Pressure-strain Elastic Modulus Research Articles

Carotid arterial stiffness is increased and related to left ventricular function in patients with hypertrophic cardiomyopathy.

To assess the carotid mechanical properties in patients with hypertrophic cardiomyopathy and the relation between arterial stiffness and left ventricular function in this setting. We have prospectively enrolled 71 patients (52 ± 16 years, 34 men) with hypertrophic cardiomyopathy, divided into two groups depending on the presence (46 patients) or absence (25 patients) of cardiovascular risk factors associated with increased arterial stiffness. Twenty-five normal subjects similar by age and gender with hypertrophic cardiomyopathy patients without risk factors formed the control group. A comprehensive echocardiography was performed in all subjects. Carotid arterial stiffness index (β index), pressure-strain elastic modulus, arterial compliance, and pulse wave velocity were also obtained using an echo-tracking system. β index, pulse wave velocity, and pressure-strain elastic modulus were significantly higher in hypertrophic cardiomyopathy patients without risk factors compared to controls. After linear regression analysis, the increase in carotid β index was independently correlated with the presence of hypertrophic cardiomyopathy [beta = 0.49, 95% confidence interval (CI) = 1.04-3.02; P < 0.001]. In the entire hypertrophic cardiomyopathy population arterial stiffness parameters correlated with age, gender, hypertension degree, presence of hypercholesterolaemia, and the E/e' ratio. In multivariable analysis, β index (beta = 0.36, 95% CI = 0.32-1.25; P = 0.001), global left ventricular longitudinal strain, and the presence of left ventricular outflow tract obstruction were independently correlated with the E/e' ratio. In patients with hypertrophic cardiomyopathy arterial stiffness is increased independently of age or presence of cardiovascular risk factors. Carotid artery stiffness is independently related to left ventricular filling pressure, increased arterial stiffness representing a possible marker of a more severe phenotype.

Carotid Artery Stiffness Accurately Predicts White Matter Hyperintensity Volume 20 Years Later: A Secondary Analysis of the Atherosclerosis Risk in the Community Study.

Arterial stiffness is a biomarker of cerebrovascular disease and dementia risk. Studies have shown an association between carotid artery stiffness and increased white matter hyperintensity volume and, as a result, reduced total brain volume on MR imaging, but none have had prolonged follow-up to fully evaluate the slow change seen in white matter hyperintensity volume and total brain volume with time. Our objective was to determine whether common carotid artery stiffness on sonography accurately predicts white matter hyperintensity volume and total brain volume on MR imaging more than 20 years later. We performed a secondary analysis of the Atherosclerosis Risk in the Community study to compare 5 measurements of carotid artery stiffness, including strain, distensibility, compliance, Stiffness index, and pressure-strain elastic modulus, with the white matter hyperintensity volume and total brain volume on a follow-up MR imaging using linear regression. We included 1402 patients enrolled in the Atherosclerosis Risk in the Community study. There was a significant relationship between increasing carotid artery stiffness and both higher white matter hyperintensity volume and lower total brain volume on MR imaging, measured at a mean of 21.5 years later. In multivariable linear regression models, the carotid strain, distensibility, Stiffness index, and pressure-strain elastic modulus were associated with white matter hyperintensity volume. Only compliance was associated with total brain volume in the multivariate models. Sonography measurements of carotid artery stiffness are predictive of white matter hyperintensity volume and total brain volume on MR imaging more than 20 years later. The association is more robust for white matter hyperintensity volume than total brain volume. These findings support the role of arterial stiffness as a method for identifying patients at risk of developing white matter hyperintensity volume and as a potential mechanism leading to small-artery disease of the brain.

Non-invasive assessment of aortic stiffness and blood pressure in young Turner syndrome patients.

