Cross-sectional Distensibility Research Articles

Aluminum Nitride Piezoelectric Micromachined Ultrasound Transducer Arrays for Non-Invasive Monitoring of Radial Artery Stiffness

An aluminum nitride (AlN) piezoelectric micromachined ultrasound transducer (PMUT) array was proposed and fabricated for non-invasive radial artery stiffness monitoring, which could be employed in human vascular health monitoring applications. Using surface micromachining techniques, four hexagonal PMUT arrays were fabricated within a chip area of 3 × 3 mm2. The mechanical displacement sensitivity and quality factor of a single PMUT were tested and found to be 24.47 nm/V at 5.94 MHz and 278 (in air), respectively. Underwater pulse-echo tests for the array demonstrated a -3 dB bandwidth of 0.76 MHz at 3.75 MHz and distance detection limit of approximately 25 mm. Using the PMUT array as an ultrasonic probe, the depth and diameter changes over cardiac cycles of the radial artery were measured to be approximately 3.8 mm and 0.23 mm, respectively. Combined with blood pressure calibration, the biomechanical parameters of the radial artery vessel were extracted using a one-dimensional vascular model. The cross-sectional distensibility, compliance, and stiffness index were determined to be 4.03 × 10-3/mmHg, 1.87 × 10-2 mm2/mmHg, and 5.25, respectively, consistent with the newest medical research. The continuous beat-to-beat blood pressure was also estimated using this model. This work demonstrated the potential of miniaturized PMUT devices for human vascular medical ultrasound applications.

Non-Invasive Assessment of Arterial Stiffness: Pulse Wave Velocity, Pulse Wave Analysis and Carotid Cross-Sectional Distensibility: Comparison between Methods.

Background: The stiffening of large elastic arteries is currently estimated in research and clinical practice by propagative and non-propagative models, as well as parameters derived from aortic pulse waveform analysis. Methods: Common carotid compliance and distensibility were measured by simultaneously recording the diameter and pressure changes during the cardiac cycle. The aortic and upper arm arterial distensibility was estimated by measuring carotid–femoral and carotid–radial pulse wave velocity (PWV), respectively. The augmentation index and blood pressure amplification were derived from the analysis of central pulse waveforms, recorded by applanation tonometry directly from the common carotid artery. Results: 75 volunteers were enrolled in this study (50 females, average age 53.5 years). A significant inverse correlation was found between carotid distensibility and carotid–femoral PWV (r = −0.75; p < 0.001), augmentation index (r = −0.63; p < 0.001) and central pulse pressure (r = −0.59; p < 0.001). A strong correlation was found also between the total slope of the diameter/pressure rate carotid curves and aortic distensibility, quantified from the inverse of the square of carotid–femoral PWV (r = 0.67). No correlation was found between carotid distensibility and carotid–radial PWV. Conclusions: This study showed a close correlation between carotid–femoral PWV, evaluating aortic stiffness by using the propagative method, and local carotid cross-sectional distensibility.

Assessing vascular characteristics of the fetal descending aorta: A feasibility study.

Research describing fetal arterial structure and function is lacking within the literature. This study's purpose was to measure intima-media thickness (IMT), compliance and distensibility of 24- to 25-week fetuses' abdominal aortas using conventional ultrasonography from 16 diabetic (DM) and 25 non-diabetic mothers (NDM). We found no significant differences in fetal abdominal aorta IMT (P = .68), diameter distensibility (P = .22), or cross-sectional distensibility (P = .23). However, both fetal abdominal aortic diameter compliance (P = .03) and cross-sectional compliance (P = .005) were greater in DM than in NDM (P = .005). This study demonstrates that it is possible and potentially useful to measure fetal abdominal aorta biometrics and biomechanical characteristics.

Relation of secondhand smoke exposure to vascular phenotypes in children and adolescents.

