area techniques (QA). 3 methods for calculating QA PWV were compared. Results PWV did not differ between the two age groups (YHV 2.4±0.3/ms, OHV 2.9±0.2/ms, p=0.1). Using a high temporal resolution sequence through the RPA using the QA accounting for wave reflections yielded consistently better within-scan, interscan, intraobserver and interobserver reproducibility. Exercise did not result in a change in either TT PWV (mean (95% CI) of the differences: −0.42 (−1.2 to 0.4), p=0.24) or QA PWV (mean (95% CI) of the differences: 0.10 (−0.5 to 0.9), p=0.49) despite a significant rise in heart rate (65±2 to 87±3, p<0.0001), blood pressure (113/68 to 130/84, p<0.0001) and cardiac output (5.4±0.4 to 6.7±0.6 L/min, p=0.004). Conclusions QA PWV performed through the RPA using a high temporal resolution sequence accounting for wave reflections yields the most reproducible measurements of pulmonary PWV. PMID:27843548

  13. Differences in central systolic blood pressure and aortic stiffness between aerobically trained and sedentary individuals.

    PubMed

    Laurent, Pierre; Marenco, Patrice; Castagna, Olivier; Smulyan, Harold; Blacher, Jacques; Safar, Michel E

    2011-01-01

    The purpose of this study was to evaluate central (carotid) artery blood pressure (BP) in endurance athletes. Carotid-femoral (= aortic) pulse wave velocity (PWV) together with radial and carotid tonometry and pulse wave analysis were performed at rest in 30 endurance athletes and 30 sedentary controls, all males matched for age, height, brachial systolic BP (SBP), and diastolic BP. Whereas brachial BP was similar in the two groups, carotid SBP and pulse pressure (PP) were higher in endurance athletes than in controls irrespective of age (123.1 ± 2.17 vs. 110.2 ± 1.29 mm Hg, and 50.9 ± 1.95 vs. 34.1 ± 1.01 mm Hg; P < .0001 for both). PP amplification evaluated from the brachial/carotid PP ratio was lower in athletes than in controls (1.05 ± 0.04 vs. 1.40 ± 0.02; P < .0001). When compared with controls, athletes had lower PWV (7.81 ± 0.17 vs. 9.8 ± 0.23 m/second; P < .0001), higher reflected wave transit time/left ventricular ejection time ratio (P = .02), and lower heart rate (52.03 ± 1.54 vs. 68.9 ± 1.72 beats/minute; P < .0001). When matched for brachial BP, central SBP and PP were higher in endurance athletes than in sedentary controls. The possible negative pathophysiological impact of increased central BP on the overall favorable effects of training deserves further study.

  14. Digital image correlation for full-field time-resolved assessment of arterial stiffness

    NASA Astrophysics Data System (ADS)

    Campo, Adriaan; Soons, Joris; Heuten, Hilde; Ennekens, Guy; Goovaerts, Inge; Vrints, Christiaan; Lava, Pascal; Dirckx, Joris

    2014-01-01

    Pulse wave velocity (PWV) of the arterial system is a very important parameter to evaluate cardiovascular health. Currently, however, there is no golden standard for PWV measurement. Digital image correlation (DIC) was used for full-field time-resolved assessment of displacement, velocity, acceleration, and strains of the skin in the neck directly above the common carotid artery. By assessing these parameters, propagation of the pulse wave could be tracked, leading to a new method for PWV detection based on DIC. The method was tested on five healthy subjects. As a means of validation, PWV was measured with ultrasound (US) as well. Measured PWV values were between 3.68 and 5.19 m/s as measured with DIC and between 5.14 and 6.58 m/s as measured with US, with a maximum absolute difference of 2.78 m/s between the two methods. DIC measurements of the neck region can serve as a test base for determining a robust strategy for PWV detection, they can serve as reference for three-dimensional fluid-structure interaction models, or they may even evolve into a screening method of their own. Moreover, full-field, time-resolved DIC can be adapted for other applications in biomechanics.

  15. Closure Using a Surgical Closure Device of Inadvertent Subclavian Artery Punctures During Central Venous Catheter Placement

    SciTech Connect

    Berlet, Matthew H.; Steffen, Diana; Shaughness, George; Hanner, James

    2001-03-15

    Severe complications can and do occur when central venous catheters are inadvertently placed into subclavian arteries. Two cases are discussed that describe how these inadvertent arterial punctures can be closed using the Perclose device (Abbott Laboratories, Redwood City, CA, USA)

  16. Accidental carotid artery catheterization during attempted central venous catheter placement: a case report.

    PubMed

    Maietta, Pauline Marie

    2012-08-01

    More than 2.1 million central venous catheters are placed annually. While carotid artery cannulation is rare, its effects can be devastating. Anesthesia providers frequently work with central venous catheters in the perioperative setting. Therefore, it is imperative that they be able to identify and react appropriately to carotid artery injury both in preexisting central lines and those that they have placed. This case report details a case of accidental carotid artery catheterization during attempted right internal jugular vein catheterization and the steps taken to treat the patient following its recognition. A discussion of technique for central venous catheterization, indications for suspicion of arterial puncture, methods for confirming venous or arterial placement, appropriate methods for management of carotid artery cannulation, and the benefit of ultrasound in central venous cannulation follow. Through the appropriate use of equipment, early detection and management of carotid artery injury, and proper training, patient outcomes may be improved.

  17. Treating Heart Failure with Preserved Ejection Fraction Related to Arterial Stiffness. Can we Kill Two Birds With One Stone?

    PubMed

    Athyros, Vasilios G; Pagourelias, Efstathios D; Gossios, Thomas D; Vasilikos, Vasilios G

    2015-01-01

    Heart failure with preserved ejection fraction (HFpEF). Arterial hypertension (AH), arterial stiffness (AS), older age, and female gender are the main determinants of HFpEF, but several cardiac or extra-cardiac pathologies are also possible causes. The combined ventricular-vascular stiffening (abnormal left atrium-left ventricle coupling related to AS) is the main contributor of the increased prevalence of HFpEF in elderly persons, particularly elderly women, and in younger persons with AH. The hospitalization and mortality rates of HFpEF are similar to those of heart failure with reduced EF (HFrEF). However, although the prognosis of HFrEF has been substantially improved during the last 2 decades, the effective treatment of HFpEF remains an unmet need. Regimens effective in HFrEF have no substantial effect on HFpEF, because of different pathophysiologies of the 2 syndromes. Pipeline drugs seem promising, but it will take some years before they are commercially available. Aggressive treatment of noncardiac comorbidities seems to be the only option at hand. Treatment of anaemia, sleep disorders, chronic kidney disease (CKD), non-alcoholic fatty liver (NAFLD), atrial fibrillation, diabetes, and careful use of diuretics to reduce preload are effective to some degree. Statin treatment, despite the presence of dyslipidaemia, deserves special attention because it has been proven, mainly in small studies or post hoc analyses of trials, that it offers a substantial improvement in quality of life and a reduction in mortality rates. We need to urgently utilize these recourses to relieve a considerable part of the general population suffering from HFpEF, a deadly disease.

  18. Effect of Spinach, a High Dietary Nitrate Source, on Arterial Stiffness and Related Hemodynamic Measures: A Randomized, Controlled Trial in Healthy Adults

    PubMed Central

    Jovanovski, Elena; Bosco, Laura; Khan, Kashif; Au-Yeung, Fei; Ho, Hoang; Zurbau, Andreea; Jenkins, Alexandra L.

    2015-01-01

    Diets rich in fruits and vegetables reduce risk of adverse cardiovascular events. However, the constituents responsible for this effect have not been well established. Lately, the attention has been brought to vegetables with high nitrate content with evidence that this might represent a source of vasoprotective nitric oxide. We hypothesized that short-term consumption of spinach, a vegetable having high dietary nitrate content, can affect the arterial waveform indicative of arterial stiffness, as well as central and peripheral blood pressure (BP). Using a placebo-controlled, crossover design, 27 healthy participants were randomly assigned to receive either a high-nitrate (spinach; 845 mg nitrate/day) or low-nitrate soup (asparagus; 0.6 mg nitrate/day) for 7 days with a 1-week washout period. On days 1 and 7, profiles of augmentation index, central, and brachial BP were obtained over 180 min post-consumption in 4 fasted visits. A postprandial reduction in augmentation index was observed at 180 min on high-nitrate compared to low-nitrate intervention (-6.54 ± 9.7% vs. -0.82 ± 8.0%, p = 0.01) on Day 1, and from baseline on Day 7 (-6.93 ± 8.7%, p < 0.001; high vs. low: -2.28 ± 12.5%, p = 0.35), suggesting that the nitrate intervention is not associated with the development of tolerance for at least 7 days of continued supplementation. High vs. low-nitrate intervention also reduced central systolic (-3.39 ± 5.6 mmHg, p = 0.004) and diastolic BP (-2.60 ± 5.8 mmHg, p = 0.028) and brachial systolic BP (-3.48 ± 7.4 mmHg, p = 0.022) at 180 min following 7-day supplementation only. These findings suggest that dietary nitrate from spinach may contribute to beneficial hemodynamic effects of vegetable-rich diets and highlights the potential of developing a targeted dietary approach in the management of elevated BP. PMID:26251834

  19. Pentraxin 3 Is a Predictor for Fibrosis and Arterial Stiffness in Patients with Nonalcoholic Fatty Liver Disease

    PubMed Central

    Ozturk, Kadir; Kurt, Omer; Dogan, Tolga; Ozen, Alptug; Demirci, Hakan; Yesildal, Fatih; Kantarcioglu, Murat; Turker, Turker; Guler, Ahmet Kerem; Karslioglu, Yıldırım; Altun, Battal; Uygun, Ahmet; Bagci, Sait

    2016-01-01

    Objective. The aim of the present study was to investigate whether pentraxin 3 (PTX3) can be a new noninvasive marker for prediction of liver fibrosis in patients with NAFLD. We also aimed to evaluate the relationship between PTX3 and atherosclerosis in patients with NAFLD. Method. Fifty-four male patients with biopsy-proven NAFLD and 20 apparently healthy male volunteers were included. PTX3 levels were determined, using an ELISA method (R&D Sysytems, Quantikine ELISA, USA). To detect the presence of subclinical atherosclerosis in NAFLD, measurements of CIMT, FMD, and cf-PWV levels were performed. Results. PTX3 levels in NAFLD patients with fibrosis were higher than both NAFLD patients without fibrosis and controls (P = 0.032 and P = 0.028, respectively), but there was no difference between controls and NAFLD patients without fibrosis in terms of PTX3 levels (P = 0.903). PTX3 levels were strongly correlated with cf-PWV (r = 0.359, P = 0.003), whereas no significant correlation was found with other atherosclerosis markers, CIMT and FMD. Conclusion. Elevated plasma PTX3 levels are associated with the presence of fibrosis in patients with NAFLD, independently of metabolic syndrome components. This study demonstrated that for the first time there is a close association between elevated PTX3 levels and increased arterial stiffness in patients with NAFLD. PMID:26997950

  20. Vitamin D Status in Rheumatoid Arthritis: Inflammation, Arterial Stiffness and Circulating Progenitor Cell Number

    PubMed Central

    Bagnato, Gianluca; Aragona, Caterina Oriana; Imbalzano, Egidio; D’Ascola, Angela; Rotondo, Francesco; Cinquegrani, Antonella; Mormina, Enricomaria; Saitta, Carlo; Versace, Antonio Giovanni; Sardo, Maria Adriana; Lo Gullo, Renato; Loddo, Saverio; Saitta, Antonino

    2015-01-01

    Background and Aims Suboptimal vitamin D status was recently acknowledged as an independent predictor of cardiovascular diseases and all-cause mortality in several clinical settings, and its serum levels are commonly reduced in Rheumatoid Arthritis (RA). Patients affected by RA present accelerated atherosclerosis and increased cardiovascular morbidity and mortality with respect to the general population. In RA, it has been reported an impairment of the number and the activity of circulating proangiogenic haematopoietic cells (PHCs), including CD34+, that may play a role in endothelial homeostasis. The purpose of the study is to investigate the association between vitamin D levels and PHCs, inflammatory markers, and arterial stiffening in patients with RA. Methods and Results CD34+ cells were isolated from 27 RA patients and 41 controls. Vitamin D levels, C-reactive protein (CRP), fibrinogen, pulse wave velocity (PWV), and carotid intima-media thickness (cIMT) were also evaluated. CD34+ count and vitamin D levels were lower in RA patients as compared to controls, while fibrinogen, CRP, PWV and cIMT were higher in RA patients. CD34+ cell number appeared to be associated with vitamin D levels, and negatively correlated to fibrinogen and early atherosclerosis markers (PWV and cIMT); vitamin D levels appear also to be inversely associated to fibrinogen. Conclusions RA patients with moderate disease activity presented with low vitamin D levels, low CD34+ cell count, increased PWV and cIMT; we found that vitamin D deficiency is associated to CD34+ cell reduction in peripheral blood, and with fibrinogen levels. This suggests that vitamin D might contribute to endothelial homeostasis in patients with RA. PMID:26241902

  1. Sex differences in associations between insulin resistance, heart rate variability, and arterial stiffness in healthy women and men: a physiology study.

    PubMed

    Rannelli, Luke Anthony; MacRae, Jennifer M; Mann, Michelle C; Ramesh, Sharanya; Hemmelgarn, Brenda R; Rabi, Doreen; Sola, Darlene Y; Ahmed, Sofia B

    2017-04-01

    Diabetes confers greater cardiovascular risk to women than to men. Whether insulin-resistance-mediated risk extends to the healthy population is unknown. Measures of insulin resistance (fasting insulin, homeostatic model assessment, hemoglobin A1c, quantitative insulin sensitivity check index, glucose) were determined in 48 (56% female) healthy subjects. Heart rate variability (HRV) was calculated by spectral power analysis and arterial stiffness was determined using noninvasive applanation tonometry. Both were measured at baseline and in response to angiotensin II infusion. In women, there was a non-statistically significant trend towards increasing insulin resistance being associated with an overall unfavourable HRV response and increased arterial stiffness to the stressor, while men demonstrated the opposite response. Significant differences in the associations between insulin resistance and cardiovascular physiological profile exist between healthy women and men. Further studies investigating the sex differences in the pathophysiology of insulin resistance in cardiovascular disease are warranted.

  2. Relation between Self-Reported Sleep Duration and Arterial Stiffness: A Cross-Sectional Study of Middle-Aged Japanese Civil Servants

    PubMed Central

    Yoshioka, Eiji; Saijo, Yasuaki; Kita, Toshiko; Okada, Eisaku; Satoh, Hiroki; Kawaharada, Mariko; Kishi, Reiko

    2011-01-01

    Objectives: The aim of this study is to examine the relationship between self-reported sleep duration and arterial stiffness in a large-scale Japanese study. Design: Cross-sectional study. Setting: Sapporo City, Hokkaido, Japan. Participants: Local government employees aged 35-62 years, who underwent annual health checkups from April 2003 to March 2004. After excluding those with incomplete data, data from 4,268 employees (males: 3,410) participants were analyzed. Interventions: N/A. Measurements and Results: Brachial-ankle pulse-wave velocity (baPWV) was investigated as an indicator of arterial stiffness. We used a self-administered questionnaire, which included items on daily sleep duration, lifestyle factors, and occupational factors. Sleep duration was classified into 5 categories; “ ≤ 5 h,” “6 h,” “7 h,” “8 h,” and “ ≥ 9 h.” Results of multiple linear regression analysis after fully adjusting the model revealed that subjects with ≥ 9 h of daily sleep had significantly elevated baPWV values compared with the reference group with 7 h of sleep. Stratified analyses by sex showed that there was a significant association among male subjects only. Conclusions: Daily sleep duration ≥ 9 h was found to be associated with elevated values of baPWV. This suggests that there is an association between long sleep duration and arterial stiffness. Citation: Yoshioka E; Saijo Y; Kita T; Okada E; Satoh H; Kawaharada M; Kishi R. Relation between self-reported sleep duration and arterial stiffness: a cross-sectional study of middle-aged Japanese civil servants. SLEEP 2011;34(12):1681-1686. PMID:22131605

  3. Diabetic Peripheral Neuropathy Is Associated With Increased Arterial Stiffness Without Changes in Carotid Intima–Media Thickness in Type 2 Diabetes

    PubMed Central

    Kim, Eun Sook; Moon, Sung-dae; Kim, Hun-Sung; Lim, Dong Jun; Cho, Jae Hyoung; Kwon, Hyuk Sang; Ahn, Chul Woo; Yoon, Kun Ho; Kang, Moo Il; Cha, Bong Yun; Son, Ho Young

    2011-01-01

    OBJECTIVE This study was conducted to investigate the association of diabetic peripheral neuropathy (DPN) with both arterial stiffness and intima–media thickness (IMT). RESEARCH DESIGN AND METHODS We conducted a cross-sectional analysis of 731 subjects with type 2 diabetes. DPN was diagnosed on the basis of neuropathic symptoms, insensitivity to a 10-g monofilament, abnormal pin-prick sensation, and abnormal current perception threshold. Arterial stiffness was assessed by cardio-ankle vascular index (CAVI), and IMT was assessed by B-mode ultrasonography. RESULTS Patients with DPN had higher CAVI than those without DPN in multivariate-adjusted models, whereas no differences in IMT were observed between patients with and without DPN after adjustment for age and sex. In the multivariate analysis, CAVI was a significant determinant of DPN (odds ratio 1.36 [95% CI 1.13–1.65], P = 0.001). CONCLUSIONS DPN is significantly associated with arterial stiffness without carotid intimal changes in patients with type 2 diabetes. PMID:21515840

  4. Arterial Stiffness and Pulse Wave Reflection Are Increased in Patients Suffering from Severe Periodontitis

    PubMed Central

    Jockel-Schneider, Yvonne; Harks, Inga; Haubitz, Imme; Fickl, Stefan; Eigenthaler, Martin; Schlagenhauf, Ulrich; Baulmann, Johannes

    2014-01-01

    Aim This single blind cross-sectional study compared the vascular health of subjects suffering from severe chronic periodontitis, severe aggressive periodontitis and periodontal healthy controls by evaluating pulse wave velocity (PWV), augmentation index (AIx) and pulse pressure amplification (PPA). Material and Methods In a total of 158 subjects, 92 suffering from severe periodontitis and 66 matched periodontal healthy controls, PWV, AIx, central and peripheral blood pressure were recorded using an oscillometric device (Arteriograph). Results Subjects suffering from severe chronic or aggressive periodontitis exhibited significantly higher PWV (p = 0.00004), higher AIx (p = 0.0049) and lower PPA (p = 0.028) than matched periodontal healthy controls. Conclusions The results of this study confirm the association between periodontal inflammation and increased cardiovascular risk shown by impaired vascular health in case of severe periodontitis. As impaired vascular health is a common finding in patients suffering from severe periodontal disease a concomitant routine cardiovascular evaluation may be advised. PMID:25084111

  5. The Carotid Intima-Media Thickness and Arterial Stiffness of Pediatric Mucopolysaccharidosis Patients Are Increased Compared to Both Pediatric and Adult Controls

    PubMed Central

    Wang, Raymond Y.; Rudser, Kyle D.; Dengel, Donald R.; Braunlin, Elizabeth A.; Steinberger, Julia; Jacobs, David R.; Sinaiko, Alan R.; Kelly, Aaron S.

    2017-01-01

    Treatments for mucopolysaccharidoses (MPSs) have increased longevity, but cardiovascular disease causes mortality in a significant percentage of survivors. Markers must be developed to predict MPS cardiac risk and monitor efficacy of investigational therapies.MPS patients underwent carotid artery ultrasonography from which carotid intima-media thickness (cIMT) and three measures of arterial stiffness were calculated: carotid artery distensibility (cCSD), compliance (cCSC), and incremental elastic modulus (cIEM). MPS carotid measurements were compared to corresponding data from pediatric and adult healthy cohorts. 33 MPS patients (17 MPS I, 9 MPS II, 4 MPS IIIA, and 3 MPS VI; mean age 12.5 ± 4.7 years), 560 pediatric controls (age 13.1 ± 4.0 years), and 554 adult controls (age 39.2 ± 2.2 years) were studied. Age and sex-adjusted aggregate MPS cIMT (0.56 ± 0.05 mm) was significantly greater than both pediatric (+0.12 mm; 95% CI +0.10 to +0.14 mm) and adult (+0.10 mm; 95% CI +0.06 to +0.14 mm) control cohorts; similar findings were observed for all MPS subtypes. Mean MPS cIMT approximated the 80th percentile of the adult cohort cIMT. MPS patients also demonstrated significantly increased adjusted arterial stiffness measurements, evidenced by reduced cCSD, cCSC, and increased cIEM, compared to pediatric and adult control cohorts. Regardless of treatment, MPS patients demonstrate increased cIMT and arterial stiffness compared to healthy pediatric and adult controls. These data suggest that relatively young MPS patients demonstrate a “structural vascular age” of at least 40 years old. PMID:28294991

  6. Arterial stiffness, pressure and flow pulsatility and brain structure and function: the Age, Gene/Environment Susceptibility--Reykjavik study.

    PubMed

    Mitchell, Gary F; van Buchem, Mark A; Sigurdsson, Sigurdur; Gotal, John D; Jonsdottir, Maria K; Kjartansson, Ólafur; Garcia, Melissa; Aspelund, Thor; Harris, Tamara B; Gudnason, Vilmundur; Launer, Lenore J

    2011-11-01

    Aortic stiffness increases with age and vascular risk factor exposure and is associated with increased risk for structural and functional abnormalities in the brain. High ambient flow and low impedance are thought to sensitize the cerebral microcirculation to harmful effects of excessive pressure and flow pulsatility. However, haemodynamic mechanisms contributing to structural brain lesions and cognitive impairment in the presence of high aortic stiffness remain unclear. We hypothesized that disproportionate stiffening of the proximal aorta as compared with the carotid arteries reduces wave reflection at this important interface and thereby facilitates transmission of excessive pulsatile energy into the cerebral microcirculation, leading to microvascular damage and impaired function. To assess this hypothesis, we evaluated carotid pressure and flow, carotid-femoral pulse wave velocity, brain magnetic resonance images and cognitive scores in participants in the community-based Age, Gene/Environment Susceptibility--Reykjavik study who had no history of stroke, transient ischaemic attack or dementia (n = 668, 378 females, 69-93 years of age). Aortic characteristic impedance was assessed in a random subset (n = 422) and the reflection coefficient at the aorta-carotid interface was computed. Carotid flow pulsatility index was negatively related to the aorta-carotid reflection coefficient (R = -0.66, P<0.001). Carotid pulse pressure, pulsatility index and carotid-femoral pulse wave velocity were each associated with increased risk for silent subcortical infarcts (hazard ratios of 1.62-1.71 per standard deviation, P<0.002). Carotid-femoral pulse wave velocity was associated with higher white matter hyperintensity volume (0.108 ± 0.045 SD/SD, P = 0.018). Pulsatility index was associated with lower whole brain (-0.127 ± 0.037 SD/SD, P<0.001), grey matter (-0.079 ± 0.038 SD/SD, P = 0.038) and white matter (-0.128 ± 0.039 SD/SD, P<0.001) volumes. Carotid-femoral pulse

  7. Omega-3 fatty acids supplementation improves endothelial function and arterial stiffness in hypertensive patients with hypertriglyceridemia and high cardiovascular risk.

    PubMed

    Casanova, Marcela A; Medeiros, Fernanda; Trindade, Michelle; Cohen, Célia; Oigman, Wille; Neves, Mario Fritsch

    2017-01-01

    Association between hypertriglyceridemia and cardiovascular (CV) disease is still controversial. The purpose of this study was to compare omega-3 and ciprofibrate effects on the vascular structure and function in low and high CV risk hypertensive patients with hypertriglyceridemia. Twenty-nine adults with triglycerides 150-499 mg/dL were divided into low (<7.5%) and high (≥7.5%) CV risk, randomized to receive omega-3 fatty acids 1800 mg/d or ciprofibrate 100 mg/d for 12 weeks. Treatment was switched after 8-week washout. Clinical evaluation and vascular tests were assessed at baseline and after intervention. Peripheral (131 ± 3 to 125 ± 3 mm Hg, P < .05) and aortic (124 ± 3 to 118 ± 2 mg/dL, P < .05) systolic blood pressure were decreased by ciprofibrate in low-risk patients. In high-risk patients, pulse wave velocity was reduced (10.4 ± 0.4 to 9.4 ± 0.3 m/s, P < .05) and flow-mediated dilation was increased (11.1 ± 1.6 to 13.5 ± 1.2%, P < .05) by omega-3. In conclusion, omega-3 improved arterial stiffness and endothelial function, pointing out the beneficial effect of this therapy on vascular aging, in high-risk patients.

  8. Nettleship collaterals: circumpapillary cilioretinal anastomoses after occlusion of the central retinal artery.

    PubMed Central

    Ragge, N K; Hoyt, W F

    1992-01-01

    In extremely rare cases, after occlusion of the central retinal artery, a complete ring of peripapillary anastomotic channels develops. One such case is described and a proposed term given to these channels--'Nettleship collaterals'--after the man who first described them. These collaterals are dilated pathways within the terminal capillary networks of the posterior ciliary arteries and the branches of the central retinal artery. Formation of the channels is believed to be promoted by prelaminar obstruction of the central retinal artery. Images PMID:1540571

  9. Anti-tumor necrosis factor-alpha therapy improves endothelial function and arterial stiffness in patients with moderate to severe psoriasis: A 6-month prospective study.

    PubMed

    Pina, Trinitario; Corrales, Alfonso; Lopez-Mejias, Raquel; Armesto, Susana; Gonzalez-Lopez, Marcos A; Gómez-Acebo, Ines; Ubilla, Begoña; Remuzgo-Martínez, Sara; Gonzalez-Vela, M Carmen; Blanco, Ricardo; Hernández, Jose L; Llorca, Javier; Gonzalez-Gay, Miguel A

    2016-11-01

    The aim of the present study was to determine if the use of the anti-tumor necrosis factor (TNF)-α monoclonal antibody adalimumab could improve endothelial function and arterial stiffness in patients with moderate to severe psoriasis. This was a prospective study on a series of consecutive patients with moderate to severe psoriasis who completed 6 months of therapy with adalimumab. Patients with history of cardiovascular events, diabetes mellitus, kidney disease, hypertension or body mass index of 35 kg/m(2) or more were excluded. Assessment of endothelial function by brachial artery reactivity measuring flow-mediated endothelial dependent vasodilatation (FMD%), and carotid arterial stiffness by pulse wave velocity (PWV) was performed at the onset of treatment (time 0) and at month 6. Twenty-nine patients were studied. Anti-TNF-α adalimumab therapy yielded a significant improvement of endothelial function. The mean ± standard deviation (SD) FMD% values increased from 6.19 ± 2.44% at the onset of adalimumab to 7.46 ± 2.43% after 6 months of treatment with this biologic agent (P = 0.008). Likewise, following the use of adalimumab, PWV levels decreased from 6.28 ± 1.04 m/s at the onset of adalimumab to 5.69 ± 1.31 m/s at 6 months (P = 0.03). In conclusion, patients with moderate to severe psoriasis exhibit improvement of endothelial function and arterial stiffness following anti-TNF-α therapy. These findings are of potential relevance due to increased risk of cardiovascular disease in patients with severe psoriasis.

  10. Time course and factors predicting arterial stiffness reversal in patients with aldosterone-producing adenoma after adrenalectomy: prospective study of 102 patients

    PubMed Central

    Liao, Che-Wei; Lin, Lian-Yu; Hung, Chi-Sheng; Lin, Yen-Tin; Chang, Yi-Yao; Wang, Shuo-Meng; Wu, Vin-Cent; Wu, Kwan-Dun; Ho, Yi-Lwun; Satoh, Fumitoshi; Lin, Yen-Hung

    2016-01-01

    Primary aldosteronism not only results in hypertension but also stiffer arteries. The time course and factors predicting the reversal of arterial stiffness after treatment are unclear. We prospectively enrolled 102 patients with aldosterone-producing adenoma (APA) from March 2006 to January 2012. We measured the pulse wave velocity (PWV) between brachial-ankle (baPWV) and heart-ankle (haPWV) before, 6 and 12 months after their adrenalectomy. After treatment, the PWV decreased significantly during the first 6 months (both p < 0.001), but no further reduction in the following 6 months. The determinant factors for baseline baPWV were age, duration of hypertension, and baseline systolic blood pressure (SBP) in multivariate linear regression analysis, similar with baseline haPWV (determinants: age, duration of hypertension, baseline SBP and diastolic blood pressure (DBP)). In multivariate linear regression analysis, the decrease in DBP at 6 months (ΔDBP0-6mo) and baseline baPWV were significantly associated with the decrease in baPWV at 6 months (ΔbaPWV0-6mo). The associated factors of the change in haPWV at 6 months (ΔhaPWV0-6mo) were baseline haPWV, ΔDBP0-6mo and change in log-transformed plasma renin activity. Our result suggested that reversal of arterial stiffness in APA patients occurred early after adrenalectomy and determined by baseline vascular condition, hemodynamic factors, and humoral factors. PMID:26883298

  11. FGF-23/Vitamin D Axis in Type 1 Diabetes: The Potential Role of Mineral Metabolism in Arterial Stiffness

    PubMed Central

    Llauradó, Gemma; Megia, Ana; Cano, Albert; Giménez-Palop, Olga; Simón, Inmaculada; González-Sastre, Montserrat; Berlanga, Eugenio; Fernández-Veledo, Sonia

    2015-01-01

    Objective To investigate the usefulness of Fibroblast Growth Factor 23 (FGF-23) and vitamin D as possible biomarkers of pre-clinical atherosclerosis, assessed as arterial stiffness (AS), in a group of subjects with type 1 diabetes (T1DM) and no previous cardiovascular events. Research Design and Methods 68 T1DM patients and 68 age- and sex-matched controls were evaluated for 1) age, sex, diabetes duration, physical activity, smoking, alcohol intake, BMI, blood pressure, fasting plasma glucose, HbA1c, estimated glomerular filtration rate (eGFR) and lipid profile; 2) microvascular complications; 3) blood concentrations of FGF-23 and mineral metabolism parameters (calcium, phosphate, parathyroid hormone (PTH) and 25-hydroxy-vitamin D (25(OH)D)); 4) AS, assessed as aortic pulse wave velocity (aPWV); and 5) low-grade inflammation (hsCRP, IL-6, sTNFαR1, sTNFαR2) and endothelial dysfunction (ED) markers (ICAM-1, VCAM-1, E-Selectin). Results Patients with T1DM had higher aPWV compared with controls (p<0.001), but they did not present differences in 25(OH)D (70.3(50.4–86.2)nmol/L vs. 70.7(59.7–83.0)nmol/L; p = 0.462) and in FGF-23 plasma concentrations (70.1(38.4–151.9)RU/mL vs. 77.6(51.8–113.9)RU/mL; p = 0.329). In T1DM patients, higher concentrations of FGF-23 were positively associated with aPWV after adjusting for eGFR and classical cardiovascular risk factors (model 1: ß = 0.202, p = 0.026), other mineral metabolism parameters (model 2: ß = 0.214, p = 0.015), microvascular complications, low-grade inflammation and ED markers (model 3: ß = 0.170, p = 0.045). Lower 25(OH)D concentrations were also associated with higher aPWV after adjusting for all the above-mentioned factors (model 3: ß = -0.241, p = 0.015). Conclusions We conclude that both FGF-23 plasma concentrations (positively) and 25(OH)D serum concentrations (negatively) are associated with AS in patients with T1DM and no previous cardiovascular events. PMID:26462160

  12. Effect of Enhanced External Counter Pulsation Treatment on Aortic Blood Pressure, Arterial Stiffness and Ejection Fraction in Patients with Coronary Artery Disease

    PubMed Central

    Nayar, Sushma; Meyyappan, Chokkalingam; Ganesh, N; Chandrakasu, Arumugam; Nayar, Pradeep G

    2016-01-01

    Introduction Enhanced External Counter Pulsation (EECP) is a non-invasive treatment option for patients with Coronary Artery Disease (CAD). The treatment has shown to augment diastolic pressure and reduce Left Ventricular (LV) after-load by reducing systemic vascular resistance. The effect of EECP in standard brachial blood pressure and central haemodynamic parameters are not known. Aim We hypothesized that EECP may have differential effect in CAD patients with low systolic blood pressure when compared to normal systolic pressure and the mechanism underlying this differential effect may be due to improvement in LV function. Materials and Methods A total of 72 consecutive patients who underwent EECP treatment for symptomatic CAD with LV dysfunction were divided into two groups based on cut-off value of 100mmHg for systolic blood pressure. First group had patients with brachial systolic blood pressure of >100mmHg and second group had patients with brachial systolic blood pressure of ≤100mmHg. We measured central aortic systolic pressure, pulse pressure, augmentation index and augmentation pressure by SphygmoCor device and Ejection Fraction (EF) was measured by echo-cardiography. All these measurements were carried out prior to and after completion of 35 days of EECP sessions. Results Central systolic pressure, brachial systolic pressure, aortic pulse pressure, augmentation pressure and augmentation index significantly decreased in patients with normal brachial systolic pressure with baseline moderate LV dysfunction. Brachial systolic, aortic systolic and aortic pulse pressure significantly increased with no change in augmentation index and pressure is observed in patients with baseline severe LV dysfunction associated with low systolic pressure post EECP treatment. Conclusion EECP treatment has haemodynamically favourable differential effect in normal and low brachial systolic pressure and this is mainly driven by improvement in LV function in patients with

  13. Noninvasive Measurement of Central Vascular Pressures With Arterial Tonometry: Clinical Revival of the Pulse Pressure Waveform?

    PubMed Central

    Nelson, Matthew R.; Stepanek, Jan; Cevette, Michael; Covalciuc, Michael; Hurst, R. Todd; Tajik, A. Jamil

    2010-01-01

    The arterial pulse has historically been an essential source of information in the clinical assessment of health. With current sphygmomanometric and oscillometric devices, only the peak and trough of the peripheral arterial pulse waveform are clinically used. Several limitations exist with peripheral blood pressure. First, central aortic pressure is a better predictor of cardiovascular outcome than peripheral pressure. Second, peripherally obtained blood pressure does not accurately reflect central pressure because of pressure amplification. Lastly, antihypertensive medications have differing effects on central pressures despite similar reductions in brachial blood pressure. Applanation tonometry can overcome the limitations of peripheral pressure by determining the shape of the aortic waveform from the radial artery. Waveform analysis not only indicates central systolic and diastolic pressure but also determines the influence of pulse wave reflection on the central pressure waveform. It can serve as a useful adjunct to brachial blood pressure measurements in initiating and monitoring hypertensive treatment, in observing the hemodynamic effects of atherosclerotic risk factors, and in predicting cardiovascular outcomes and events. Radial artery applanation tonometry is a noninvasive, reproducible, and affordable technology that can be used in conjunction with peripherally obtained blood pressure to guide patient management. Keywords for the PubMed search were applanation tonometry, radial artery, central pressure, cardiovascular risk, blood pressure, and arterial pulse. Articles published from January 1, 1995, to July 1, 2009, were included in the review if they measured central pressure using radial artery applanation tonometry. PMID:20435839

  14. Rationale and study design of the Prospective comparison of Angiotensin Receptor neprilysin inhibitor with Angiotensin receptor blocker MEasuring arterial sTiffness in the eldERly (PARAMETER) study

    PubMed Central

    Williams, Bryan; Cockcroft, John R; Kario, Kazuomi; Zappe, Dion H; Cardenas, Pamela; Hester, Allen; Brunel, Patrick; Zhang, Jack

    2014-01-01

    Introduction Hypertension in elderly people is characterised by elevated systolic blood pressure (SBP) and increased pulse pressure (PP), which indicate large artery ageing and stiffness. LCZ696, a first-in-class angiotensin receptor neprilysin inhibitor (ARNI), is being developed to treat hypertension and heart failure. The Prospective comparison of Angiotensin Receptor neprilysin inhibitor with Angiotensin receptor blocker MEasuring arterial sTiffness in the eldERly (PARAMETER) study will assess the efficacy of LCZ696 versus olmesartan on aortic stiffness and central aortic haemodynamics. Methods and analysis In this 52-week multicentre study, patients with hypertension aged ≥60 years with a mean sitting (ms) SBP ≥150 to <180 and a PP>60 mm Hg will be randomised to once daily LCZ696 200 mg or olmesartan 20 mg for 4 weeks, followed by a forced-titration to double the initial doses for the next 8 weeks. At 12–24 weeks, if the BP target has not been attained (msSBP <140  and ms diastolic BP <90 mm Hg), amlodipine (2.5–5 mg) and subsequently hydrochlorothiazide (6.25–25 mg) can be added. The primary and secondary endpoints are changes from baseline in central aortic systolic pressure (CASP) and central aortic PP (CAPP) at week 12, respectively. Other secondary endpoints are the changes in CASP and CAPP at week 52. A sample size of 432 randomised patients is estimated to ensure a power of 90% to assess the superiority of LCZ696 over olmesartan at week 12 in the change from baseline of mean CASP, assuming an SD of 19 mm Hg, the difference of 6.5 mm Hg and a 15% dropout rate. The primary variable will be analysed using a two-way analysis of covariance. Ethics and dissemination The study was initiated in December 2012 and final results are expected in 2015. The results of this study will impact the design of future phase III studies assessing cardiovascular protection. Clinical trials identifier EUDract number 2012

  15. Iatrogenic central retinal artery occlusion after carotid body tumor embolization and excision

    PubMed Central

    Rangel, Carlos M.; Jaramillo, Sergio; Varón, Clara L.; Prada, Angélica M.