Background Females with Turner syndrome (TS) carry an elevated risk of aortic dissection. The objective of the study was to assess the biophysical properties of the aorta and ambulatory blood pressure (BP) in females with TS and compare these findings to those in healthy female age-matched controls. Methods This was a prospective cohort study including subjects aged 8-25 years. Utilizing two-dimensional (2D) echocardiography and Doppler, proximal aortic dimensions were measured and biophysical properties of the aorta were calculated including pulse wave velocity (PWV), arterial pressure-strain elastic modulus and stiffness index. Resting BP was measured and ambulatory blood pressure monitoring (ABPM) was performed. Results Of 23 TS patients and 46 controls (median age 16.3 years), aortic annulus, sinus of Valsalva and sinotubular (ST) junction diameters, as well as left ventricular (LV) mass, were significantly greater in TS patients compared with controls when scaled for height2.7, but not for body surface area (BSA), although ascending aorta diameter was greater when scaled for both. Median PWV was faster in TS patients compared to controls (451 vs. 360 cm/s) while arterial pressure-strain elastic modulus and stiffness index were similar. Resting BP was abnormal in seven out of 22 patients and ABPM was abnormal in 16 out of 21 patients. Conclusions Young patients with TS had dilated proximal aortas when scaled for height2.7 and stiffer aortas when compared with healthy female age-matched controls. Moreover, resting BP underdiagnosed pre-hypertension and hypertension compared to ABPM. These findings are consistent with the presence of a primary aortopathy in TS.

Progression of atherosclerosis versus arterial stiffness with age within and between arteries in systemic lupus erythematosus.

The progression of atherosclerosis versus arterial stiffness with age within and between arteries has not been defined. Systemic lupus erythematosus (SLE) is a human model of accelerated arterial disease that may permit this determination. 76 SLE patients (69 women, age 37 ± 12years) and 26 age-and-sex-matched controls (22 women, age 34 ± 11years) underwent transesophageal echocardiography and carotid ultrasonography for assessment of atherosclerosis [plaques and intima-media thickening (IMT)] and arterial stiffness [increased pressure-strain elastic modulus (PSEM)] of the descending thoracic aorta and carotid arteries. Since IMT is highly associated with plaques, IMT was used as a marker of atherosclerosis to assess its progression in relation with age and PSEM. Aortic and carotid plaques, IMT, and PSEM were greater in patients than in controls (all p ≤ 0.05). Within the aorta and within the carotid arteries, the average percent increases per decade of age for IMT versus PSEM were similar in patients (8.55% versus 9.33% and 3.39% versus 2.46%, respectively) and controls (5.53% versus 6.60% and 4.75% versus 3.49%, respectively) (all p ≥ 0.58). However, in SLE patients, the average percent increases per decade of age for IMT and PSEM were higher in the aorta than in the carotid arteries (8.55% and 9.33% versus 3.39% and 2.46%, respectively, both p ≤ 0.03). In patients with SLE, atherosclerosis and arterial stiffness progress with age parallel to each other within arteries, but divergently between arteries with different anatomy and hemodynamics.

Local carotid arterial stiffness is an independent determinant of left ventricular remodeling in never-treated hypertensive patients

Purpose: The aim was to investigate the association between blood pressure (BP), carotid stiffness, carotid-femoral pulse wave velocity (cfPWV) and left ventricular (LV) remodeling in never-treated hypertensive patients.Material and methods: 178 never-treated hypertensive underwent transthoracic echocardiography, 24-hour ambulatory BP monitoring (ABPM), local carotid stiffness and regional cfPWV assessed using a high-definition echo-tracking ultrasound system and a tonometric transducer, respectively. LV parameters and arterial stiffness were also considered in dippers and non-dippers. Results: Mean night-time BP best correlated with carotid and LV parameters. Carotid stiffness parameters (β-index, pressure-strain elastic modulus, one-point PWV) correlated with LV mass, relative wall thickness, and E/A ratio while cfPWV correlated only with E/A ratio. In multiple regression analysis, age and mean night-time ABPM had a stroger relation with carotid stiffness than cfPWV. In a second multiple regression analysis, day and night ABPM and carotid stiffness were independently related with LV remodeling and left atrial volume. In non-dippers, local carotid stiffness parameters were significantly higher than in dippers, whereas cfPWV was not significantly different.Conclusions: Carotid stiffness parameters are independently associated with LV remodeling and have an additive effect to BP and over cfPWV moreover local arterial stiffness is higher in non-dippers.

Echo-tracking evaluation of changes in common carotid artery wall elasticity after smoking cessation.