INTRODUCTIONSubclinical cardiovascular risks of secondhand smoke (SHS) exposure among children and adolescents remains insufficiently described.METHODSThis was a cross-sectional study of 298 children and adolescents (48.0% male, body mass index: 27.0±8.9kg/m2), including 49 self-reported cases with SHS. Arterial elasticity and stiffness (distensibility, compliance, incremental elastic modulus [IEM]) were obtained via ultrasound imaging in the abdominal aorta, brachial, and carotid arteries. A one-way analysis of variance compared differences between groups, and multiple linear regression adjusted for covariates.RESULTSSHS was associated with lower abdominal aorta diameter distensibility (aDD) (13.4±3.6% vs. 16.0±5.2%, p=0.009), and abdominal aorta cross-sectional distensibility (aCSD) (28.8±8.3% vs. 35.1±12.2% p=0.009), as well as higher abdominal aorta IEM (aIEM) (1241±794mmHg vs. 935±388mmHg, p=0.001). After adjustment for covariates, aDD (p=0.047), aCSD (p=0.040), and aIEM (p=0.017) remained significant; this significance persisted with the additional adjustment of percent body fat. Measures of brachial and carotid compliance and distensibility were not associated with SHS.CONCLUSIONSSHS was associated with abdominal aorta stiffness; the majority of vascular measures within the brachial and carotid artery remained unaffected following adjustment for covariates, including hypertension and adiposity. SHS may predispose individuals to increased abdominal aorta stiffness, an artery previously reported to exhibit increased susceptibility to atherosclerosis.

A13373 A study on the reproducibility of measurement of aortic cross-sectional distensibility of patients with essential hypertension by MR imaging

A13373 A study on the reproducibility of measurement of aortic cross-sectional distensibility of patients with essential hypertension by MR imaging

Vascular Structure and Function in Cancer Survivors after Hematopoietic Stem Cell Transplantation

This study examined the effects of hematopoietic cell transplantation (HCT) and associated preparative regimens on vascular structure and function. Measures of carotid artery stiffness and brachial artery endothelial-dependent dilation were obtained in patients who had survived ≥ 2 years after HCT for hematologic malignancy and were diagnosed at ≤21 years. HCT survivors (n = 108) were examined: 66 received total body irradiation (TBI) alone or with a low-dose cranial radiation boost (TBI±LD-CRT), 19 received TBI plus high-dose cranial radiation (TBI+HD-CRT), and 23 received a chemotherapy-only preparative regimen (CHEMO). Siblings (n = 83) were invited to participate as control subjects. Although endothelial-dependent dilation did not differ between siblings and HCT survivors, carotid cross-sectional compliance, cross-sectional distensibility, diameter compliance, and diameter distensibility were greater in siblings than HCT survivors. Comparing the HCT preparative regimens, carotid cross-sectional compliance, cross-sectional distensibility, diameter compliance, diameter distensibility, and incremental elastic modulus were significantly lower in the TBI+HD-CRT group compared with siblings or with TBI±LD-CRT and CHEMO treatment groups. Cross-sectional distensibility and diameter compliance were significantly lower in the TBI±LD-CRT group compared with siblings. TBI±LD-CRT and CHEMO groups did not differ from each other in these vascular measures. HCT preparative regimens containing TBI+HD-CRT resulted in greater arterial decrements, indicating increased risk for cardiovascular disease.

A non-invasive methodology for ATAA rupture risk estimation

Ascending thoracic aortic aneurysms (ATAA) are a life-threatening pathology provoking an irreversible dilation with a high associated risk of aortic rupture or dissection and death of the patient. Rupture or dissection of ATAAs remains unpredictable and has been documented to occur at diameters less than 4.5 cm for nearly 60% of patients. Other factors than the aneurysm diameter may highly affect the predisposition to rupture. In order to have a better insight in rupture risk prediction, a bulge inflation bench was developed to test ATAAs samples collected on patients during surgical interventions. Preoperative dynamic CT scans on a cohort of 13 patients were analyzed to estimate volumetric and cross-sectional distensibility. A failure criteria based on in vitro ultimate stretch showed a significant correlation with the aortic membrane stiffness deduced from in vivo distensibility. These results reinforce the significance of stretch-based rupture criteria and their possible non-invasive prediction in clinical practice.