    2017-01-01

    Objective: To report a case of iatrogenic central retinal artery occlusion after embolization and surgical resection of carotid body paraganglioma. Methods: Case report Results: One adult female patient presented with persistent unilateral visual loss after embolization with Embosphere® and Contour® microparticles of carotid body tumor. Fluorescein angiography revealed intraluminal microspheres in the central retinal artery ramifications. OCT revealed intraretinal spherical, hyporeflective particles with posterior shadowing. Conclusions: Central retinal artery occlusion should be assessed as a possible complication after surgical repair of head and neck paragangliomas.

  16. Rheumatoid arthritis is sufficient to cause atheromatosis but not arterial stiffness or hypertrophy in the absence of classical cardiovascular risk factors.

    PubMed

    Arida, Aikaterini; Zampeli, Evi; Konstantonis, George; Fragiadaki, Kalliope; Kitas, George D; Protogerou, Athanasios D; Sfikakis, Petros P

    2015-05-01

    Rheumatoid arthritis (RA) associates with increased cardiovascular disease (CVD) mortality thought to be due to accelerated arterial disease. Different components of arterial disease, namely, atheromatosis, arteriosclerosis, and arterial wall hypertrophy, are differentially affected by classical CVD risk factors, which are highly prevalent in these patients. We hypothesized that RA disease per se may also differentially affect these components. Of 267 consecutive RA patients, we selected specifically those who were free of established CVD and CVD risk factors (18 %); of them, 41 patients (36 women, 49 ± 13 years) could be matched effectively 1:1 for age and gender to healthy controls. Atheromatosis was assessed by the presence of carotid and/or femoral artery plaques, arteriosclerosis by pulse wave velocity and local wall elasticity, and arterial hypertrophy by intima-media thickness and cross-sectional area. More patients had atheromatic plaques than controls (29 vs. 12 %, p = 0.039), and multiarterial atheromatosis was more prevalent in RA (22 vs. 2 %, p = 0.026). Accelerated atheromatosis was not associated with rheumatoid factor, or anti-cyclic citrullinated peptide (CCP) autoantibody status. Plaque burden in patients with less than 5 years disease duration (aged 41 ± 13 years) was comparable to their matched controls. In contrast, all indices of arterial stiffness and hypertrophy were similar between controls and RA patients, even in those with long-standing disease. RA per se is sufficient to cause atheromatosis in the absence of classical CVD risk factors, but has minimal, if any, effect on arteriosclerosis and arterial wall hypertrophy.

  17. Combined occlusion of the central retinal artery and central retinal vein following blunt ocular trauma: a case report.

    PubMed Central

    Noble, M J; Alvarez, E V

    1987-01-01

    A healthy young woman suffered complete loss of the vision of one eye following a blunt ocular injury. She sustained a combined occlusion of the central retinal artery and central retinal vein of the affected eye. Initially few retinal haemorrhages were present, but they increased considerably in number and size during the day following injury. Images PMID:3689734

  18. Fluid-structure interaction analysis on the effect of vessel wall hypertrophy and stiffness on the blood flow in carotid artery bifurcation

    NASA Astrophysics Data System (ADS)

    Lee, Sang Hoon; Choi, Hyoung Gwon; Yoo, Jung Yul

    2012-11-01

    The effect of artery wall hypertrophy and stiffness on the flow field is investigated using three-dimensional finite element method for simulating the blood flow. To avoid the complexity due to the necessity of additional mechanical constraints, we use the combined formulation which includes both the fluid and structural equations of motion into single coupled variational equation. A P2P1 Galerkin finite element method is used to solve the Navier-Stokes equations for fluid flow and arbitrary Lagrangian-Eulerian formulation is used to achieve mesh movement. The Newmark method is employed for solving the dynamic equilibrium equations for linear elastic solid mechanics. The pulsatile, incompressible flows of Newtonian fluids constrained in the flexible wall are analyzed with Womersley velocity profile at the inlet and constant pressure at the outlet. The study shows that the stiffness of carotid artery wall affects significantly the flow phenomena during the pulse cycle. Similarly, it is found that the flow field is also strongly influenced by wall hypertrophy. This work was supported by Mid-career Researcher Program and Priority Research Centers Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education, Science and Technology (2009-0079936 & 2011-0029613).

  19. Black Raspberry Extract Increased Circulating Endothelial Progenitor Cells and Improved Arterial Stiffness in Patients with Metabolic Syndrome: A Randomized Controlled Trial.

    PubMed

    Jeong, Han Saem; Kim, Sohyeon; Hong, Soon Jun; Choi, Seung Cheol; Choi, Ji-Hyun; Kim, Jong-Ho; Park, Chi-Yeon; Cho, Jae Young; Lee, Tae-Bum; Kwon, Ji-Wung; Joo, Hyung Joon; Park, Jae Hyoung; Yu, Cheol Woong; Lim, Do-Sun

    2016-04-01

    Administration of black raspberry (Rubus occidentalis) is known to improve vascular endothelial function in patients at a high risk for cardiovascular (CV) disease. We investigated short-term effects of black raspberry on circulating endothelial progenitor cells (EPCs) and arterial stiffness in patients with metabolic syndrome. Patients with metabolic syndrome (n = 51) were prospectively randomized into the black raspberry group (n = 26, 750 mg/day) and placebo group (n = 25) during the 12-week follow-up. Central blood pressure, augmentation index, and EPCs, such as CD34/KDR(+), CD34/CD117(+), and CD34/CD133(+), were measured at baseline and at 12-week follow-up. Radial augmentation indexes were significantly decreased in the black raspberry group compared to the placebo group (-5% ± 10% vs. 3% ± 14%, P < .05). CD34/CD133(+) cells at 12-week follow-up were significantly higher in the black raspberry group compared to the placebo group (19 ± 109/μL vs. -28 ± 57/μL, P < .05). Decreases from the baseline in interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α) were significantly greater in the black raspberry group compared to the placebo group (-0.5 ± 1.4 pg/mL vs. -0.1 ± 1.1 pg/mL, P < .05 and -5.4 ± 4.5 pg/mL vs. -0.8 ± 4.0 pg/mL, P < .05, respectively). Increases from the baseline in adiponectin levels (2.9 ± 2.1 μg/mL vs. -0.2 ± 2.5 μg/mL, P < .05) were significant in the black raspberry group. The use of black raspberry significantly lowered the augmentation index and increased circulating EPCs, thereby improving CV risks in patients with metabolic syndrome during the 12-week follow-up.

  20. Peripheral Endothelial (Dys)Function, Arterial Stiffness and Carotid Intima-Media Thickness in Patients after Kawasaki Disease: A Systematic Review and Meta-Analyses

    PubMed Central

    Dietz, Sanne M.; Tacke, Carline E. A.; Hutten, Barbara A.; Kuijpers, Taco W.

    2015-01-01

    Background Kawasaki disease (KD) is a systemic pediatric vasculitis. Its main complication is the development of coronary arterial aneurysms (CAA), causing an increased risk for ischemia and myocardial infarction. It is unclear whether KD patients, apart from the presence of CAA, have an increased cardiovascular disease (CVD) risk due to the previous systemic vasculitis. The aim of this study was to systematically review and meta-analyse the literature regarding surrogate markers for CVD risk in KD patients. Methods Medline and Embase were searched for articles comparing endothelial dysfunction (flow-mediated dilation, nitroglycerin-mediated dilation and peripheral arterial tonometry), vascular stiffness (stiffness index, pulse wave velocity) and carotid intima-media thickness (cIMT) between patients and controls. Two investigators assessed the articles for eligibility and evaluated quality. Results Thirty studies were included. For all outcomes, moderate to high heterogeneity between studies was found. Most studies reported a decreased flow-mediated dilation in the whole KD- and CAA-positive group compared to controls, while data on CAA-negative patients were conflicting. The stiffness index was increased in the majority of studies evaluating the whole KD- and CAA-positive group, but not in most studies on CAA-negative patients. Mean cIMT was neither significantly increased in the whole KD-group nor in the CAA-positive group nor in most studies studying CAA-negative patients. Studies measuring maximum cIMT were conflicting. Conclusion Literature suggests that surrogate markers for CVD risk in KD patients are increased in CAA-positive but not in CAA-negative patients. This may indicate that CAA-positive patients should be monitored for CVD in later life. The results of this review have to be interpreted with care due to substantial heterogeneity between studies and methodological limitations, as well as the lack of long-term follow-up studies. PMID:26161871

  1. Maldevelopment of conotruncal and aorto-pulmonary septum with absent left central pulmonary artery: anatomical and clinical implications.

    PubMed Central

    Schulze-Neick, I.; Hausdorf, G.; Lange, P. E.

    1994-01-01

    In a patient with pulmonary valve atresia with hypoplastic main pulmonary artery selective angiography showed absence of the central left pulmonary artery and a right pulmonary artery originating from the ascending aorta close to the left coronary artery. This unusual anatomical arrangement complicates interventional and surgical treatment. Images PMID:8297705

  2. Management of acute central retinal artery occlusion: Intravenous thrombolysis is feasible and safe.

    PubMed

    Préterre, Cécile; Godeneche, Gaelle; Vandamme, Xavier; Ronzière, Thomas; Lamy, Matthias; Breuilly, Christophe; Urbanczyk, Cédric; Wolff, Valérie; Lebranchu, Pierre; Sevin-Allouet, Mathieu; Guillon, Benoit

    2017-01-01

    Background Although acute central retinal artery occlusion is as a stroke in the carotid territory (retinal artery), its management remains controversial. The aim of this study was to assess the feasibility and safety of intravenous thrombolysis delivered within 6 h of central retinal artery occlusion in French stroke units. Methods We performed a retrospective analysis of patients treated with intravenous alteplase (recombinant tissue-plasminogen activator), based on stroke units thrombolysis registers from June 2005 to June 2015, and we selected those who had acute central retinal artery occlusion. The feasibility was assessed by the ratio of patients that had received intravenous alteplase within 6 h after central retinal artery occlusion onset among those who had been admitted to the same hospital for acute central retinal artery occlusion. All adverse events were documented. Results Thirty patients were included. Visual acuity before treatment was limited to "hand motion", or worse, in 90% of the cases. The mean onset-to-needle time was 273 min. The individuals treated with intravenous alteplase for central retinal artery occlusion represented 10.2% of all of the patients hospitalized for central retinal artery occlusion in 2013 and 2014. We observed one occurrence of major bleeding, a symptomatic intracerebral hemorrhage. Conclusion When applied early on, intravenous thrombolysis appears to be feasible and safe, provided that contraindications are given due consideration. Whether intravenous thrombolysis is more effective than conservative therapy remains to be determined. In order to conduct a well-designed prospective randomized control trial, an organized network should be in place.

  3. Indirect measure of visceral adiposity ‘A Body Shape Index’ (ABSI) is associated with arterial stiffness in patients with type 2 diabetes

    PubMed Central

    Bouchi, Ryotaro; Asakawa, Masahiro; Ohara, Norihiko; Nakano, Yujiro; Takeuchi, Takato; Murakami, Masanori; Sasahara, Yuriko; Numasawa, Mitsuyuki; Minami, Isao; Izumiyama, Hajime; Hashimoto, Koshi; Yoshimoto, Takanobu; Ogawa, Yoshihiro

    2016-01-01

    Objective Among indirect measures of visceral adiposity, A Body Shape Index (ABSI), which is defined as waist circumference (WC)/(body mass index (BMI)2/3×height1/2), is unique in that ABSI is positively correlated with visceral adiposity and is supposed to be independent of BMI. ABSI has been also shown to be linearly and positively associated with visceral fat mass and all-cause and cardiovascular disease (CVD) in the general population. It is, however, uncertain whether ABSI could be associated with arterial stiffness in patients with diabetes. Methods This is a cross-sectional study of 607 patients with type 2 diabetes (mean age 64±12 years; 40.0% female). Visceral fat area (VFA, cm2) and subcutaneous fat area (SFA, cm2) were assessed with a dual-impedance analyzer. In order to estimate the risk for CVD, brachial-ankle pulse wave velocity (baPWV, cm) was used for the assessment of arterial stiffness. Results ABSI was significantly and positively correlated with VFA (r=0.138, p=0.001) and negatively associated with BMI (r=−0.085, p=0.037). The correlation of z-score for ABSI with VFA remained significant (r=0.170, p<0.001) but not with BMI (r=0.009, p=0.820). ABSI (standardized β 0.095, p=0.043) but not WC (standardized β −0.060, p=0.200) was significantly and positively correlated with baPWV in the multivariate model including BMI as a covariate. Conclusions ABSI appears to reflect visceral adiposity independently of BMI and to be a substantial marker of arterial stiffening in patients with type 2 diabetes. PMID:27026809

  4. Uncertainty quantification of inflow boundary condition and proximal arterial stiffness-coupled effect on pulse wave propagation in a vascular network.

    PubMed

    Brault, Antoine; Dumas, Laurent; Lucor, Didier

    2016-12-10

    This work aims at quantifying the effect of inherent uncertainties from cardiac output on the sensitivity of a human compliant arterial network response based on stochastic simulations of a reduced-order pulse wave propagation model. A simple pulsatile output form is used to reproduce the most relevant cardiac features with a minimum number of parameters associated with left ventricle dynamics. Another source of significant uncertainty is the spatial heterogeneity of the aortic compliance, which plays a key role in the propagation and damping of pulse waves generated at each cardiac cycle. A continuous representation of the aortic stiffness in the form of a generic random field of prescribed spatial correlation is then considered. Making use of a stochastic sparse pseudospectral method, we investigate the sensitivity of the pulse pressure and waves reflection magnitude over the arterial tree with respect to the different model uncertainties. Results indicate that uncertainties related to the shape and magnitude of the prescribed inlet flow in the proximal aorta can lead to potent variation of both the mean value and standard deviation of blood flow velocity and pressure dynamics due to the interaction of different wave propagation and reflection features. Lack of accurate knowledge in the stiffness properties of the aorta, resulting in uncertainty in the pulse wave velocity in that region, strongly modifies the statistical response, with a global increase in the variability of the quantities of interest and a spatial redistribution of the regions of higher sensitivity. These results will provide some guidance in clinical data acquisition and future coupling of arterial pulse wave propagation reduced-order model with more complex beating heart models.

  5. Low serum free thyroxine concentrations associate with increased arterial stiffness in euthyroid subjects: a population-based cross-sectional study.

    PubMed

    Wang, Jian; Zheng, Xuqin; Sun, Min; Wang, Zhixiao; Fu, Qi; Shi, Yun; Cao, Mengdie; Zhu, Zhenxin; Meng, Chuchen; Mao, Jia; Yang, Fan; Huang, Xiaoping; Xu, Jingjing; Zhou, Hongwen; Duan, Yu; He, Wei; Zhang, Mei; Yang, Tao

    2015-11-01

    Some studies suggest that even in euthyroid subjects, thyroid function may affect arteriosclerotic risk factors. We aimed to determine whether thyroid hormones or thyroid autoantibodies are associated with arterial stiffness in middle-aged and elderly Chinese subjects with euthyroidism. A cross-sectional, population-based study was conducted in Nanjing, China. A total of 812 euthyroid subjects (mean age [56.75 ± 8.34] years; 402 men) without vascular disease and major arteriosclerotic risk factors were included. Clinical factors, oral glucose tolerance test results, homeostasis model assessment for insulin resistance (HOMA-IR) results, and serum levels of lipids, free triiodothyronine (FT3), free thyroxine (FT4), thyroid-stimulating hormone (TSH), and thyroid autoantibodies were measured. Arterial stiffness was assessed using brachial-ankle pulse wave velocity (baPWV). In Pearson correlation analyses, baPWV correlated inversely with FT4 (r = -0.146, P < 0.001), but not with FT3 (r = 0.008, P = 0.816) or TSH (r = 0.055, P = 0.118). Subsequently, a multiple stepwise regression analysis revealed a significant and independent association of FT4 with baPWV in euthyroid subjects (β = -0.076, P = 0.005). After adjusting for potential cardiovascular risk factors, mean diastolic blood pressure (DBP), HOMA-IR, and baPWV levels decreased across increasing FT4 quartiles (DBP, P < 0.001; HOMA-IR, P < 0.001; baPWV, P = 0.003). No difference in baPWV was observed between the positive and the negative thyroid antibody groups (15.23 ± 3.30 m/s vs. 15.73 ± 3.05 m/s, P > 0.05). FT4 levels were inversely associated with arterial stiffness in euthyroid subjects. A prospective study is warranted to validate whether subjects with low-normal FT4 levels have a high incidence of cardiovascular disease.

  6. Impact of lifetime opioid exposure on arterial stiffness and vascular age: cross-sectional and longitudinal studies in men and women

    PubMed Central

    Reece, Albert Stuart; Hulse, Gary Kenneth

    2014-01-01

    Objective To characterise and compare the potentiation of arterial stiffness and vascular ageing by opioids in men and women. Design Cross-sectional and longitudinal studies of 576 clinical controls and 687 opioid-dependent patients (ODP) on 710 and 1305 occasions, respectively, over a total of 2382 days (6.52 years), 2006–2011. Methodology Radial pulse wave analysis with Atcor SphygmoCor system (Sydney). Setting Primary care. Participants Controls: General practice patients with non-cardiovascular disorders, and university student controls. ODP: Patients undergoing clinical management of their opioid dependence. Controls had lower chronological ages (CAs) than ODP (30.0±0.5 vs 34.5±0.3, mean±SEM, p<0.0001). 69.6% and 67.7% participants were men, and 16% and 92.3% were smokers (p<0.0001) for controls and ODP, respectively. 86.3%, 10.3% and 3.4% of ODP were treated with buprenorphine (6.98±0.21 mg), methadone (63.04±4.01 mg) or implant naltrexone, respectively. Body mass index (BMI) was depressed in ODP. Interventions Nil. Primary outcome measures Vascular Reference Age (RA) and the ratio of vascular age to chronological age (RA/CA). Secondary outcome measures Arterial stiffness including Augmentation Index. Results After BMI adjustment, RA in ODP was higher as a function of CA and of time (both p<0.05). Modelled mean RA in control and ODP was 35.6 and 36.3 years (+1.97%) in men, and 34.5 and 39.2 years (+13.43%) in women, respectively. Changes in RA and major arterial stiffness indices were worse in women both as a factor (p = 0.0036) and in interaction with CA (p = 0.0040). Quadratic, cubic and quartic functions of opioid exposure duration outperformed linear models with RA/CA over CA and over time. The opioid dose–response relationship persisted longitudinally after multiple adjustments from p=0.0013 in men and p=0.0073 in women. Conclusions Data show that lifetime opioid exposure, an interactive cardiovascular risk factor

  7. Implantation of a stent graft in the right pulmonary artery enables radical resection of a central endothelial sarcoma of the left pulmonary artery.

    PubMed

    Kissling, Pascal; Brosi, Philippe; Kull, Christof; Toia, Damien; Maurer, Christoph Andreas

    2013-09-01

    In a patient with a huge endothelial sarcoma of the left pulmonary artery, we report successful implantation of a stent graft in the right pulmonary artery, including the pulmonary arterial trunk. This preoperative measure enabled a safe and radical left-sided pneumonectomy, including the tumor and the central parts of the left pulmonary artery. No major blood loss occurred, and neither use of a heart-lung machine nor cardiopulmonary bypass was necessary.

  8. Subclavian artery pseudoaneurysm: a rare and serious complication of central venous catheterization in an infant.

    PubMed

    Koklu, Esad; Poyrazoglu, Hakan; Yikilmaz, Ali; Canpolat, Mehmet; Konuskan, Bahadir

    2008-02-01

    Serious complications of central venous access occur in 0.4-9.9% of patients undergoing attempted central venepuncture. We report an unusual case of an 18-month-old infant in whom a right subclavian artery pseudoaneurysm developed rapidly after attempted subclavian vein catheterization without US guidance failed.

  9. Influence of central venous pressure upon sinus node responses to arterial baroreflex stimulation in man

    NASA Technical Reports Server (NTRS)

    Mark, A. L.; Takeshita, A.; Eckberg, D. L.; Abboud, F. M.

    1978-01-01

    Measurements were made of sinus node responses to arterial baroreceptor stimulation with phenylephrine injection or neck suction, before and during changes of central venous pressure provoked by lower body negative pressure or leg and lower truck elevation. Variations of central venous pressure between 1.1 and 9.0 mm Hg did not influence arterial baroreflex mediated bradycardia. Baroreflex sinus node responses were augmented by intravenous propranolol, but the level of responses after propranolol was comparable during the control state, lower body negative pressure, and leg and trunk elevation. Sinus node responses to very brief baroreceptor stimuli applied during the transitions of central venous pressure also were comparable in the three states. The authors conclude that physiological variations of central venous pressure do not influence sinus node responses to arterial baroreceptor stimulation in man.

  10. Ambulatory arterial stiffness index is not associated with magnetic resonance imaging markers of cerebral small vessel disease in lacunar stroke patients.

    PubMed

    Klarenbeek, Pim; van Oostenbrugge, Robert J; Staals, Julie

    2015-05-01

    Ambulatory arterial stiffness index (AASI) is associated with microvascular damage in other organs, but the association with microvascular brain damage is unknown. The association of AASI with magnetic resonance imaging (MRI) markers of cerebral small vessel disease in 143 patients with lacunar stroke was investigated. We performed 24-hour ambulatory blood pressure monitoring and scored the presence of lacunes, white matter hyperintensities, perivascular spaces, and cerebral microbleeds on brain MRI. In logistic regression analyses, AASI was associated with white matter hyperintensities, but, after adjustment for age and sex, this association lost significance. AASI was not associated with lacunes, microbleeds, or perivascular spaces. Systolic and diastolic 24-hour blood pressure values were associated with lacunes, perivascular spaces, and microbleeds independent of age and sex. Despite its significance and growing interest as a possible prognostic and therapeutic target in (micro)vascular diseases, AASI seems to have no added value over standard 24-hour blood pressure in cerebral small vessel disease.

  11. Vitamin D deficiency is associated with digital ulcer but not with atherosclerosis or arterial stiffness in patients with systemic sclerosis: a pilot study.

    PubMed

    Park, Eun-Kyoung; Park, Ji-Heh; Kweon, Seong-Min; Kim, Geun-Tae; Lee, Seung-Geun

    2017-04-01

    The objective of this study was to investigate the association of vitamin D deficiency with digital ulcers (DUs) that result from microvasculopathy, carotid intima-media thickness (CIMT) as surrogate markers of atherosclerosis, and brachial-ankle pulse wave velocity (baPWV) representing arterial stiffness in patients with systemic sclerosis (SSc). In this cross-sectional study, 40 female SSc patients and 80 healthy controls matched for sex, age, and blood sampling season were recruited. Vitamin D deficiency was defined as serum 25-OHD levels <30 ng/mL. "DUs ever" included active and healed DUs. CIMT and carotid plaque were examined using high-resolution ultrasonography, and baPWV was measured using an automatic waveform analyzer. Vitamin D deficiency was more prevalent in SSc patients than in controls (30 vs. 11.3%). Regarding SSc patients, 9 (22.5%) had DUs ever, and the mean CIMT and baPWV were 0.68 mm and 1561.1 cm/s, respectively; carotid plaque was detected in 13 (34.2%) patients. The frequency of DUs ever was significantly higher for SSc patients with vitamin D deficiency than those without this feature (50 vs. 10.7%, p = 0.012), but the median CIMT and baPWV and the frequency of carotid plaque did not differ according to the presence of vitamin D deficiency. Multivariable logistic regression analysis showed that vitamin D deficiency was an independent risk factor for DUs ever (OR = 7.72, p = 0.024). Vitamin D deficiency was associated with DUs, but not with atherosclerosis or arterial stiffness, potentially indicating that vitamin D may have different effects on the microvascular and macrovascular involvement in SSc pathophysiology.

  12. Arterial Pulse Pressure and Its Association With Reduced Stroke Volume During Progressive Central Hypovolemia

    DTIC Science & Technology

    2006-09-01

    NM, Joyner MJ. Influence of increased central venous pressure on baroreflex control of sympathetic activity in humans. Am J Physiol Heart Circ Physiol...Arterial Pulse Pressure and Its Association With Reduced Stroke Volume During Progressive Central Hypovolemia Victor A. Convertino, PhD, William H...reduction of SV and change in MSNA during graded central hypovolemia in humans. Methods: After a 12-minute baseline data collection period, 13 men were

  13. No influence of lower leg heating on central arterial pulse pressure in young men.

    PubMed

    Kosaki, Keisei; Sugawara, Jun; Akazawa, Nobuhiko; Tanahashi, Koichiro; Kumagai, Hiroshi; Ajisaka, Ryuichi; Maeda, Seiji

    2015-07-01

    Central arterial pulse pressure (PP), a strong predictor of cardiovascular disease, mainly consists of an incident wave generated by left ventricular ejection and a late-arriving reflected wave emanating from the lower body. We have tested the hypothesis that a reduction in leg vascular tone by heat treatment of the lower leg attenuates the central arterial PP. Pressure and wave properties of the peripheral and central arteries were measured in eight young men before and after heat treatment of the lower leg (temperature approx. 43 °C) for 30 and 60 min, respectively. Following the lower leg heat trial, leg (femoral-ankle) pulse wave velocity (PWV) was significantly decreased, but aortic (carotid-femoral) PWV and parameters of wave reflection and carotid arterial PP did not change significantly. No significant changes were observed in these parameters in the control trial. These results suggest that the reduction in leg vascular tone induced by heat treatment of the lower leg may not affect wave reflection and central arterial PP in young men.

  14. Relations among Adiposity and Insulin Resistance with Flow-Mediated Dilation, Carotid Intima-Media Thickness, and Arterial Stiffness in Children

    PubMed Central

    Ryder, Justin R.; Dengel, Donald R.; Jacobs, David R.; Sinaiko, Alan; Kelly, Aaron S.; Steinberger, Julia

    2015-01-01

    Objective To determine the associations of adiposity and insulin resistance with measures of vascular structure and function in children. Study design A cross-sectional study included 252 children (age 15.1±2.4 yrs; body mass index (BMI)-percentile 68.2±26.5%; Tanner 2–5). Measurements of body fat percentage (BF%) were obtained with dual-energy X-ray absorptiometry (DXA) and visceral fat (VAT) with computed tomography (CT). Insulin resistance was measured with hyperinsulinemic euglycemic clamp. Vascular measurements for endothelial function (brachial artery flow-mediated dilation [FMD]), vascular structure (carotid intima-media thickness [cIMT]), vascular stiffness (carotid incremental elastic modulus [cIEM]), and pulse wave velocity (PWV) were analyzed by tertiles of adiposity and insulin resistance. Additional analyses with ANCOVA and linear regression, were adjusted for Tanner, sex, race, and family relationship; FMD was also adjusted for baseline artery diameter. Results FMD was positively associated with high adiposity (BMI, BF%, and VAT) (p<0.01 all). Insulin resistance was not associated with FMD. cIMT was significantly, positively related to obesity, VAT, and insulin resistance (p<0.05 all). No differences in cIEM and PWV were observed in relation to adiposity or insulin resistance. Conclusions The findings suggest that adiposity is associated with higher FMD, and insulin resistance and VAT are associated with higher cIMT in children. Further research is needed to clarify the progression of these relations. PMID:26427963

  15. A comparison of central venous-arterial and mixed venous-arterial carbon dioxide tension gradient in circulatory failure.

    PubMed

    Ho, K M; Harding, R; Chamberlain, J

    2007-10-01

    The arterial and mixed venous carbon dioxide tension gradient has been shown to increase when there is a decrease in cardiac output. Monitoring central venous gases is an attractive alternative to monitoring mixed venous gases in circulatory failure because central venous catheterisation is a less invasive procedure than pulmonary artery catheterisation. This study aims to evaluate the agreement between central venous-arterial carbon dioxide (CVA-CO2) and mixed venous-arterial carbon dioxide (SVA-CO2) tension gradients and assess whether CVA-CO2 tension gradient can be used to predict cardiac output in circulatory failure. Samples of arterial, central venous and mixed venous blood were obtained from 16 patients with circulatory failure at different inspired oxygen concentrations and cardiac indexes within 24 hours of study enrolment. CVA-CO2 and SVA-CO2 tension gradient were not interchangeable numerically (bias = 0.14 mmHg, 95% limits of agreement: -3.0 to 3.2 mmHg). CVA-CO2 (Spearman correlation coefficient r = -0.385) and SVA-CO, (r = -0.578) tension gradient were significantly correlated with the cardiac index but the cardiac index only accounted for 21% and 32% of the variability of CVA-CO, and SVA-CO2 tension gradient, respectively. The ability of CVA-CO2 tension gradient (area under the ROC curve = 0.77, 95% confidence interval [CI]: 0.49-0.99; P = 0.08) to predict a low cardiac output state (cardiac index < 2.5 l/min/m2) was lower than SVA-CO2 (area under the ROC curve = 0.95, 95% CI: 0.88-0.99; P = 0.003). The utility of CVA-CO2 and SVA-CO2 tension gradient appeared to be limited to their negative predictive value to exclude a low cardiac output state when CVA-CO, or SVA-CO, tension gradient was normal (< or =5 mmHg).

  16. Central retinal artery occlusion in association with fibromuscular dysplasia

    PubMed Central

    Altun, Ahmet; Altun, Gulengul; Olcaysu, Osman Okan; Kurna, Sevda Aydin; Aki, Suat Fazil

    2013-01-01

    A 14 year-old female, whose chief complaint was severe vision loss in the right eye for 2 days, presented to the Clinic of Ophthalmology of Fatih Sultan Mehmet Education and Research Hospital. The patient had been attending follow-up visits for 4 years, following a diagnosis of fibromuscular dysplasia by the Clinic of Pediatrics. The patient underwent a complete ophthalmo-logic, angiographic, hematologic, and systemic evaluation. Fundus fluorescein angiography was performed immediately, because of the cherry-red spot sign in the macula of the right eye. Fundus fluorescein angiography revealed evidence of marked stasis of the retinal arterial circulation in the right eye. Best corrected visual acuity was 20/400 in the right eye and 20/20 in the left eye. PMID:24293990

  17. Central retinal artery occlusion in association with fibromuscular dysplasia.

    PubMed

    Altun, Ahmet; Altun, Gulengul; Olcaysu, Osman Okan; Kurna, Sevda Aydin; Aki, Suat Fazil

    2013-01-01

    A 14 year-old female, whose chief complaint was severe vision loss in the right eye for 2 days, presented to the Clinic of Ophthalmology of Fatih Sultan Mehmet Education and Research Hospital. The patient had been attending follow-up visits for 4 years, following a diagnosis of fibromuscular dysplasia by the Clinic of Pediatrics. The patient underwent a complete ophthalmo-logic, angiographic, hematologic, and systemic evaluation. Fundus fluorescein angiography was performed immediately, because of the cherry-red spot sign in the macula of the right eye. Fundus fluorescein angiography revealed evidence of marked stasis of the retinal arterial circulation in the right eye. Best corrected visual acuity was 20/400 in the right eye and 20/20 in the left eye.

  18. Characterization and calibration of the central arterial pressure waveform obtained from vibrocardiographic signal

    NASA Astrophysics Data System (ADS)

    Casacanditella, L.; Cosoli, G.; Casaccia, S.; Rohrbaugh, J. W.; Scalise, L.; Tomasini, E. P.

    2016-06-01

    Laser Doppler Vibrometry (LDV) has been demonstrated to be a non-contact technique with high sensitivity, able to measure the skin vibrations related to cardiac activity. The obtainable mechanical signal (i.e. a velocity signal), VibroCardioGram (VCG), is able to provide significant physiological parameters, such as Heart Rate (HR). In this work, the authors aim to present a non-contact measurement method to obtain the arterial blood pressure signal from the mechanical vibrations assessed by LDV, in a central district of the arterial tree, such as carotid artery. In fact, in this way it is possible to indirectly assess Central Arterial Blood Pressure (CABP), which indicates the hemodynamic load on the heart, so that it is considered an important index predicting the cardiac risk of a subject. The measurement setup involves the use of an oscillometric cuff, to measure peripheral blood pressure at the radial artery level. Diastolic and Mean Arterial Pressure (MAP) at radial level were used to calibrate the integrated LDV signal (i.e. a displacement signal). As regard calibration, an exponential mathematical model was adopted to derive the pressure waveform from the displacement of the vessel detected by LDV. Results show an average difference of around 20% between systolic pressure measured at brachial level (i.e. peripheral pressure value) and systolic pressure derived from VCG signal measured over the carotid artery (i.e. central pressure). This is a physiological difference, consistent with the literature about the physiological increase of Systolic Blood Pressure (SBP) and Pressure Pulse (PP) at increased distances from the heart. However, this non-contact technique is affected by movement artifacts and by reflection phenomena not related to the studied vessel and so it is necessary to account of such issues in the results.

  19. Accidental subclavian artery catheterization during attempted internal jugular central venous catheter placement: a case report.

    PubMed

    Paliwal, Bharat; Kamal, Manoj; Purohit, Anamika; Rana, Kirti; Chouhan, Dilip Singh

    2015-01-01

    Central venous catheter placement has been routinely employed for anesthetic and intensive care management. Despite proper technique used and expertise complications do occur; some of which are related to catheter misplacements. We report a case in which subclavian artery was accidently catheterized during attempted internal jugular venous cannulation.

  20. The relationship between inhibitors of the Wnt signalling pathway (Dickkopf-1(DKK1) and sclerostin), bone mineral density, vascular calcification and arterial stiffness in post-menopausal women.

    PubMed

    Hampson, Geeta; Edwards, Sylvie; Conroy, Soraya; Blake, Glen M; Fogelman, Ignac; Frost, Michelle L

    2013-09-01

    Epidemiological studies have shown an association between bone loss/osteoporosis and vascular calcification (VC). Recent studies have implicated the Wnt signalling pathway in the pathogenesis of VC. We investigated the association between circulating concentrations of Wnt inhibitors; DKK1 and sclerostin with bone mineral density (BMD), abdominal aortic calcification (AAC) and arterial stiffness in post-menopausal women. One hundred and forty six post-menopausal women aged (mean [SD]) 61.5[6.5] years were studied. Sclerostin and DKK1 were measured in serum. BMD was measured at the lumbar spine (LS), femoral neck (FN), total hip (TH). AAC was detected by Vertebral Fracture Assessment (VFA) imaging and quantified using an 8- and 24- point scoring methods. Arterial stiffness was determined by aortic pulse wave velocity (PWV). A significant positive correlation was observed between sclerostin and BMD at the FN (r = 0.166, p = 0.043) and TH (r = 0.165, p = 0.044). The association remained significant at the FN (p = 0.045) and TH (p = 0.026) following adjustment for confounders. No significant correlation was observed between DKK1 and BMD. In contrast, there was a significant negative correlation between log DKK1 and AAC (24-point score: r = -0.25, p = 0.008 and 8-point score: r = -0.21, p = 0.024). Subjects with AAC score of 1 or less had significantly higher DKK1 (p = 0.01). The association between DKK1 and AAC remained significant following correction for age, blood pressure, cholesterol (24-point score: p = 0.017, 8-point score: p = 0.044). In adjusted linear regression analysis, sclerostin was positively associated with AAC (24-point score: p = 0.048, 8-point score: p = 0.031). Subjects with a PWV>9 m/s had significantly higher sclerostin than those with PWV <9 m/s: 23.8[12.3], vs 29.7 [14] pmol/l, p = 0.03). No association was observed between DKK1 and PWV. The opposite association between AAC and the 2 Wnt signaling inhibitors is of interest and merits further

  1. A randomized trial of once-daily fluticasone furoate/vilanterol or vilanterol versus placebo to determine effects on arterial stiffness in COPD

    PubMed Central

    Bhatt, Surya P; Dransfield, Mark T; Cockcroft, John R; Wang-Jairaj, Jie; Midwinter, Dawn A; Rubin, David B; Scott-Wilson, Catherine A; Crim, Courtney

    2017-01-01

    Introduction Chronic obstructive pulmonary disease (COPD) is associated with increased cardiovascular morbidity and mortality. Elevated arterial stiffness, measured by aortic pulse wave velocity (aPWV), is a cardiovascular risk surrogate and is potentially modifiable by inhaled corticosteroid/long-acting beta2-agonist combinations in patients with COPD. Materials and methods The effects of once-daily inhaled fluticasone furoate/vilanterol (FF/VI) 100/25 µg, VI 25 µg, versus placebo on arterial stiffness in patients with COPD and baseline aPWV ≥11.0 m/s were investigated in a 24-week, multicenter, double-blind, randomized, stratified (by COPD exacerbation history), parallel-group, placebo-controlled trial. Eligible patients were ≥40 years old, with ≥10 pack-year smoking history, forced expiratory volume in 1 s (FEV1)/forced vital capacity ≤0.70, and post-bronchodilator FEV1 ≤70% of predicted. Patients with a major cardiovascular event in the previous 6 months/current severe heart failure/uncontrolled hypertension were excluded. Primary endpoint is change from baseline in aPWV after 24 weeks of treatment. Safety analyses included adverse events (AEs). Results The intent-to-treat population included 430 patients: FF/VI (n=135), VI (n=154), and placebo (n=141). Patients were predominantly male (79%) and Asian or White (each 48%), with a mean age of 68.5 years (standard deviation [SD] =7.9), percentage predicted post-bronchodilator FEV1 50.1% (SD =13.3), and aPWV 13.26 m/s (SD =2.22) at screening. At 24 weeks, mean (standard error [SE]) changes from baseline in aPWV were −1.75 m/s (SE =0.26, FF/VI), −1.95 m/s (SE =0.24, VI), and −1.97 m/s (SE =0.28, placebo). AEs occurred in 57% (FF/VI), 51% (VI), and 41% (placebo) of patients. Conclusion No differences were observed in aPWV-adjusted mean change from baseline for FF/VI 100/25 µg, compared with placebo. PMID:28176907

  2. Resveratrol prevents high fat/sucrose diet-induced central arterial wall inflammation and stiffening in nonhuman primates.