The aim of this study was to explore changes in the common carotid arterial wall elasticity after smoking cessation. Carotid artery ultrasonographic examination was performed in 136 patients, then 1 or 2 years after smoking cessation. We used echo-tracking (ET) to measure stiffness index (β), pressure-strain elasticity modulus (Ep), arterial compliance (AC), augmentation index (AI), and local pulse wave velocity (PWVβ). Patients were divided into four groups based on whether or not they successfully stopped smoking (groups M and N, respectively) and whether (groups M2 and N2, respectively) or not (groups M1 and N1, respectively) they showed comorbidities. In group M1, β, Ep and PWVβ were lower at 1 year than before smoking cessation, while AC and AI did not change. At 2 years, β, Ep, PWVβ, and AC, but not AI, improved further. In group M2, β, Ep, and PWVβ decreased at 2 years, whereas AC and AI did not change. In groups N1 and N2, none of the variables changed significantly. ET can be used quantitatively to evaluate the impact of smoking cessation on the elasticity of the common carotid artery wall.

Evaluation of carotid artery elasticity in patients with uremia by echo tracking.

The purpose of this study was to compare the carotid artery wall elasticity between patients with uremia and controls using echo tracking (ET). Ninety-three patients with uremia and 35 control subjects (Group A) were enrolled in this study. In the ET mode, the carotid artery elasticity parameters including stiffness index (β), pressure-strain elasticity modulus (EP), arterial compliance (AC), and one-point pulse wave velocity (PWVβ) were measured, and carotid intima-media thickness (IMT) was measured with B-mode ultrasonography. The patients were classified into three groups: Group B (normal IMT), Group C (thickened IMT), and Group D (one single atheroma plaque). β, EP, and PWVβ were significantly higher in Group B, C, and D (especially in group D) than those of the control group (P<0.05), and there were significant differences between Group A and Group B, while AC was lower than in controls, but there were no statistically significant differences among the four groups. ET is a noninvasive method that can demonstrate a loss in carotid artery elasticity in uremia patients with normal IMT.

Association between endothelial dysfunction, epicardial fat and subclinical atherosclerosis during menopause

BackgroundMenopausal transition is critical for the development of early, subclinical vascular damage. Multiple factors, such as atherosclerosis, increased epicardial fat, and endothelial dysfunction can play a role. Hence, the objective of this study was the comparison of epicardial adipose tissue and carotid intima media thickness in order to establish the best predictor of carotid stiffness in middle-aged women with endothelial dysfunction. MethodsA total of 43 healthy women aged 40•59 years old with endothelial dysfunction previously demonstrated by flow mediated dilation were recruited to have anthropometric, biochemical, hormonal and ultrasound determinations of carotid intima media thickness and epicardial fat thickness. ResultsCarotid arterial stiffness parameters (local pulse wave velocity [4.7±0.7 vs 4.8±0.5 vs 5.6±0.5m/s, respectively, p<0.001], pressure strain elastic modulus [55.2±13.4 vs 59.2±11.8 vs 81.9±15.6kPa, respectively, p<0.001], arterial stiffness index β [4.4±1.4 vs 5.0±1.1 vs 6.4±1.3, respectively, p<0.001]) and epicardial fat thickness (2.98±1.4 vs 3.28±1.9 vs 4.70±1.0mm, respectively, p=0.007) showed a significant and proportional increase in the group of late post-menopausal women when compared to early post-menopausal and pre-menopausal groups, respectively. Among body fat markers, epicardial fat was the strongest predictor of local pulse wave velocity, independent of age. ConclusionsIn menopausal women with endothelial dysfunction, menopausal transition is associated with increased carotid arterial stiffness and epicardial fat thickness, independent of age. Ultrasound measured epicardial fat was a better independent predictor of arterial stiffness than carotid intima media thickness in these women.

Arterial Wall Properties in Men and Women: Hemodynamic Analysis and Clinical Implications.

The properties of arterial walls are dictated by their underlying structure, which is responsible for the adequate perfusion of conduit branching arteries and their vascular beds. Beginning with the mechanobiology of arteries in terms of their composition and individual contributions to overall viscoelastic behavior in men and women, pressure-flow relations are analyzed and noted in terms of sex differences. Hemodynamic function in terms of indices of vascular stiffness-such as pressure-strain elastic modulus, pulse wave velocity, augmentation index, and cardio-ankle vascular index-are evaluated. They all showed differences between the sexes, and these differences also were shown among people of different cultures. Recent studies also showed, in heart failure patients, a comparatively greater increase in peripheral resistance and a greater decreased arterial compliance in women. Wave separation into forward and reflected waves allows elucidation of mechanical and drug-treated similarities and differences in induced hypertension. This may provide insight into treatment strategy in terms of improving mechanobiology and designing drug therapy for the sexes. Finally, modeling studies are useful in identifying how arterial compliance and its pressure dependence can be better used in differentiating aging- and hypertension-induced changes that differentially affect the sexes.