PP.13.01] ASSOCIATION BETWEEN NECK CIRCUMFERENCE, AORTIC AND CAROTID STIFFNESS IN HEALTHY ADOLECENTS THE MACISTE STUDY

Objective: Introduction: Obesity has a negative impact on arterial distensibility. Neck circumference (NC) is a marker of upper body adiposity and is linked to unfavourable metabolic profile among young subjects. The association between NC and arterial stiffness is unknown. We evaluated the association between NC and other measures of adiposity, with carotid-femoral pulse wave velocity (cf-PWV) and carotid stiffness (CS) in healthy adolescents. Design and method: Methods: 431 individuals (mean age 16.9 ± 1.4y, SBP/DBP 124/67 ± 11/7 mmHg) attending the Liceo Donatelli High School in Terni, Italy, were evaluated. cf-PWV was measured with applanation tonometry (SphygmoCor device, subtracted distance). CS was measured with Carotid Studio (Quipu): a contour tracking algorithm was applied to B-mode longitudinal scans of common carotid artery to obtain diameter changes, stroke change in lumen area (δA) and lumen area (A). The cross-sectional distensibility coefficient (DC = δA /(A*PP)) was converted (Bramwell-Hill equation) into a carotid stiffness parameter (CS = (DC*ρ)-1/2, ρ=blood density) with same measurement units of PWV. Carotid waveform was calibrated to brachial MAP/DBP. Brachial MAP was derived from brachial tonometry calibrated to brachial SBP/DBP. Results: Average NC was 33 ± 3 cm, average cf-PWV 4.9 ± 0.8 m/s, average CS 4.3 ± 0.6 m/s. NC, as well as other measures of adiposity (BMI, BMI z-score, waist and hip circumferences, waist-hip ratio, waist-height ratio), showed some degrees of association with both cf-PWV and CS (Table). The association between NC and CS was the only association which remained significant after adjustement for age, sex and MAP (partial R = 0.13, p < 0.01), and also after further adjustment for BMI (partial R = 0.10, p = 0.03).Conclusions: In adolescents, NC and other measures of global and local adiposity showed significant associations with cf-PWV and CS. The association between NC and CS was independent from age, sex, MAP and BMI. Both local and systemic factors may be involved in explaining this relationship. NC may help in identifying adolescents with increased CS.

Free-breathing black-blood CINE fast-spin echo imaging for measuring abdominal aortic wall distensibility: a feasibility study

The paper reports a free-breathing black-blood CINE fast-spin echo (FSE) technique for measuring abdominal aortic wall motion. The free-breathing CINE FSE includes the following MR techniques: (1) variable-density sampling with fast iterative reconstruction; (2) inner-volume imaging; and (3) a blood-suppression preparation pulse. The proposed technique was evaluated in eight healthy subjects. The inner-volume imaging significantly reduced the intraluminal artifacts of respiratory motion (p = 0.015). The quantitative measurements were a diameter of 16.3 ± 2.8 mm and wall distensibility of 2.0 ± 0.4 mm (12.5 ± 3.4%) and 0.7 ± 0.3 mm (4.1 ± 1.0%) for the anterior and posterior walls, respectively. The cyclic cross-sectional distensibility was 35 ± 15% greater in the systolic phase than in the diastolic phase. In conclusion, we developed a feasible CINE FSE method to measure the motion of the abdominal aortic wall, which will enable clinical scientists to study the elasticity of the abdominal aorta.

Determination of Bilateral Symmetry of Carotid Artery Structure and Function in Children and Adolescents.