    PubMed

    Mattison, Julie A; Wang, Mingyi; Bernier, Michel; Zhang, Jing; Park, Sung-Soo; Maudsley, Stuart; An, Steven S; Santhanam, Lakshmi; Martin, Bronwen; Faulkner, Shakeela; Morrell, Christopher; Baur, Joseph A; Peshkin, Leonid; Sosnowska, Danuta; Csiszar, Anna; Herbert, Richard L; Tilmont, Edward M; Ungvari, Zoltan; Pearson, Kevin J; Lakatta, Edward G; de Cabo, Rafael

    2014-07-01

    Central arterial wall stiffening, driven by a chronic inflammatory milieu, accompanies arterial diseases, the leading cause of cardiovascular (CV) morbidity and mortality in Western society. An increase in central arterial wall stiffening, measured as an increase in aortic pulse wave velocity (PWV), is a major risk factor for clinical CV disease events. However, no specific therapies to reduce PWV are presently available. In rhesus monkeys, a 2 year diet high in fat and sucrose (HFS) increases not only body weight and cholesterol, but also induces prominent central arterial wall stiffening and increases PWV and inflammation. The observed loss of endothelial cell integrity, lipid and macrophage infiltration, and calcification of the arterial wall were driven by genomic and proteomic signatures of oxidative stress and inflammation. Resveratrol prevented the HFS-induced arterial wall inflammation and the accompanying increase in PWV. Dietary resveratrol may hold promise as a therapy to ameliorate increases in PWV.

  3. Central retinal artery occlusion following forehead injection with a corticosteroid suspension.

    PubMed

    Edwards, Albert O

    2008-01-01

    Intralesional injection of corticosteroid suspensions into or adjacent to the ocular adnexa is performed by a number of medical specialists including dermatologists. Although not widely known outside of the ophthalmic community, these injections can lead to blindness through embolization of the central retinal artery. A case of blindness following injection into the forehead lesion of a child with the rare dermatologic condition pyogenic arthritis and pyodermic gangrenosum syndrome is reported. Injection into or near the ocular adnexa may be performed in small boluses to reduce the chance of retinal embolization following entry into the arterial system.

  4. The effects of 12-week psyllium fibre supplementation or healthy diet on blood pressure and arterial stiffness in overweight and obese individuals.

    PubMed

    Pal, Sebely; Khossousi, Alireza; Binns, Colin; Dhaliwal, Satvinder; Radavelli-Bagatini, Simone

    2012-03-01

    Endothelial dysfunction and increased arterial stiffness occur early in the pathogenesis of the metabolic syndrome and they are both powerful independent predictors of cardiovascular risk. A high-fibre diet has been correlated with lower BMI and a lower incidence of hyperlipidaemia, CVD, hypertension and diabetes. The present randomised, parallel-design study compared the effects of fibre intake from a healthy diet v. fibre supplement diets on blood pressure (BP) and vascular function over 12 weeks. Overweight and obese adults were randomised to one of three groups: control (with placebo), fibre supplement (FIB) or healthy eating group with placebo (HLT). Systolic blood pressure (SBP) was lower in the FIB group compared with the control group at week 6, but not at week 12. However, SBP was lower in the HLT group compared with control group at week 12. At week 6, the FIB group presented lower diastolic blood pressure and augmentation index compared with the control group, but this result did not persist to the end of the study. The present study did not show any improvements in BP or vascular function in overweight and obese individuals with psyllium fibre supplementation over 12 weeks of intervention. However, a healthy diet provided the greatest improvements in BP in overweight and obese subjects. Further research with hypertensive individuals is necessary to elucidate whether increased fibre consumption in the form of psyllium supplementation may provide a safe and acceptable means to reduce BP, vascular function and the risk of developing CVD.

  5. Loss of Gspt1l disturbs the patterning of the brain central arteries in zebrafish.

    PubMed

    Wang, Hongcheng; Luo, Lingfei; Yang, Deqin

    2017-04-22

    The cranial vasculature is crucial for the survival and development of the central nervous system and is closely related to brain pathologies. Characterizations of the underlying mechanisms by which cranial vessels acquire their stereotypic patterning remain to be the key interest in the cerebrovascular research. In this report, we show an interesting zebrafish cq37 mutant displaying aberrant patterning of the central arteries. Genetic mapping results indicate that the gene responsible for cq37 encodes G1 to S phase transition 1, like (Gspt1l) with a nonsense mutation. Complementation studies with a CRISPR-generated allele, as well as mRNA rescues, together strongly demonstrate that gspt1l is the cq37 gene. Zebrafish gspt1l is broadly expressed in the brain with enhanced expression in hindbrain during central artery sprouting. Further studies reveal that vascular endothelial growth factor (VEGF) signaling and unfolded protein response (UPR) pathway are activated in gspt1l(cq37) mutants. In addition, expression analysis shows that vegfa and activating transcription factor-4 (atf4) are strongly upregulated in regions of gspt1l expression. Our results suggest that loss of Gspt1l activates the UPR pathway, which in turn induces ectopic expression of vegfa via Atf4, thus disturbing the patterning of the central arteries.

  6. Successful treatment of central retinal artery thromboembolism with ocular massage and intravenous acetazolamide.

    PubMed

    Duxbury, Oliver; Bhogal, Pervinder; Cloud, Geoffrey; Madigan, Jeremy

    2014-12-05

    A 67-year-old woman presented with left-sided headache and blurred vision, worse during hypertensive episodes. CT angiography showed a 4 mm left internal carotid artery (ICA) aneurysm incorporating the ophthalmic artery. She passed a test balloon occlusion, so the aneurysm was coil occluded, without immediate complication. Four days postprocedure she experienced sudden loss of vision in the left eye and funduscopy showed central retinal artery occlusion secondary to emboli from the coiled aneurysm. She was treated promptly with intravenous acetazolamide and ocular massage and regained full visual acuity. Thromboembolism to the eye during or after neurointerventional treatment is a relatively rare but devastating complication. This report demonstrates the effectiveness of combined intravenous acetazolamide and ocular massage in dealing with this complication when delivered promptly.

  7. Mild central chemoreflex activation does not alter arterial baroreflex function in healthy humans

    PubMed Central

    Simmons, Grant H; Manson, Julie M; Halliwill, John R

    2007-01-01

    We have previously shown that activation of peripheral chemoreceptors with isocapnic hypoxia resets arterial baroreflex control of heart rate and sympathetic vasoconstrictor outflow to higher pressures, without changes in baroreflex gain. We tested the hypothesis that activation of central chemoreceptors with mild hyperoxic hypercapnia also causes resetting of the arterial baroreflex, but that this resetting would not occur with matched volume and frequency hyperpnoea. Baroreflex control of heart rate (n = 16) and muscle sympathetic nerve activity (microneurography; n = 11) was assessed in healthy men and women, age 20–33 years, using the modified Oxford technique during hyperoxic eucapnia, hyperoxic hyperpnoea and hyperoxic hypercapnia (end-tidal PCO2+ 5 mmHg above eucapnia). Baroreflex trials were separated by 30 min of rest. While neither hyperpnoea nor hypercapnia changed mean arterial pressure (92.0 ± 1.8 during eucapnia versus 91.0 ± 1.2 and 90.7 ± 1.4 mmHg during hyperpnoea and hypercapnia; P = 0.427) or muscle sympathetic nerve activity (2301 ± 687 during eucapnia versus 2959 ± 987 and 2272 ± 414 total integrated units min−1 during hyperpnoea and hypercapnia; P = 0.653), heart rate was increased from 59.3 ± 2.7 during eucapnia to 63.2 ± 3.0 and 62.4 ± 2.8 beats min−1 during hyperpnoea and hypercapnia (both P < 0.017). Baroreflex gain was not altered by hyperpnoea or hypercapnia. Thus, acute activation of central chemoreceptors with mild hyperoxic hypercapnia does not affect arterial pressure, sympathetic vasoconstrictor outflow, or baroreflex gain. Heart rate is elevated during hyperoxic hypercapnia, but this response is not different from the increase in heart rate produced by matched volume and frequency hyperpnoea. Therefore, mild activation of central chemoreceptors does not appear to alter arterial baroreflex function. PMID:17640930

  8. Central Retinal and Posterior Ciliary Artery Occlusion After Intralesional Injection of Sclerosant to Glabellar Subcutaneous Hemangioma

    SciTech Connect

    Matsuo, Toshihiko; Fujiwara, Hiroyasu; Gobara, Hideo; Mimura, Hidefumi; Kanazawa, Susumu

    2009-03-15

    The aim of this study is to describe vision loss caused by central retinal artery and posterior ciliary artery occlusion as a consequence of sclerotherapy with a polidocanol injection to a glabellar hemangioma. An 18-year-old man underwent direct injection with a 23-gauge needle of 1 mL of a polidocanol-carbon dioxide emulsion into the glabellar subcutaneous hemangioma under ultrasound visualization of the needle tip by radiologists. He developed lid swelling the next day, and 3 days later at referral, the visual acuity in the left eye was no light perception. Funduscopy revealed central retinal artery occlusion and fluorescein angiography disclosed no perfusion at all in the left fundus, indicating concurrent posterior ciliary artery occlusion. The patient also showed mydriasis, blepharoptosis, and total external ophthalmoplegia on the left side. Magnetic resonance imaging demonstrated the swollen medial rectus muscle. In a month, blepharoptosis and ophthalmoplegia resolved but the visual acuity remained no light perception. Sclerosing therapy for facial hemangioma may develop a severe complication such as permanent visual loss.

  9. Epidemiology of congenital coronary artery anomalies: a coronary arteriography study on a central European population.

    PubMed

    Kardos, A; Babai, L; Rudas, L; Gaál, T; Horváth, T; Tálosi, L; Tóth, K; Sárváry, L; Szász, K

    1997-11-01

    The anatomical patterns and frequency of occurrence of congenital coronary anomalies (CCA) in a Central European cohort has not yet been studied. The angiographic data of 7,694 consecutive patients undergoing coronary arteriography at the Albert Szent-Györgyi Medical University, Szeged, Hungary, from 1984 to 1994 were analyzed. CCA were found in 103 patients (1.34% incidence). Ninety-eight of them (95.2%) had anomalies of origin and distribution, and five (4.8%) had coronary artery fistulae. The incidence was the highest for the separate origin of left descending artery and left circumflex from the left sinus of Valsalva (52.42%). Anomalous origin of the left circumflex coronary artery from the right coronary was 8.7% while from the right sinus of Valsalva 18.4%. CCA, which may be associated with potentially serious events, such as ectopic coronary origin from the opposite aortic sinus (1.9%) and single coronary arteries (3.88%), were not frequent. The incidence of CCA in the Central European cohort under study was similar to that of the largest North American study. The anatomic classification presented can be useful from both clinical and surgical standpoints.

  10. Correlation between Arterial Lactate and Central Venous Lactate in Children with Sepsis

    PubMed Central

    Araque, Paula; Yepes, María; Mulett, Hernando; Tovar, Ximena; Rodriguez, Fabio

    2016-01-01

    Introduction. Lactate is an important indicator of tissue perfusion. The objective of this study is to evaluate if there are significant differences between the arterial and central venous measurement of lactate in pediatric patients with sepsis and/or septic shock. Methods. Longitudinal retrospective observational study. Forty-two patients were included between the age of 1 month and 17 years, with a diagnosis of sepsis and septic shock, who were admitted to the intensive care unit of a university referral hospital. The lactate value obtained from an arterial blood sample and a central venous blood sample drawn simultaneously, and within 24 hours of admission to the unit, was recorded. Results. The median age was 2.3 years (RIC 0,3–15), with a predominance of males (71.4%), having a 2.5 : 1 ratio to females. Most of the patients had septic shock (78.5%) of pulmonary origin (50.0%), followed by those of gastrointestinal origin (26.1%). Using Spearman's Rho, a 0.872 (p < 0.001) correlation was found between arterial and venous lactate, which did not vary when adjusted for age (p < 0.05) and the use of vasoactive drugs (p < 0.05). Conclusion. There is a good correlation between arterial and venous lactate in pediatric patients with sepsis and septic shock, which is not affected by demographic variables or type of vasoactive support. PMID:27822386

  11. Selective Heart Rate Reduction With Ivabradine Increases Central Blood Pressure in Stable Coronary Artery Disease.

    PubMed

    Rimoldi, Stefano F; Messerli, Franz H; Cerny, David; Gloekler, Steffen; Traupe, Tobias; Laurent, Stéphane; Seiler, Christian

    2016-06-01

    Heart rate (HR) lowering by β-blockade was shown to be beneficial after myocardial infarction. In contrast, HR lowering with ivabradine was found to confer no benefits in 2 prospective randomized trials in patients with coronary artery disease. We hypothesized that this inefficacy could be in part related to ivabradine's effect on central (aortic) pressure. Our study included 46 patients with chronic stable coronary artery disease who were randomly allocated to placebo (n=23) or ivabradine (n=23) in a single-blinded fashion for 6 months. Concomitant baseline medication was continued unchanged throughout the study except for β-blockers, which were stopped during the study period. Central blood pressure and stroke volume were measured directly by left heart catheterization at baseline and after 6 months. For the determination of resting HR at baseline and at follow-up, 24-hour ECG monitoring was performed. Patients on ivabradine showed an increase of 11 mm Hg in central systolic pressure from 129±22 mm Hg to 140±26 mm Hg (P=0.02) and in stroke volume by 86±21.8 to 107.2±30.0 mL (P=0.002). In the placebo group, central systolic pressure and stroke volume remained unchanged. Estimates of myocardial oxygen consumption (HR×systolic pressure and time-tension index) remained unchanged with ivabradine.The decrease in HR from baseline to follow-up correlated with the concomitant increase in central systolic pressure (r=-0.41, P=0.009) and in stroke volume (r=-0.61, P<0.001). In conclusion, the decrease in HR with ivabradine was associated with an increase in central systolic pressure, which may have antagonized possible benefits of HR lowering in coronary artery disease patients. CLINICAL TRIALSURL: http://www.clinicaltrials.gov. Unique identifier NCT01039389.

  12. Sagittal abdominal diameter is a more independent measure compared with waist circumference to predict arterial stiffness in subjects with type 2 diabetes - a prospective observational cohort study

    PubMed Central

    2013-01-01

    Background Anthropometric measurements are useful in clinical practice since they are non-invasive and cheap. Previous studies suggest that sagittal abdominal diameter (SAD) may be a better measure of visceral fat depots. The aim of this study was to prospectively explore and compare how laboratory and anthropometric risk markers predicted subclinical organ damage in 255 patients, with type 2 diabetes, after four years. Methods Baseline investigations were performed in 2006 and were repeated at follow-up in 2010. Carotid intima-media thickness (IMT) was evaluated by ultrasonography and aortic pulse wave velocity (PWV) was measured with applanation tonometry over the carotid and femoral arteries at baseline and at follow-up in a cohort of subjects with type 2 diabetes aged 55–65 years old. Results There were significant correlations between apolipoprotein B (apoB) (r = 0.144, p = 0.03), C - reactive protein (CRP) (r = 0.172, p = 0.009) at baseline and IMT measured at follow-up. After adjustment for sex, age, treatment with statins and Hba1c, the associations remained statistically significant. HbA1c, total cholesterol or LDL-cholesterol did not correlate to IMT at follow-up. Baseline body mass index (BMI) (r = 0.130, p = 0.049), waist circumference (WC) (r = 0.147, p = 0.027) and sagittal Abdominal Diameter (SAD) (r = 0.184, p = 0.007) correlated to PWV at follow-up. Challenged with sex, SBP and HbA1c, the association between SAD, not WC nor BMI, and PWV remained statistically significant (p = 0.036). In a stepwise linear regression, entering both SAD and WC, the association between SAD and PWV was stronger than the association between WC and PWV. Conclusions We conclude that apoB and CRP, but not LDL-cholesterol predicted subclinical atherosclerosis. Furthermore, SAD was more independent in predicting arterial stiffness over time, compared with WC, in middle-aged men and women with type 2 diabetes. PMID:23536999

  13. Low-sodium dietary approaches to stop hypertension diet reduces blood pressure, arterial stiffness, and oxidative stress in hypertensive heart failure with preserved ejection fraction.

    PubMed

    Hummel, Scott L; Seymour, E Mitchell; Brook, Robert D; Kolias, Theodore J; Sheth, Samar S; Rosenblum, Hannah R; Wells, Joanna M; Weder, Alan B

    2012-11-01

    Recent studies suggest that oxidative stress and vascular dysfunction contribute to heart failure with preserved ejection fraction (HFPEF). In salt-sensitive HFPEF animal models, diets low in sodium and high in potassium, calcium, magnesium, and antioxidants attenuate oxidative stress and cardiovascular damage. We hypothesized that the sodium-restricted Dietary Approaches to Stop Hypertension diet (DASH/SRD) would have similar effects in human hypertensive HFPEF. Thirteen patients with treated hypertension and compensated HFPEF consumed the DASH/SRD for 21 days (all food/most beverages provided). The DASH/SRD reduced clinic systolic (155-138 mm Hg; P=0.02) and diastolic blood pressure (79-72 mm Hg; P=0.04), 24-hour ambulatory systolic (130-123 mm Hg; P=0.02) and diastolic blood pressure (67-62 mm Hg; P=0.02), and carotid-femoral pulse wave velocity (12.4-11.0 m/s; P=0.03). Urinary F2-isoprostanes decreased by 31% (209-144 pmol/mmol Cr; P=0.02) despite increased urinary aldosterone excretion. The reduction in urinary F2-isoprostanes closely correlated with the reduction in urinary sodium excretion on the DASH/SRD. In this cohort of HFPEF patients with treated hypertension, the DASH/SRD reduced systemic blood pressure, arterial stiffness, and oxidative stress. These findings are characteristic of salt-sensitive hypertension, a phenotype present in many HFPEF animal models and suggest shared pathophysiological mechanisms linking these 2 conditions. Further dietary modification studies could provide insights into the development and progression of hypertensive HFPEF.

  14. Associations of dietary intake patterns identified using reduced rank regression with markers of arterial stiffness among youth with type 1 diabetes

    PubMed Central

    Lamichhane, Archana P.; Liese, Angela D.; Urbina, Elaine M.; Crandell, Jamie L.; Jaacks, Lindsay M.; Dabelea, Dana; Black, Mary Helen; Merchant, Anwar T.; Mayer-Davis, Elizabeth J.

    2014-01-01

    BACKGROUND/OBJECTIVES Youth with type 1 diabetes (T1DM) are at substantially increased risk for adverse vascular outcomes, but little is known about the influence of dietary behavior on cardiovascular disease (CVD) risk profile. We aimed to identify dietary intake patterns associated with CVD risk factors and evaluate their impact on arterial stiffness (AS) measures collected thereafter in a cohort of youth with T1DM. SUBJECTS/METHODS Baseline diet data from a food frequency questionnaire and CVD risk factors (triglycerides, LDL-cholesterol, systolic BP, HbA1c, C-reactive protein and waist circumference) were available for 1,153 youth aged ≥10 years with T1DM from the SEARCH for Diabetes in Youth Study. A dietary intake pattern was identified using 33 food-groups as predictors and six CVD risk factors as responses in reduced rank regression (RRR) analysis. Associations of this RRR-derived dietary pattern with AS measures [augmentation index(AIx75), n=229; pulse wave velocity(PWV), n=237; and brachial distensibility(BrachD), n=228] were then assessed using linear regression. RESULTS The RRR-derived pattern was characterized by high intakes of sugar-sweetened beverages (SSB) and diet soda, eggs, potatoes and high-fat meats, and low intakes of sweets/desserts and low-fat dairy; major contributors were SSB and diet soda. This pattern captured the largest variability in adverse CVD risk profile and was subsequently associated with AIx75 (β=0.47; p<0.01). The mean difference in AIx75 concentration between the highest and the lowest dietary pattern quartiles was 4.3% in fully adjusted model. CONCLUSIONS Intervention strategies to reduce consumption of unhealthful foods and beverages among youth with T1DM may significantly improve CVD risk profile and ultimately reduce the risk for AS. PMID:24865480

  15. An Integrative Model of the Cardiovascular System Coupling Heart Cellular Mechanics with Arterial Network Hemodynamics

    PubMed Central

    Kim, Young-Tae; Lee, Jeong Sang; Youn, Chan-Hyun; Choi, Jae-Sung

    2013-01-01

    The current study proposes a model of the cardiovascular system that couples heart cell mechanics with arterial hemodynamics to examine the physiological role of arterial blood pressure (BP) in left ventricular hypertrophy (LVH). We developed a comprehensive multiphysics and multiscale cardiovascular model of the cardiovascular system that simulates physiological events, from membrane excitation and the contraction of a cardiac cell to heart mechanics and arterial blood hemodynamics. Using this model, we delineated the relationship between arterial BP or pulse wave velocity and LVH. Computed results were compared with existing clinical and experimental observations. To investigate the relationship between arterial hemodynamics and LVH, we performed a parametric study based on arterial wall stiffness, which was obtained in the model. Peak cellular stress of the left ventricle and systolic blood pressure (SBP) in the brachial and central arteries also increased; however, further increases were limited for higher arterial stiffness values. Interestingly, when we doubled the value of arterial stiffness from the baseline value, the percentage increase of SBP in the central artery was about 6.7% whereas that of the brachial artery was about 3.4%. It is suggested that SBP in the central artery is more critical for predicting LVH as compared with other blood pressure measurements. PMID:23960442

  16. [Tunnelled central venous line-associated infections in patients with pulmonary arterial hypertension treated with intravenous prostacyclin].

    PubMed

    Boucly, Athénaïs; O'Connell, Caroline; Savale, Laurent; O'Callaghan, Dermot S; Jaïs, Xavier; Montani, David; Humbert, Marc; Simonneau, Gérald; Sitbon, Olivier

    2016-01-01

    Intravenous prostacyclins are a valuable treatment for patients with severe pulmonary arterial hypertension, leading to improved exercise capacity, haemodynamics, quality of life and survival. Unfortunately, due to the short half-life of these drugs, they need to be administered continuously through central venous catheters. Despite aseptic technique, regular dressing changes, tunneled central venous catheters and patient education, patients are exposed to central venous catheter associated infections. These infections cause significant morbidity and mortality. The clinical presentation, microbiology, consequences and management of these central venous catheter associated infections in pulmonary arterial hypertension patients treated with intravenous prostacyclins are discussed.

  17. Stiff-person syndrome (SPS) and anti-GAD-related CNS degenerations: protean additions to the autoimmune central neuropathies.

    PubMed

    Ali, Fatima; Rowley, Merrill; Jayakrishnan, Bindu; Teuber, Suzanne; Gershwin, M Eric; Mackay, Ian R

    2011-09-01

    Stiff Person Syndrome (SPS) is a rare autoimmune neurological disease attributable to autoantibodies to glutamic acid decarboxylase (anti-GAD) more usually associated with the islet beta cell destruction of autoimmune type 1 diabetes (T1D). SPS is characterized by interference in neurons with the synthesis/activity of the inhibitory neurotransmitter gamma amino butyric acid (GABA) resulting in the prototypic progressive spasmodic muscular rigidity of SPS, or diverse neurological syndromes, cerebellar ataxia, intractable epilepsy, myoclonus and several others. Remarkably, a single autoantibody, anti-GAD, can be common to widely different disease expressions, i.e. T1D and SPS. One explanation for these data is the differences in epitope engagement between the anti-GAD reactivity in SPS and T1D: in both diseases, anti-GAD antibody reactivity is predominantly to a conformational epitope region in the PLP- and C-terminal domains of the 65 kDa isoform but, additionally in SPS, there is reactivity to conformational epitope(s) on GAD67, and short linear epitopes in the C-terminal region and at the N-terminus of GAD65. Another explanation for disease expressions in SPS includes ready access of anti-GAD to antigen sites due to immune responsiveness within the CNS itself according to intrathecal anti-GAD-specific B cells and autoantibody. Closer study of the mysterious stiff-person syndrome should enhance the understanding of this disease itself, and autoimmunity in general.

  18. Indices of vascular stiffness and wave reflection in relation to body mass index or body fat in healthy subjects.

    PubMed

    Wykretowicz, Andrzej; Adamska, Karolina; Guzik, Przemyslaw; Krauze, Tomasz; Wysocki, Henryk

    2007-10-01

    1. Obesity appears to influence vascular stiffness, an important cardiovascular risk factor. An accurate picture of arterial stiffness may be obtained when a combination of various techniques is used. 2. The purpose of the present study was to assess whether the body mass index (BMI) and body fat content obtained by bioimpedance were of equal value in estimating the influence of body fatness on various indices of vascular stiffness and wave reflection. 3. A total of 175 healthy subjects was studied. Anthropometric measurements and total body bio-impedance analysis were performed to assess fat mass as a proportion of total body composition. Arterial stiffness and wave reflection were assessed using digital volume pulse analysis and tonometric measurement of the wave reflection indices and central haemodynamics. 4. Significant differences in the stiffness index (SI(DVP); P < 0.0001), peripheral augmentation index (pAI(x); P < 0.0001), central augmentation index (cAI(x); P < 0.0001), peripheral pulse pressure (pPP; P = 0.026) and central pulse pressure (cPP; P < 0.0001) were found when the population examined was divided accordingly to tertile of body fat content. However, subdividing various indices of arterial stiffness according to the tertile of BMI did not reveal any significant differences between groups, except for pPP and cPP. 5. Body fat content was significantly correlated with SI(DVP), pAI(x), cAI(x), pPP and cPP. The BMI correlated weakly with SI(DVP), pPP and cPP. 6. In conclusion, the BMI is not very useful in predicting changes in arterial stiffness and wave reflection due to obesity. However, stiffness and wave reflection indices derived from digital volume pulse analysis, the characteristics of radial and aortic pressure waveforms and peripheral and aortic pulse pressure are all related to body fat content, as estimated by bioimpedance.

  19. Effect of Improving Dietary Quality on Arterial Stiffness in Subjects with Type 1 and Type 2 Diabetes: A 12 Months Randomised Controlled Trial

    PubMed Central

    Petersen, Kristina S.; Clifton, Peter M.; Lister, Natalie; Keogh, Jennifer B.

    2016-01-01

    People with diabetes have accelerated arterial stiffening. The aim of this study was to determine the effect of increasing fruit, vegetable and dairy intake for 12 months on carotid femoral pulse wave velocity (cfPWV), augmentation index (AIx), and central blood pressure (cBP), compared to a usual diet control, in people with type 1 and type 2 diabetes. In a 12 months randomised controlled trial, cfPWV, AIx and cBP were measured every 3 months. The intervention group received dietary counselling to increase consumption of fruit (+1 serving/day; 150 g/day), vegetables (+2 servings/day; 150 g/day) and dairy (+1 serving/day; 200–250 g/day) at baseline, 1, 3, 6 and 9 months. The control group continued on their usual diet. One hundred and nine participants were randomised and 92 (intervention n = 45; control n = 47) completed. At 3 months, fruit (184 g/day; p = 0.001) and dairy (83 g/day; p = 0.037) intake increased in the intervention group compared with the control group but this increase was not maintained at 12 months. After adjustment for baseline measurements there was no time by treatment effect for central systolic or diastolic BP, AIx or cfPWV. A time effect existed for AIx which modestly increased over time. Peripheral diastolic BP and central pulse pressure were improved in the intervention group compared with the control group at 12 months. In the cohort with type 1 and type 2 diabetes, improving dietary quality by increasing consumption of fruit, vegetables and dairy did not improve cBP, AIx or cfPWV, compared with a control group continuing on their usual diet, after 12 months. PMID:27338467

  20. Bronchial and arterial sleeve resection for centrally-located lung cancers

    PubMed Central

    D’Andrilli, Antonio; Venuta, Federico; Rendina, Erino Angelo

    2016-01-01

    The use of bronchial and arterial sleeve resections for the treatment of centrally-located lung cancers, when available, has become the option of choice in comparison with pneumonectomy (PN). Technical expertise, in particular in vascular reconstruction, and perioperative management improved over time allowing excellent short-term and long-term results. This is even truer if considering literature data from the main experiences published in the last years. These evidences have given to such lung sparing reconstructive procedures more and more acceptance among the surgical community. This article focuses on the main technical aspects and literature data regarding bronchovascular sleeve resections. PMID:27942409

  1. Intelligent transportation systems case study: central artery (I-93)/tunnel (I-90) project, Boston, Massachusetts, USA

    NASA Astrophysics Data System (ADS)

    Luchian, Sergiu F.; Krechmer, Daniel

    1995-01-01

    The Central Artery/Tunnel (CA/T) project provides an excellent opportunity to implement and test the application of Intelligent Transportation Systems (ITS) technology to improve traffic safety in a congested urban corridor. As currently designed, the CA/T project will have the most extensive ITS capabilities of any highway in the U.S.A., and numerous opportunities exist to build upon these capabilities. Advances in the state-of-the-art of both ITS technology and applications can improve the safety and convenience of the travelling public in Eastern Massachusetts and provide significant regional economic benefits as well.

  2. Inspiratory Resistance Maintains Arterial Pressure During Central Hypovolemia: Implications For Treatment Of Combat Casualties With Severe Hemorrhage

    DTIC Science & Technology

    2006-11-01

    INSPIRATORY RESISTANCE MAINTAINS ARTERIAL PRESSURE DURING CENTRAL HYPOVOLEMIA: IMPLICATIONS FOR TREATMENT OF COMBAT CASUALTIES WITH SEVERE...threshold device” (ITD) has recently been developed that acutely increases central blood volume by forcing the thoracic muscles to develop increased...supports further consideration of using inspiratory resistance as a countermeasure against circulatory collapse associated with orthostatic instability

  3. Central retinal artery occlusion following laser treatment for ocular ischemic aortic arch syndrome

    PubMed Central

    Shah, Payal J.; Ellis, Brian; DiGiovine, Lauren R.; Hogg, Jeffery P.; Leys, Monique J.

    2015-01-01

    Objective: Ocular ischemic syndrome is a rare blinding condition generally caused by disease of the carotid artery. We describe a 69-year-old female with a 50 pack-year smoking history with aortic arch syndrome causing bilateral ocular ischemic syndrome. Methods: The patient presented with progressive visual loss and temple pain. Slit lamp biomicroscopy revealed bilateral iris neovascularization. This finding prompted a cardiovascular work up. Panretinal photocoagulation with retrobulbar block was performed in the right eye. Results: A temporal artery biopsy was negative. The carotid duplex ultrasound showed only a 1–39% stenosis. MRA revealed a more proximal occlusion of the aortic branch for which she underwent subclavian carotid bypass surgery. At the one month follow up, the right eye suffered profound vision loss secondary to a central retinal artery occlusion. Conclusion: Ocular neovascularization may be one of the clinical manifestations of aortic arch syndrome. This case also illustrates the limitations of relying solely on carotid duplex ultrasound testing. We caution against overly aggressive panretinal photocoagulation utilizing retrobulbar anesthesia. PMID:27625958

  4. Panitumumab-Associated Encephalopathy after Accidental Intra-arterial Application through Dislocated Central Venous Access Device

    PubMed Central

    Pikija, Slaven; Pilz, Georg; Gschwandtner, Gerald; Rösler, Cornelia; Schlick, Konstantin; Greil, Richard; Sellner, Johann

    2016-01-01

    Acute central nervous system (CNS) toxicity and immune-related side effects are increasingly recognized with the use of monoclonal antibodies for cancer therapy. Here, we report a patient who developed of acute-onset encephalopathy and coma, which began shortly after administration of panitumumab for the treatment of metastatic colorectal cancer. Echocardiography revealed that the drug had been infused into the left cardiac ventricle via a dislocated central venous line. Diffusion-weighted magnetic resonance imaging disclosed multiple cortical hyperintensities, which were preferentially located in the frontal lobes. While the neurological condition improved within a few days, the patient died 4 weeks later. It seems likely that the administration of the antibody via the intra-arterial route contributed to the development of this condition. Toxic encephalopathy may be a hitherto unrecognized complication of panitumumab treatment and should be taken into consideration in patients developing CNS symptoms undergoing this therapy. PMID:27872609

  5. RI in central retinal artery as assessed by CDI does not correspond to retinal vascular resistance.

    PubMed

    Polska, E; Kircher, K; Ehrlich, P; Vecsei, P V; Schmetterer, L

    2001-04-01

    The aim of the present study was to investigate the association between ultrasound Doppler measurements of resistive index (RI) in the central retinal artery and retinal vascular resistance (R) assessed with laser Doppler velocimetry, vessel size measurement, and calculation of ocular perfusion pressure (PP) in healthy subjects. An increase in vascular resistance was induced by inhalation of 100% O(2). During hyperoxia no significant changes in PP were observed. Mean flow velocity in main retinal veins was reduced by -27.5 +/- 2.0%. The average decrease in diameter was -11.5 +/- 1.0%. R, which was calculated as the ratio of PP to flow rate, increased by 97.6 +/- 7.7%. RI increased as well, but the effect was much smaller (6.6 +/- 2.2%). In addition, a negative correlation was found between baseline values of R and RI (r = -0.83). During hyperoxia R and RI were not associated. In conclusion, our data indicate that RI as assessed with color Doppler imaging in the central retinal artery is not an adequate measure of R.

  6. Comparison of Computed Tomography and Cineangiography in the Demonstration of Central Pulmonary Arteries in Cyanotic Congenital Heart Disease

    SciTech Connect

    Taneja, Karuna; Sharma, Sanjiv; Kumar, Krishan; Rajani, Mira

    1996-03-15

    Purpose: To assess the diagnostic accuracy of contrast-enhanced computed tomography (CT) for central pulmonary artery pathology in patients with cyanotic congenital heart disease (CCHD) and right ventricular outflow obstruction. Methods: We compared contrast-enhanced CT and cine pulmonary arteriography in 24 patients with CCHD to assess central pulmonary arteries including the confluence. Both investigations were interpreted by a cardiac radiologist in a double-blinded manner at an interval of 3 weeks. Angiography was used as the gold standard for comparison. Results: The sensitivity for visualization of main pulmonary artery (MPA), right pulmonary artery (RPA), left pulmonary artery (LPA), and confluence on CT was 94%, 100%, 92.8%, and 92.8%, respectively. Diagnostic specificity for the same entities was 28.5%, 100%, 80%, and 50%, respectively. The positive predictive value for each was 76.2%, 100%, 94.1%, and 72.2%, respectively. The low specificity of CT in the evaluation of the MPA and the confluence is perhaps due to distorted right ventricular outflow anatomy in CCHD. Large aortopulmonary collaterals in this region were mistaken for the MPA in some patients with pulmonary atresia. Conclusion: CT is a useful, relatively noninvasive, imaging technique for the central pulmonary arteries in selected patients. It can supplement diagnostic information from angiography but cannot replace it. LPA demonstration on axial images alone is inadequate.

  7. Stiff railguns

    NASA Astrophysics Data System (ADS)

    Weldon, W. F.; Bacon, J. L.; Weeks, D. A.; Zowarka, R. C., Jr.

    1991-01-01

    Stiff guns have been operated with both plasma and solid armatures. A performance gain was seen in the plasma railgun as stiffness was increased. A stiff gun will help to maintain the bore shape and preserve the integrity of the seam between rail and insulator under the extreme asymmetric loads sustained during high-pressure operation. The hydraulically preloaded moly and ceramic gun has been fired six times at pressures as high as 87 ksi, and the bore still holds roughing vacuum up to two hours after the test. The elimination of seam leakage helps control bore erosion associated with plasma reconstitution from the rail and plasma perturbation that might result in loss-initiating instabilities. Reduced rail deflection allows solid and transitioning armatures to track the bore surface. An analysis of the strain energy associated with the deflection of the railgun structure is presented, and this mechanism is found to be a small fraction of the energy associated with armature loss and the rail resistive loss.