Carotid and Femoral Arterial Wall Distensibility During Long-Duration Spaceflight.

This study aimed to assess changes in common carotid (CA) and superficial femoral (FA) arterial stiffness during long-duration spaceflight. Ultrasound imaging was used to investigate the CA and FA of 10 astronauts preflight (PRE), on flight day 15 (FD15), after 4-5 mo (FD4-5m), and 4 d after return to Earth (R+4). Arterial wall properties were assessed through the calculation of strain, stiffness (β), pressure-strain elastic modulus (Ep), and distensibility (DI). Stiffness indices were assessed for potential correlations to measurements of intima-media thickness (IMT). Significant effects of spaceflight were found for all CA stiffness indices, indicating an increase in arterial stiffness. CA strain was reduced by 34 ± 31% on FD15 and 50 ± 16% on FD4-5m and remained reduced by 42 ± 14% on R+4 with respect to PRE values. On FD4-5m, with respect to PRE values, DI was reduced by 46 ± 25% and β and Ep were increased by 124 ± 95% and 118 ± 92%, respectively. FA arterial stiffness indices appeared to show similar changes; however, a main effect of spaceflight was only found for strain. Correlation analysis showed weak but significant relationships between measurements of CA IMT and arterial stiffness indices, but no relationships were found for FA measurements. The observed change in CA and FA stiffness indices suggest that spaceflight results in an increase in arterial stiffness. That these changes were not strongly related to measurements of IMT suggests the possibility of different mechanisms contributing to the observed results.Arbeille P, Provost R, Zuj K. Carotid and femoral arterial wall distensibility during long-duration spaceflight. Aerosp Med Hum Perform. 2017; 88(10):924-930.

Association between endothelial dysfunction, epicardial fat and subclinical atherosclerosis during menopause

BackgroundMenopausal transition is critical for the development of early, subclinical vascular damage. Multiple factors, such as atherosclerosis, increased epicardial fat, and endothelial dysfunction can play a role. Hence, the objective of this study was the comparison of epicardial adipose tissue and carotid intima media thickness in order to establish the best predictor of carotid stiffness in middle-aged women with endothelial dysfunction. MethodsA total of 43 healthy women aged 40–59 years old with endothelial dysfunction previously demonstrated by flow mediated dilation were recruited to have anthropometric, biochemical, hormonal and ultrasound determinations of carotid intima media thickness and epicardial fat thickness. ResultsCarotid arterial stiffness parameters (local pulse wave velocity [4.7±0.7 vs 4.8±0.5 vs 5.6±0.5m/s, respectively, p<0.001], pressure strain elastic modulus [55.2±13.4 vs 59.2±11.8 vs 81.9±15.6kPa, respectively, p<0.001], arterial stiffness index β [4.4±1.4 vs 5.0±1.1 vs 6.4±1.3, respectively, p<0.001]) and epicardial fat thickness (2.98±1.4 vs 3.28±1.9 vs 4.70±1.0mm, respectively, p=0.007) showed a significant and proportional increase in the group of late post-menopausal women when compared to early post-menopausal and pre-menopausal groups, respectively. Among body fat markers, epicardial fat was the strongest predictor of local pulse wave velocity, independent of age. ConclusionsIn menopausal women with endothelial dysfunction, menopausal transition is associated with increased carotid arterial stiffness and epicardial fat thickness, independent of age. Ultrasound measured epicardial fat was a better independent predictor of arterial stiffness than carotid intima media thickness in these women.

Carotid artery stiffness evaluated early by wave intensity in normal left ventricular function in post-radiotherapy patients with nasopharyngeal carcinoma.