We compared the symmetry of carotid arteries in youth with high-resolution ultrasound. Participants (n=230 (121 females),13.8 ± 2.9 years old) were assessed for: intima media thickness (cIMT), lumen diameter (cLD), incremental elastic modulus (cIEM), diameter compliance (cDC), cross-sectional compliance (cCSC), diameter distensibility (cDD), and cross-sectional distensibility (cCSD). No significant differences (P >0.05 all) were found for cIMT (0.49 ± 0.09 mm vs. 0.49 ± 0.08 mm), cIEM (1095 ± 382 mmHg vs. 1116 ± 346mmHg), cDC (0.01 ± 0.0 mm/mmHg vs. 0.01 ± 0.0 mm/mmHg), cCSC (0.01 ± 0.001/mmHg vs. 0.01 ± 0.001/mmHg), cDD (14.0 ± 3.16% vs. 13.7 ± 3.18%), and cCSD (30.1 ± 7.37% vs. 29.4 ± 7.36%). Significant differences were found for cLD (6.06 ± 0.62 mm vs. 6.33 ± 0.64 mm, P <0.001). These data suggest that these values may be used interchangeably if one side is inaccessible.

Te Comparison of the Effects of the Cilostazol on the Stiffness Parameters in Different Arterial Systems in the Patients with Peripheral Arterial Disease

Objective : Object of this study is to determine the effect of cilostazol on arterial compliance, distensibilty and vascular stiffness in carotid, femoral and brachial arteries through non-invasive methods in patients with stable IC/PAD. Material and Methods: Twenty-nine patients (22 male, 7 female) who had been treated with cilostazol 100 mg twice daily during six month were included in the study. Ultrasound measurements of carotid, femoral and brachial arteries were performed at baseline, at 3 and 6 months afer starting of treatment and the evaluation of the arterial stiffness measurements were performed by the pre-defned method. Results : Te mean age of the participants was 64 years. Pulsatility index, resistive index, systolic/diastolic velocity ratio, intima-media thickness and elastic modulus values were decreased while cross-sectional compliance, cross-sectional distensibility and diastolic wall stress values were increased with treatment in carotid, femoral and brachial arteries. Carotid, femoral and brachial arteries have similar rates of change. Conclusion : Cilostazol treatment reduced the progression of atherosclerosis without increasing the risk of bleeding in patients with peripheral arterial disease during a long-term follow-up

Abstract 11198: Heritability of Vascular Structure and Function: A Parent-child Study

Introduction: Vascular structure and function can be measured non-invasively in both children and adults. Understanding the heritability of these measures may aid in risk stratification and atherosclerosis prevention efforts. Data on the heritable contribution from parent to offspring for vascular measures are limited. Hypothesis: We hypothesized that measures of vascular structure and function would be modestly heritable in this large parent-child study. Methods: High-resolution ultrasound scans of the brachial and carotid arteries were obtained in parents (n=558; mean age=39.2±2.1) and their offspring (n=369; mean age 12.4±4.6). In the brachial artery, flow-mediated dilation (FMD) and lumen diameter (bLD) were measured. In the carotid artery, intima-media thickness (cIMT), lumen diameter (cLD), incremental elastic modulus (cIEM), diameter distensibility (cDD), and cross-sectional distensibility were measured (cCSD). Carotid-radial pulse wave velocity (PWV) was also obtained. Heritability analysis (h 2 , expressed as %) was performed using SOLAR on the entire cohort and adjusted for age, gender, race, body-mass index, smoking, and systolic blood pressure. Data are presented as mean (SE). Results: Measures of bLD (h 2 = 25.2(8.6), p&lt;0.001), cLD (h 2 = 55.4(8.8), p&lt;0.001), cIMT (h 2 = 28.1(12.6), p=0.014), cDD (h 2 = 28.2(7.1), p&lt;0.001), cCSD (h 2 = 27.1(6.9), p&lt;0.001), and PWV (h 2 = 26.3(8.9), p&lt;0.001) were significantly heritable. Only FMD (h 2 = 1.6(8.4), p=0.44), and cIEM (h 2 = 12.7(9.3), p=0.081) were not significantly heritable. Conclusions: These data suggest that the majority of non-invasive measures of vascular structure and function are modestly heritable from parent to child. Early interventions targeted at youth with elevated vascular risk and/or a high familial cardiovascular risk profile may be able to modify vascular structure and function to prevent further dysfunction as these children transition into adulthood.