  8. Spontaneous central retinal artery occlusion in a teenager with sickle cell trait.

    PubMed

    Pai, Sivakami A; Hebri, Sudhira Pai; Dekhain, Moza A

    2015-01-01

    Sickle cell trait (SCT) is traditionally considered a benign condition by ophthalmologists. Several studies have reported ocular complications in SCT, but these complications have been described as a consequence of trauma, exertion, and associated systemic disorders. We here in the report a case of an Arab teen boy, who presented with a sudden loss of vision in his left eye of 1 h duration. The ocular examination revealed acute central retinal artery occlusion. He underwent a series of laboratory and radiological investigations. The blood investigations revealed SCT and abnormal partial thromboplastin time. The fundus fluorescein angiography revealed abnormal retinal vascular perfusion. Marked blood rheological impairment and activation of the coagulation pathway can occur without any contributing factors in SCT leading to severe ocular complications. This is one of the young patients with spontaneous vascular occlusion in SCT.

  9. [The radionuclide assessment of the central hemodynamic indices in patients with urolithiasis, arterial hypertension and varicocele].

    PubMed

    Darenkov, A F; Vladimirova, N N; Derevianko, I I; Darenkov, S P; Evdokimov, V V; Borisik, V I

    1991-01-01

    Basic parameters of central and intracardiac hemodynamics were studied in 49 urological patients 24 of which with urolithiasis entered group I, 13 with hypertension-group II and 12 with varicocele-group III. The patients' age averaged 46.4, 41.6 and 28.6 years, respectively. The data were provided by routine clinical and laboratory examinations, ECG, one-passage radionuclide cardiography with 132I-albumin using a radiocirculographer of Hungarian manufacture and radiocardioanalyzer RKAZ-01 made in this country. Neither marked ischemic disturbances of the myocardium nor valvular defects were revealed. Ambiguous group-specific shifts presented in central and intracardiac hemodynamics. Total peripheral vascular resistance exhibited a moderate increase while left ventricular circulation time grew 1.5-2-fold. The greater resistance can be attributed to activation of renin-angiotensin system in prolonged ischemia of renal parenchyma due to nephrolithiasis. Group II patients demonstrated parallel elevation of arterial pressure, peripheral resistance, left ventricular performance and output suggesting myocardial functional stress. In group III there was a rise in blood volume, left ventricular performance and output, cardiac index, stroke volume. This myocardial overloading may result from changes in intravascular volumetric relations characteristic of hypervolemia. These hemodynamic changes reflect adaptation in urological patients and should be accounted for in treatment and operative interventions.

  10. Arterial blood flow characteristics in central retinal vein occlusion and effects of panretinal photocoagulation treatment: an investigation by colour Doppler imaging

    PubMed Central

    Avunduk, A. M.; Dinc, H.; Kapicioglu, Z.; Ugurlu, S.; Dayanir, V.; Korkmaz, E.

    1999-01-01

    AIMS—To determine whether an increase in vascular resistance in the central retinal and ophthalmic arterial circulations contributes to the development of central retinal vein occlusion (CRVO), or haemodynamic alterations in central retinal and ophthalmic arteries occur secondary to the vein occlusion as increased intravascular pressure is transferred through the capillary bed to the arterial side and the effect of panretinal photocoagulation treatment on these circulations in ischaemic cases.
METHODS—The ophthalmic and central retinal arteries of the affected and non-affected eyes of 20 patients with non-ischaemic CRVO, 13 patients with ischaemic CRVO, and 22 control subjects were investigated by colour Doppler imaging. Panretinal photocoagulation (PRP) treatment was applied to the eyes with ischaemic CRVO. Maximum and minimum blood flow velocities, and resistivity indexes were calculated in the affected and healthy eyes of patients and in the control eyes.
RESULTS—Average blood flow velocity in the central retinal and ophthalmic arteries of patients with non-ischaemic CRVO did not differ from their fellow eyes, but a significantly lower average blood flow velocity was found in the ophthalmic and central retinal arteries of the patients with ischaemic CRVO compared with their fellow eyes. Patients with ischaemic CRVO had significantly lower blood flow velocities in their ophthalmic and central retinal arteries than non-ischaemic cases that were further reduced following PRP treatment.
CONCLUSION—This study suggests that impaired arterial blood flow observed in patients with CRVO may be partly related to secondary changes in the retrobulbar arterial circulation as a result of enhanced arterial resistance following CRVO. These data also demonstrate that PRP treatment decreases retinal and ophthalmic blood flow velocities in patients with ischaemic CRVO.

 Keywords: central retinal vein occlusion; panretinal photocoagulation; arterial circulation

  11. Neural control of circulation and exercise: a translational approach disclosing interactions between central command, arterial baroreflex, and muscle metaboreflex

    PubMed Central

    Michelini, Lisete C.; O'Leary, Donal S.; Raven, Peter B.

    2015-01-01

    The last 100 years witnessed a rapid and progressive development of the body of knowledge concerning the neural control of the cardiovascular system in health and disease. The understanding of the complexity and the relevance of the neuroregulatory system continues to evolve and as a result raises new questions. The purpose of this review is to articulate results from studies involving experimental models in animals as well as in humans concerning the interaction between the neural mechanisms mediating the hemodynamic responses during exercise. The review describes the arterial baroreflex, the pivotal mechanism controlling mean arterial blood pressure and its fluctuations along with the two main activation mechanisms to exercise: central command (parallel activation of central somatomotor and autonomic descending pathways) and the muscle metaboreflex, the metabolic component of exercise pressor reflex (feedback from ergoreceptors within contracting skeletal muscles). In addition, the role of the cardiopulmonary baroreceptors in modulating the resetting of arterial baroreflex is identified, and the mechanisms in the central nervous system involved with the resetting of baroreflex function during dynamic exercise are also described. Approaching a very relevant clinical condition, the review also presents the concept that the impaired arterial baroreflex function is an integral component of the metaboreflex-mediated exaggerated sympathetic tone in subjects with heart failure. This increased sympathetic activity has a major role in causing the depressed ventricular function observed during submaximal dynamic exercise in these patients. The potential contribution of a metaboreflex arising from respiratory muscles is also considered. PMID:26024683

  12. Early intervention of long-acting nifedipine GITS reduces brachial–ankle pulse wave velocity and improves arterial stiffness in Chinese patients with mild hypertension: a 24-week, single-arm, open-label, prospective study

    PubMed Central

    Zhang, Jidong; Wang, Yan; Hu, Haijuan; Yang, Xiaohong; Tian, Zejun; Liu, Demin; Gu, Guoqiang; Zheng, Hongmei; Xie, Ruiqin; Cui, Wei

    2016-01-01

    Background Nifedipine gastrointestinal therapeutic system (GITS) is used to treat angina and hypertension. The authors aimed to study the early intervention impact on arterial stiffness and pulse wave velocity (PWV) independent of its blood-pressure-(BP) lowering effect in mild hypertensive patients. Methods This single-center, single-arm, open-label, prospective, Phase IV study recruited patients with mild hypertension and increased PWV from December 2013 to December 2014 (N=138; age, 18–75 years; systolic blood pressure, 140–160 mmHg; diastolic BP, 90–100 mmHg; increased brachial–ankle pulse wave velocity [baPWV, ≥12 m/s]). Nifedipine GITS (30 mg/d) was administered for 24 weeks to achieve target BP of <140/90 mmHg. The dose was uptitrated at 60 mg/d in case of unsatisfactory BP reduction after 4 weeks. Primary study end point was the change in baPWV after nifedipine GITS treatment. Hemodynamic parameters (office BP, 24-hour ambulatory BP monitoring, and heart rate and adverse events) were evaluated at baseline and followed-up at 2, 4, 8, 12, 18, and 24 weeks. Results Majority of patients (n=117; 84.8%) completed the study. baPWV decreased significantly at 4 weeks compared with baseline (1,598.87±239.82 vs 1,500.89±241.15 cm/s, P<0.001), was stable at 12 weeks (1,482.24±215.14 cm/s, P<0.001), and remained steady through 24 weeks (1,472.58±205.01 cm/s, P<0.001). Office BP reduced from baseline to week 4 (154/95 vs 136/85 mmHg) and remained steady until 24 weeks. Nifedipine GITS significantly decreased 24-hour ambulatory BP monitoring (P<0.001) after 24 weeks from baseline. Mean arterial pressure and pulse pressure were lowered significantly after 4, 12, and 24 weeks of treatment (P<0.001). These changes in baPWV were significantly correlated with changes in systolic blood pressure, diastolic BP, and mean arterial pressure (P<0.05), but not with changes in pulse pressure (P>0.05). There were no other drug-related serious adverse events. Conclusion

  13. Central Venous Pressure After Coronary Artery Bypass Surgery: Does it Predict Postoperative Mortality or Renal Failure?

    PubMed Central

    Williams, Judson B.; Peterson, Eric D.; Wojdyla, Daniel; Ferguson, T. Bruce; Smith, Peter K.; Milano, Carmelo A.; Lopes, Renato D.

    2015-01-01

    Background While hemodynamic monitoring is often performed following coronary artery bypass grafting (CABG), the relationship between postoperative central venous pressure (CVP) measurement and clinical outcomes is unknown. Methods Detailed clinical data were analyzed from 2,390 randomly selected patients undergoing high risk CABG or CABG/valve at 55 hospitals participating in the Society of Thoracic Surgeons' National Cardiac Surgery Database from 2004 to 2005. Eligible patients underwent elective/urgent isolated CABG with an ejection fraction < 40%, or elective/urgent CABG at age ≥65 years with diabetes or a glomerular filtration rate 60 mL/min per 1.73 m2. Correlation between post-operative CVP and in-hospital / 30-day mortality and renal failure was assessed as a continuous variable, both unadjusted and after adjusting for important clinical factors using logistic regression modeling. Results Mean age was 72 years, 54% of patients had diabetes mellitus, 49% were urgent procedures, and mean cardiopulmonary bypass time was 105 minutes. Patients’ CVP 6 hours post-operation was strongly associated with in-hospital and 30 day mortality: odds ratio (OR) 1.5 (95% confidence interval [CI] 1.23, 1.87) for every 5 mmHg increase in CVP, p<0.0001. This association remained significant after risk-adjustment for cardiac index: adjusted OR 1.44 (95% CI 1.10, 1.89), p<0.01. A model adjusting for cardiac index also revealed increased incidence of mortality or renal failure: adjusted OR 1.5 (95% CI 1.28, 1.86) for every 5 mmHg increase in CVP, p<0.0001. Conclusion Patients’ central venous pressure at 6 hours following CABG surgery was highly predictive of operative mortality or renal failure, independent of cardiac index and other important clinical variables. Future studies will need to assess whether post-operative CVP can be used to guide intervention and improve outcomes. PMID:25035048

  14. Cardiovascular system identification: Simulation study using arterial and central venous pressures.

    PubMed

    Karamolegkos, Nikolaos; Vicario, Francesco; Chbat, Nicolas W

    2015-08-01

    The paper presents a study of the identifiability of a lumped model of the cardiovascular system. The significance of this work from the existing literature is in the potential advantage of using both arterial and central venous (CVP) pressures, two signals that are frequently monitored in the critical care unit. The analysis is done on the system's state-space representation via control theory and system identification techniques. Non-parametric state-space identification is preferred over other identification techniques as it optimally assesses the order of a model, which best describes the input-output data, without any prior knowledge about the system. In particular, a recent system identification algorithm, namely Observer Kalman Filter Identification with Deterministic Projection, is used to identify a simplified version of an existing cardiopulmonary model. The outcome of the study highlights the following two facts. In the deterministic (noiseless) case, the theoretical indicators report that the model is fully identifiable, whereas the stochastic case reveals the difficulty in determining the complete system's dynamics. This suggests that even with the use of CVP as an additional pressure signal, the identification of a more detailed (high order) model of the circulatory system remains a challenging task.

  15. The association of leptin with dyslipidemia, arterial hypertension and obesity in Kyrgyz (Central Asian nation) population

    PubMed Central

    2014-01-01

    Background Leptin, an adipocytokine produced by adipose tissue, along with the traditional cardiometabolic risk factors, contributes to the development of cardiovascular complications. At the same time, ethnic features of adipocytokines have been insufficiently investigated, especially among Asians, who have an increased risk of cardiovascular complications compared with Europeans. Aim of study was to investigate the relationship between leptin levels and age, gender, anthropometric parameters, lipid parameters, arterial hypertension (AH), and obesity in the adult population of ethnic Kyrgyz people living in Central Asia. Results In total, 322 ethnic Kyrgyz (145 men, 177 women) aged ≥ 30 years were studied. Waist and hip circumference, body mass index, blood glucose, lipids, leptin, and homeostatic model assessment were measured. Patients in the upper quartile of leptin levels had high values of BMI, WC, systolic and diastolic blood pressure, glucose, and HOMA index compared with patients with lower leptin levels. The prevalence of metabolic syndrome and AH increased with higher levels of leptin. Leptin positively correlated with BMI, WC, triglycerides, and glucose concentrations in patients of both sexes. According to the multivariate logistic regression analysis, elevated leptin levels increased by 30 times the risk of obesity in men, regardless of the presence of type 2 diabetes, and 17.7 times in women. Conclusion Leptin is associated with general and abdominal obesity, dyslipidemia, and insulin resistance in Kyrgyz patients. PMID:24981337

  16. Subclavian artery pseudoaneurysm complicating central venous catheterization: endovascular treatment with Amplatzer Vascular Plug 4 and covered stent.

    PubMed

    Rossi, Umberto G; Petrocelli, Francesco; Ferro, Carlo

    2013-12-01

    Central venous catheterization is a routine vascular access procedure; however, it may be associated with life-threatening complications such as arterial puncture, leading to pseudoaneurysm formation. We report a case of a 41-year-old female that developed an iatrogenic left subclavian pseudoaneurysm complicating the attempt of left internal jugular vein cannulation for temporary hemodialysis therapy. The patient underwent urgent endovascular treatment with deployment of covered stent into the left subclavian artery (SCA) after embolization of the origin of the left internal mammary artery with Amplatzer Vascular Plug 4. The patient's recovery was unremarkable. Follow-up till 24 months reveals total exclusion of the pseudoaneurysm of the left SCA with patency of the distal branches.

  17. Successful Retrieval of a Dismembered Central Venous Catheter Stuck to the Right Pulmonary Artery Using a Stepwise Approach

    PubMed Central

    Nomura, Hidekimi; Isomura, Daichi; Sugiura, Ryo; Oka, Toshiaki

    2016-01-01

    Recent advances in anticancer chemotherapy have resulted in an increase in the number of patients requiring a central venous port catheter, and the incidence of catheter pinch-off syndrome has been increasing. Catheter pinch-off syndrome is a rare and unusual complication. It is difficult to retrieve dislodged catheters from the pulmonary artery, especially if the catheter is stuck to the peripheral pulmonary artery. We herein describe the successful removal of a catheter stuck in the pulmonary artery with a stepwise approach. First, a pigtail catheter was used to tug the dislodged catheter in order to free the unilateral end. Then, a gooseneck snare was used to catch and pull the catheter out of the patient. The key to success is to free the end of the catheter. PMID:27668096

  18. Guidelines for the prevention of central venous catheter-related blood stream infections with prostanoid therapy for pulmonary arterial hypertension.

    PubMed

    Doran, A K; Ivy, D D; Barst, R J; Hill, N; Murali, S; Benza, R L

    2008-07-01

    Intravenous prostanoids are the backbone of therapy for advanced pulmonary arterial hypertension (PAH) and have improved long-term outcome and quality of life. Currently, two prostanoids are approved by the US Food and Drug administration for parenteral administration: epoprostenol (Flolan) and treprostinil (Remodulin). Chronic intravenous therapy presents considerable challenges for patients and caregivers who must learn sterile preparation of the medication, operation of the pump, and care of the central venous catheter. Patients are routinely counseled and advised regarding the risks of CR-BSIs and catheter care before central line insertion. Central line infections as well as bacteremia are well documented risks of chronic intravenous therapy and may significantly contribute to morbidity and mortality. Recent reports have suggested a possible increase in CR-BSI; therefore, the Scientific Leadership Council of the Pulmonary Hypertension Association decided to provide guidelines for good clinical practice regarding catheter care. Although data exits regarding patients with central venous catheters and the risk of blood stream infections in patients with cancer or other disorders, there is little data regarding the special needs of patients with pulmonary arterial hypertension requiring central venous access. These guidelines are extrapolated from the diverse body of literature regarding central venous catheter care.

  19. Calcium release by noradrenaline from central sarcoplasmic reticulum in rabbit main pulmonary artery smooth muscle.

    PubMed Central

    Kowarski, D; Shuman, H; Somlyo, A P; Somlyo, A V

    1985-01-01

    The subcellular composition of relaxed and noradrenaline-contracted rabbit main pulmonary artery smooth muscle cells was measured by electron probe X-ray microanalysis of cryosections of rapidly frozen tissue. Some of the preparations were made permeable with saponin and exposed to a known free Ca ion concentration, rapidly frozen, freeze-substituted, and also analysed by electron probe X-ray microanalysis. 98% of intracellular K could be replaced by Rb. This was done to remove the K peak that partially overlaps the Ca peak in the X-ray spectra. The final [Rb]i plus residual [K]i was not significantly different from the [K]i of normal tissue. The [Ca]i in Rb-containing tissue was not significantly different from the [Ca]i in normal, K-containing tissue. Non-mitochondrial micro-regions containing high [Ca] (up to 33 mmol/kg dry wt.) were found at sites 200 nm or more away from the plasma membrane. These micro-regions also contained high [P]. We consider the identification of these regions containing high [Ca] as sarcoplasmic reticulum (s.r.), validated by: (a) conventional electron micrographs that show no other structures in main pulmonary artery smooth muscle in sufficient quantity and location to account for the frequency of these regions, (b) the previous localization of strontium, a functional calcium analogue, in the central s.r. in these smooth muscles (Somlyo & Somlyo, 1971 a), (c) the present demonstration that the central s.r. in this tissue can accumulate large amounts of calcium oxalate. The proportion of regions containing high [Ca] (greater than 12.0 mmol/kg dry wt.) was significantly higher in relaxed (35 of 330 measurements) than in the contracted (14 of 337) tissues (P less than 0.005), or 26 of 34 vs. 6 of 31 high [Ca] measurements in regions identified as s.r. through their high phosphorus content (P less than 0.006). This difference is thought to represent Ca release from the central s.r. There was no significant difference (P greater than 0

  20. Comparison of optical coherence tomography findings in a patient with central retinal artery occlusion in one eye and end-stage glaucoma in the fellow eye.

    PubMed

    Greene, Daniel P; Richards, Charles P; Ghazi, Nicola G

    2012-01-01

    This case describes a patient with chronic central retinal artery occlusion in one eye and end-stage traumatic glaucoma in the fellow eye. Optical coherence tomography (OCT) of the macula of the chronic phase of central retinal artery occlusion of the right eye indicated loss of the normal foveal depression, extensive inner retinal atrophy, and marked retinal thinning. In contrast, scans of the left eye with end-stage glaucoma demonstrated an intact foveal depression and limited retinal thinning. The pattern of macular OCT findings in this patient illustrates distinguishing features between chronic central retinal artery occlusion and chronic optic neuropathy due to end-stage glaucoma.

  1. Reversibility of retinal ischemia due to central retinal artery occlusion by hyperbaric oxygen

    PubMed Central

    Hadanny, Amir; Maliar, Amit; Fishlev, Gregory; Bechor, Yair; Bergan, Jacob; Friedman, Mony; Avni, Isaac; Efrati, Shai

    2017-01-01

    Purpose Ischemic retinal damage can be reversed by hyperbaric oxygen therapy (HBOT) as long as irreversible infarction damage has not developed. However, the time window till irreversible damage develops is still unknown. The study aim was to evaluate the effect of HBOT and determine possible markers for irreversible retinal damage. Materials and methods Retrospective analysis of 225 patients treated with HBOT for central retinal artery occlusion (CRAO) in 1999–2015. One hundred and twenty-eight patients fulfilled inclusion/exclusion criteria: age >18 years, symptoms <20 hours, and best-corrected visual acuity (BCVA) <0.5 logMAR. Results Time delay from symptoms to treatment was 7.8±3.8 hours. The BCVA was significantly improved after HBOT, from 2.14±0.50 to 1.61±0.78 (P<0.0001). The proportion of patients with clinically meaningful visual improvement was significantly higher in patients without cherry-red spot (CRS) compared to patients with CRS at presentation (86.0% vs 57.6%, P<0.0001). The percentage of patients with final BCVA better than 1.0 was also significantly higher in patients without CRS vs patients with CRS at presentation (61.0% vs 7.1%, P<0.0001). There was no correlation between CRS and the time from symptoms. HBOT was found to be safe, and only 5.5% of patients had minor, reversible, adverse events. Conclusion HBOT is an effective treatment for non-arteritic CRAO as long as CRS has not formed. The fundus findings, rather than the time delay, should be used as a marker for irreversible damage. PMID:28096655

  2. New Insight into Effects of β-Blockers on Arterial Functions

    PubMed Central

    Eguchi, Kazuo

    2016-01-01

    The effects of β-blockers on arterial properties are not well investigated. In our recent study, we compared the effects of the two β-blockers celiprolol and bisoprolol on blood pressure, baroreflex sensitivity (BRS), flow-mediated vasodilatation, and vascular stiffness. We found that bisoprolol achieved a greater reduction in the pulse rate and improved BRS and vascular stiffness, whereas celiprolol reduced the central blood pressure level. In this review, the mechanisms of different types of β-blockers and their effects on arteries are discussed, and the appropriate use of β-blockers in hypertensive subjects will be proposed. PMID:27195240

  3. New Insight into Effects of β-Blockers on Arterial Functions.

    PubMed

    Eguchi, Kazuo

    2016-04-01

    The effects of β-blockers on arterial properties are not well investigated. In our recent study, we compared the effects of the two β-blockers celiprolol and bisoprolol on blood pressure, baroreflex sensitivity (BRS), flow-mediated vasodilatation, and vascular stiffness. We found that bisoprolol achieved a greater reduction in the pulse rate and improved BRS and vascular stiffness, whereas celiprolol reduced the central blood pressure level. In this review, the mechanisms of different types of β-blockers and their effects on arteries are discussed, and the appropriate use of β-blockers in hypertensive subjects will be proposed.

  4. Pulmonary Artery Versus Central Venous Catheter Monitoring in the Outcome of Patients Undergoing Bilateral Total Knee Replacement

    PubMed Central

    YaDeau, Jacques T.; Urban, Michael K.

    2008-01-01

    Bilateral total knee replacement (BTKR) has been associated with a higher incidence of fat embolism (FES) compared to single knee replacement. Consequently, intraoperative monitoring with a pulmonary artery catheter (PAC) has been recommended. This study compares clinical outcome in BTKR patients monitored with central venous pressure versus PAC. A retrospective chart review of 249 consecutive patients undergoing BTKR, 132 of whom had PAC insertion versus 117 who had central line insertion, over a 1-year period were included in the study. Their medical records were reviewed for co-morbidities, baseline characteristics, and type of intraoperative monitoring. Need and duration for postoperative monitoring in the postoperative care, length of hospital stay (LOHS), signs of fat embolism, development of arrhythmias, and respiratory failure were all outcome measures. A total of four patients (1.6%) had FES as per Schonfeld criteria. One of these patients died within 48 h of surgery. They all had PAC monitoring intraoperatively. Pulmonary artery pressure (PAP) remained unchanged during surgery which raises doubt as to the clinical utility and advisability of the use of PAC’s in this setting. There was no statistically significant difference in cardiac or pulmonary complications, or LOHS between the two groups. Central venous pressure monitoring appears to be sufficient in patients undergoing BTKR. PMID:19002531

  5. Central Arterial Hemodynamic Effects of Dark Chocolate Ingestion in Young Healthy People: A Randomized and Controlled Trial

    PubMed Central

    Pereira, T.; Maldonado, J.; Laranjeiro, M.; Coutinho, R.; Cardoso, E.; Andrade, I.; Conde, J.

    2014-01-01

    Introduction. The aim of this study was to assess the vascular benefits of dark chocolate in healthy and young individuals. Methods. A randomized and controlled trial was carried out involving 60 healthy volunteers, randomized into two groups: control group (CG; n = 30) and intervention group (IG; n = 30). The IG ingested a daily dosage of 10 g of dark chocolate (>75% cocoa) for a month. Blood pressure (BP), flow-mediated dilation (FMD), arterial stiffness index (ASI), aortic pulse wave velocity (PWV), and pulse wave analysis (PWA) were assessed at baseline and one week after the one-month intervention period. Results. Arterial function improved after intervention in the IG, with PWV decreasing from 6.13 ± 0.41 m/s to 5.83 ± 0.53 m/s (P = 0.02), with no significant differences observed in the CG. A significant decrease in ASI (0.16 ± 0.01 to 0.13 ± 0.01; P < 0.001) and AiX (−15.88 ± 10.75 to −22.57 ± 11.16; P = 0.07) was also depicted for the IG. Endothelial function improved in the IG, with the FMD increasing 9.31% after the 1-month intervention (P < 0.001), with no significant variation in the CG. Conclusion. The daily ingestion of 10 g dark chocolate (>75% cocoa) during a month significantly improves vascular function in young and healthy individuals. PMID:24982813

  6. Changes in central retinal artery blood flow after ocular warming and cooling in healthy subjects

    PubMed Central

    Shamshad, M A; Amitava, A K; Ahmad, I; Wahab, S

    2010-01-01

    Context: Retinal perfusion variability impacts ocular disease and physiology. Aim: To evaluate the response of central retinal artery (CRA) blood flow to temperature alterations in 20 healthy volunteers. Setting and Design: Non-interventional experimental human study. Materials and Methods: Baseline data recorded: Ocular surface temperature (OST) in °C (thermo-anemometer), CRA peak systolic velocity (PSV) and end diastolic velocity (EDV) in cm/s using Color Doppler. Ocular laterality and temperature alteration (warming by electric lamp/cooling by ice-gel pack) were randomly assigned. Primary outcomes recorded were: OST and intraocular pressure (IOP) immediately after warming or cooling and ten minutes later; CRA-PSV and EDV at three, six and nine minutes warming or cooling. Statistical Analysis: Repeated measures ANOVA. Results: (n = 20; μ ± SD): Pre-warming values were; OST: 34.5 ± 1.02°C, CRA-PSV: 9.3 ± 2.33 cm/s, CRA-EDV: 4.6 ± 1.27 cm/s. OST significantly increased by 1.96°C (95% CI: 1.54 to 2.37) after warming, but returned to baseline ten minutes later. Only at three minutes, the PSV significantly rose by 1.21 cm/s (95% CI: 0.51to1.91). Pre-cooling values were: OST: 34.5 ± 0.96°C, CRA-PSV: 9.7 ± 2.45 cm/s, CRA-EDV: 4.7 ± 1.12 cm/s. OST significantly decreased by 2.81°C (95% CI: −2.30 to −3.37) after cooling, and returned to baseline at ten minutes. There was a significant drop in CRA-PSV by 1.10cm/s (95% CI: −2.05 to −0.15) and CRA-EDV by 0.81 (95% CI: −1.47 to −0.14) at three minutes. At six minutes both PSV (95% CI: −1.38 to −0.03) and EDV (95% CI: −1.26 to −0.02) were significantly lower. All values at ten minutes were comparable to baseline. The IOP showed insignificant alteration on warming (95% CI of difference: −0.17 to 1.57mmHg), but was significantly lower after cooling (95% CI: −2.95 to −4.30mmHg). After ten minutes, IOP had returned to baseline. Conclusion: This study confirms that CRA flow significantly

  7. Effects of age-associated regional changes in aortic stiffness on human hemodynamics revealed by computational modeling

    PubMed Central

    Cuomo, Federica; Roccabianca, Sara; Dillon-Murphy, Desmond; Xiao, Nan; Humphrey, Jay D.

    2017-01-01

    Although considered by many as the gold standard clinical measure of arterial stiffness, carotid-to-femoral pulse wave velocity (cf-PWV) averages material and geometric properties over a large portion of the central arterial tree. Given that such properties may evolve differentially as a function of region in cases of hypertension and aging, among other conditions, there is a need to evaluate the potential utility of cf-PWV as an early diagnostic of progressive vascular stiffening. In this paper, we introduce a data-driven fluid-solid-interaction computational model of the human aorta to simulate effects of aging-related changes in regional wall properties (e.g., biaxial material stiffness and wall thickness) and conduit geometry (e.g., vessel caliber, length, and tortuosity) on several metrics of arterial stiffness, including distensibility, augmented pulse pressure, and cyclic changes in stored elastic energy. Using the best available biomechanical data, our results for PWV compare well to findings reported for large population studies while rendering a higher resolution description of evolving local and global metrics of aortic stiffening. Our results reveal similar spatio-temporal trends between stiffness and its surrogate metrics, except PWV, thus indicating a complex dependency of the latter on geometry. Lastly, our analysis highlights the importance of the tethering exerted by external tissues, which was iteratively estimated until hemodynamic simulations recovered typical values of tissue properties, pulse pressure, and PWV for each age group. PMID:28253335

  8. Stiff person syndrome.

    PubMed

    Ciccoto, Giuseppe; Blaya, Maike; Kelley, Roger E

    2013-02-01

    Recognizing stiff person syndrome is clinically important. It is uncommon, characterized by body stiffness associated with painful muscle spasms, and varies in location and severity. It is subdivided into stiff trunk versus stiff limb presentation, and as a progressive encephalomyelitis. Stiff person-type syndrome also reflects a paraneoplastic picture. Most patients demonstrate exaggerated lumbar lordosis. Roughly 60% of patients have antiglutamic acid decarboxylase antibodies in the blood and the cerebrospinal fluid. The differential diagnosis includes many severe conditions. There are reports of response to muscle relaxants, immunosuppressants, intravenous gamma globulin, plasma exchange, a number of anticonvulsants, and botulinum toxin.

  9. Arterial structure and function in vascular ageing: are you as old as your arteries?

    PubMed

    Thijssen, Dick H J; Carter, Sophie E; Green, Daniel J

    2016-04-15

    Advancing age may be the most potent independent predictor of future cardiovascular events, a relationship that is not fully explained by time-related changes in traditional cardiovascular risk factors. Since some arteries exhibit differential susceptibility to atherosclerosis, generalisations regarding the impact of ageing in humans may be overly simplistic, whereas in vivo assessment of arterial function and health provide direct insight. Coronary and peripheral (conduit, resistance and skin) arteries demonstrate a gradual, age-related impairment in vascular function that is likely to be related to a reduction in endothelium-derived nitric oxide bioavailability and/or increased production of vasoconstrictors (e.g. endothelin-1). Increased exposure and impaired ability for defence mechanisms to resist oxidative stress and inflammation, but also cellular senescence processes, may contribute to age-related changes in vascular function and health. Arteries also undergo structural changes as they age. Gradual thickening of the arterial wall, changes in wall content (i.e. less elastin, advanced glycation end-products) and increase in conduit artery diameter are observed with older age and occur similarly in central and peripheral arteries. These changes in structure have important interactive effects on artery function, with increases in small and large arterial stiffness representing a characteristic change with older age. Importantly, direct measures of arterial function and structure predict future cardiovascular events, independent of age or other cardiovascular risk factors. Taken together, and given the differential susceptibility of arteries to atherosclerosis in humans, direct measurement of arterial function and health may help to distinguish between biological and chronological age-related change in arterial health in humans.

  10. Aortic Stiffness, Cerebrovascular Dysfunction, and Memory

    PubMed Central

    Cooper, Leroy L.; Mitchell, Gary F.

    2016-01-01

    Background Aortic stiffness is associated with cardiovascular and cerebrovascular events and cognitive decline. This mini-review focuses on relations of aortic stiffness with microvascular dysfunction and discusses the contribution of abnormal pulsatile hemodynamics to cerebrovascular damage and cognitive decline. We also provide a rationale for considering aortic stiffness as a putative and important contributor to memory impairment in older individuals. Summary Aging is associated with stiffening of the aorta but not the muscular arteries, which reduces wave reflection and increases the transmission of pulsatility into the periphery. Aortic stiffening thereby impairs a protective mechanism that shields the peripheral microcirculation from excessive pulsatility within downstream target organs. Beyond midlife, aortic stiffness increases rapidly and exposes the cerebral microcirculation to abnormal pulsatile mechanical forces that are associated with microvascular damage and remodeling in the brain. Aortic stiffening and high-flow pulsatility are associated with alterations in the microvasculature of the brain; however, a mechanistic link between aortic stiffness and memory has not been established. We showed that in a community-based sample of older individuals, cerebrovascular resistance and white matter hyperintensities - markers of cerebrovascular remodeling and damage - mediated the relation between higher aortic stiffness and lower performance on memory function tests. These data suggest that microvascular and white matter damage associated with excessive aortic stiffness contribute to impaired memory function with advancing age. Key Messages Increasing evidence suggests that vascular etiologies - including aortic stiffness and microvascular damage - contribute to memory impairment and the pathogenesis of dementia, including Alzheimer's disease. Interventions that reduce aortic stiffness may delay memory decline among older individuals. PMID:27752478

  11. Tolerance to Central Hypovolemia: The Influence of Oscillations in Arterial Pressure and Cerebral Blood Velocity

    DTIC Science & Technology

    2011-10-01

    specific details about whether they were taking oral contraceptive medications, both of which can impact cardiovascular responses to hypovo- lemia (4, 20...37). High tolerance (HT) to LBNP has been attributed to a number of factors , including elevated release of vasoactive hormones (11, 26), enhanced...sympathetic nerve activity was driving LF oscillations (53), although a centrally mediated mechanism could also be an important contributing factor (33

  12. Materials with negative stiffness

    NASA Astrophysics Data System (ADS)

    Jaglinski, Tim

    Negative stiffness, or a reversal in the usual assumed direction between causal forces and ensuing deformations, has been proposed as a pathway to materials which exceed theoretical performance bounds. Negative stiffness, as a concept, represents a relaxation of tacitly assumed material behavior, but it violates no natural laws. Negative stiffness, normally unstable without constraint, is permissible for stability under special conditions, for example a rigid boundary constraint so long as the material satisfies strong ellipticity in the parlance of elasticity. Hence, negative stiffness is not observed in materials or structures which are not constrained. If negative stiffness is allowed for inclusions of material, which are surrounded by a stabilizing positive stiffness matrix, composite theory predicts large increases in the mechanical damping and composite stiffness. The work herein explores several material systems which possess negative stiffness, and seeks to characterize the composite mechanical properties of these systems. Two metal matrix composite systems, namely Sn-VO2 and Sn-BaTIO3, were investigated. Here, negative stiffness arises from the ferroelastic phase transformations in the ceramic inclusions; stability is imparted by the tin matrix. Polycrystalline In-Tl and BaTIO 3 were also studied. Here, the entire material volume is phase transforming. Constraint is imparted on a small volume fraction of crystallites by the surrounding material. Various manifestations of negative stiffness were observed. Thermally broad damping peaks which depended upon thermal cycling were observed in the Sn-VO2 composites. Furthermore, mechanical instabilities were seen in composites intentionally designed to be unstable. Negative stiffness was indicated in the In-Tl alloy by magnification of damping peaks over those observed in single crystals, increases in damping peaks with increased cooling rates, occurrence of damping peaks before the appearance of martensite and

  13. Exercise, Vascular Stiffness, and Tissue Transglutaminase

    PubMed Central

    Steppan, Jochen; Sikka, Gautam; Jandu, Simran; Barodka, Viachaslau; Halushka, Marc K.; Flavahan, Nicholas A.; Belkin, Alexey M.; Nyhan, Daniel; Butlin, Mark; Avolio, Alberto; Berkowitz, Dan E.; Santhanam, Lakshmi

    2014-01-01

    Background Vascular aging is closely associated with increased vascular stiffness. It has recently been demonstrated that decreased nitric oxide (NO)‐induced S‐nitrosylation of tissue transglutaminase (TG2) contributes to age‐related vascular stiffness. In the current study, we tested the hypothesis that exercise restores NO signaling and attenuates vascular stiffness by decreasing TG2 activity and cross‐linking in an aging rat model. Methods and Results Rats were subjected to 12 weeks of moderate aerobic exercise. Aging was associated with diminished phosphorylated endothelial nitric oxide synthase and phosphorylated vasodilator‐stimulated phosphoprotein abundance, suggesting reduced NO signaling. TG2 cross‐linking activity was significantly increased in old animals, whereas TG2 abundance remained unchanged. These alterations were attenuated in the exercise cohort. Simultaneous measurement of blood pressure and pulse wave velocity (PWV) demonstrated increased aortic stiffness in old rats, compared to young, at all values of mean arterial pressure (MAP). The PWV‐MAP correlation in the old sedentary and old exercise cohorts was similar. Tensile testing of the vessels showed increased stiffness of the aorta in the old phenotype with a modest restoration of mechanical properties toward the young phenotype with exercise. Conclusions Increased vascular stiffness during aging is associated with decreased TG2 S‐nitrosylation, increased TG2 cross‐linking activity, and increased vascular stiffness likely the result of decreased NO bioavailability. In this study, a brief period of moderate aerobic exercise enhanced NO signaling, attenuated TG cross‐linking activity, and reduced ex vivo tensile properties, but failed to reverse functional vascular stiffness in vivo, as measured by PWV. PMID:24721796

  14. Inhibition of SRF/myocardin reduces aortic stiffness by targeting vascular smooth muscle cell stiffening in hypertension

    PubMed Central

    Zhou, Ning; Lee, Jia-Jye; Stoll, Shaunrick; Ma, Ben; Wiener, Robert; Wang, Charles; Costa, Kevin D.; Qiu, Hongyu

    2017-01-01

    Aims Increased aortic stiffness is a fundamental manifestation of hypertension. However, the molecular mechanisms involved remain largely unknown. We tested the hypothesis that abnormal intrinsic vascular smooth muscle cell (VSMC) mechanical properties in large arteries, but not in distal arteries, contribute to the pathogenesis of aortic stiffening in hypertension, mediated by the serum response factor (SRF)/myocardin signalling pathway. Methods and results Four month old male spontaneously hypertensive rats (SHR) and normotensive Wistar-Kyoto (WKY) rats were studied. Using atomic force microscopy, significant VSMC stiffening was observed in the large conducting aorta compared with the distal arteries in SHR (P < 0.001), however, this regional variation was not observed in WKY rats (P > 0.4). The increase of VSMC stiffness was accompanied by a parallel increase in the expression of SRF by 9.8-fold and of myocardin by 10.5-fold in thoracic aortic VSMCs from SHR vs. WKY rats, resulting in a significant increase of downstream stiffness-associated genes (all, P < 0.01 vs. WKY). Inhibition of SRF/myocardin expression selectively attenuated aortic VSMC stiffening, and normalized downstream targets in VSMCs isolated from SHR but not from WKY rats. In vivo, 2 weeks of treatment with SRF/myocardin inhibitor delivered by subcutaneous osmotic minipump significantly reduced aortic stiffness and then blood pressure in SHR but not in WKY rats, although concomitant changes in aortic wall remodelling were not detected during this time frame. Conclusions SRF/myocardin pathway acts as a pivotal mediator of aortic VSMC mechanical properties and plays a central role in the pathological aortic stiffening in hypertension. Attenuation of aortic VSMC stiffening by pharmacological inhibition of SRF/myocardin signalling presents a novel therapeutic strategy for the treatment of hypertension by targeting the cellular contributors to aortic stiffness. PMID:28003268

  15. A Review on Atherosclerotic Biology, Wall Stiffness, Physics of Elasticity, and Its Ultrasound-Based Measurement.

    PubMed

    Patel, Anoop K; Suri, Harman S; Singh, Jaskaran; Kumar, Dinesh; Shafique, Shoaib; Nicolaides, Andrew; Jain, Sanjay K; Saba, Luca; Gupta, Ajay; Laird, John R; Giannopoulos, Argiris; Suri, Jasjit S

    2016-12-01

    Functional and structural changes in the common carotid artery are biomarkers for cardiovascular risk. Current methods for measuring functional changes include pulse wave velocity, compliance, distensibility, strain, stress, stiffness, and elasticity derived from arterial waveforms. The review is focused on the ultrasound-based carotid artery elasticity and stiffness measurements covering the physics of elasticity and linking it to biological evolution of arterial stiffness. The paper also presents evolution of plaque with a focus on the pathophysiologic cascade leading to arterial hardening. Using the concept of strain, and image-based elasticity, the paper then reviews the lumen diameter and carotid intima-media thickness measurements in combined temporal and spatial domains. Finally, the review presents the factors which influence the understanding of atherosclerotic disease formation and cardiovascular risk including arterial stiffness, tissue morphological characteristics, and image-based elasticity measurement.