This study aims to assess carotid elasticity early in normal left ventricular function in post-radiotherapy patients with nasopharyngeal carcinoma (NPC) by wave intensity. Sixty-seven post-radiotherapy patients all with normal left ventricular function were classified into group NPC1 and group NPC2 based on their carotid intima-media thickness. Thirty age- and sex-matched NPC patients without any history of irradiation and chemotherapy were included as a control group. Carotid parameters, including stiffness constant (β), pressure-strain elastic modulus (Ep), arterial compliance (AC), stiffness constant pulse wave velocity (PWVβ), and wave intensity pulse wave velocity (PWVWI) were measured. There were no significant differences in conventional echocardiographic variables among the three groups. In comparison with the control group, β, Ep, PWVβ, and PWVWI were significantly increased, while AC was significantly decreased in the NPC1 and NPC2 groups, and there were differences between the NPC1 group and NPC2 group (all P<0.05). This study suggested that carotid artery stiffness increased with reduced carotid compliance in post-RT with NPC.

Quantitative evaluation of cardiovascular function in patients with subclinical atherosclerosis by ultrasonography

Objective To evaluate the carotid and left ventricular function changes in patients with subclinical atherosclerosis(SA) using echo-tracking (ET) and three-dimensional speckle tracking echocardiography (3D-STE). Methods Eighty patients with SA were divided into low-risk group (27 cases), middle-risk group (26 cases) and high-risk group (27 cases) according to the Framingham risk score (FRS). Each of them was examined by echocardiography and carotid ultrasound to obtain the parameters including carotid intima-media thickness (cIMT), stiffness parameter (β), Pressure-strain elastic modulus (Ep), pulse wave conducting velocity(PWVβ), LV peak systolic global longitudinal strain (GLS), LV peak systolic global circumferential strain (GCS), myocardial wall stress (MWS) and left ventricular ejection fraction(LVEF) for analysis. The study got approval from the Ethics Committee of Tongji Medical College, Huazhong University of Science and Technology (NO: IORG00371). Results Ep, left atrial volume (LAV) and MWS had significantly differences among the three groups (all P 0.05). β was positively correlated with age and FRS, and negatively correlated with GLS (all P<0.05). LAV was positively correlated with age and E/e (all P<0.05). GLS was negatively correlated with FRS and β (all P<0.05). MWS was positively correlated with β and SBP, and negatively correlated with LVEF (all P<0.01). Conclusions ET combined with 3D-STE could be applied to evaluate the carotid and left ventricular function accurately in patients with subclinical atherosclerosis, and provide scientific bases for establishing intervention strategy. Key words: Echocardiography; Subclinical atherosclerosis; Carotid arteries; Ventricular function, left

Esophagogastric junction in systemic sclerosis: A study with the functional lumen imaging probe.

Fibrosis and atrophy of esophageal smooth muscle cells cause gastro-esophageal reflux and dysphagia in most patients with systemic sclerosis (SSc). Recent studies indicate that distensibility of the esophagogastric junction (EGJ), assessed with the Functional Lumen Imaging Probe (FLIP) may be a more sensitive and accurate measure of sphincter function than manometry. We aim to describe and compare distension parameters of the EGJ in a well-characterized group of patients with SSc. Twelve patients with SSc reporting reflux or dysphagia (11 women, median age 53 [range 35-72], duration of disease: 1-20years) were investigated using distensibility testing of the EGJ. Patients were compared with 11 healthy volunteers (HV) (10 women, median age 53 [range 40-68]). The pressure and minimum diameter along the EGJ during ramp distension were used for distensibility analysis. Patients with SSc had significantly lower EGJ yield pressure (median: 4.0mmHg [Inter Quartile Range (IQR): 2.8-7.7]) than HV (median: 6.2mmHg [IQR: 9.4-26]) (P=.007). Likewise, the pressure-strain elastic modulus was lower in SSc patients (median 1.73 kPa [IQR: 1.16-2.15]) than in HV (median 2.41 kPa [IQR: 1.85-2.67]) (P=.03), indicating the reduced resistance to distension in SSc patient. Patients with SSc and symptoms of reflux and dysphagia have significantly reduced resistance to distension of the EGJ.

High Blood Pressure States in Children, Adolescents, and Young Adults Associate Accelerated Vascular Aging, with a Higher Impact in Females' Arterial Properties.

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.

A Novel Apparatus for the Multifaceted Evaluation of Arterial Function Through Transmural Pressure Manipulation.