Carotid-Ventricular Coupling During Exercise: A Pilot Study.

To evaluate carotid elasticity and left ventricular elastance during a graded bicycle semisupine exercise test in patients with known or suspected coronary artery disease and compare them with a control group of healthy young volunteers. Thirty-six elderly patients and 18 young healthy volunteers were recruited. The right carotid diameter was estimated by an automatic system applied to B-mode sonographic sequences, central mean blood and pulse pressures by radial artery tonometry, and cardiac volumes by 2-dimensional transthoracic echocardiography; from these direct measurements, the carotid cross-sectional distensibility coefficient and left ventricular elastance index were obtained. Analyses were performed at rest, at peak stress, and during the recovery phase. The elderly patients included 20 men (mean age ± SD, 61 ± 8 years); the volunteers included 9 men (mean age, 34 ± 3 years). The mean blood pressure (at rest: patients, 97 ± 7 mm Hg; controls, 93 ± 9 mm Hg; not significant) increased similarly in both groups during exercise and decreased during the recovery phase. The diameter was higher in patients than controls (7.5 ± 1.1 versus 6.2 ± 0.5 mm) and increased significantly with exercise only in the latter group (at peak: 6.5 ± 0.6 mm; P < .05). The distensibility coefficient and elastance index were lower in patients than controls during the test phases [at rest: 24.5 ± 10.2 versus 60.8 ± 21.3 × 10(-3)/kPa and 3.6 ± 1.4 versus 1.6 ± 0.8 mm Hg/(mL/m(2))] and mostly changed in the controls, showing a decreased distensibility coefficient (peak: 40.6 ± 15.1 × 10(-3)/kPa) and an increased elastance index [peak: 5.9 ± 2.8 mm Hg/(mL/m(2))]. In older patients with multiple cardiovascular risk factors or established coronary artery disease, an abnormal carotid-ventricular adaptation to exercise was observed when compared to young healthy individuals.

Endothelial Function and Vascular Properties in Children with Sickle Cell Disease.

Sickle cell disease (SCD) is an inherited disorder characterized by recurrent painful crises with ischemia resulting from vascular occlusion. Adults with SCD have increased arterial stiffness and reduced flow-mediated dilation (FMD), due to impaired release of substances such as nitric oxide. We aimed to assess the vascular properties of carotid and brachial arteries in children with SCD compared with a control group without cardiovascular risk factors. Thirty patients with SCD, mean age 12.3±4.5years, were prospectively enrolled. A control group was made up of 30 age- and gender-matched healthy subjects. Carotid intima-media thickness (IMT), cross-sectional compliance (CSC), cross-sectional distensibility (CSD), diastolic wall stress (DWS), incremental elastic modulus (Einc), and FMD were determined in both groups. There was no significant difference in FMD between the two groups (8.2±5.0% in the SCD group vs. 9.3±4.2% in the control group, P=0.15). There was no significant correlation between FMD and age, hemoglobin, LDH level, or transcranial Doppler findings. CSD was significantly elevated in the SCD group (0.96±0.44 vs. 0.59±0.21, P=0.0002), whereas DWS and Einc were significantly lower in the SCD group. CSC did not differ significantly between the two groups. Children with SCD have no marked endothelial dysfunction or change in arterial stiffness. These manifestations may be related to disease severity and duration. Changes may become evident later in life as the disease progresses.

An investigation of atherosclerotic markers in patients with posterior semi-circular canal benign paroxysmal positional vertigo

This study aims to investigate the presence and incidence of arteriosclerosis in patients with benign paroxysmal positional vertigo (BPPV). A total of 89 patients who were admitted to the ear, nose, throat outpatient clinic with complaint of vertigo and were diagnosed with BPPV based on the positive Dix-Hallpike test results were included (BPPV group) between January 2010 and July 2010. Data from otological asymptomatic controls (n=129) who were referred to the radiology department from other clinics for ultrasound examination were obtained. Intima-media thickness and arteriosclerosis measurements were carried out. Arteriosclerosis measurement was performed through a Doppler ultrasound. No statistically significant difference in carotid, femoral intima-media thicknesses and elastic modulus measurements between the controls and BPPV group. In the BPPV group, carotid artery cross-sectional compliance, cross-sectional distensibility, femoral artery cross-sectional compliance and cross-sectional distensibility were statistically significantly lower. Our study results suggest that atherosclerotic changes may play a role in the underlying etiology of BPPV.