  16. Resting Heart Rate and Aortic Stiffness in Normotensive Adults

    PubMed Central

    Logan, Jeongok G.

    2016-01-01

    Background and Objectives Large-artery stiffness is an independent predictor of cardiovascular disease (CVD), and carotid-femoral pulse wave velocity (cfPWV) is considered the gold standard measure of arterial stiffness. A resting heart rate is an easily measured vital sign that is also associated with CVD morbidity and mortality. Previous studies have reported the significant relationship of a resting heart rate with arterial stiffness as measured by cfPWV only in hypertensive subjects; their relationship in nonhypertensive subjects remains unknown. The present study, therefore, examined their relationship in normotensive subjects. Subjects and Methods In 102 healthy Korean Americans between ages 20 and 60 years, their resting heart rate was measured by an automated blood pressure measuring device after a 10 minute rest in the supine position. Arterial stiffness was measured by cfPWV using the SphygmoCor device. Results The mean resting heart rate of participants (mean age, 39.64 years; 59% women) was 61.91 bpm (standard deviation [SD], 9.62 bpm) and mean the cfPWV was 6.99 (SD, 1.14) m/s. A multiple regression analysis showed that a resting heart rate is a significant predictor of cfPWV after controlling for age, body mass index, and mean arterial pressure. For one bpm increase of resting heart rate, cfPWV increased approximately 0.02 m/s. Conclusion Our results suggest that a higher resting heart rate is independently associated with increased arterial stiffness as measured by cfPWV in normotensive adults. Arterial stiffness may explain the prognostic role of an individual's heart rate in cardiovascular morbidity and mortality. PMID:27826343

  17. Enhanced central and conduit pulmonary arterial reservoir function offsets reduced ductal systolic outflow during constriction of the fetal ductus arteriosus.

    PubMed

    Smolich, Joseph J; Penny, Daniel J; Mynard, Jonathan P

    2012-01-01

    Constriction of the fetal ductus arteriosus (DA) has disparate effects on mean and phasic hemodynamics, as mean DA blood flow is preserved until constriction is severe, but DA systolic and diastolic blood velocities change with only mild constriction. To determine the basis of this disparity and its physiological significance, seven anesthetized late-gestation fetal sheep were instrumented with pulmonary trunk (PT), DA, and left pulmonary artery (PA) micromanometer catheters and transit-time flow probes. Blood flow profile and wave intensity analyses were performed at baseline and during mild, moderate, and severe DA constriction (defined as pulmonary-aortic mean pressure differences of 4, 8, and 14 mmHg, respectively), produced with an adjustable snare. With DA constriction, mean DA flow was initially maintained but decreased with severe constriction (P < 0.05) in conjunction with a reduction (P < 0.05) in PT flow (i.e., right ventricular output). By contrast, DA systolic flow fell progressively during DA constriction (P < 0.001), due to decreased transmission of both early and midsystolic proximal flow-enhancing forward-running compression waves into the DA. However, DA constriction was also accompanied by greater systolic storage of blood in the PT and main PA (P < 0.025), and increased retrograde diastolic flow from compliant major branch PA (P < 0.001). Transductal discharge of these central and conduit PA blood reservoirs in diastole offset systolic DA flow reductions. These data suggest that, during DA constriction in the fetus, enhanced central and conduit PA reservoir function constitutes an important compensatory mechanism that contributes to preservation of mean DA flow via a systolic-to-diastolic redistribution of phasic DA flow.

  18. Assessment of conduit artery vasomotion using photoplethysmography

    NASA Astrophysics Data System (ADS)

    Kanders, Karlis; Grabovskis, Andris; Marcinkevics, Zbignevs; Aivars, Juris Imants

    2013-11-01

    Vasomotion is a spontaneous oscillation of vascular tone. The phenomenon has been observed in small arterioles and capillaries as well as in the large conduit arteries. The layer of smooth muscle cells that surrounds a blood vessel can spontaneously and periodically change its tension and thereby the arterial wall stiffness also changes. As the understanding of the phenomenon is still rather obscure, researchers would benefit from a low-cost and reliable investigation technique such as photoplethysmography (PPG). PPG is an optical blood pulsation measurement technique that can offer substantial information about the arterial stiffness. The aims of this pilot study were to evaluate the usefulness of the PPG technique in the research of vasomotion and to investigate vasomotion in the relatively large conduit arteries. Continuous 15 minute long measurements of posterior tibial artery wall stiffness were taken. Artery diameter, electrocardiogram, blood pressure and respiration were also simultaneously registered. Fast Fourier Transform power spectra were calculated to identify unique stiffness oscillations that did not correspond to fluctuations in the systemic parameters and thus would indicate vasomotion. We concluded that photoplethysmography is a convenient method for the research of the vasomotion in large arteries. Local stiffness parameter b/a is more accurate to use and easier to measure than the pulse wave velocity which describes stiffness of a segment of an artery. Conduit arteries might exhibit a low amplitude high frequency vasomotion ( 9 to 27 cycles per minute). Low frequency vasomotion is problematic to distinguish from the passive oscillations imposed by the arterial pressure.

  19. Posttraumatic stiff elbow

    PubMed Central

    Mittal, Ravi

    2017-01-01

    Posttraumatic stiff elbow is a frequent and disabling complication and poses serious challenges for its management. In this review forty studies were included to know about the magnitude of the problem, causes, pathology, prevention, and treatment of posttraumatic stiff elbow. These studies show that simple measures such as internal fixation, immobilization in extension, and early motion of elbow joint are the most important steps that can prevent elbow stiffness. It also supports conservative treatment in selected cases. There are no clear guidelines about the choice between the numerous procedures described in literature. However, this review article disproves two major beliefs-heterotopic ossification is a bad prognostic feature, and passive mobilization of elbow causes elbow stiffness. PMID:28216745

  20. Brachial arterial pressure to assess cardiovascular structural damage: an overview and lessons from clinical trials.

    PubMed

    London, Gérald M

    2008-01-01

    Epidemiological studies have emphasized the relationship between blood pressure (BP) and the incidence of cardiovascular diseases. Severity of hypertension was in the past judged on the basis of diastolic BP. More recent epidemiological studies have directed attention to systolic pressure as a better guide to cardiovascular and all-cause mortality. Traditionally, hypertension was appreciated by measures of BP recorded in peripheral arteries, usually brachial artery which was assumed to reflect pressures in all parts of arterial system. All these studies neglected that peripheral systolic BP differs from pressure recorded in the aorta and central arteries. While mean and diastolic pressures are almost constant along the arterial tree, due to the stiffness and geometric heterogeneity of large arteries and the timing and magnitude of wave reflections systolic BP and pulse pressure are amplified from the aorta to peripheral arteries, and brachial systolic BP only indirectly reflects the systolic BP in the aorta and central arteries. Several recent studies have shown that the effects of antihypertensive drugs are not the same in peripheral and central arteries, fact which could account for different effects of various drugs on end-organ damage, such as regression of left ventricular hypertrophy. Moreover, it has been shown that aortic and central artery pressure (or their determinants) are stronger predictors of end-organ damage and cardiovascular outcome than conventionally measured brachial pressure. These studies have focused the attention on the physical properties of large arteries and on the way they influence the level of systolic and pulse pressures along the arterial tree.

  1. A database of virtual healthy subjects to assess the accuracy of foot-to-foot pulse wave velocities for estimation of aortic stiffness

    PubMed Central

    Chowienczyk, Phil; Alastruey, Jordi

    2015-01-01

    While central (carotid-femoral) foot-to-foot pulse wave velocity (PWV) is considered to be the gold standard for the estimation of aortic arterial stiffness, peripheral foot-to-foot PWV (brachial-ankle, femoral-ankle, and carotid-radial) are being studied as substitutes of this central measurement. We present a novel methodology to assess theoretically these computed indexes and the hemodynamics mechanisms relating them. We created a database of 3,325 virtual healthy adult subjects using a validated one-dimensional model of the arterial hemodynamics, with cardiac and arterial parameters varied within physiological healthy ranges. For each virtual subject, foot-to-foot PWV was computed from numerical pressure waveforms at the same locations where clinical measurements are commonly taken. Our numerical results confirm clinical observations: 1) carotid-femoral PWV is a good indicator of aortic stiffness and correlates well with aortic PWV; 2) brachial-ankle PWV overestimates aortic PWV and is related to the stiffness and geometry of both elastic and muscular arteries; and 3) muscular PWV (carotid-radial, femoral-ankle) does not capture the stiffening of the aorta and should therefore not be used as a surrogate for aortic stiffness. In addition, our analysis highlights that the foot-to-foot PWV algorithm is sensitive to the presence of reflected waves in late diastole, which introduce errors in the PWV estimates. In this study, we have created a database of virtual healthy subjects, which can be used to assess theoretically the efficiency of physiological indexes based on pulse wave analysis. PMID:26055792

  2. Aortic stiffness determines diastolic blood flow reversal in the descending thoracic aorta: potential implication for retrograde embolic stroke in hypertension.

    PubMed

    Hashimoto, Junichiro; Ito, Sadayoshi

    2013-09-01

    Aortic stiffening often precedes cardiovascular diseases, including stroke, but the underlying pathophysiological mechanisms remain obscure. We hypothesized that such abnormalities could be attributable to altered central blood flow dynamics. In 296 patients with uncomplicated hypertension, Doppler velocity pulse waveforms were recorded at the proximal descending aorta and carotid artery to calculate the reverse/forward flow ratio and diastolic/systolic flow index, respectively. Tonometric waveforms were recorded on the radial artery to estimate aortic pressure and characteristic impedance (Z0) and to determine carotid-femoral (aortic) and carotid-radial (peripheral) pulse wave velocities. In all subjects, the aortic flow waveform was bidirectional, comprising systolic forward and diastolic reverse flows. The aortic reverse/forward flow ratio (35 ± 10%) was positively associated with parameters of aortic stiffness (including pulse wave velocity, Z0, and aortic/peripheral pulse wave velocity ratio), independent of age, body mass index, aortic diameter, and aortic pressure. The carotid flow waveform was unidirectional and bimodal with systolic and diastolic maximal peaks. There was a positive relationship between the carotid diastolic/systolic flow index (28 ± 9%) and aortic reverse/forward flow ratio, which remained significant after adjustment for aortic stiffness and other related parameters. The Bland-Altman plots showed a close time correspondence between aortic reverse and carotid diastolic flow peaks. In conclusion, aortic stiffness determines the extent of flow reversal from the descending aorta to the aortic arch, which contributes to the diastolic antegrade flow into the carotid artery. This hemodynamic relationship constitutes a potential mechanism linking increased aortic stiffness, altered flow dynamics, and increased stroke risk in hypertension.

  3. Is venous blood drawn from femoral access adequate to estimate the central venous oxygen saturation and arterial lactate levels in critically ill patients?

    PubMed Central

    Marti, Yara Nishiyama; de Freitas, Flávio Geraldo Rezende; de Azevedo, Rodrigo Palácio; Leão, Milena; Bafi, Antônio Tonete; Machado, Flavia Ribeiro

    2015-01-01

    Objectives The purpose of this study was to test if venous blood drawn from femoral access can be used to estimate the central venous oxygen saturation and arterial lactate levels in critically ill patients. Methods Bland-Altman analysis and Spearman correlations were used to compare the femoral venous oxygen saturation and central venous oxygen saturation as well as arterial lactate levels and femoral lactate. A pre-specified subgroup analysis was conducted in patients with signs of hypoperfusion. In addition, the clinical agreement was also investigated. Results Blood samples were obtained in 26 patients. In 107 paired samples, there was a moderate correlation (r = 0.686, p < 0.0001) between the central venous oxygen saturation and femoral venous oxygen saturation with a bias of 8.24 ± 10.44 (95% limits of agreement: -12.23 to 28.70). In 102 paired samples, there was a strong correlation between the arterial lactate levels and femoral lactate levels (r = 0.972, p < 0.001) with a bias of -2.71 ± 9.86 (95% limits of agreement: -22.03 to 16.61). The presence of hypoperfusion did not significantly change these results. The clinical agreement for venous saturation was inadequate, with different therapeutic decisions in 22.4% of the situation; for lactate, this was the case only in 5.2% of the situations. Conclusion Femoral venous oxygen saturation should not be used as a surrogate of central venous oxygen saturation. However, femoral lactate levels can be used in clinical practice, albeit with caution. PMID:26761471

  4. [Stiff-person syndrome and related autoantibodies].

    PubMed

    Tomioka, Ryo; Tanaka, Keiko

    2013-04-01

    Central nervous system hyperexcitability disorders, known as stiff-man/person syndrome (SPS), are thought to be related to the regulatory disturbance of inhibitory synaptic transmission of motor neurons in the brainstem and spinal cord. SPS is characterized by stiffness and spasms of the axis and limbs and is divided into two clinical subgroups: classic SPS, which affects the lumbar, trunk, and proximal limb muscles, and SPS-plus syndrome. The latter comprises (1) the stiff-limb subtype, in which symptom is limited to the lower limbs; (2) jerking stiff-man syndrome, characterized by chronically progressive stiffness and myoclonus; and (3) acute-onset and progressive encephalomyelitis with rigidity and myoclonus. Almost 80% of patients with classic SPS harbor autoantibodies against glutamic acid decarboxylase 65 (GAD65). In approximately 30-40% of patients, SPS accompanies type I diabetes, and anti-GAD65 antibodies are detected frequently in type I diabetes. However, the antibody-recognizing epitopes might be different between SPS and diabetes. Other autoantibodies against glycine receptor α1 (12% of patients with SPS) and GABA(A)-receptor associated protein (70% of patients with SPS) have been reported. In paraneoplastic SPS, anti-amphiphysin antibodies have been shown in patients with breast cancer or small cell lung cancer. One case of mediastinal tumor with anti-gephyrin antibodies has also been reported. However, the roles of these autoantibodies in the pathomechanisms of SPS have not yet been elucidated.

  5. Neuropathy optic glaucomatosa induced by systemic hypertension through activation endothelin-1 signaling pathway in central retinal artery in rats

    PubMed Central

    Prayitnaningsih, Seskoati; Sujuti, Hidayat; Effendi, Maksum; Abdullah, Aulia; Anandita, Nanda Wahyu; Yohana, Febriani; Permatasari, Nur; Widodo, Mohamad Aris

    2016-01-01

    AIM To evaluate effect of hypertension on retinal ganglion cell (RGC) apoptosis, intraocular pressure (IOP), and the activation of endothelin-1 (ET-1) signaling pathway in central retinal artery (CRA) in rats. METHODS The experimental study was performed on 20 male Sprague Dawley rats that were divided into control group, and hypertension groups. The hypertension was induced by subcutaneous deoxycorticoacetate (DOCA) 10 mg/kg twice a week and administered 0.9% NaCl solution daily for 2, 6, and 10wk. Blood pressure (BP) was measured using animal BP analyzer. IOP was measured by handheld tonometry. Retinal tissue preparations by paraffin blocks were made after enucleation. The expression of ET-1, eNOS, ET-1 receptor A (ETRA), ET-1 receptor B (ETRB), and phosphorylated myosin light chain kinase (MLCK), and caldesmon (CaD) in CRA and RGC apoptosis were evaluated through immunofluorescent staining method then observed using laser scanning confocal microscopy. RESULTS BP significantly increased in all of the hypertension groups compared to control (P=0.001). Peak IOP elevation (7.78±4.14 mm Hg) and RGC apoptosis (576.15±33.28 Au) occurred on 2wk of hypertension. ET-1 expression (1238.6±55.1 Au) and eNOS expression (2814.2±70.7 Au) were found highest in 2wk of hypertension, although the ratio of ET-1/eNOS decreased since 2wk. ETRA reached peak expression in 10wk of hypertension (1219.4±6.3 Au), while ETRB significantly increased only in 2 weeks group (1069.2±9.6 Au). The highest MLCK expression (1190.09±58.32 Au), CaD (1670.28±18.36 Au) were also found in 2wk of hypertension. CONCLUSION Hypertension effects to activation of ET-1 signaling pathway significantly in CRA, elevation of IOP, and RGC apoptosis. The highest value was achieved at 2wk, which is the development phase of hypertension. PMID:27990358

  6. Effect of habitual aerobic exercise on body weight and arterial function in overweight and obese men.

    PubMed

    Miyaki, Asako; Maeda, Seiji; Yoshizawa, Mutsuko; Misono, Maiko; Saito, Yoko; Sasai, Hiroyuki; Kim, Maeng-Kyu; Nakata, Yoshio; Tanaka, Kiyoji; Ajisaka, Ryuichi

    2009-09-15

    The effect of habitual exercise on vascular function, including central arterial distensibility and endothelial function, in obese subjects has not yet been clarified. We investigated whether aerobic exercise training affects central arterial distensibility and endothelial function in middle-age overweight and obese men. A total of 21 overweight and obese men (age 50 +/- 2 years, body mass index 30 +/- 1 kg/m(2)) completed a 12-week aerobic exercise intervention. Aerobic exercise training significantly reduced their body weight and resulted in a significant decrease in body mass index. After the weight-reduction exercise program, carotid arterial compliance (determined by simultaneous B-mode ultrasonography and arterial applanation tonometry on the common carotid artery) significantly increased; and the beta-stiffness index, an index of arterial compliance adjusted for distending pressure, significantly decreased. The concentrations of plasma endothelin-1, a potent vasoconstrictor peptide produced by vascular endothelial cells, significantly decreased and plasma nitric oxide (measured as the stable end product [nitrite/nitrate]), a potent vasodilator produced by vascular endothelial cells, significantly increased after the weight-reduction exercise program. In conclusion, weight reduction by aerobic exercise training in overweight and obese men increased the central arterial distensibility. This increase might contribute to the improvement in endothelial function, as assessed by a decrease in endothelin-1 and an increase in nitric oxide, after exercise training-induced weight loss.

  7. Stiff person syndrome.

    PubMed

    Hadavi, Shahrzad; Noyce, Alastair J; Leslie, R David; Giovannoni, Gavin

    2011-10-01

    Stiff person syndrome (SPS) is a rare disorder, characterised by fluctuating rigidity and stiffness of the axial and proximal lower limb muscles, with superimposed painful spasms and continuous motor unit activity on electromyography. Although rare in general neurology practice, once observed it is unforgettable. The general neurologist may see only one or two cases during his or her career and as such it remains underdiagnosed. Left untreated, SPS symptoms can progress to cause significant disability. Patients have a poor quality of life and an excess rate of comorbidity and mortality. The severity of symptoms and lack of public awareness of the condition create anxiety and uncertainty for people with the disease. This review aims to raise awareness of SPS and to improve the likelihood of its earlier diagnosis and treatment.

  8. Usefulness of the maximum rate of pressure rise in the central and peripheral arteries after weaning from cardiopulmonary bypass in pediatric congenital heart surgery

    PubMed Central

    Kim, Jung-Won; Bang, Ji-Yeon; Park, Chun Soo; Gwak, Mijeung; Shin, Won-Jung; Hwang, Gyu-Sam

    2016-01-01

    Abstract The maximum rate of pressure rise (dP/dtmax) in radial artery has been proposed as a noninvasive surrogate of aortic dp/dtmax, reflecting left ventricular (LV) contractility in children. The aim of this study was to investigate relationship between aortic and radial dp/dtmax at weaning from cardiopulmonary bypass (CPB) and usefulness of these indices for estimating postoperative outcomes in pediatric congenital heart surgery. Aortic and radial arterial pressure waveforms were analyzed simultaneously during weaning from CPB in 29 congenital heart surgery. The maximum first derivatives of aortic and radial arterial waveforms were calculated and averaged from 3 consecutive respiratory cycles. We obtained the maximum vasoactive inotropic score during the first 36 postoperative hours, LV ejection fraction, and fractional shortening on transthoracic echocardiography performed within postoperative day 7. A significant difference between aortic and radial dP/dtmax was observed (mean difference 356 mm Hg/s, 44% of averages), and radial dP/dtmax was weakly correlated with aortic dP/dtmax (r =0.373, P = 0.047). Aortic dP/dtmax was significantly associated with the maximum vasoactive inotropic score (P < 0.001), postoperative LV ejection fraction (P = 0.018), and fractional shortening (P = 0.015); however, radial dP/dtmax was not. On Receiver operating characteristic analysis, aortic dP/dtmax had a greater area under the curve than radial dP/dtmax in predicting higher vasoactive inotropic score (0.827 vs 0.673). Immediately after CPB in pediatric congenital heart surgery, radial dP/dtmax may not replace aortic dP/dtmax because of a discrepancy between central and peripheral arterial waveforms. In this critical period, aortic dP/dtmax can be useful to estimate postoperative ventricular function rather than peripherally derived dP/dtmax. PMID:27930515

  9. A Novel Two-Step Technique for Retrieving Fractured Peripherally Inserted Central Catheter Segments Migrating into the Heart or the Pulmonary Artery

    PubMed Central

    Peng, Juan; Zhang, Xiao-Ming; Xu, Hao; Miao, Nan-Dong; Ren, Yong-Jun; Liu, Kang; Min, Xu-Li; Yang, Ke; Yang, Shi; Yang, Cheng

    2016-01-01

    Objective. To report the experience of a percutaneous technique for retrieving fractured peripherally inserted central catheter (PICC) segments migrating into the heart or the pulmonary artery. Method. From April 2013 to July 2015, we performed percutaneous retrieval of fractured PICC segments migrating into the heart or the pulmonary artery in five cancer patients who had undergone chemotherapy via PICC. The fractures were diagnosed with chest plain radiography. The patients included three cases of breast cancer, one case of rectal cancer, and one case of lower limb Ewing's tumor. The fractures were retained in the vessels of the patients for 1 to 3 days. All the fractures were retrieved by using a novel two-step technique in the digital subtraction angiography (DSA) suite. This two-step technique involves inserting a pigtail catheter to the heart or the pulmonary artery to grasp the fractured catheter fragment and bring it to the lower segment of the inferior vena cava, followed by grasping and removing the catheter fragment with a retrieval loop system of the vena cava filter retrieval set. Result. The fractured PICC segments were removed successfully in all five patients via unilateral (four patients) or bilateral (one patient) femoral vein access. No complications occurred during the interventional procedure. Conclusion. Percutaneous retrieval can be a safe, convenient, and minimally invasive method for the removal of fractured PICC segments. The technique reported in this paper will be applicable for the retrieval of fractured PICC segments and other catheter fragments migrating into the heart or the pulmonary artery. PMID:27642604

  10. Improved Stiff ODE Solvers for Combustion CFD

    NASA Astrophysics Data System (ADS)

    Imren, A.; Haworth, D. C.

    2016-11-01

    Increasingly large chemical mechanisms are needed to predict autoignition, heat release and pollutant emissions in computational fluid dynamics (CFD) simulations of in-cylinder processes in compression-ignition engines and other applications. Calculation of chemical source terms usually dominates the computational effort, and several strategies have been proposed to reduce the high computational cost associated with realistic chemistry in CFD. Central to most strategies is a stiff ordinary differential equation (ODE) solver to compute the change in composition due to chemical reactions over a computational time step. Most work to date on stiff ODE solvers for computational combustion has focused on backward differential formula (BDF) methods, and has not explicitly considered the implications of how the stiff ODE solver couples with the CFD algorithm. In this work, a fresh look at stiff ODE solvers is taken that includes how the solver is integrated into a turbulent combustion CFD code, and the advantages of extrapolation-based solvers in this regard are demonstrated. Benefits in CPU time and accuracy are demonstrated for homogeneous systems and compression-ignition engines, for chemical mechanisms that range in size from fewer than 50 to more than 7,000 species.

  11. PC-PLC/sphingomyelin synthase activity plays a central role in the development of myogenic tone in murine resistance arteries.

    PubMed

    Mauban, Joseph R H; Zacharia, Joseph; Fairfax, Seth; Wier, Withrow Gil

    2015-06-15

    Myogenic tone is an intrinsic property of the vasculature that contributes to blood pressure control and tissue perfusion. Earlier investigations assigned a key role in myogenic tone to phospholipase C (PLC) and its products, inositol 1,4,5-trisphosphate (IP3) and diacylglycerol (DAG). Here, we used the PLC inhibitor, U-73122, and two other, specific inhibitors of PLC subtypes (PI-PLC and PC-PLC) to delineate the role of PLC in myogenic tone of pressurized murine mesenteric arteries. U-73122 inhibited depolarization-induced contractions (high external K(+) concentration), thus confirming reports of nonspecific actions of U-73122 and its limited utility for studies of myogenic tone. Edelfosine, a specific inhibitor of PI-PLC, did not affect depolarization-induced contractions but modulated myogenic tone. Because PI-PLC produces IP3, we investigated the effect of blocking IP3 receptor-mediated Ca(2+) release on myogenic tone. Incubation of arteries with xestospongin C did not affect tone, consistent with the virtual absence of Ca(2+) waves in arteries with myogenic tone. D-609, an inhibitor of PC-PLC and sphingomyelin synthase, strongly inhibited myogenic tone and had no effect on depolarization-induced contraction. D-609 appeared to act by lowering cytoplasmic Ca(2+) concentration to levels below those that activate contraction. Importantly, incubation of pressurized arteries with a membrane-permeable analog of DAG induced vasoconstriction. The results therefore mandate a reexamination of the signaling pathways activated by the Bayliss mechanism. Our results suggest that PI-PLC and IP3 are not required in maintaining myogenic tone, but DAG, produced by PC-PLC and/or SM synthase, is likely through multiple mechanisms to increase Ca(2+) entry and promote vasoconstriction.

  12. Dynamically variable negative stiffness structures

    PubMed Central

    Churchill, Christopher B.; Shahan, David W.; Smith, Sloan P.; Keefe, Andrew C.; McKnight, Geoffrey P.

    2016-01-01

    Variable stiffness structures that enable a wide range of efficient load-bearing and dexterous activity are ubiquitous in mammalian musculoskeletal systems but are rare in engineered systems because of their complexity, power, and cost. We present a new negative stiffness–based load-bearing structure with dynamically tunable stiffness. Negative stiffness, traditionally used to achieve novel response from passive structures, is a powerful tool to achieve dynamic stiffness changes when configured with an active component. Using relatively simple hardware and low-power, low-frequency actuation, we show an assembly capable of fast (<10 ms) and useful (>100×) dynamic stiffness control. This approach mitigates limitations of conventional tunable stiffness structures that exhibit either small (<30%) stiffness change, high friction, poor load/torque transmission at low stiffness, or high power active control at the frequencies of interest. We experimentally demonstrate actively tunable vibration isolation and stiffness tuning independent of supported loads, enhancing applications such as humanoid robotic limbs and lightweight adaptive vibration isolators. PMID:26989771

  13. [Right ventricular perforation and cardiac tamponade caused by a central venous catheter].

    PubMed

    Fukuda, H; Kasuda, H; Shimizu, R

    1993-02-01

    A 5 year old girl with ASD was scheduled for open heart surgery. A central venous catheter was placed via the right infraclavicular vein after induction of anesthesia. Thirty minutes after insertion of the catheter, a decrease in arterial pressure and pulse pressure, an increase in heart rate and central venous pressure were observed. Cardiac tamponade was revealed by rapid opening of the chest. Gushing blood out of a hole in the right ventricular free wall was confirmed by pericardiotomy. The hemodynamics were stabilized by blood transfusion and surgical closure of the hole on the ventricle. This perforation was thought to be caused by careless insertion of a relatively stiff central venous catheter.

  14. Central venous-to-arterial carbon dioxide difference and the effect of venous hyperoxia: A limiting factor, or an additional marker of severity in shock?

    PubMed

    Saludes, P; Proença, L; Gruartmoner, G; Enseñat, L; Pérez-Madrigal, A; Espinal, C; Mesquida, J

    2016-11-10

    Central venous-to-arterial carbon dioxide difference (PcvaCO2) has demonstrated its prognostic value in critically ill patients suffering from shock, and current expert recommendations advocate for further resuscitation interventions when PcvaCO2 is elevated. PcvaCO2 combination with arterial-venous oxygen content difference (PcvaCO2/CavO2) seems to enhance its performance when assessing anaerobic metabolism. However, the fact that PCO2 values might be altered by changes in blood O2 content (the Haldane effect), has been presented as a limitation of PCO2-derived variables. The present study aimed at exploring the impact of hyperoxia on PcvaCO2 and PcvaCO2/CavO2 during the early phase of shock. Prospective interventional study. Ventilated patients suffering from shock within the first 24 h of ICU admission. Patients requiring FiO2 ≥ 0.5 were excluded. At inclusion, simultaneous arterial and central venous blood samples were collected. Patients underwent a hyperoxygenation test (5 min of FiO2 100%), and arterial and central venous blood samples were repeated. Oxygenation and CO2 variables were calculated at both time points. Twenty patients were studied. The main cause of shock was septic shock (70%). The hyperoxygenation trial increased oxygenation parameters in arterial and venous blood, whereas PCO2 only changed at the venous site. Resulting PcvaCO2 and PcvaCO2/CavO2 significantly increased [6.8 (4.9, 8.1) vs. 7.6 (6.7, 8.5) mmHg, p 0.001; and 1.9 (1.4, 2.2) vs. 2.3 (1.8, 3), p < 0.001, respectively]. Baseline PcvaCO2, PcvaCO2/CavO2 and ScvO2 correlated with the magnitude of PO2 augmentation at the venous site within the trial (ρ -0.46, p 0.04; ρ 0.6, p < 0.01; and ρ 0.7, p < 0.001, respectively). Increased PcvaCO2/CavO2 values were associated with higher mortality in our sample [1.46 (1.21, 1.89) survivors vs. 2.23 (1.86, 2.8) non-survivors, p < 0.01]. PcvaCO2 and PcvaCO2/CavO2 are influenced by oxygenation changes not related to flow. Elevated

  15. Central command: control of cardiac sympathetic and vagal efferent nerve activity and the arterial baroreflex during spontaneous motor behaviour in animals.

    PubMed

    Matsukawa, Kanji

    2012-01-01

    Feedforward control by higher brain centres (termed central command) plays a role in the autonomic regulation of the cardiovascular system during exercise. Over the past 20 years, workers in our laboratory have used the precollicular-premammillary decerebrate animal model to identify the neural circuitry involved in the CNS control of cardiac autonomic outflow and arterial baroreflex function. Contrary to the traditional idea that vagal withdrawal at the onset of exercise causes the increase in heart rate, central command did not decrease cardiac vagal efferent nerve activity but did allow cardiac sympathetic efferent nerve activity to produce cardiac acceleration. In addition, central command-evoked inhibition of the aortic baroreceptor-heart rate reflex blunted the baroreflex-mediated bradycardia elicited by aortic nerve stimulation, further increasing the heart rate at the onset of exercise. Spontaneous motor activity and associated cardiovascular responses disappeared in animals decerebrated at the midcollicular level. These findings indicate that the brain region including the caudal diencephalon and extending to the rostral mesencephalon may play a role in generating central command. Bicuculline microinjected into the midbrain ventral tegmental area of decerebrate rats produced a long-lasting repetitive activation of renal sympathetic nerve activity that was synchronized with the motor nerve discharge. When lidocaine was microinjected into the ventral tegmental area, the spontaneous motor activity and associated cardiovascular responses ceased. From these findings, we conclude that cerebral cortical outputs trigger activation of neural circuits within the caudal brain, including the ventral tegmental area, which causes central command to augment cardiac sympathetic outflow at the onset of exercise in decerebrate animal models.

  16. Effective leg stiffness in running.

    PubMed

    Blum, Yvonne; Lipfert, Susanne W; Seyfarth, Andre

    2009-10-16

    Leg stiffness is a common parameter used to characterize leg function during bouncing gaits, like running and hopping. In the literature, different methods to approximate leg stiffness based on kinetic and kinematic parameters are described. A challenging point in estimating leg stiffness is the definition of leg compression during contact. In this paper four methods (methods A-D) based on ground reaction forces (GRF) and one method (method E) relying on temporal parameters are described. Leg stiffness calculated by these five methods is compared with running patterns, predicted by the spring mass model. The best and simplest approximation of leg stiffness is method E. It requires only easily accessible parameters (contact time, flight time, resting leg length, body mass and the leg's touch down angle). Method D is of similar quality but additionally requires the time-dependent progression of the GRF. The other three methods show clear differences from the model predictions by over- or underestimating leg stiffness, especially at slow speeds. Leg stiffness is derived from a conceptual model of legged locomotion and does not exist without this model. Therefore, it is important to prove which experimental method is suited best for approximating the stiffness in a specific task. This will help to interpret the predictions of the conceptual model in comparison with experimental data.