A novel apparatus for the multifaceted evaluation of artery function was developed. It measures endothelial and smooth muscle functions and the pressure-strain elastic modulus (E p). A rigid airtight chamber with an ultrasound probe was attached to the upper arm to manipulate the transmural pressure of the brachial artery. Endothelial function was measured via a standard flow-mediated dilation (FMD) protocol. Smooth muscle function was evaluated via a myogenic contraction of the artery following the application of negative pressure to the chamber and was named pressure-mediated contraction (PMC). E p was obtained by measuring the instantaneous increase in the artery diameter following the negative pressure application. The PMC and FMD values had a significant negative correlation with age, indicating that the age-related decrease in FMD is caused by the decay of endothelial and smooth muscle function. A consideration of PMC may help improve the accuracy of artery function measurement. E p in subjects aged>40years was found to be significantly higher in the supra-physiological pressure range than in the physiological one (p=0.02); this did not occur in younger subjects. Artery stiffening may begin in the supra-physiological range, and this stiffness may also be used for the diagnosis of atherosclerosis.

Xuezhikang reduced arterial stiffness in patients with essential hypertension: a preliminary study.

This study aimed to test the effects of xuezhikang, a cholestin extract that contains statin-like components, on arterial stiffness in patients with essential hypertension. One hundred hypertensive patients from the Chinese PLA General Hospital were randomly allocated to receive xuezhikang (1200 mg/day, orally) or placebo (same capsules containing only pharmaceutical excipients). Physical examination outcomes, lipid profile, high sensitivity C-reactive protein (hs-CRP) levels, matrix metalloproteinases-9 (MMP-9) levels, and arterial outcomes, including stiffness parameter (β), pressure-strain elasticity modulus (Ep), arterial compliance (AC), augmentation index (AI), and one-point pulse wave velocity (PWVβ) were obtained at baseline and after 6 months of the intervention. Xuezhikang significantly reduced β (8.4±3.1 vs 6.8±2.1, P=0.007), Ep (122.8±43.9 vs 100.7±33.2, P=0.009), PWVβ (6.7±1.2 vs 6.1±1.0, P=0.013), low-density lipoprotein cholesterol (3.4±0.6 vs 2.9±0.5, P=0.001), hs-CRP [2.1 (0.4-10.0) vs 1.4 (0.3-4.1), P=0.020], and MMP-9 (17.2±2.4 vs 12.7±3.8, P <0.001) compared to baseline. The placebo had no effect on these parameters. The changes of PWVβ in the xuezhikang group was significantly associated with the changes of hs-CRP and MMP-9 (r=0.144, P=0.043; r=0.278, P=0.030, respectively) but not with lipid profile changes. Our research showed xuezhikang can improve the parameters of arterial stiffness in hypertensive patients, and its effect was independent of lipid lowering.

Relation Between LV Diastolic Function and Aortic Compliance as Assessed by Transthoracic Echo

Arterial compliance and stiffness of the ascending aorta are important components of the elastic nature of the arterial system. Several pathological conditions are known to potentially affect arterial compliance properties as occurs with the arterial hypertension, and diabetes mellitus. Factors known to affect LV elasticity are similar to those affecting aortic elasticity. Our aim in that study is to study correlation of aortic stiffness and LV diastolic function and the factors that affect each. We scanned 254 patients presenting for routine echocardiography to Ain Shams University Hospitals Echocardiography unit; where clinical history was taken, examination and 2D echocardiography done where we indexed the elastic properties of the aorta by calculating of aortic distensibility (AD), aortic stiffness index (ASI), and pressure-strain elastic modulus (Ep), and LV diastolic function was evaluated as well. Both presence and grade of left ventricular diastolic dysfunction were significantly correlated with each of arterial hypertension and diabetes mellitus separately and presence of both hypertension and diabetes mellitus was correlated with LVDD. Aortic compliance-with its three studied elements; AS%, AD and ASI-was significantly correlated with grade of LVDD yet only elastic modulus was independently correlated with diastolic dysfunction.