  17. Jerking stiff-man syndrome.

    PubMed Central

    Alberca, R; Romero, M; Chaparro, J

    1982-01-01

    A female patient had permanent axial muscular rigidity similar to the "stiff-man syndrome", together with axial myoclonus triggered by stretch reflexes and by supramaximal stimulation of the supraorbital nerve. The disorder responded to treatment with diazepam and baclofen. This disorder bore a marked similarity to the so-called "jerking stiff-man syndrome". PMID:7161612

  18. Rho-kinase mediated cytoskeletal stiffness in skinned smooth muscle

    PubMed Central

    Lan, Bo; Wang, Lu; Zhang, Jenny; Pascoe, Chris D.; Norris, Brandon A.; Liu, Jeffrey C.-Y.; Solomon, Dennis; Paré, Peter D.; Deng, Linhong

    2013-01-01

    The structurally dynamic cytoskeleton is important in many cell functions. Large gaps still exist in our knowledge regarding what regulates cytoskeletal dynamics and what underlies the structural plasticity. Because Rho-kinase is an upstream regulator of signaling events leading to phosphorylation of many cytoskeletal proteins in many cell types, we have chosen this kinase as the focus of the present study. In detergent skinned tracheal smooth muscle preparations, we quantified the proteins eluted from the muscle cells over time and monitored the muscle's ability to respond to acetylcholine (ACh) stimulation to produce force and stiffness. In a partially skinned preparation not able to generate active force but could still stiffen upon ACh stimulation, we found that the ACh-induced stiffness was independent of calcium and myosin light chain phosphorylation. This indicates that the myosin light chain-dependent actively cycling crossbridges are not likely the source of the stiffness. The results also indicate that Rho-kinase is central to the ACh-induced stiffness, because inhibition of the kinase by H1152 (1 μM) abolished the stiffening. Furthermore, the rate of relaxation of calcium-induced stiffness in the skinned preparation was faster than that of ACh-induced stiffness, with or without calcium, suggesting that different signaling pathways lead to different means of maintenance of stiffness in the skinned preparation. PMID:24072407

  19. MRI measurement of transmission of arterial pulsation to the brain on propranolol versus amlodipine

    PubMed Central

    Webb, Alastair JS; Rothwell, Peter M

    2017-01-01

    Background and Purpose Cerebral arterial pulsatility is associated with leukoaraiosis and depends upon central arterial pulsatility and arterial stiffness. The effect of antihypertensive drugs on transmission of central arterial pulsatility to the cerebral circulation is unknown, partly due to limited methods of assessment. Methods In a technique-development pilot study, 10 healthy volunteers were randomised to crossover treatment with amlodipine and propranolol. At baseline and on each drug, we assessed aortic (Sphygmocor) and middle cerebral artery pulsatility (TCDtranscranial ultrasound). We also performed whole-brain, 3-tesla multiband BOLD-MRI (MB factor 6, TR=0.43s), concurrent with a novel method of continuous non-invasive BP monitoring. Drug effects on relationships between cardiac cycle variation in BP and BOLD were determined (FEAT-FSL). Results Aortic pulsatility was similar on amlodipine (27.3mmHg) and propranolol (27.9mmHg, p-diff=0.33) whilst MCA pulsatility increased non-significantly more from baseline on propranolol (+6%, p=0.09) than amlodipine (+1.5%,p=0.58). On MRI, cardiac frequency BP variations were significantly more strongly associated with BOLD on propranolol than amlodipine. Conclusions We piloted a novel method of assessment of arterial pulsatility with concurrent high-frequency BOLD-MRI and non-invasive BP monitoring. This method was able to identify greater transmission of aortic pulsation on propranolol than amlodipine, which warrants further investigation. PMID:27143273

  20. Major contribution of central pulmonary reservoir discharge to increased pulmonary arterial diastolic blood flow after birth in near-term lambs.

    PubMed

    Smolich, Joseph J; Mynard, Jonathan P

    2016-10-01

    Recent fetal lamb data have suggested that the pulmonary trunk (PT) region displays a reservoir function and that a pharmacologically induced fall in pulmonary vascular resistance (PVR) increases and redistributes diastolic discharge from this central pulmonary reservoir toward the lungs, thereby producing a positive diastolic offset in the pulmonary arterial (PA) blood flow profile. As a similar offset in PA flow characteristically occurs after birth, this study tested the hypotheses that 1) central pulmonary reservoir discharge is both redistributed toward the lungs and increased in magnitude during the birth transition and 2) discharge from this reservoir constitutes a major component of increased PA diastolic blood flow after birth. Six anesthetized near-term fetal lambs were instrumented with PT, ductal and left PA transit-time flow probes, and aortic, PT and left atrial catheters. Hemodynamic data were recorded in fetuses and at regular intervals during 2-h mechanical ventilation following cesarean section delivery. Diastolic PA blood flow rose from near zero in fetuses to 468 ± 188 ml/min by 15 min (P < 0.001). Central pulmonary reservoir discharge in fetuses (99 ± 44 ml/min) passed primarily right-to-left across the ductus. However, this reservoir discharge redistributed entirely to the lungs by 1 min after birth, and then doubled to a peak of 214 ± 167 ml/min at 15 min (P < 0.001). Reservoir discharge subsequently stabilized at 151 ± 60 ml/min at 30-120 min, which comprised ∼50% of diastolic and ∼20% of mean PA blood flow. These findings suggest that enhanced diastolic central pulmonary reservoir discharge plays a major role in supporting an increased pulmonary perfusion after birth.

  1. DPP-4 Inhibitor Reduces Central Blood Pressure in a Diabetic and Hypertensive Patient

    PubMed Central

    Cosenso-Martin, Luciana Neves; Giollo-Junior, Luiz Tadeu; Vilela-Martin, José Fernando

    2015-01-01

    Abstract Hypertension and type 2 diabetes mellitus (DM) are among the main risk factors for the development of cardiovascular disease. Pharmacotherapy for DM should not only improve blood glucose control, but also provide beneficial glucose-independent cardiovascular effects. The central systolic blood pressure (SBP) has become more important than the brachial SBP in the assessment of cardiovascular risk. This case report describes the effect of vildagliptin, a dipeptidyl peptidase-4 (DPP-4) inhibitor, on the central SBP in a 54-year-old woman with hypertension and DM. She was submitted to applanation tonometry (AT) before and after vildagliptin association. AT of the radial artery is a non-invasive method that indirectly assesses arterial stiffness by calculating the central SBP and the augmentation index (AIx). After 3 months of follow-up using vildagliptin, central SBP and AIx were improved. Moreover, she presented better glycemic control. This case suggests an effect of DPP-4 inhibitor on arterial stiffness parameter (central SBP) in a hypertensive and diabetic patient, which shows a glucose-independent beneficial cardiovascular effect of this group of drugs. PMID:26166078

  2. A Reply to Stiff and Boster.

    ERIC Educational Resources Information Center

    Petty, Richard E.; And Others

    1987-01-01

    Addresses the major errors and misconceptions perpetuated by Stiff and Boster's response to criticism of Stiff's 1986 article. Focuses on the major conceptual and methodological issues of Stiff's model. (NKA)

  3. Relation of epicardial fat to central aortic pressure and left ventricular diastolic function in patients with known or suspected coronary artery disease.

    PubMed

    Hachiya, Kenta; Fukuta, Hidekatsu; Wakami, Kazuaki; Goto, Toshihiko; Tani, Tomomitsu; Ohte, Nobuyuki

    2014-10-01

    The present study tested the hypothesis that epicardial fat may be associated with augmented central aortic pressure and impaired left ventricular (LV) function. We studied 134 consecutive patients undergoing left-sided cardiac catheterization for coronary artery disease (CAD) and examined the relation of epicardial fat volume measured by multi-detector computed tomography to ascending aortic pressure and LV ejection fraction determined by cardiac catheterization as well as indices of LV diastolic function assessed by Doppler echocardiography [early diastolic mitral annular velocity (e') and a ratio of early diastolic mitral inflow to annular velocities (E/e')]. Epicardial fat volume indexed to body surface area correlated positively with age (r = 0.24, P < 0.01), body mass index (r = 0.38, P < 0.001), systolic aortic pressure (r = 0.21, P < 0.05), aortic pulse pressure (r = 0.23, P < 0.01), LV ejection fraction (r = 0.22, P < 0.05) and E/e' (r = 0.24, P < 0.05) and did negatively with e' (r = -0.31, P < 0.05). In multivariate linear regression including potential confounders, increased epicardial fat volume index correlated with aortic systolic and pulse pressure and LV diastolic function indices, but not LV ejection fraction. In conclusion, we found that epicardial fat was associated with augmented central aortic pressure and LV diastolic dysfunction in patients with known or suspected CAD.

  4. Central blood pressure and chronic kidney disease

    PubMed Central

    Ohno, Yoichi; Kanno, Yoshihiko; Takenaka, Tsuneo

    2016-01-01

    In this review, we focused on the relationship between central blood pressure and chronic kidney diseases (CKD). Wave reflection is a major mechanism that determines central blood pressure in patients with CKD. Recent medical technology advances have enabled non-invasive central blood pressure measurements. Clinical trials have demonstrated that compared with brachial blood pressure, central blood pressure is a stronger risk factor for cardiovascular (CV) and renal diseases. CKD is characterized by a diminished renal autoregulatory ability, an augmented direct transmission of systemic blood pressure to glomeruli, and an increase in proteinuria. Any elevation in central blood pressure accelerates CKD progression. In the kidney, interstitial inflammation induces oxidative stress to handle proteinuria. Oxidative stress facilitates atherogenesis, increases arterial stiffness and central blood pressure, and worsens the CV prognosis in patients with CKD. A vicious cycle exists between CKD and central blood pressure. To stop this cycle, vasodilator antihypertensive drugs and statins can reduce central blood pressure and oxidative stress. Even in early-stage CKD, mineral and bone disorders (MBD) may develop. MBD promotes oxidative stress, arteriosclerosis, and elevated central blood pressure in patients with CKD. Early intervention or prevention seems necessary to maintain vascular health in patients with CKD. PMID:26788468

  5. Coronary Arteries

    MedlinePlus

    ... and animations for grades K-6. The Coronary Arteries Coronary Circulation The heart muscle, like every other ... into two main coronary blood vessels (also called arteries). These coronary arteries branch off into smaller arteries, ...

  6. Assessment of stiffness changes in the ex vivo porcine aortic wall using magnetic resonance elastography

    PubMed Central

    Xu, Lei; Chen, Jun; Yin, Meng; Glaser, Kevin J.; Chen, Qingshan; Woodrum, David A.; Ehman, Richard L.

    2011-01-01

    Magnetic resonance elastography (MRE) is a noninvasive phase-contrast technique for estimating the mechanical properties of tissues by imaging propagating mechanical waves within the tissue. In this study, we hypothesize that changes in arterial wall stiffness, experimentally induced by formalin fixation, can be measured using MRE in ex vivo porcine aortas. In agreement with our hypothesis, the significant stiffness increase after sample fixation were clearly demonstrated by MRE and confirmed by mechanical testing. The results indicate that MRE can be used to examine the stiffness changes of the aorta. This study has provided evidence of the effectiveness of using MRE to directly assess the stiffness change in aortic wall. The results offer motivation to pursue MRE as a noninvasive method for the evaluation of arterial wall mechanical properties. PMID:22055848

  7. [Aortic stiffness and its influencing factors in patients with chronic kidney disease].

    PubMed

    Ye, Binxian; Zhao, Li; Shen, Wei; Ren, Yan; Lin, Bo; Chen, Maosheng; Tang, Junda; Jiang, Xinxin; Li, Yiwen; He, Qiang

    2016-05-25

    Objective: To investigate the changes of aortic stiffness and its influencing factors in patients with chronic kidney diseases (CKD). Methods: Eightyfour patients with CKD from Department of Nephrology, Zhejiang Provincial People's Hospital were divided into the dialysis group (CKD stage 5, n=48) and non-dialysis group (CKD stage 3-5, n=36). Clinical data, biochemical parameters and echocardiography findings were collected. SphygmoCor pulse wave analysis system was used to obtain pulse wave analysis (PWA) parameters including central aortic systolic blood pressure (CSP), central pulse pressure (CPP), augmented pressure (AP), augmentation index (AIX), and heart rate 75-adjusted augmentation index (HR75AIX). The influencing factors of aortic stiffness were analyzed by spearman correlation analysis and multiple regression analysis. Results: CSP, CPP, AP, AIX and HR75AIX in dialysis patients had no significant differences compared with those in non-dialysis group (all P>0.05). Spearman correlation analysis showed that CSP was positively correlated with systolic blood pressure, diastolic blood pressure, cholesterol, low-density lipoprotein cholesterol, left atrial diameter (LA),left ventricular systolic diameter (LVDs), left ventricular diastolic diameter (LVDd), and negatively correlated with calcium and hemoglobin levels. CPP was positively correlated with systolic blood pressure, age, LA, LVDd, and negatively correlated with diastolic blood pressure and hemoglobin levels. AP was positively correlated with systolic blood pressure, age, LA, LVDd, and negatively correlated with hemoglobin levels. AIX was positively correlated with systolic blood pressure, age, sodium, and negatively correlated with phosphorus levels. HR75AIX was positively correlated with systolic blood pressure, sodium, cholesterol, and negatively correlated with hemoglobin and albumin levels. Multiple regression analysis showed that higher systolic blood pressure was the independent risk factor for

  8. Stiffness of compressed fiber mats

    NASA Astrophysics Data System (ADS)

    Åström, J. A.; Mäkinen, J. P.; Hirvonen, H.; Timonen, J.

    2000-11-01

    We investigate, using an analytical and a numerical model, the in-plane stiffness of fiber mats. A mat is modeled by randomly depositing thin linear-elastic fibers on top of each other under the influence of an external pressure. The external pressure has the effect of bending the fibers over each other. The fibers are assumed rigidly bonded at contacts. For a low external pressure the stiffness of the mat deviates from that of its two-dimensional projection only by a geometrical factor, and the effective Poisson contraction is close to zero. For higher pressures, stiffness is governed by two competing effects and a maximum appears in the stiffness. The effective Poisson ratio is clearly negative in this range. An approximative analytical description is developed for the stiffness of mats formed under low external pressure. The stiffness is given as a function of only a few parameters: the degree of bonding, the dimensions of the fibers, the elastic constants of the fiber material, and the density of fibers.

  9. Effect of angiotensin II-induced arterial hypertension on the voltage-dependent contractions of mouse arteries.

    PubMed

    Fransen, Paul; Van Hove, Cor E; Leloup, Arthur J A; Schrijvers, Dorien M; De Meyer, Guido R Y; De Keulenaer, Gilles W

    2016-02-01

    Arterial hypertension (AHT) affects the voltage dependency of L-type Ca(2+) channels in cardiomyocytes. We analyzed the effect of angiotensin II (AngII)-induced AHT on L-type Ca(2+) channel-mediated isometric contractions in conduit arteries. AHT was induced in C57Bl6 mice with AngII-filled osmotic mini-pumps (4 weeks). Normotensive mice treated with saline-filled osmotic mini-pumps were used for comparison. Voltage-dependent contractions mediated by L-type Ca(2+) channels were studied in vaso-reactive studies in vitro in isolated aortic and femoral arteries by using extracellular K(+) concentration-response (KDR) experiments. In aortic segments, AngII-induced AHT significantly sensitized isometric contractions induced by elevated extracellular K(+) and depolarization. This sensitization was partly prevented by normalizing blood pressure with hydralazine, suggesting that it was caused by AHT rather than by direct AngII effects on aortic smooth muscle cells. The EC50 for extracellular K(+) obtained in vitro correlated significantly with the rise in arterial blood pressure induced by AngII in vivo. The AHT-induced sensitization persisted when aortic segments were exposed to levcromakalim or to inhibitors of basal nitric oxide release. Consistent with these observations, AngII-treatment also sensitized the vaso-relaxing effects of the L-type Ca(2+) channel blocker diltiazem during K(+)-induced contractions. Unlike aorta, AngII-treatment desensitized the isometric contractions to depolarization in femoral arteries pointing to vascular bed specific responses of arteries to hypertension. AHT affects the voltage-dependent L-type Ca(2+) channel-mediated contraction of conduit arteries. This effect may contribute to the decreased vascular compliance in AHT and explain the efficacy of Ca(2+) channel blockers to reduce vascular stiffness and central blood pressure in AHT.

  10. Relationship between two proprioceptive measures and stiffness at the ankle.

    PubMed

    Docherty, Carrie L; Arnold, Brent L; Zinder, Steven M; Granata, Kevin; Gansneder, Bruce M

    2004-06-01

    Previous research has investigated the role of proprioception and stiffness in the control of joint stability. However, to date, no research has been done on the relationship between proprioception and stiffness. Therefore, the purpose of this study was to determine the relationship between force sense, joint reposition sense, and stiffness at the ankle. A heterogeneous sample was obtained for this study; 20 of the 40 participants had a history of ankle sprains, and 13 of the 20 had been diagnosed by a physician (two mild ankle sprains, seven moderate sprains, four severe sprains). All subjects were asymptomatic and active at the time of the study. Active joint reposition sense was measured using a custom-built ankle goniometer, force sense was measured unilaterally and contralaterally with a load cell, and ankle muscle stiffness was measured via transient oscillation using a custom-built inversion-eversion cradle. We found no significant correlations between stiffness and joint reposition sense, with values of r ranging from 0.01 to 0.21. Significant correlations were found between stiffness and force sense. Specifically, contralateral force sense reproduction was significantly correlated to stiffness in the injured or "involved" ankle (r's ranging from 0.47 to 0.65; P< or =0.008). Whether the decreased ability to appropriately sense force (increased error) sends information to the central nervous system to increase muscle stiffness in response to an unexpected loss of stability, or whether these two phenomena function independently and both change concurrently as a result of injury to the system requires further investigation.

  11. Aortic Stiffness as a Surrogate Endpoint to Micro- and Macrovascular Complications in Patients with Type 2 Diabetes

    PubMed Central

    Cardoso, Claudia R. L.; Salles, Gil F.

    2016-01-01

    Increased aortic stiffness has been recognized as a predictor of adverse cardiovascular outcomes in some clinical conditions, such as in patients with arterial hypertension and end-stage renal disease, in population-based samples and, more recently, in type 2 diabetic patients. Patients with type 2 diabetes have higher aortic stiffness than non-diabetic individuals, and increased aortic stiffness has been correlated to the presence of micro- and macrovascular chronic diabetic complications. We aimed to review the current knowledge on the relationships between aortic stiffness and diabetic complications, their possible underlying physiopathological mechanisms, and their potential applications to clinical type 2 diabetes management. PMID:27929441

  12. The compensatory renin-angiotensin system in the central regulation of arterial pressure: new avenues and new challenges.

    PubMed

    Mendoza, Alberto; Lazartigues, Eric

    2015-08-01

    Hypertension is a widespread condition that affects millions of people around the world and has a major impact in public health. The classic renin-angiotensin system is a complex system comprised of multiple peptides and pathways that have been the driver of drug development over the years to control hypertension. However, there are still patients whose hypertension is very difficult to control with current drugs and strategies, thus motivating further research in this field. In the past two decades, important discoveries have expanded our knowledge of this system and new pathways are emerging that are helping us understand the complex interaction taking place not only in the periphery, but also in the central nervous system where the renin-angiotensin system is also very active. A new arm, called the ACE2/Ang-(1-7)/Mas receptor axis, was shown to exert antihypertensive properties and serve as a counterbalance to the classic ACE/angiotensin II/AT1 receptor axis, in this way modulating or even counteracting the negative effects of angiotensin II in blood pressure regulation and water retention. Modulation of this new axis through ACE2 activation, ADAM17 regulation or AT1 receptor internalization are some of the novel avenues and challenges that have the potential to become a target for new drug research and development for the treatment of hypertension.

  13. Central venous line complications with chronic ambulatory infusion of prostacyclin analogues in pediatric patients with pulmonary arterial hypertension.

    PubMed

    Marr, Courtney R; McSweeney, Julia E; Mullen, Mary P; Kulik, Thomas J

    2015-06-01

    Chronic infusion of prostacyclin (PGI2) via a Broviac central venous line (CVL) is attended by risk of CVL-related complications, but we know of only one report regarding CVL-associated bloodstream infection (BSI) with PGI2 in children and none regarding other complications. We conducted a retrospective cohort study involving pediatric patients with pulmonary hypertension treated with chronic intravenous infusion of PGI2 at Boston Children's Hospital and determined the rate (per 1,000 line-days) of various CVL-related complications. We also determined how often complications necessitated line replacement and hospitalization, time to replacement of CVLs, and interpatient variability in the incidence of complications. From 1999 until 2014, 26 patients meeting follow-up criteria had PGI2 infusion, representing 43,855 line-days; mean follow-up was 56 months (range, 1.4-161 months). The CVL complication rates (per 1,000 line-days) were as follows: CVL-BSI, 0.25; superficial line infection, 0.48; impaired integrity, 0.59; occlusion, 0.09; and malposition, 0.32. The total complication rate was 1.73 cases per 1,000 line-days. All CVL-BSI and malposition cases were treated with CVL removal and replacement. Of CVLs with impaired integrity, 23 could be repaired and 3 required replacement. Six of 21 superficial CVL infections required replacement of the CVL. Three of 4 occluded CVLs were replaced. CVL complications occasioned 65 hospitalizations. There was marked interpatient variability in the rate of complications, much but not all of which appeared to be related to duration of CVL placement. We conclude that non-BSI complications are very significant and that efforts to teach and emphasize other aspects of line care are therefore very important.

  14. Central venous line complications with chronic ambulatory infusion of prostacyclin analogues in pediatric patients with pulmonary arterial hypertension

    PubMed Central

    Mullen, Mary P.

    2015-01-01

    Abstract Chronic infusion of prostacyclin (PGI2) via a Broviac central venous line (CVL) is attended by risk of CVL-related complications, but we know of only one report regarding CVL-associated bloodstream infection (BSI) with PGI2 in children and none regarding other complications. We conducted a retrospective cohort study involving pediatric patients with pulmonary hypertension treated with chronic intravenous infusion of PGI2 at Boston Children’s Hospital and determined the rate (per 1,000 line-days) of various CVL-related complications. We also determined how often complications necessitated line replacement and hospitalization, time to replacement of CVLs, and interpatient variability in the incidence of complications. From 1999 until 2014, 26 patients meeting follow-up criteria had PGI2 infusion, representing 43,855 line-days; mean follow-up was 56 months (range, 1.4–161 months). The CVL complication rates (per 1,000 line-days) were as follows: CVL-BSI, 0.25; superficial line infection, 0.48; impaired integrity, 0.59; occlusion, 0.09; and malposition, 0.32. The total complication rate was 1.73 cases per 1,000 line-days. All CVL-BSI and malposition cases were treated with CVL removal and replacement. Of CVLs with impaired integrity, 23 could be repaired and 3 required replacement. Six of 21 superficial CVL infections required replacement of the CVL. Three of 4 occluded CVLs were replaced. CVL complications occasioned 65 hospitalizations. There was marked interpatient variability in the rate of complications, much but not all of which appeared to be related to duration of CVL placement. We conclude that non-BSI complications are very significant and that efforts to teach and emphasize other aspects of line care are therefore very important. PMID:26064457

  15. ARTHROSCOPIC TREATMENT OF ELBOW STIFFNESS

    PubMed Central

    Vieira, Luis Alfredo Gómez; Dal Molin, Fabio Farina; Visco, Adalberto; Fernandes, Luis Filipe Daneu; dos Santos, Murilo Cunha Rafael; Cardozo Filho, Nivaldo Souza; Gómez Cordero, Nicolas Gerardo

    2015-01-01

    To present the arthroscopic surgical technique and the evaluation of the results from this technique for treating elbow stiffness. Methods: Between April 2007 and January 2010, ten elbows of ten patients with elbow stiffness underwent arthroscopic treatment to release the range of motion. The minimum follow-up was 11 months, with an average of 27 months. All the patients were male and their average age was 32.8 years (ranging from 22 to 48 years). After the arthroscopic treatment, they were followed up weekly in the first month and every three months thereafter. The clinical evaluation was made using the criteria of the University of California at Los Angeles (UCLA). Results: All the patients were satisfied with the results from the arthroscopic treatment. The average UCLA score was 33.8 points. Conclusion: Arthroscopic treatment for elbow stiffness is a minimally invasive surgical technique that was shown to be efficient for treating this complication. PMID:27027027

  16. Monitoring stiffness contrast in elastography

    NASA Astrophysics Data System (ADS)

    Kiss, Miklos; Bharat, Shyam; Varghese, Tomy; Techavipoo, Udomchai; Liu, Wu

    2005-03-01

    Elastography is an imaging modality used to image tissue strains resulting from external quasi-static compression of tissue. Therefore, elastograms can be used to study variations in the stiffness of thermally coagulated regions of tissue. In this study, the variations in stiffness contrast of lesions formed by radio frequency (RF) ablation of canine liver tissue have been investigated. RF ablation was performed on in vitro canine liver tissue over a range of temperatures from 70 - 100 degrees C, and over a range of ablation times from 1 -- 8 minutes. Elastography was then performed on these samples and on normal tissue. It was expected that stiffness contrast would increase with increasing lesion temperature and ablation duration, on the basis that higher temperature and greater ablation durations lead to increased protein denaturation. This increase was seen with ablation duration, but is not obvious with ablation temperature. These and other results will be discussed.

  17. Arterial insufficiency

    MedlinePlus

    ... the most common causes of arterial insufficiency is atherosclerosis or "hardening of the arteries." Fatty material (called ... Images Arteries of the brain Developmental process of atherosclerosis References Hansson GK, Hamsten A. Atherosclerosis, thrombosis, and ...

  18. Lase Ultrasonic Web Stiffness tester

    SciTech Connect

    Tim Patterson, Ph.D., IPST at Ga Tech

    2009-01-12

    The objective is to provide a sensor that uses non-contact, laser ultrasonics to measure the stiffness of paper during the manufacturing process. This will allow the manufacturer to adjust the production process in real time, increase filler content, modify fiber refining and as result produce a quality product using less energy. The sensor operates by moving back and forth across the paper web, at pre-selected locations firing a laser at the sheet, measuring the out-of-plane velocity of the sheet then using that measurement to calculate sheet stiffness.

  19. Growing-Related Changes in Arterial Properties of Healthy Children, Adolescents, and Young Adults Nonexposed to Cardiovascular Risk Factors: Analysis of Gender-Related Differences

    PubMed Central

    Curcio, S.; García-Espinosa, V.; Arana, M.; Farro, I.; Chiesa, P.; Giachetto, G.; Zócalo, Y.; Bia, D.

    2016-01-01

    The aims of our work were to determine normal aging rates for structural and functional arterial parameters in healthy children, adolescents, and young adults and to identify gender-related differences in these aging rates. Methods. 161 subjects (mean: 15 years (range: 4–28 years), 69 females) were studied. Subjects included had no congenital or chronic diseases, nor had they been previously exposed to traditional cardiovascular risk factors. Arterial parameters assessed were (1) central blood pressure (BP) and aortic pulse wave analysis, (2) arterial local (pressure-strain elastic modulus) and regional (pulse wave velocity, PWV) stiffness, and (3) arterial diameters and carotid intima-media thickness (CIMT). Simple linear regression models (age as the independent variable) were obtained for all the parameters and the resulting rates of change were compared between genders. Results. No gender-related differences were found in mean values of arterial structural and functional parameters in prepubertal ages (4–8 years), but they started to appear at ~15 years. Boys showed a greater rate of change for central systolic BP, central pulse pressure, CIMT, and carotid-femoral PWV. Conclusion. Gender-related differences in arterial characteristics of adults can be explained on the basis of different growing-related patterns between boys and girls, with no existing differences in prepubertal ages. PMID:26989504

  20. Impact of biological aging on arterial aging in American Indians: findings from the Strong Heart Family Study

    PubMed Central

    Peng, Hao; Zhu, Yun; Yeh, Fawn; Cole, Shelley A.; Best, Lyle G.; Lin, Jue; Blackburn, Elizabeth; Devereux, Richard B.; Roman, Mary J.; Lee, Elisa T.; Howard, Barbara V.; Zhao, Jinying

    2016-01-01

    Telomere length, a marker of biological aging, has been associated with cardiovascular disease (CVD). Increased arterial stiffness, an indicator of arterial aging, predicts adverse CVD outcomes. However, the relationship between telomere length and arterial stiffness is less well studied. Here we examined the cross-sectional association between leukocyte telomere length (LTL) and arterial stiffness in 2,165 American Indians in the Strong Heart Family Study (SHFS). LTL was measured by qPCR. Arterial stiffness was assessed by stiffness index β. The association between LTL and arterial stiffness was assessed by generalized estimating equation model, adjusting for sociodemographics (age, sex, education level), study site, metabolic factors (fasting glucose, lipids, systolic blood pressure, and kidney function), lifestyle (BMI, smoking, drinking, and physical activity), and prevalent CVD. Results showed that longer LTL was significantly associated with a decreased arterial stiffness (β=-0.070, P=0.007). This association did not attenuate after further adjustment for hsCRP (β=-0.071, P=0.005) or excluding participants with overt CVD (β=-0.068, P=0.012), diabetes (β=-0.070, P=0.005), or chronic kidney disease (β=-0.090, P=0.001). In summary, shorter LTL was significantly associated with an increased arterial stiffness, independent of known risk factors. This finding may shed light on the potential role of biological aging in arterial aging in American Indians. PMID:27540694

  1. Distinct effects of losartan and atenolol on vascular stiffness in Marfan syndrome.

    PubMed

    Bhatt, Ami B; Buck, J Stewart; Zuflacht, Jonah P; Milian, Jessica; Kadivar, Samoneh; Gauvreau, Kimberlee; Singh, Michael N; Creager, Mark A

    2015-08-01

    We conducted a randomized, double-blind trial of losartan (100 mg QD) versus atenolol (50 mg QD) for 6 months in adults with Marfan syndrome. Carotid-femoral pulse wave velocity (PWV), central augmentation index (AIx), aortic diameter and left ventricular (LV) function were assessed with arterial tonometry and echocardiography. Thirty-four subjects (18 female; median age 35 years, IQR 27, 45) were randomized. Central systolic and diastolic blood pressure decreased comparably with atenolol and losartan (p = 0.64 and 0.31, respectively); heart rate decreased with atenolol (p = 0.02), but not with losartan. PWV decreased in patients treated with atenolol (-1.15 ± 1.68 m/s; p = 0.01), but not in those treated with losartan (-0.22 ± 0.59 m/s; p = 0.15; between-group difference p = 0.04). In contrast, AIx decreased in the losartan group (-9.6 ± 8.6%; p < 0.001) but not in the atenolol group (0.9 ± 6.2%, p = 0.57; between-group difference p < 0.001). There was no significant change in aortic diameters or LV ejection fraction in either treatment group. In adults with Marfan syndrome, 6 months of treatment with atenolol improves PWV, whereas losartan reduces the AIx. By improving vascular stiffness via distinct mechanisms of action, there is physiologic value to considering the use of both medications in individuals with Marfan syndrome.

  2. Quantification of plaque stiffness by Brillouin microscopy (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Antonacci, Giuseppe; Pedrigi, Ryan; Krams, Rob; Török, Peter

    2016-03-01

    Spontaneous Brillouin scattering is an inelastic scattering process arising from inherent thermal density fluctuations, or acoustic phonons, propagating in a medium. Over the last few years, Brillouin spectroscopy has shown great potential to become a reliable non-invasive diagnostic tool due to its unique capability of retrieving viscoelastic properties of materials such as strain and stiffness. The detection of the weak scattered light, in addition to the resolution of the Brillouin peaks (typically shifted by few GHz from the central peak) represent one of the greatest challenges in Brillouin. The recent development of high sensitivity CCD cameras has brought Brillouin spectroscopy from a point sampling technique to a new imaging modality. Furthermore, the application of Virtually Imaged Phased Array (VIPA) etalons has dramatically reduced insertion loss simultaneously allowing fast (<1s) collection of the entire spectrum. Hitherto Brillouin microscopy has been shown the ability to provide unique stiffness maps of biological samples, such as the human lens, in a non-destructive manner. In this work, we present results obtained using our Brillouin microscope to map the stiffness variations in the walls of blood vessels in particular when atherosclerotic plaques are formed. The stiffness of the membrane that covers the plaques is critical in developing acute myocardial infarction yet it is not currently possible to credibly assess its stiffness due to lack of suitable methods.

  3. Coronary Artery Fistula

    DTIC Science & Technology

    2007-04-01

    Figure 1A; oblique, Figure 1B), the left circumflex artery was identified by its black central lumen and noted to arise normally from the left main...but the mid left circumflex coronary artery was less well seen because of volume averaging with the left atrium and pulmonary venous confluence which...Figures 1C-D. Select oblique conventional x-ray views (C, early phase; D, late phase) from a coronary catheterization study following injection of

  4. Vascular Stiffness in Children With Chronic Kidney Disease.

    PubMed

    Savant, Jonathan D; Betoko, Aisha; Meyers, Kevin E C; Mitsnefes, Mark; Flynn, Joseph T; Townsend, Raymond R; Greenbaum, Larry A; Dart, Allison; Warady, Bradley; Furth, Susan L

    2017-05-01

    Carotid-femoral pulse wave velocity (cfPWV) is a measure of arterial stiffness associated with cardiovascular events in the general population and in adults with chronic kidney disease. However, few data exist regarding cfPWV in children with chronic kidney disease. We compared observed cfPWV assessed via applanation tonometry in children enrolled in the CKiD cohort study (Chronic Kidney Disease in Children) to normative data in healthy children and examined risk factors associated with elevated cfPWV. cfPWV Z score for height/gender and age/gender was calculated from and compared with published pediatric norms. Multivariable linear regression was used to assess the relationship between cfPWV and age, gender, race, body mass index, diagnosis, urine protein-creatinine ratio, mean arterial pressure, heart rate, number of antihypertensive medications, uric acid, and serum low-density lipoprotein. Of the 95 participants with measured cfPWV, 60% were male, 19% were black, 46% had glomerular cause of chronic kidney disease, 22% had urine protein-creatinine ratio 0.5 to 2.0 mg/mg and 9% had >2.0 mg/mg, mean age was 15.1 years, average mean arterial pressure was 80 mm Hg, and median glomerular filtration rate was 63 mL/min per 1.73 m(2) Mean cfPWV was 5.0 m/s (SD, 0.8 m/s); mean cfPWV Z score by height/gender norms was -0.1 (SD, 1.1). cfPWV increased significantly with age, mean arterial pressure, and black race in multivariable analysis; no other variables, including glomerular filtration rate, were independently associated with cfPWV. In this pediatric cohort with mild kidney dysfunction, arterial stiffness was comparable to that of normal children. Future research is needed to examine the impact of chronic kidney disease progression on arterial stiffness and associated cardiovascular parameters in children.

  5. Objective measures of joint stiffness.

    PubMed

    Roberson, L; Giurintano, D J

    1995-01-01

    Objective measures of joint stiffness allow for the evaluation of the effectiveness of treatment modalities. Without this, the effectiveness of therapy is not quantifiable. Presently, joint stiffness can be quantified by either passive range of motion (PROM) measurement or torque range of motion (TqROM) measurement. PROM measurement does not control the force applied, nor does it require that the other joints in the kinematic chain be held fixed. Also, it demonstrates poor interrater reliability. An idealized device melding existing technologies of constant passive motion devices and computerized workstations is proposed to allow for easier measurement of TqROM angles for analysis data for the determination of the effectiveness of treatment modalities.

  6. Analysis of Arterial Mechanics During Head-Down-Tilt Bed Rest

    NASA Technical Reports Server (NTRS)

    Elliott, Morgan B.; Martin, David S.; Westby, Christian M.; Stenger, Michael B.; Platts, Steven H.

    2014-01-01

    Carotid, brachial, and tibial arteries reacted differently to HDTBR. Previous studies have not analyzed the mechanical properties of the human brachial or anterior tibial arteries. After slight variations during bed-rest, arterial mechanical properties and IMT returned to pre-bed rest values, with the exception of tibial stiffness and PSE, which continued to be reduced post-bed rest while the DC remained elevated. The tibial artery remodeling was probably due to decreased pressure and volume. Resulting implications for longer duration spaceflight are unclear. Arterial health may be affected by microgravity, as shown by increased thoracic aorta stiffness in other ground based simulations (Aubert).

  7. Reference values of one-point carotid stiffness parameters determined by carotid echo-tracking and brachial pulse pressure in a large population of healthy subjects.

    PubMed

    Vriz, Olga; Aboyans, Victor; Minisini, Rosalba; Magne, Julien; Bertin, Nicole; Pirisi, Mario; Bossone, Eduardo

    2017-03-02

    Arterial stiffness can predict cardiovascular events, and the aim of this study was to produce age- and sex-specific reference values for echo-tracking carotid stiffness in healthy subjects. A total of 900 subjects (500 males, mean age 45.8±19 years) were enrolled. Common carotid artery stiffness and compliance, using a high-definition echo-tracking ultrasound system, were evaluated. To compare stiffness parameters across the different age groups, individual scores were transformed into T-scores, indicating how many standard deviation (s.d.) units an individual's score was above or below the mean that was observed in the group including same-sex individuals aged 36 to 44 years. Carotid stiffness was similar among genders, except compliance, which was lower in women (P<0.0001). These characteristics were also maintained when the studied population was divided into seven age groups. Stiffness parameters increased significantly with age, but the opposite occurred for compliance. The T-score was found to increase significantly across all age groups, with a steeper increase in stiffness around the age of 60 years in women. For each T-score s.d., the corresponding carotid absolute values for arterial stiffness and compliance were obtained. In a multivariate model, carotid stiffness parameters were constantly and independently associated with age, mean arterial pressure, pulse pressure, heart rate and body mass index. Our study provides a normogram of carotid arterial stiffness and compliance indices obtained with the echo-tracking method in a large population of healthy subjects stratified by gender and age that can be used in clinical practice.Hypertension Research advance online publication, 2 March 2017; doi:10.1038/hr.2017.24.

  8. Arterial Catheterization

    MedlinePlus

    ... The arterial catheter allows accurate, second-to-second measurement of the blood pressure; repeated meas- urement is ... pressure must be lowered gradually in steps, and measurements with an arterial catheter help guide the treatment. ■ ...

  9. Proximal aortic stiffness is increased in systemic lupus erythematosus activity in children and adolescents.

    PubMed

    El Gamal, Yehia Mohamad; Elmasry, Ola Abd Elaziz; El Hadidi, Iman Saleh; Soliman, Ola Kamel

    2013-01-01

    Patients with systemic lupus erythematosus (SLE) are prone to premature atherosclerosis and are at risk for the development of cardiovascular disease. Increased arterial stiffness is emerging as a marker of subclinical atherosclerosis. Purpose. To measure proximal aortic stiffness in children and adolescents with SLE. Methods. We studied 16 patients with SLE in activity (mean age 15 ± 2.42 years; 16 females), 14 patients with SLE not in activity (mean age 15.7 ± 1.89 years; 4 males, 10 females), and 16 age- and sex-comparable healthy children and adolescents (15.5 ± 1.71 years; 4 males, 12 females). Disease activity was determined by the SLE disease activity index (SLEDAI). All subjects underwent echocardiography for assessment of proximal aortic pulse wave velocity (PWV) [Ao distance/Ao wave transit time in the aortic arch]. Venous blood samples were collected for ESR. Results. Patients in activity had significantly higher PWV values than controls (P < 0.05), while no significant difference was found between patients not in activity and controls. Conclusions. SLE patients with disease activity demonstrate increased PWV and arterial stiffness of the proximal aorta, while patients without disease activity do not. This suggests that inflammation secondary to SLE activity, and not subclinical atherosclerosis, is the major underlying cause for increased arterial stiffness in this age group.

  10. Arterial stiffening precedes systolic hypertension in diet-induced obesity.

    PubMed

    Weisbrod, Robert M; Shiang, Tina; Al Sayah, Leona; Fry, Jessica L; Bajpai, Saumendra; Reinhart-King, Cynthia A; Lob, Heinrich E; Santhanam, Lakshmi; Mitchell, Gary; Cohen, Richard A; Seta, Francesca

    2013-12-01

    Stiffening of conduit arteries is a risk factor for cardiovascular morbidity. Aortic wall stiffening increases pulsatile hemodynamic forces that are detrimental to the microcirculation in highly perfused organs, such as the heart, brain, and kidney. Arterial stiffness is associated with hypertension but presumed to be due to an adaptive response to increased hemodynamic load. In contrast, a recent clinical study found that stiffness precedes and may contribute to the development of hypertension although the mechanisms underlying hypertension are unknown. Here, we report that in a diet-induced model of obesity, arterial stiffness, measured in vivo, develops within 1 month of the initiation of the diet and precedes the development of hypertension by 5 months. Diet-induced obese mice recapitulate the metabolic syndrome and are characterized by inflammation in visceral fat and aorta. Normalization of the metabolic state by weight loss resulted in return of arterial stiffness and blood pressure to normal. Our findings support the hypothesis that arterial stiffness is a cause rather than a consequence of hypertension.

  11. Experimental stiffness of tapered bore seals

    NASA Technical Reports Server (NTRS)

    Fleming, D. P.

    1985-01-01

    The stiffness of tapered-bore ring seals was measured with air as the sealed fluid. Static stiffness agreed fairly well with results of a previous analysis. Cross-coupled stiffness due to shaft rotation was much less than predicted. It is suggested that part of the disparity may be due to simplifying assumptions in the analysis; however, these do not appear to account for the entire difference observed.

  12. Gradual stiffness versus magnetic imaging-guided variable stiffness colonoscopes: A randomized noninferiority trial

    PubMed Central

    Wiig, Håvard; Hasund, Audun; Matre, Jon; Holme, Øyvind; Noraberg, Geir; Løberg, Magnus; Kalager, Mette; Adami, Hans-Olov; Bretthauer, Michael

    2016-01-01

    Background Colonoscopes with gradual stiffness have recently been developed to enhance cecal intubation. Objective We aimed to determine if the performance of gradual stiffness colonoscopes is noninferior to that of magnetic endoscopic imaging (MEI)-guided variable stiffness colonoscopes. Methods Consecutive patients were randomized to screening colonoscopy with Fujifilm gradual stiffness or Olympus MEI-guided variable stiffness colonoscopes. The primary endpoint was cecal intubation rate (noninferiority limit 5%). Secondary endpoints included cecal intubation time. We estimated absolute risk differences with 95% confidence intervals (CIs). Results We enrolled 475 patients: 222 randomized to the gradual stiffness instrument, and 253 to the MEI-guided variable stiffness instrument. Cecal intubation rate was 91.7% in the gradual stiffness group versus 95.6% in the variable stiffness group. The adjusted absolute risk for cecal intubation failure was 4.3% higher in the gradual stiffness group than in the variable stiffness group (upper CI border 8.1%). Median cecal intubation time was 13 minutes in the gradual stiffness group and 10 minutes in the variable stiffness group (p < 0.001). Conclusions The study is inconclusive with regard to noninferiority because the 95% CI for the difference in cecal intubation rate between the groups crosses the noninferiority margin. (ClinicalTrials.gov identifier: NCT01895504).

  13. Surgical management of extensive pulmonary artery sarcoma.

    PubMed

    Shehatha, Jaffar; Saxena, Pankaj; Clarke, Belinda; Dunning, John; Konstantinov, Igor E

    2009-04-01

    Primary pulmonary artery sarcoma is a rare tumor that can be misdiagnosed as acute or chronic pulmonary thromboembolic disease. This article reports a patient with a preoperative diagnosis of pulmonary embolism who was found to have an extensive pulmonary artery tumor. Surgical resection of the primary pulmonary artery sarcoma and reconstruction of the central pulmonary arteries, followed by adjuvant chemoradiotherapy, provided significant improvement in his clinical symptoms.

  14. Crumpling of a Stiff Tethered Membrane

    NASA Astrophysics Data System (ADS)

    Åström, J. A.; Timonen, J.; Karttunen, Mikko

    2004-12-01

    A first-principles numerical model for crumpling of a stiff tethered membrane is introduced. This model displays wrinkles, ridge formation, ridge collapse, and initiation of stiffness divergence. The amplitude and wavelength of the wrinkles and the scaling exponent of the stiffness divergence are consistent with both theory and experiment. Close to the stiffness divergence further buckling is hindered by the nonzero thickness of the membrane, and its elastic behavior becomes similar to that of dry granular media. No change in the distribution of contact forces can be observed at the crossover, implying that the network of ridges is then simultaneously a granular force-chain network.

  15. The Autophagy Enhancer Spermidine Reverses Arterial Aging

    PubMed Central

    LaRocca, Thomas J.; Gioscia-Ryan, Rachel A.; Hearon, Christopher M.; Seals, Douglas R.

    2013-01-01

    Arterial aging, characterized by stiffening of large elastic arteries and the development of arterial endothelial dysfunction, increases cardiovascular disease (CVD) risk. We tested the hypothesis that spermidine, a nutrient associated with the anti-aging process autophagy, would improve arterial aging. Aortic pulse wave velocity (aPWV), a measure of arterial stiffness, was ~20% greater in old (O, 28 months) compared with young C57BL6 mice (Y, 4 months, P < 0.05). Arterial endothelium-dependent dilation (EDD), a measure of endothelial function, was ~25% lower in O (P < 0.05 vs. Y) due to reduced nitric oxide (NO) bioavailability. These impairments were associated with greater arterial oxidative stress (nitrotyrosine), superoxide production, and protein cross-linking (advanced glycation end-products, AGEs) in O (all P < 0.05). Spermidine supplementation normalized aPWV, restored NO-mediated EDD and reduced nitrotyrosine, superoxide, AGEs and collagen in O. These effects of spermidine were associated with enhanced arterial expression of autophagy markers, and in vitro experiments demonstrated that vascular protection by spermidine was autophagy-dependent. Our results indicate that spermidine exerts a potent anti-aging influence on arteries by increasing NO bioavailability, reducing oxidative stress, modifying structural factors and enhancing autophagy. Spermidine may be a promising nutraceutical treatment for arterial aging and prevention of age-associated CVD. PMID:23612189

  16. Acute arterial occlusion - kidney

    MedlinePlus

    Acute renal arterial thrombosis; Renal artery embolism; Acute renal artery occlusion; Embolism - renal artery ... kidneys need a good blood supply. The main artery to the kidney is called the renal artery. ...

  17. The mechanical buckling of curved arteries.

    PubMed

    Han, Hai-Chao

    2009-06-01

    Though tortuosity and kinking are often observed in various arteries and arterioles, little is known about the underlying mechanisms. This paper presents a biomechanical analysis of bent buckling in long arterial segments with a small initial curvature using a thick-walled elastic cylindrical arterial model. The critical buckling pressure was established as a function of wall stiffness, wall dimensions, and the axial tension (or axial stretch ratio). The effects of both wall dimensions and axial stretch ratio on the critical pressure, as well as the thin-walled approximation were discussed. The buckling equation sheds light on the biomechanical mechanism of artery tortuosity and provides guidance for the development of new techniques to treat and prevent artery tortuosity and kinking.

  18. Effects of repeated Achilles tendon vibration on triceps surae stiffness and reflex excitability.

    PubMed

    Lapole, Thomas; Pérot, Chantal

    2011-02-01

    Clinical studies frequently report an increase in stiffness and a loss of range of motion at joints placed in disuse or immobilization. This is notably the case for subjects maintained in bed for a long period, whilst their joints are not affected. Recently we documented on healthy subjects the benefit in terms of force and activation capacities of the triceps surae offered by vibrations applied to the Achilles tendon. Knowing that stiffness changes may contribute to force changes, the aim of the present study was to investigate the effects of tendon vibration on the triceps surae stiffness of healthy subjects. The vibration program consisted in 14 days of 1h daily Achilles tendon vibration applied at rest. Nineteen healthy students were involved in this study. Before and at the end of the vibration program, musculo-tendinous stiffness in active conditions was determined by use of a quick-release test. Passive stiffness was also analyzed by a flexibility test: passive torque-angle relationships were established from maximal plantar-flexion to maximal dorsiflexion. Passive stiffness indexes at 10°, 15° and 20° dorsiflexion were defined as the slope of the relationships at the corresponding angle. Tendinous reflex, influenced by stiffness values, was also investigated as well as the H reflex to obtain an index of the central reflex excitability. After the program, musculo-tendinous stiffness was significantly decreased (p=.01). At the same time, maximal passive dorsiflexion was increased (p=.005) and passive stiffness indexes at 10°, 15° and 20° dorsiflexion decreased (p<.001; p<.001 and p=.011, respectively). Tendinous reflex also significantly decreased. As the triceps surae parameters are diminished after the vibration program, it could be beneficial to immobilized persons as hypo-activity is known to increase muscular stiffness.

  19. Impact of excess body weight on arterial structure, function, and blood pressure in firefighters.

    PubMed

    Fahs, Christopher A; Smith, Denise L; Horn, Gavin P; Agiovlasitis, Stamatis; Rossow, Lindy M; Echols, George; Heffernan, Kevin S; Fernhall, Bo

    2009-11-15

    Cardiovascular disease is the leading cause of death among firefighters. The purpose of the present study was to examine the effect of excess body weight on arterial structure and function and blood pressure (BP) in relatively young, apparently healthy, firefighters. The body mass index, brachial BP, carotid BP, aortic BP, radial augmentation index, central pulse wave velocity, forearm blood flow, forearm vasodilatory capacity, carotid arterial compliance, carotid intima-media thickness, and brachial flow-mediated dilation were assessed in 110 firefighters (aged 29.7 +/- 8.0 years). The group was divided into equal tertiles according to the body mass index (<25.9, 25.9 to 29.4, and >or=29.5 kg/m(2)). Group differences in hemodynamics, anthropometrics, microvascular function, and macrovascular structure and function were tested using multivariate analysis of variance. The obese group was older, heavier, and had a larger waist circumference compared to the lean and overweight groups (p <0.05). The overweight group was also older, heavier, and had a larger waist circumference than the lean group (p <0.05). Compared to the lean group, the overweight and obese groups had a greater systolic BP (p <0.05). The obese group also had a significantly greater mean arterial BP and carotid systolic BP than the lean group (p <0.05). The obese group had greater beta stiffness and elastic modulus compared to the lean and overweight groups (p <0.05), but no group differences were found in endothelial function. In conclusion, in a population of relatively young firefighters, an increased body mass index was associated with elevated peripheral BP and arterial stiffness, with no apparent decrements in endothelial function.

  20. Multi-scale computational model of three-dimensional hemodynamics within a deformable full-body arterial network

    SciTech Connect

    Xiao, Nan; Humphrey, Jay D.; Figueroa, C. Alberto

    2013-07-01

    In this article, we present a computational multi-scale model of fully three-dimensional and unsteady hemodynamics within the primary large arteries in the human. Computed tomography image data from two different patients were used to reconstruct a nearly complete network of the major arteries from head to foot. A linearized coupled-momentum method for fluid–structure-interaction was used to describe vessel wall deformability and a multi-domain method for outflow boundary condition specification was used to account for the distal circulation. We demonstrated that physiologically realistic results can be obtained from the model by comparing simulated quantities such as regional blood flow, pressure and flow waveforms, and pulse wave velocities to known values in the literature. We also simulated the impact of age-related arterial stiffening on wave propagation phenomena by progressively increasing the stiffness of the central arteries and found that the predicted effects on pressure amplification and pulse wave velocity are in agreement with findings in the clinical literature. This work demonstrates the feasibility of three-dimensional techniques for simulating hemodynamics in a full-body compliant arterial network.

  1. Analysis of Arterial Mechanics During Head-down Tilt Bed Rest

    NASA Technical Reports Server (NTRS)

    Elliot, Morgan; Martin, David S.; Westby, Christian M.; Stenger, Michael B.; Platts, Steve

    2014-01-01

    Arterial health may be affected by microgravity or ground based analogs of spaceflight, as shown by an increase in thoracic aorta stiffness1. Head-down tilt bed rest (HDTBR) is often used as a ground-based simulation of spaceflight because it induces physiological changes similar to those that occur in space2, 3. This abstract details an analysis of arterial stiffness (a subclinical measure of atherosclerosis), the distensibility coefficient (DC), and the pressure-strain elastic modulus (PSE) of the arterial walls during HDTBR. This project may help determine how spaceflight differentially affects arterial function in the upper vs. lower body.

  2. Nonparticipatory Stiffness in the Male Perioral Complex

    ERIC Educational Resources Information Center

    Chu, Shin-Ying; Barlow, Steven M.; Lee, Jaehoon

    2009-01-01

    Purpose: The objective of this study was to extend previous published findings in the authors' laboratory using a new automated technology to quantitatively characterize nonparticipatory perioral stiffness in healthy male adults. Method: Quantitative measures of perioral stiffness were sampled during a nonparticipatory task using a…

  3. Stiff person syndrome: a case report.

    PubMed

    Kelly, Patricia A; Kuberski, Carolyn

    2014-08-01

    The case report features a patient who had a diagnosis of a common type of breast cancer with an uncommon neurologic syndrome. She had extreme pain and progressive stiffness with cognitive and functional decline. This article includes the pathogenesis and treatment options for a rare, but treatable, autoimmune disorder of malignancy called stiff person syndrome.

  4. Stiffness Control of Surgical Continuum Manipulators

    PubMed Central

    Mahvash, Mohsen; Dupont, Pierre E.

    2013-01-01

    This paper introduces the first stiffness controller for continuum robots. The control law is based on an accurate approximation of a continuum robot’s coupled kinematic and static force model. To implement a desired tip stiffness, the controller drives the actuators to positions corresponding to a deflected robot configuration that produces the required tip force for the measured tip position. This approach provides several important advantages. First, it enables the use of robot deflection sensing as a means to both sense and control tip forces. Second, it enables stiffness control to be implemented by modification of existing continuum robot position controllers. The proposed controller is demonstrated experimentally in the context of a concentric tube robot. Results show that the stiffness controller achieves the desired stiffness in steady state, provides good dynamic performance, and exhibits stability during contact transitions. PMID:24273466

  5. Stiffness Control of Surgical Continuum Manipulators.

    PubMed

    Mahvash, Mohsen; Dupont, Pierre E

    2011-04-01

    This paper introduces the first stiffness controller for continuum robots. The control law is based on an accurate approximation of a continuum robot's coupled kinematic and static force model. To implement a desired tip stiffness, the controller drives the actuators to positions corresponding to a deflected robot configuration that produces the required tip force for the measured tip position. This approach provides several important advantages. First, it enables the use of robot deflection sensing as a means to both sense and control tip forces. Second, it enables stiffness control to be implemented by modification of existing continuum robot position controllers. The proposed controller is demonstrated experimentally in the context of a concentric tube robot. Results show that the stiffness controller achieves the desired stiffness in steady state, provides good dynamic performance, and exhibits stability during contact transitions.

  6. Rolling Element Bearing Stiffness Matrix Determination (Presentation)

    SciTech Connect

    Guo, Y.; Parker, R.

    2014-01-01

    Current theoretical bearing models differ in their stiffness estimates because of different model assumptions. In this study, a finite element/contact mechanics model is developed for rolling element bearings with the focus of obtaining accurate bearing stiffness for a wide range of bearing types and parameters. A combined surface integral and finite element method is used to solve for the contact mechanics between the rolling elements and races. This model captures the time-dependent characteristics of the bearing contact due to the orbital motion of the rolling elements. A numerical method is developed to determine the full bearing stiffness matrix corresponding to two radial, one axial, and two angular coordinates; the rotation about the shaft axis is free by design. This proposed stiffness determination method is validated against experiments in the literature and compared to existing analytical models and widely used advanced computational methods. The fully-populated stiffness matrix demonstrates the coupling between bearing radial, axial, and tilting bearing deflections.

  7. Brachioradial arteries with anastomotic arteries connecting to brachial arteries bilaterally.

    PubMed

    Hong, Tong; Qiuhong, Dan; Haipeng, Cai

    2010-01-01

    We present a patient with a failed radial coronary angioplasty as a result of bilateral brachioradial arteries, the radial arteries anomalously originating from the axillary arteries. We review the literature concerning abnormal origins of the radial artery and propose the left ulnar artery as optimal access of choice in cases with a right brachioradial artery of relatively small size in its proximal part.

  8. Pulmonary Vascular Stiffness: Measurement, Modeling, and Implications in Normal and Hypertensive Pulmonary Circulations

    PubMed Central

    Hunter, Kendall S.; Lammers, Steven R.; Shandas, Robin

    2014-01-01

    This article introduces the concept of pulmonary vascular stiffness, discusses its increasingly recognized importance as a diagnostic marker in the evaluation of pulmonary vascular disease, and describes methods to measure and model it clinically, experimentally, and computationally. It begins with a description of systems-level methods to evaluate pulmonary vascular compliance and recent clinical efforts in applying such techniques to better predict patient outcomes in pulmonary arterial hypertension. It then progresses from the systems-level to the local level, discusses proposed methods by which upstream pulmonary vessels increase in stiffness, introduces concepts around vascular mechanics, and concludes by describing recent work incorporating advanced numerical methods to more thoroughly evaluate changes in local mechanical properties of pulmonary arteries. PMID:23733649

  9. A biomechanical model of artery buckling.

    PubMed

    Han, Hai-Chao

    2007-01-01

    The stability of arteries under blood pressure load is essential to the maintenance of normal arterial function and the loss of stability can lead to tortuosity and kinking that are associated with significant clinical complications. However, mechanical analysis of arterial bent buckling is lacking. To address this issue, this paper presents a biomechanical model of arterial buckling. Using an elastic cylindrical arterial model, the mechanical equations for arterial buckling were developed and the critical buckling pressure was found to be a function of the wall stiffness (Young's modulus), arterial radius, length, wall thickness, and the axial strain. Both the model equations and experimental results demonstrated that the critical pressure is related to the axial strain. Arteries may buckle and become tortuous due to reduced (subphysiological) axial strain, hypertensive pressure, and a weakened wall. These results are in accordance with, and provide a possible explanation to the clinical observations that hypertension and aging are the risk factors for arterial tortuosity and kinking. The current model is also applicable to veins and ureters.

  10. A Biomechanical Model of Artery Buckling

    PubMed Central

    Han, Hai-Chao

    2010-01-01

    The stability of arteries under blood pressure load is essential to the maintenance of normal arterial function and the loss of stability can lead to tortuosity and kinking that are associated with significant clinical complications. However, mechanical analysis of arterial bent buckling is lacking. To address this issue, this paper presents a biomechanical model of arterial buckling. Using a linear elastic cylindrical arterial model, the mechanical equations for arterial buckling were developed and the critical buckling pressure was found to be a function of the wall stiffness (Young’s modulus), arterial radius, length, wall thickness, and the axial strain. Both the model equations and experimental results demonstrated that the critical pressure is related to the axial strain. Arteries may buckle and become tortuous due to reduced (sub-physiological) axial strain, hypertensive pressure, and a weakened wall. These results are in accordance with, and provide a possible explanation to the clinical observations that these changes are the risk factors for arterial tortuosity and kinking. The current model is also applicable to veins and ureters. PMID:17689541

  11. Effect of wire tension on stiffness of tensioned fine wires in external fixation: a mechanical study.

    PubMed

    Antoci, Valentin; Voor, Michael J; Antoci, Valentin; Roberts, Craig S

    2007-09-01

    To determine the effect of changes in magnitude of transfixion wire tension on stiffness of fine-wire external-fixation load deformation, we compared results obtained with different wire tensions (50-140 kg) under identical conditions of central axial compression, medial compression-bending, posterior compression-bending, posteromedial compression-bending, and torsion. Stiffness values were calculated from the load-deformation and torque-angle curves. Tension of 140 kg provided the most stiffness, and there was a trend toward increasing overall stiffness with increasing wire tension. The 1.8-mm wires should be tensioned to at least 110 kg in most cases of fine-wire external fixation; compared with all tensions less than 110 kg, this tension provides significantly more mechanical stability in all loading modes.

  12. Topology optimization under stochastic stiffness

    NASA Astrophysics Data System (ADS)

    Asadpoure, Alireza

    Topology optimization is a systematic computational tool for optimizing the layout of materials within a domain for engineering design problems. It allows variation of structural boundaries and connectivities. This freedom in the design space often enables discovery of new, high performance designs. However, solutions obtained by performing the optimization in a deterministic setting may be impractical or suboptimal when considering real-world engineering conditions with inherent variabilities including (for example) variabilities in fabrication processes and operating conditions. The aim of this work is to provide a computational methodology for topology optimization in the presence of uncertainties associated with structural stiffness, such as uncertain material properties and/or structural geometry. Existing methods for topology optimization under deterministic conditions are first reviewed. Modifications are then proposed to improve the numerical performance of the so-called Heaviside Projection Method (HPM) in continuum domains. Next, two approaches, perturbation and Polynomial Chaos Expansion (PCE), are proposed to account for uncertainties in the optimization procedure. These approaches are intrusive, allowing tight and efficient coupling of the uncertainty quantification with the optimization sensitivity analysis. The work herein develops a robust topology optimization framework aimed at reducing the sensitivity of optimized solutions to uncertainties. The perturbation-based approach combines deterministic topology optimization with a perturbation method for the quantification of uncertainties. The use of perturbation transforms the problem of topology optimization under uncertainty to an augmented deterministic topology optimization problem. The PCE approach combines the spectral stochastic approach for the representation and propagation of uncertainties with an existing deterministic topology optimization technique. The resulting compact representations

  13. Altered diastolic function and aortic stiffness in Alzheimer’s disease

    PubMed Central

    Çalık, Ali Nazmi; Özcan, Kazım Serhan; Yüksel, Gülbün; Güngör, Barısş; Aruğarslan, Emre; Varlibas, Figen; Ekmekci, Ahmet; Osmonov, Damirbek; Tatlısu, Mustafa Adem; Karaca, Mehmet; Bolca, Osman; Erdinler, İzzet

    2014-01-01

    Background Alzheimer’s disease (AD) is closely linked to cardiovascular risk factors. Methods Echocardiographic studies were performed, including left ventricular diastolic functions, left and right atrial conduction times, and arterial stiffness parameters, namely stiffness index, pressure-strain elastic modulus, and distensibility, on 29 patients with AD and 24 age-matched individuals with normal cognitive function. Results The peak mitral flow velocity of the early rapid filling wave (E) was lower, and the peak velocity of the late filling wave caused by atrial contraction (A), deceleration time of peak E velocity, and isovolumetric relaxation time were higher in the AD group. The early myocardial peak (Ea) velocity was significantly lower in AD patients, whereas the late diastolic (Aa) velocity and E/Ea ratio were similar between the two groups. In Alzheimer patients, stiffness index and pressure-strain elastic modulus were higher, and distensibility was significantly lower in the AD group compared to the control. Interatrial electromechanical delay was significantly longer in the AD group. Conclusion Our findings suggest that patients with AD are more likely to have diastolic dysfunction, higher atrial conduction times, and increased arterial stiffness compared to the controls of same sex and similar age. PMID:25075180

  14. Wave reflection augments central systolic and pulse pressures during facial cooling.

    PubMed

    Edwards, David G; Roy, Matthew S; Prasad, Raju Y

    2008-06-01

    Cardiovascular events are more common in the winter months, possibly because of hemodynamic alterations in response to cold exposure. The purpose of this study was to determine the effect of acute facial cooling on central aortic pressure, arterial stiffness, and wave reflection. Twelve healthy subjects (age 23 +/- 3 yr; 6 men, 6 women) underwent supine measurements of carotid-femoral pulse wave velocity (PWV), brachial artery blood pressure, and central aortic pressure (via the synthesis of a central aortic pressure waveform by radial artery applanation tonometry and generalized transfer function) during a control trial (supine rest) and a facial cooling trial (0 degrees C gel pack). Aortic augmentation index (AI), an index of wave reflection, was calculated from the aortic pressure waveform. Measurements were made at baseline, 2 min, and 7 min during each trial. Facial cooling increased (P < 0.05) peripheral and central diastolic and systolic pressures. Central systolic pressure increased more than peripheral systolic pressure (22 +/- 3 vs. 15 +/- 2 mmHg; P < 0.05), resulting in decreased pulse pressure amplification ratio. Facial cooling resulted in a robust increase in AI and a modest increase in PWV (AI: -1.4 +/- 3.8 vs. 21.2 +/- 3.0 and 19.9 +/- 3.6%; PWV: 5.6 +/- 0.2 vs. 6.5 +/- 0.3 and 6.2 +/- 0.2 m/s; P < 0.05). Change in mean arterial pressure but not PWV predicted the change in AI, suggesting that facial cooling may increase AI independent of aortic PWV. Facial cooling and the resulting peripheral vasoconstriction are associated with an increase in wave reflection and augmentation of central systolic pressure, potentially explaining ischemia and cardiovascular events in the cold.

  15. Arterial calcifications

    PubMed Central

    Rennenberg, Roger J M W; Schurgers, Leon J; Kroon, Abraham A; Stehouwer, Coen D A

    2010-01-01

    Abstract Arterial calcifications as found with various imaging techniques, like plain X-ray, computed tomography or ultrasound are associated with increased cardiovascular risk. The prevalence of arterial calcification increases with age and is stimulated by several common cardiovascular risk factors. In this review, the clinical importance of arterial calcification and the currently known proteins involved are discussed. Arterial calcification is the result of a complex interplay between stimulating (bone morphogenetic protein type 2 [BMP-2], RANKL) and inhibitory (matrix Gla protein, BMP-7, osteoprotegerin, fetuin-A, osteopontin) proteins. Vascular calcification is especially prevalent and related to adverse outcome in patients with renal insufficiency and diabetes mellitus. We address the special circumstances and mechanisms in these patient groups. Treatment and prevention of arterial calcification is possible by the use of specific drugs. However, it remains to be proven that reduction of vascular calcification in itself leads to a reduced cardiovascular risk. PMID:20716128

  16. POA 02-2 ATHEROGENIC VASCULAR STIFFNESS AND HYPERTENSION: CAUSE OR EFFECT?

    PubMed

    Avolio, Alberto

    2016-09-01

    Blood vessels function as conduits for distribution of blood throughout the circulatory system. Large arteries, in addition to the essential conduit function, also serve to dampen the effect of pulsatile ventricular ejection that generates pulsatile pressure with each cardiac cycle; that is, they exhibit a 'cushion' function. The conduit function can be compromised by intimal effects that cause obstruction to flow, generally attributed to plaque formation due to intimal changes affected by atherosclerotic processes. The cushion function is affected by medial changes altering the wall stiffness, and so the capacity of arteries to absorb pulsatile energy. This modulates pulse pressure through changes in wall stiffness and vessel compliance and characteristics of wave propagation. In addition, these changes are further affected by arterial pressure. Intimal changes related to obstructive phenomena are generally thought to be related to atherosclerosis, and medial change affecting vessel buffering capacity related to arteriosclerosis. This lecture explores aspects that characterise the potential inter-relationship between the two phenomena and arterial pressure. With advances in molecular biology, imaging and computational modelling, pathways involved in cell-signalling affecting intimal changes through endothelial function and medial changes through both endothelial and smooth muscle function are increasingly being identified. The nitric oxide pathway has been shown to influence protein expression affecting the stiffness of the extracellular matrix through alteration of cross-link formation. In turn, bioavailablity of endothelial nitric oxide is also affected by wall stiffness. Changes in distribution of internal wall stress due to altered structure of the wall matrix can alter the mechanotransduction effects on the endothelial cell, modifying intimal changes. The phenotypic transdifferentiation of the smooth muscle cell is associated with changes in structural

  17. Extracellular Matrix Disarray as A Mechanism for Greater Abdominal vs. Thoracic Aortic Stiffness with Aging in Primates

    PubMed Central

    Zhang, Jie; Zhao, Xin; Vatner, Dorothy E; McNulty, Tara; Bishop, Sanford; Sun, Zhe; Shen, You-Tang; Chen, Li; Meininger, Gerald A; Vatner, Stephen F

    2016-01-01

    Objective Increased vascular stiffness is central to the pathophysiology of aging, hypertension, diabetes and atherosclerosis. However, relatively few studies have examined vascular stiffness in both the thoracic and abdominal aorta with aging, despite major differences in anatomy, embryological origin and relation to aortic aneurysm. Approach and Results The two other unique features of this study were 1) to study young (9±1 years) and old (26±1 years) male monkeys, and 2) to study direct and continuous measurements of aortic pressure and thoracic and abdominal aortic diameters in conscious monkeys. As expected, aortic stiffness, β, was increased p<0.05, 2–3 fold, in old vs. young thoracic aorta, and augmented further with superimposition of acute hypertension with phenylephrine. Surprisingly, stiffness was not greater in old thoracic aorta than young abdominal aorta. These results can be explained in part by the collagen/elastin ratio, but more importantly, by disarray of collagen and elastin, which correlated best with vascular stiffness. However, vascular smooth muscle cell stiffness, was not different in thoracic vs. abdominal aorta in either young or old monkeys. Conclusions Thus, aortic stiffness increases with aging as expected, but the most severe increases in aortic stiffness observed in the abdominal aorta is novel, where values in young monkeys equaled, or even exceeded, values of thoracic aortic stiffness in old monkeys. These results can be explained by alterations in collagen/elastin ratio, but even more importantly by collagen and elastin disarray. PMID:26891739

  18. Importance of DNA stiffness in protein-DNA binding specificity

    NASA Astrophysics Data System (ADS)

    Hogan, M. E.; Austin, R. H.

    1987-09-01

    From the first high-resolution structure of a repressor bound specifically to its DNA recognition sequence1 it has been shown that the phage 434 repressor protein binds as a dimer to the helix. Tight, local interactions are made at the ends of the binding site, causing the central four base pairs (bp) to become bent and overtwisted. The centre of the operator is not in contact with protein but repressor binding affinity can be reduced at least 50-fold in response to a sequence change there2. This observation might be explained should the structure of the intervening DNA segment vary with its sequence, or if DNA at the centre of the operator resists the torsional and bending deformation necessary for complex formation in a sequence dependent fashion. We have considered the second hypothesis by demonstrating that DNA stiffness is sequence dependent. A method is formulated for calculating the stiffness of any particular DNA sequence, and we show that this predicted relationship between sequence and stiffness can explain the repressor binding data in a quantitative manner. We propose that the elastic properties of DNA may be of general importance to an understanding of protein-DNA binding specificity.

  19. Model-Based Estimation of Knee Stiffness

    PubMed Central

    Pfeifer, Serge; Vallery, Heike; Hardegger, Michael; Riener, Robert; Perreault, Eric J.

    2013-01-01

    During natural locomotion, the stiffness of the human knee is modulated continuously and subconsciously according to the demands of activity and terrain. Given modern actuator technology, powered transfemoral prostheses could theoretically provide a similar degree of sophistication and function. However, experimentally quantifying knee stiffness modulation during natural gait is challenging. Alternatively, joint stiffness could be estimated in a less disruptive manner using electromyography (EMG) combined with kinetic and kinematic measurements to estimate muscle force, together with models that relate muscle force to stiffness. Here we present the first step in that process, where we develop such an approach and evaluate it in isometric conditions, where experimental measurements are more feasible. Our EMG-guided modeling approach allows us to consider conditions with antagonistic muscle activation, a phenomenon commonly observed in physiological gait. Our validation shows that model-based estimates of knee joint stiffness coincide well with experimental data obtained using conventional perturbation techniques. We conclude that knee stiffness can be accurately estimated in isometric conditions without applying perturbations, which presents an important step towards our ultimate goal of quantifying knee stiffness during gait. PMID:22801482

  20. Stiff substrates enhance cultured neuronal network activity.

    PubMed

    Zhang, Quan-You; Zhang, Yan-Yan; Xie, Jing; Li, Chen-Xu; Chen, Wei-Yi; Liu, Bai-Lin; Wu, Xiao-an; Li, Shu-Na; Huo, Bo; Jiang, Lin-Hua; Zhao, Hu-Cheng

    2014-08-28

    The mechanical property of extracellular matrix and cell-supporting substrates is known to modulate neuronal growth, differentiation, extension and branching. Here we show that substrate stiffness is an important microenvironmental cue, to which mouse hippocampal neurons respond and integrate into synapse formation and transmission in cultured neuronal network. Hippocampal neurons were cultured on polydimethylsiloxane substrates fabricated to have similar surface properties but a 10-fold difference in Young's modulus. Voltage-gated Ca(2+) channel currents determined by patch-clamp recording were greater in neurons on stiff substrates than on soft substrates. Ca(2+) oscillations in cultured neuronal network monitored using time-lapse single cell imaging increased in both amplitude and frequency among neurons on stiff substrates. Consistently, synaptic connectivity recorded by paired recording was enhanced between neurons on stiff substrates. Furthermore, spontaneous excitatory postsynaptic activity became greater and more frequent in neurons on stiff substrates. Evoked excitatory transmitter release and excitatory postsynaptic currents also were heightened at synapses between neurons on stiff substrates. Taken together, our results provide compelling evidence to show that substrate stiffness is an important biophysical factor modulating synapse connectivity and transmission in cultured hippocampal neuronal network. Such information is useful in designing instructive scaffolds or supporting substrates for neural tissue engineering.

  1. Cooperative effects of matrix stiffness and fluid shear stress on endothelial cell behavior.

    PubMed

    Kohn, Julie C; Zhou, Dennis W; Bordeleau, François; Zhou, Allen L; Mason, Brooke N; Mitchell, Michael J; King, Michael R; Reinhart-King, Cynthia A

    2015-02-03

    Arterial hemodynamic shear stress and blood vessel stiffening both significantly influence the arterial endothelial cell (EC) phenotype and atherosclerosis progression, and both have been shown to signal through cell-matrix adhesions. However, the cooperative effects of fluid shear stress and matrix stiffness on ECs remain unknown. To investigate these cooperative effects, we cultured bovine aortic ECs on hydrogels matching the elasticity of the intima of compliant, young, or stiff, aging arteries. The cells were then exposed to laminar fluid shear stress of 12 dyn/cm(2). Cells grown on more compliant matrices displayed increased elongation and tighter EC-cell junctions. Notably, cells cultured on more compliant substrates also showed decreased RhoA activation under laminar shear stress. Additionally, endothelial nitric oxide synthase and extracellular signal-regulated kinase phosphorylation in response to fluid shear stress occurred more rapidly in ECs cultured on more compliant substrates, and nitric oxide production was enhanced. Together, our results demonstrate that a signaling cross talk between stiffness and fluid shear stress exists within the vascular microenvironment, and, importantly, matrices mimicking young and healthy blood vessels can promote and augment the atheroprotective signals induced by fluid shear stress. These data suggest that targeting intimal stiffening and/or the EC response to intima stiffening clinically may improve vascular health.