OP.3C.05] CHARACTERISTICS OF CEREBRAL HEMODYNAMICS AND CAROTID STIFFNESS IN PATIENTS WITH ISCHEMIC LEUKOARAIOSIS AND NEW ULTRASOUND INDICES OF ISCHEMIC LEUKOARAIOSIS

Objective: Leukoaraiosis (ILA) is believed to be ischaemic in origin due its association with cerebrovascular risk factors and similar location as lacunar infarctions. Its pathophysiology is not well understood and its diagnosis is still based on magnetic resonance imaging (MRI) as well as exclusion of other causes of white matter hyperintensities (WMH). So far there are no known confirming or screening diagnostic tests of ILA. Ultrasound studies have recently shown increased large artery stiffness, increased cerebrovascular resistance and lower cerebral blood flow in ILA patients. Increased arterial stiffness and decreased blood flow could have a synergistic effect and their ratio could be a useful diagnostic index of ILA. Design and method: We used Trans Cerebral Doppler sonography (TCD) and carotid duplex ultrasound to compeare cerebral blood flow and carotid stiffness in 53 ILA patients to 40 risk factor matched controls. The ILA diagnosis was based on head MRI and exclusion of other causes of WMH. Middle cerebral artery (MCA) systolic, diastolic and mean blood flow velocities (v-MCAs, v-MCAd, v-MCAm) and resistance indices (RI, PI) were determined. Carotid stiffness was accessed by pulse wave velocityβ (PWVβ, m/s), pressure–strain elasticity modulus (Ep, kPa) and β index. In addition we introduced new ILA indices (ILAi) that are rations of carotid stiffness parameters and MCA mean blood flow velocity. The diagnostic significance of ILAi for the prediction of ILA was analysed. Results: We found significantly lower diastolic, systolic and mean MCA blood flow velocities and increased carotid stiffness in the ILA group (p < 0,05). Higher pulsatility and resistivity indices of MCA were found in the ILA group, but they did not reached statistical significance. All the ILAi were significantly higher in the ILA group, the most significant was PWVβ/v-ACMm (p = 0.003). All ILAi were allso significantly associated with ILA and were sensitive and specific for predicting ILA (p < 0.05). Conclusions: MCA blood flow velocities are lower and carotid stiffness increased in ILA patients compared to risk factors matched controls. The combination of lower velocities and increased carotid stiffness represented as ILA indices could have a potential diagnostic value for ILA.

OP.4A.06] RELATIONSHIP BETWEEN CIRCADIAN PATTERNS OF BLOOD PRESSURE AND CAROTID ARTERY STIFFNESS AND WAVE INTENSITY IN PATIENTS WITH ARTERIAL HYPERTENSION

Objective: The aim of the study is to investigate the relationship between daytime and night-time mean blood pressure (BP) on carotid artery stiffness (CAS) and wave intensity (WI) in 1) hypertensive patients (pts) and in 2) the subgroups formed according to the circadian patterns of BP. Design and method: We investigated 148 hypertensive pts, mean age 58 years. The subgroups were created according to the circadian patterns (64 dippers, 56 non-dippers, 14 extreme dippers, 14 reverse dippers). Measurements of CAS and WI were performed on right common carotid artery (CCA) using ultrasound combined with echo-tracking. We analysed stiffness parameters: stiffness index (beta), pressure-strain elasticity modulus (Ep), arterial compliance (AC), augmentation index (AIx) and one-point pulse wave velocity (PWV). Parameters of WI: W1- correlates with the maximum rate of left ventricular pressure; W2 - occurs towards the end of ejection; negative area (NA) - indicates the effects of reflected waves, pre-ejection period (r-W1), ejection period (W1–2), provide the information about ventricular-arterial coupling. Results: Systolic daytime and night-time mean BP correlated with AIx (r = -0.32, p < 0.0001; r = -0.32, p < 0.0001), with mean CCA diameter (r = 0.30, p < 0.0001; r = 0.37, p < 0.0001) and with mean W1 (r = 0.31, p < 0.0001; r = 0.32, p < 0.0001). Daytime and night-time diastolic BP significantly correlated with AIx. Compared with dippers the stiffness values were higher in non-dippers, but highest in reverse dippers (PWVdipper = 7.2m/s, reverse dipper = 7.9m/s, p = 0.03). Similarly mean diameter was larger in non-dippers and largest in reverse dippers. On the other hand AIx was lower in non-dippers and lowest in reverse dippers. Value r-W1 was lowest in reverse group (r-W1 dipper = 98ms, reverse dipper = 80.5ms, p < 0.01). Differences between the stiffness values in dippers and extreme dippers were statistically not significant. Conclusions: Relationship between systolic daytime and night-time BP with AIx and W1 may provide information about the impact of BP on wave reflection and ventricular-arterial coupling. The stiffness values were significantly elevated in non-dippers and mainly in reverse dippers.