  2. Basic study of intrinsic elastography: Relationship between tissue stiffness and propagation velocity of deformation induced by pulsatile flow

    NASA Astrophysics Data System (ADS)

    Nagaoka, Ryo; Iwasaki, Ryosuke; Arakawa, Mototaka; Kobayashi, Kazuto; Yoshizawa, Shin; Umemura, Shin-ichiro; Saijo, Yoshifumi

    2015-07-01

    We proposed an estimation method for a tissue stiffness from deformations induced by arterial pulsation, and named this proposed method intrinsic elastography (IE). In IE, assuming that the velocity of the deformation propagation in tissues is closely related to the stiffness, the propagation velocity (PV) was estimated by spatial compound ultrasound imaging with a high temporal resolution of 1 ms. However, the relationship between tissue stiffness and PV has not been revealed yet. In this study, the PV of the deformation induced by the pulsatile pump was measured by IE in three different poly(vinyl alcohol) (PVA) phantoms of different stiffnesses. The measured PV was compared with the shear wave velocity (SWV) measured by shear wave imaging (SWI). The measured PV has trends similar to the measured SWV. These results obtained by IE in a healthy male show the possibility that the mechanical properties of living tissues could be evaluated by IE.

  3. Wave propagation of myocardial stretch: correlation with myocardial stiffness.

    PubMed

    Pislaru, Cristina; Pellikka, Patricia A; Pislaru, Sorin V

    2014-01-01

    The mechanism of flow propagation during diastole in the left ventricle (LV) has been well described. Little is known about the associated waves propagating along the heart walls. These waves may have a mechanism similar to pulse wave propagation in arteries. The major goal of the study was to evaluate the effect of myocardial stiffness and preload on this wave transmission. Longitudinal late diastolic deformation and wave speed (Vp) of myocardial stretch in the anterior LV wall were measured using sonomicrometry in 16 pigs. Animals with normal and altered myocardial stiffness (acute myocardial infarction) were studied with and without preload alterations. Elastic modulus estimated from Vp (E VP; Moens-Korteweg equation) was compared to incremental elastic modulus obtained from exponential end-diastolic stress-strain relation (E SS). Myocardial distensibility and α- and β-coefficients of stress-strain relations were calculated. Vp was higher at reperfusion compared to baseline (2.6 ± 1.3 vs. 1.3 ± 0.4 m/s; p = 0.005) and best correlated with E SS (r2 = 0.80, p < 0.0001), β-coefficient (r2 = 0.78, p < 0.0001), distensibility (r2 = 0.47, p = 0.005), and wall thickness/diameter ratio (r2 = 0.42, p = 0.009). Elastic moduli (E VP and E SS) were strongly correlated (r2 = 0.83, p < 0.0001). Increasing preload increased Vp and E VP and decreased distensibility. At multivariate analysis, E SS, wall thickness, and end-diastolic and systolic LV pressures were independent predictors of Vp (r2 model = 0.83, p < 0.0001). In conclusion, the main determinants of wave propagation of longitudinal myocardial stretch were myocardial stiffness and LV geometry and pressure. This local wave speed could potentially be measured noninvasively by echocardiography.

  4. Characteristics of high-stiffness superconducting bearing

    SciTech Connect

    Okano, M.; Tamada, N.; Fuchino, S.; Ishii, I.

    1996-07-01

    Magnetic bearings using a high-Tc superconductor have been studied. Generally the bearing makes use of the pinning effects to get the levitation force. The stiffness of the bearing, however, is extremely low as compared with industrial-scale conventional one. To improve the bearing stiffness the authors propose a disc-type repulsive superconducting thrust bearing with a slit for the restraint of the flux. Both theoretical and experimental evaluation on the load performance was carried out, and it is clarified that the proposed superconducting bearing has higher stiffness.

  5. Peripheral Artery Disease

    MedlinePlus

    ... Physician Resources Professions Site Index A-Z Peripheral Artery Disease (PAD) Peripheral artery disease (PAD) refers to ... is peripheral artery disease treated? What is peripheral artery disease (PAD)? Peripheral artery disease, or PAD, refers ...

  6. Mesenteric artery ischemia

    MedlinePlus

    ... bowel - mesenteric; Dead gut - mesenteric; Atherosclerosis - mesenteric artery; Hardening of the arteries - mesenteric artery ... the aorta, the main artery from the heart. Hardening of the arteries occurs when fat, cholesterol, and ...

  7. Ruptured retinal arterial macroaneurysm: diagnosis and management.

    PubMed

    Speilburg, Ashley M; Klemencic, Stephanie A

    2014-01-01

    Retinal arterial macroaneurysm is an acquired, focal dilation of a retinal artery, typically occurring within the first three bifurcations of the central retinal artery. The clinical presentation of a retinal arterial macroaneurysm is highly variable, making initial diagnosis difficult and differentials many. Identification of retinal arterial macroaneurysms is crucial to appropriately co-manage with the primary care physician for hypertension control. Prognosis is generally good and observation is often an adequate treatment. However, in cases of macular threat or involvement, some treatment options are available and referral to a retinal specialist is indicated.

  8. Abnormal arterial flows by a distributed model of the fetal circulation.

    PubMed

    van den Wijngaard, Jeroen P H M; Westerhof, Berend E; Faber, Dirk J; Ramsay, Margaret M; Westerhof, Nico; van Gemert, Martin J C

    2006-11-01

    Modeling the propagation of blood pressure and flow along the fetoplacental arterial tree may improve interpretation of abnormal flow velocity waveforms in fetuses. The current models, however, either do not include a wide range of gestational ages or do not account for variation in anatomical, vascular, or rheological parameters. We developed a mathematical model of the pulsating fetoumbilical arterial circulation using Womersley's oscillatory flow theory and viscoelastic arterial wall properties. Arterial flow waves are calculated at different arterial locations from which the pulsatility index (PI) can be determined. We varied blood viscosity, placental and brain resistances, placental compliance, heart rate, stiffness of the arterial wall, and length of the umbilical arteries. The PI increases in the umbilical artery and decreases in the cerebral arteries, as a result of increasing placental resistance or decreasing brain resistance. Both changes in resistance decrease the flow through the placenta. An increased arterial stiffness increases the PIs in the entire fetoplacental circulation. Blood viscosity and peripheral bed compliance have limited influence on the flow profiles. Bradycardia and tachycardia increase and decrease the PI in all arteries, respectively. Umbilical arterial length has limited influence on the PI but affects the mean arterial pressure at the placental cord insertion. The model may improve the interpretation of arterial flow pulsations and thus may advance both the understanding of pathophysiological processes and clinical management.

  9. ME 04-1 ASSESSMENT OF CENTRAL BLOOD PRESSURE FOR CLINICAL APPLICATION.

    PubMed

    Morgan, Trefor

    2016-09-01

    Central Systolic Blood Pressure is lower than brachial artery blood Pressure due to reflected waves and greater augmentation at the periphery. The relationship is not consistent during life and alters with aging of the blood vessels. Increasing stiffness means that a greater component of the reflected waves returns to the central aorta during systolic contraction causing more amplification and a higher systolic blood pressure. Diastolic blood pressure on the other hand is always higher in the aorta than at the periphery allowing blood flow. The heart contracts against the central aortic pressure and it is likely that cardiac hypertrophy iis dependent on this value. Likewise damage to the larger blood vessels are more likely to be related to central rather than brachial pressure and this may reflect a greater association with stroke.Central aortic pressure may be measured directly but not practicable in large groups of patients or indirect using tonometry and transformation equations. While the correlation is not ideal there is significant correlation. Central aortic systolic blood pressure is associated with mortality, stokes, heart attacks and cardiac hypertrophy with a higher p value than brachial artery blood pressure. The question is whether it is an independent predictor of these events and whether measurement is justifiable in clinical practice. There is a strong correlation between aortic and brachial systolic blood pressure reducing the ability of the central BP to be independent. In addition the question arises does the measurement of central systolic BP provide extra information above pulse wave velocity?Measuring central systolic blood pressure has allowed an exploration of the effects of different drug classes on central systolic blood pressure. Thus beta blockers increase the amplification index meaning that the fall in central systolic blood pressure is not as great as the fall in brachial artery systolic BP. This may explain in part why beta blockers

  10. Macroscopic Stiffness of Breast Tumors Predicts Metastasis

    PubMed Central

    Fenner, Joseph; Stacer, Amanda C.; Winterroth, Frank; Johnson, Timothy D.; Luker, Kathryn E.; Luker, Gary D.

    2014-01-01

    Mechanical properties of tumors differ substantially from normal cells and tissues. Changes in stiffness or elasticity regulate pro-metastatic behaviors of cancer cells, but effects have been documented predominantly in isolated cells or in vitro cell culture systems. To directly link relative stiffness of tumors to cancer progression, we combined a mouse model of metastatic breast cancer with ex vivo measurements of bulk moduli of freshly excised, intact tumors. We found a high, inverse correlation between bulk modulus of resected tumors and subsequent local recurrence and metastasis. More compliant tumors were associated with more frequent, larger local recurrences and more extensive metastases than mice with relatively stiff tumors. We found that collagen content of resected tumors correlated with bulk modulus values. These data establish that relative differences in tumor stiffness correspond with tumor progression and metastasis, supporting further testing and development of tumor compliance as a prognostic biomarker in breast cancer. PMID:24981707

  11. High Blood Pressure States in Children, Adolescents, and Young Adults Associate Accelerated Vascular Aging, with a Higher Impact in Females' Arterial Properties.

    PubMed

    Curcio, S; García-Espinosa, V; Castro, J M; Peluso, G; Marotta, M; Arana, M; Chiesa, P; Giachetto, G; Bia, D; Zócalo, Yanina

    2017-03-13

    The aims of the study were to determine (1) whether the presence of High blood pressure (HBP) states in the youth associate a steeper rate of age-related change in arterial geometrical and wall properties with respect to subjects with no previous cardiovascular risk factor (CRF) exposure, (2) in which parameters and in what magnitude, and (3) the existence of a gender-related difference in the impact of this condition on arterial properties. 300 individuals (mean/range: 15/4-29 years; 133 females) were included. Two groups were assembled: (1) Reference: nonprevious exposure to traditional CRF and (2) HBP: subjects with arterial hypertension and/or elevated blood pressure (BP) levels during the study. Additionally, HBP subjects were separated in BP-related subgroups. Measured parameters were (1) central (aortic) arterial BP and aortic pulse wave analysis parameters, (2) carotid and femoral artery local (pressure-strain elastic modulus) and regional (pulse wave velocity; PWV) stiffness, and (3) arterial diameters and carotid intima-media thickness (CIMT). Age-related changes in these parameters (absolute values and z-scores) were explored by obtaining simple linear regression models for each group. HBP presented a steeper rate of change (accelerated vascular aging; VA) for most of the parameters assessed, mainly in central (aortic) hemodynamics. VA increased as the HBP level got higher. Both males' and females' aging rates were affected by this condition, but females presented a more marked relative age-related increase with HBP exposure. HBP states in the youth gradually associate accelerated VA, with a progressive hemodynamic-structural-functional onset of damage, with females presenting a more marked relative HBP-associated arterial repercussion.

  12. Artery Buckling: New Phenotypes, Models, and Applications

    PubMed Central

    Han, Hai-Chao; Chesnutt, Jennifer K. W.; Garcia, Justin R.; Liu, Qin; Wen, Qi

    2012-01-01

    Arteries are under significant mechanical loads from blood pressure, flow, tissue tethering, and body movement. It is critical that arteries remain patent and stable under these loads. This review summarizes the common forms of buckling that occur in blood vessels including cross-sectional collapse, longitudinal twist buckling, and bent buckling. The phenomena, model analyses, experimental measurements, effects on blood flow, and clinical relevance are discussed. It is concluded that mechanical buckling is an important issue for vasculature, in addition to wall stiffness and strength, and requires further studies to address the challenges. Studies of vessel buckling not only enrich vascular biomechanics but also have important clinical applications. PMID:23192265

  13. OroSTIFF: Face-referenced measurement of perioral stiffness in health and disease

    PubMed Central

    Chu, Shin-Ying; Kieweg, Douglas; Lee, Jaehoon

    2010-01-01

    A new device and automated measurement technology known as OroSTIFF is described to characterize non-participatory perioral stiffness in healthy adults for eventual application to patients with orofacial movement disorders associated with neuromotor disease, traumatic injury, or congenital clefts of the upper lip. Previous studies of perioral biomechanics required head stabilization for extended periods of time during measurement which precluded sampling patients with involuntary body/head movements (dyskinesias), or pediatric subjects. The OroSTIFF device is face-referenced and avoids the complications associated with head-restraint. Supporting data of non-participatory perioral tissue stiffness using OroSTIFF are included from 10 male and 10 female healthy subjects. The OroSTIFF device incorporates a pneumatic glass air cylinder actuator instrumented for pressure, and an integrated subminiature displacement sensor to encode lip aperture. Perioral electromyograms were simultaneously sampled to confirm passive muscle state for the superior and inferior divisions of the orbicularis oris muscles. Perioral stiffness, derived as a quotient from resultant force (ΔF) and interangle span (ΔX), was modeled with multilevel regression techniques. Real-time calculation of the perioral stiffness function demonstrated a significant quadratic relation between imposed interangle stretch and resultant force. This stiffness growth function also differed significantly between males and females. This study demonstrates the OroSTIFF ‘proof-of-concept’ for cost-effective non-invasive stimulus generation and derivation of perioral stiffness in a group of healthy unrestrained adults, and a case study to illustrate the dose-dependent effects of Levodopa on perioral stiffness in an individual with advanced Parkinson’s disease who exhibited marked dyskinesia and rigidity. PMID:20185131

  14. Stiffness transition in anisotropic fiber nets

    NASA Astrophysics Data System (ADS)

    Åström, J. A.; Sunil Kumar, P. B.; Karttunen, Mikko

    2012-08-01

    We demonstrate the existence of a percolationlike stiffness transition in fiber networks with a bidisperse orientation distribution and with fiber densities clearly above the geometrical and the ordinary stiffness transition. The fibers are oriented parallel and perpendicular to a strain direction and they have a large fiber aspect ratio. The stiffness K of the fiber nets can be described by a scaling relation, K∝ταg[(ɛ-ɛc)/τ-β], where τ is the fraction of fibers parallel to strain. g is a scaling function that is roughly described by a power law g(x)∝xγ for stiffness above the transition and by a constant below the transition. The transition point is characterized by qualitative changes in the distribution of the elastic deformation energy of the fibers, the deformation mode of the fibers, the effective Poisson ratio of the nets, the distribution of elastic energy on fibers and cross links, and the ratio of elastic and viscous dissipation energy. This transition opens the possibility of extreme stiffness variations with minimal mesh manipulations in the vicinity of the transition (i.e., a stiffness gate). It is possible that this transition affects the mechanical behavior of the cytoskeleton in cells.

  15. Stiffness of Railway Soil-Steel Structures

    NASA Astrophysics Data System (ADS)

    Machelski, Czesław

    2015-12-01

    The considerable influence of the soil backfill properties and that of the method of compacting it on the stiffness of soil-steel structures is characteristic of the latter. The above factors (exhibiting randomness) become apparent in shell deformation measurements conducted during construction and proof test loading. A definition of soil-shell structure stiffness, calculated on the basis of shell deflection under the service load, is proposed in the paper. It is demonstrated that the stiffness is the inverse of the deflection influence function used in structural mechanics. The moving load methodology is shown to be useful for testing, since it makes it possible to map the shell deflection influence line also in the case of group loads (concentrated forces), as in bridges. The analyzed cases show that the shell's span, geometry (static scheme) and the height of earth fill influence the stiffness of the structure. The soil-steel structure's characteristic parameter in the form of stiffness k is more suitable for assessing the quality of construction works than the proposed in code geometric index ω applied to beam structures. As shown in the given examples, parameter k is more effective than stiffness parameter λ used to estimate the deformation of soil-steel structures under construction. Although the examples concern railway structures, the methodology proposed in the paper is suitable also for road bridges.

  16. Comparative study of diastolic filling under varying left ventricular wall stiffness

    NASA Astrophysics Data System (ADS)

    Mekala, Pritam; Santhanakrishnan, Arvind

    2014-11-01

    Pathological remodeling of the human cardiac left ventricle (LV) is observed in hypertensive heart failure as a result of pressure overload. Myocardial stiffening occurs in these patients prior to chronic maladaptive changes, resulting in increased LV wall stiffness. The goal of this study was to investigate the change in intraventricular filling fluid dynamics inside a physical model of the LV as a function of wall stiffness. Three LV models of varying wall stiffness were incorporated into an in vitro flow circuit driven by a programmable piston pump. Windkessel elements were used to tune the inflow and systemic pressure in the model with least stiffness to match healthy conditions. Models with stiffer walls were comparatively tested maintaining circuit compliance, resistance and pump amplitude constant. 2D phase-locked PIV measurements along the central plane showed that with increase in wall stiffness, the peak velocity and cardiac output inside the LV decreased. Further, inflow vortex ring propagation toward the LV apex was reduced with increasing stiffness. The above findings indicate the importance of considering LV wall relaxation characteristics in pathological studies of filling fluid dynamics.

  17. Performance, pain, and quality of life on use of central venous catheter for management of pericardial effusions in patients undergoing coronary artery bypass graft surgery

    PubMed Central

    Ghods, Kamran; Razavi, Mohammad Reza; Forozeshfard, Mohammad

    2016-01-01

    Different pericardial catheters have been suggested as an effective alternative method for drainage of pericardial effusion. The aim of this study was to determine the performance, pain, and quality of life on use of central venous catheter (CVC) for drainage of pericardial effusion in patients undergoing open heart surgery. Fifty-five patients who had developed pericardial effusion after an open heart surgery (2012–2015) were prospectively assessed. Triple-lumen central catheters were inserted under echocardiographic guidance. Clinical, procedural, complication, and outcome details were analyzed. Intensity of pain and quality of life of patients were assessed using the numerical rating scale and Short-Form Health Survey. CVC was inserted for 36 males and 19 females, all of whom had a mean age of 58.5±15 years, and the mean duration of the open heart surgery was 8±3.5 hours. The mean central venous pressure catheter life span was 14.6 days. No cases of recurrent effusion and complication were reported. The technical success rate of procedure was 100%. Intensity of pain and quality of life of patients had improved during follow-up. CVC insertion is a safe and effective technique for the management of pericardial effusion in patients after open heart surgery. PMID:27826210

  18. Anatomy of the ocular arteries in the horse.

    PubMed

    Simoens, P; Muylle, S; Lauwers, H

    1996-09-01

    Orbital and intrabulbar arteries were studied in 20 equine eyes by means of latex injections and methylmethacrylate casts. The orbital branches of the external ophthalmic artery arise far caudal to the posterior pole of the eyeball and present a variable topographic arrangement. The intrabulbar arteries are supplied by ciliary and choroidoretinal arteries. Dependent on their entrance into the eyeball, the ciliary arteries are subdivided into a posterior and an anterior group. The posterior ciliary arteries perforate the sclera post equatorially and consist of 4 major vessels that penetrate in the lateral, medial, dorsal and ventral meridian of the eyeball, respectively. The lateral and medial of these arteries follow a long intrabulbar trajectory after having supplied several short posterior ciliary arteries to the choroid. The anterior ciliary arteries consist of a dorsal and a ventral vessel which penetrate the eyeball in the pericorneal area. The choroidoretinal arteries form an arterial network around the optic nerve at the posterior pole of the eyeball. They give rise to all retinal arterioles and some peridiscal choroidal branches. The larger part of the choroid is supplied by branches of the posterior ciliary arteries. Additionally, the anterior choroid receives recurrent branches from an arterial circle that lies externally in the ciliary ring. The iris contains a major arterial circle formed by the lateral and medial long posterior ciliary arteries and both anterior ciliary arteries. A minor iridic arterial circle nor central retinal artery could be found in the equine eyes examined.

  19. Photonic sensing of arterial distension

    PubMed Central

    Ruh, Dominic; Subramanian, Sivaraman; Sherman, Stanislav; Ruhhammer, Johannes; Theodor, Michael; Dirk, Lebrecht; Foerster, Katharina; Heilmann, Claudia; Beyersdorf, Friedhelm; Zappe, Hans; Seifert, Andreas

    2016-01-01

    Most cardiovascular diseases, such as arteriosclerosis and hypertension, are directly linked to pathological changes in hemodynamics, i.e. the complex coupling of blood pressure, blood flow and arterial distension. To improve the current understanding of cardiovascular diseases and pave the way for novel cardiovascular diagnostics, innovative tools are required that measure pressure, flow, and distension waveforms with yet unattained spatiotemporal resolution. In this context, miniaturized implantable solutions for continuously measuring these parameters over the long-term are of particular interest. We present here an implantable photonic sensor system capable of sensing arterial wall movements of a few hundred microns in vivo with sub-micron resolution, a precision in the micrometer range and a temporal resolution of 10 kHz. The photonic measurement principle is based on transmission photoplethysmography with stretchable optoelectronic sensors applied directly to large systemic arteries. The presented photonic sensor system expands the toolbox of cardiovascular measurement techniques and makes these key vital parameters continuously accessible over the long-term. In the near term, this new approach offers a tool for clinical research, and as a perspective, a continuous long-term monitoring system that enables novel diagnostic methods in arteriosclerosis and hypertension research that follow the trend in quantifying cardiovascular diseases by measuring arterial stiffness and more generally analyzing pulse contours. PMID:27699095

  20. Big bang nucleosynthesis with a stiff fluid

    SciTech Connect

    Dutta, Sourish; Scherrer, Robert J.

    2010-10-15

    Models that lead to a cosmological stiff fluid component, with a density {rho}{sub S} that scales as a{sup -6}, where a is the scale factor, have been proposed recently in a variety of contexts. We calculate numerically the effect of such a stiff fluid on the primordial element abundances. Because the stiff fluid energy density decreases with the scale factor more rapidly than radiation, it produces a relatively larger change in the primordial helium-4 abundance than in the other element abundances, relative to the changes produced by an additional radiation component. We show that the helium-4 abundance varies linearly with the density of the stiff fluid at a fixed fiducial temperature. Taking {rho}{sub S10} and {rho}{sub R10} to be the stiff fluid energy density and the standard density in relativistic particles, respectively, at T=10 MeV, we find that the change in the primordial helium abundance is well-fit by {Delta}Y{sub p}=0.00024({rho}{sub S10}/{rho}{sub R10}). The changes in the helium-4 abundance produced by additional radiation or by a stiff fluid are identical when these two components have equal density at a 'pivot temperature', T{sub *}, where we find T{sub *}=0.55 MeV. Current estimates of the primordial {sup 4}He abundance give the constraint on a stiff fluid energy density of {rho}{sub S10}/{rho}{sub R10}<30.

  1. Waves in geomaterials exhibiting negative stiffness behaviour

    NASA Astrophysics Data System (ADS)

    Esin, Maxim; Dyskin, Arcady; Pasternak, Elena

    2016-04-01

    Negative stiffness denotes the type of material behaviour when the force applied to the body decreases the body's deformation increases. Some geomaterials, for instance, rocks, demonstrate behaviour of this type at certain loads: during the compression tests the loading curves exhibit descending branch (post-peak softening). One of the possible mechanisms of the negative stiffness appearance in geomaterials is rotation of non-spherical grains. It is important to emphasize that in this case the descending branch may be reversible given that the testing machine is stiff enough (in general case it means an importance of boundary conditions). Existence of geomaterials with a negative modulus associated with rotations may have significant importance. In particular, important is understanding of the wave propagation in such materials. We study the stability of geomaterials with negative stiffness inclusions and wave propagation in it using two approaches: Cosserat continuum and discrete mass-spring models. In both cases we consider the rotational degrees of freedom in addition to the conventional translational ones. We show that despite non positiveness of the energy the materials with negative stiffness elements can be stable if certain conditions are met. In the case of Cosserat continuum the Cosserat shear modulus (the modulus relating the non-symmetrical part of shear stress and internal rotations) is allowed to assume negative values as long as its value does not exceed the value of the standard (positive) shear modulus. In the case of discrete mass-spring systems (with translational and rotational springs) the concentration of negative stiffness springs and the absolute values of negative spring stiffness are limited. The critical concentration when the system loses stability and the amplitude of the oscillations tends to infinity is equal to 1/2 and 3/5 for two- and three-dimensional cases respectively.

  2. Smooth Muscle Cell Mineralocorticoid Receptors Are Mandatory for Aldosterone–Salt to Induce Vascular Stiffness

    PubMed Central

    Galmiche, Guillaume; El Moghrabi, Soumaya; Ouvrard-Pascaud, Antoine; Berger, Stefan; Challande, Pascal; Jaffe, Iris Z.; Labat, Carlos; Lacolley, Patrick; Jaisser, Frédéric

    2015-01-01

    Arterial stiffness is recognized as a risk factor for many cardiovascular diseases. Aldosterone via its binding to and activation of the mineralocorticoid receptors (MRs) is a main regulator of blood pressure by controlling renal sodium reabsorption. Although both clinical and experimental data indicate that MR activation by aldosterone is involved in arterial stiffening, the molecular mechanism is not known. In addition to the kidney, MR is expressed in both endothelial and vascular smooth muscle cells (VSMCs), but the specific contribution of the VSMC MR to aldosterone-induced vascular stiffness remains to be explored. To address this question, we generated a mouse model with conditional inactivation of the MR in VSMC (MRSMKO). MRSMKO mice show no alteration in renal sodium handling or vascular structure, but they have decreased blood pressure when compared with control littermate mice. In vivo at baseline, large vessels of mutant mice presented with normal elastic properties, whereas carotids displayed a smaller diameter when compared with those of the control group. As expected after aldosterone/salt challenge, the arterial stiffness increased in control mice; however, it remained unchanged in MRSMKO mice, without significant modification in vascular collagen/elastin ratio. Instead, we found that the fibronectin/α5-subunit integrin ratio is profoundly altered in MRSMKO mice because the induction of α5 expression by aldosterone/salt challenge is prevented in mice lacking VSMC MR. Altogether, our data reveal in the aldosterone/salt hypertension model that MR activation specifically in VSMC leads to the arterial stiffening by modulation of cell-matrix attachment proteins independent of major vascular structural changes. PMID:24296280

  3. Nonparticipatory Stiffness in the Male Perioral Complex

    PubMed Central

    Chu, Shin-Ying; Lee, Jaehoon

    2008-01-01

    Purpose The objective of this study was to extend previous published findings in the authors’ laboratory using a new automated technology to quantitatively characterize nonparticipatory perioral stiffness in healthy male adults. Method Quantitative measures of perioral stiffness were sampled during a nonparticipatory task using a computer-controlled linear motor servo programmed to impose a series of tensile displacements over a span of approximately 24 mm at the oral angle in 20 healthy young male adults. Perioral electromyograms were simultaneously sampled to confirm nonparticipation or passive muscle state. Perioral stiffness, derived as a quotient from resultant force (ΔF) and oral span (ΔX), was modeled with regression techniques, and subsequently compared to previously reported perioral stiffness data for female adults. Results Multilevel regression analysis revealed a significant quadratic relation between the perioral stiffness and interangle span; however, no significant difference was found between adult males and females. Conclusion These normative measures will have application to future studies designed to objectively assess the effects of pathology (i.e., progressive neuromotor disease, traumatic brain insult) and intervention (pharmacologic, neurosurgical, and reconstructive surgery of the face [i.e., cleft lip, trauma, missile injuries]) on facial animation and speech kinematics. PMID:19717655

  4. Torso flexion modulates stiffness and reflex response.

    PubMed

    Granata, K P; Rogers, E

    2007-08-01

    Neuromuscular factors that contribute to spinal stability include trunk stiffness from passive and active tissues as well as active feedback from reflex response in the paraspinal muscles. Trunk flexion postures are a recognized risk factor for occupational low-back pain and may influence these stabilizing control factors. Sixteen healthy adult subjects participated in an experiment to record trunk stiffness and paraspinal muscle reflex gain during voluntary isometric trunk extension exertions. The protocol was designed to achieve trunk flexion without concomitant influences of external gravitational moment, i.e., decouple the effects of trunk flexion posture from trunk moment. Systems identification analyses identified reflex gain by quantifying the relation between applied force disturbances and time-dependent EMG response in the lumbar paraspinal muscles. Trunk stiffness was characterized from a second order model describing the dynamic relation between the force disturbances versus the kinematic response of the torso. Trunk stiffness increased significantly with flexion angle and exertion level. This was attributed to passive tissue contributions to stiffness. Reflex gain declined significantly with trunk flexion angle but increased with exertion level. These trends were attributed to correlated changes in baseline EMG recruitment in the lumbar paraspinal muscles. Female subjects demonstrated greater reflex gain than males and the decline in reflex gain with flexion angle was greater in females than in males. Results reveal that torso flexion influences neuromuscular factors that control spinal stability and suggest that posture may contribute to the risk of instability injury.

  5. Post-traumatic knee stiffness: surgical techniques.

    PubMed

    Pujol, N; Boisrenoult, P; Beaufils, P

    2015-02-01

    Post-traumatic knee stiffness and loss of range of motion is a common complication of injuries to the knee area. The causes of post-traumatic knee stiffness can be divided into flexion contractures, extension contractures, and combined contractures. Post-traumatic stiffness can be due to the presence of dense intra-articular adhesions and/or fibrotic transformation of peri-articular structures. Various open and arthroscopic surgical treatments are possible. A precise diagnosis and understanding of the pathology is mandatory prior to any surgical treatment. Failure is imminent if all pathologies are not addressed correctly. From a general point of view, a flexion contracture is due to posterior adhesions and/or anterior impingement. On the other hand, extension contractures are due to anterior adhesions and/or posterior impingement. This overview will describe the different modern surgical techniques for treating post-traumatic knee stiffness. Any bony impingements must be treated before soft tissue release is performed. Intra-articular stiff knees with a loss of flexion can be treated by an anterior arthroscopic arthrolysis. Extra-articular pathology causing a flexion contracture can be treated by open or endoscopic quadriceps release. Extension contractures can be treated by arthroscopic or open posterior arthrolysis. Postoperative care (analgesia, rehabilitation) is essential to maintaining the range of motion obtained intra-operatively.

  6. Carotid β-stiffness index is associated with slower processing speed but not working memory or white matter integrity in healthy middle-aged/older adults.

    PubMed

    DuBose, Lyndsey E; Voss, Michelle W; Weng, Timothy B; Kent, James D; Dubishar, Kaitlyn M; Lane-Cordova, Abbi; Sigurdsson, Gardar; Schmid, Phillip; Barlow, Patrick B; Pierce, Gary L

    2017-04-01

    Aging is associated with increased carotid artery stiffness, a predictor of incident stroke, and reduced cognitive performance and brain white matter integrity (WMI) in humans. Therefore, we hypothesized that higher carotid stiffness/lower compliance would be independently associated with slower processing speed, higher working memory cost, and lower WMI in healthy middle-aged/older (MA/O) adults. Carotid β-stiffness (P < 0.001) was greater and compliance (P < 0.001) was lower in MA/O (n = 32; 64.4 ± 4.3 yr) vs. young (n = 19; 23.8 ± 2.9 yr) adults. MA/O adults demonstrated slower processing speed (27.4 ± 4.6 vs. 35.4 ± 5.0 U/60 s, P < 0.001) and higher working memory cost (-15.4 ± 0.14 vs. -2.2 ± 0.05%, P < 0.001) vs. young adults. Global WMI was lower in MA/O adults (P < 0.001) and regionally in the frontal lobe (P = 0.020) and genu (P = 0.009). In the entire cohort, multiple regression analysis that included education, sex, and body mass index, carotid β-stiffness index (B = -0.53 ± 0.15 U, P = 0.001) and age group (B = -4.61 ± 1.7, P = 0.012, adjusted R(2) = 0.4) predicted processing speed but not working memory cost or WMI. Among MA/O adults, higher β-stiffness (B = -0.60 ± 0.18, P = 0.002) and lower compliance (B = 0.93 ± 0.26, P = 0.002) were associated with slower processing speed but not working memory cost or WMI. These data suggest that greater carotid artery stiffness is independently and selectively associated with slower processing speed but not working memory among MA/O adults. Carotid artery stiffening may modulate reductions in processing speed earlier than working memory with healthy aging in humans.NEW & NOTEWORTHY Previously, studies investigating the relation between large elastic artery stiffness, cognition, and brain structure have focused mainly on aortic stiffness in aged individuals with cardiovascular disease risk factors and other comorbidities. This study adds to the field by demonstrating that the age-related increases in

  7. Dynamic stiffness model of spherical parallel robots

    NASA Astrophysics Data System (ADS)

    Cammarata, Alessandro; Caliò, Ivo; D`Urso, Domenico; Greco, Annalisa; Lacagnina, Michele; Fichera, Gabriele

    2016-12-01

    A novel approach to study the elastodynamics of Spherical Parallel Robots is described through an exact dynamic model. Timoshenko arches are used to simulate flexible curved links while the base and mobile platforms are modelled as rigid bodies. Spatial joints are inherently included into the model without Lagrangian multipliers. At first, the equivalent dynamic stiffness matrix of each leg, made up of curved links joined by spatial joints, is derived; then these matrices are assembled to obtain the Global Dynamic Stiffness Matrix of the robot at a given pose. Actuator stiffness is also included into the model to verify its influence on vibrations and modes. The latter are found by applying the Wittrick-Williams algorithm. Finally, numerical simulations and direct comparison to commercial FE results are used to validate the proposed model.

  8. Electrochemical stiffness in lithium-ion batteries

    NASA Astrophysics Data System (ADS)

    Tavassol, Hadi; Jones, Elizabeth M. C.; Sottos, Nancy R.; Gewirth, Andrew A.

    2016-11-01

    Although lithium-ion batteries are ubiquitous in portable electronics, increased charge rate and discharge power are required for more demanding applications such as electric vehicles. The high-rate exchange of lithium ions required for more power and faster charging generates significant stresses and strains in the electrodes that ultimately lead to performance degradation. To date, electrochemically induced stresses and strains in battery electrodes have been studied only individually. Here, a new technique is developed to probe the chemomechanical response of electrodes by calculating the electrochemical stiffness via coordinated in situ stress and strain measurements. We show that dramatic changes in electrochemical stiffness occur due to the formation of different graphite-lithium intercalation compounds during cycling. Our analysis reveals that stress scales proportionally with the lithiation/delithiation rate and strain scales proportionally with capacity (and inversely with rate). Electrochemical stiffness measurements provide new insights into the origin of rate-dependent chemomechanical degradation and the evaluation of advanced battery electrodes.

  9. Coronary Artery Bypass Grafting

    MedlinePlus

    ... from the NHLBI on Twitter. What Is Coronary Artery Bypass Grafting? Coronary artery bypass grafting (CABG) is ... bypass multiple coronary arteries during one surgery. Coronary Artery Bypass Grafting Figure A shows the location of ...

  10. Improved Pulse Transit Time Estimation by System Identification Analysis of Proximal and Distal Arterial Waveforms

    DTIC Science & Technology

    2011-10-01

    only), electrical im- pedance, pulse oximetry, and even noncontact laser Doppler vibrometry (8). The disadvantage of the approach is that it may not...Morbiducci U, Scalise L, Tomasini EP, Delbeke D, Baets R, Van Bortel LM, Segers P. A noncontact approach for the evaluation of large artery stiffness: a...management of arterial hypertension: the Task Force for the management of arterial hypertension of the European Society of Hypertension (ESH) and of the

  11. Elastic-Stiffness Coefficients of Titanium Diboride

    PubMed Central

    Ledbetter, Hassel; Tanaka, Takaho

    2009-01-01

    Using resonance ultrasound spectroscopy, we measured the monocrystal elastic-stiffness coefficients, the Voigt Cij, of TiB2. With hexagonal symmetry, TiB2 exhibits five independent Cij: C11, C33, C44, C12, C13. Using Voigt-Reuss-Hill averaging, we converted these monocrystal values to quasiisotropic (polycrystal) elastic stiffnesses. Briefly, we comment on effects of voids. From the Cij, we calculated the Debye characteristic temperature, the Grüneisen parameter, and various sound velocities. Our study resolves the enormous differences between two previous reports of TiB2’s Cij. PMID:27504232

  12. Experimental investigation of the influence of the aortic stiffness on hemodynamics in the ascending aorta.

    PubMed

    Gülan, Utku; Lüthi, Beat; Holzner, Markus; Liberzon, Alex; Tsinober, Arkady; Kinzelbach, Wolfgang

    2014-11-01

    A three-dimensional (3-D) pulsatile aortic flow in a human ascending aorta is studied to investigate the effect of the aortic stiffness on the flow field and turbulent fluctuating velocities in the ascending aorta. A nonintrusive optical measurement technique, 3-D particle tracking velocimetry (3D-PTV), has been applied to anatomically accurate phantoms under clinically realistic conditions. A compliant silicon phantom was used to mimic the healthy aorta, and a rigid model was used to imitate the pathological case that appears in aortas for example as a result of aging. The realistic models are transparent which allows optical access to the investigation domain, and the index of refraction was matched to avoid optical distortions. Our results revealed that the aortic stiffness leads to an increase in systolic velocity and a decrease in the Windkessel effect, which is associated with the diastolic blood pressure. Furthermore, we found that the turbulent kinetic energy is about an order of magnitude higher for the rigid aorta, that is, an increase in aortic stiffness increases the magnitude of turbulent fluctuating velocities. The spatial distribution of the flow velocity showed that the flow is more organized and coherent spiraling patterns develop for the compliant aorta which helps to dampen the influence of disturbed flow. Finally, we observed higher Lagrangian acceleration and hence higher instantaneous forces acting on blood particles in the stiff case which implies that aging and hence