Carotid intima–media thickness is increased in patients with treated mucopolysaccharidosis types I and II, and correlates with arterial stiffness

BackgroundTreatments for mucopolysaccharidoses (MPSs) have increased longevity, but coronary artery disease (CAD) and cardiovascular complications cause mortality in a high percentage of patients. Non-invasive measures of sub-clinical atherosclerosis, such as carotid intima–media thickness (cIMT) and arterial stiffness, may be useful for prediction of CAD outcomes in MPS patients. ObjectivesThe aim of the study was to determine if cIMT and arterial stiffness are abnormal in MPS I and II patients compared to healthy controls. MethodsMPS patients underwent carotid artery ultrasonography, and electronic wall-tracking software was used to measure cIMT, carotid artery cross-sectional compliance (cCSC), cross-sectional distensibility (cCSD), and incremental elastic modulus (cIEM). Control data from healthy subjects were obtained from a different study that utilized identical testing within the same laboratory. ResultsA total of 406 healthy controls and 25 MPS patients (16 MPS I, 9 MPS II) were studied. All MPS patients had or were receiving treatment: 15 patients (6 MPS I, 9 MPS II) were receiving enzyme replacement therapy (ERT), 9 patients (all MPS I) had received hematopoietic stem cell transplant (HSCT), and 1 patient with MPS I had received HSCT and was receiving enzyme replacement therapy (ERT). MPS patients had significantly higher mean (±SD) cIMT (0.56±0.05mm) compared to controls (0.44±0.04mm; adjusted p<0.001). MPS patients also had increased stiffness compared to controls, showing significantly lower cCSC (0.14±0.09mm2/mmHg versus 0.16±0.05mm2/mmHg; adjusted p=0.019), and higher cIEM (1362±877mmHg versus 942±396mmHg; adjusted p<0.001). cCSD in MPS patients was lower than that of controls (29.7±16.4% versus 32.0±8.2%) but was not statistically significant; p=0.12. Among MPS patients, cCSD showed a significant association with cIMT (p=0.047), while the association between cIEM and cIMT approached significance (p=0.077). No significant differences were observed in cIMT, cCSD, cCSC, and cIEM between MPS I and MPS II patients. ConclusionsDespite treatment, MPS patients had higher cIMT compared to healthy controls, indicating this marker of sub-clinical atherosclerosis may be a useful predictor of CAD outcomes. The association of arterial stiffness measures with cIMT suggests that mechanical and structural changes may occur in concert among MPS patients. Although yet to be confirmed, increased cIMT and arterial stiffness in MPS I and II patients may be a consequence of inflammatory signaling pathways triggered by heparan or dermatan sulfate-derived oligosaccharides. Prospective, longitudinal studies will need to be performed in order to evaluate the usefulness of these carotid measurements as predictors of adverse CAD outcomes in MPS patients.

Longitudinal Displacement of the Carotid Wall and Cardiovascular Risk Factors: Associations with Aging, Adiposity, Blood Pressure and Periodontal Disease Independent of Cross-Sectional Distensibility and Intima-Media Thickness

The recently discovered longitudinal displacement of the common carotid arterial wall (i.e., the motion along the same plane as the blood flow), may be associated with incident cardiovascular events and represents a novel and relevant clinical information. At present, there have only been a few studies that have been conducted to investigate this longitudinal movement. We propose here a method to assess noninvasively the wall bi-dimensional (two-dimensional [2-D], cross-sectional and longitudinal) motion and present an original approach that combines a robust speckle tracking scheme to guidance by minimal path contours segmentation. Our method is well suited to large clinical population studies as it does not necessitate strong imaging prerequisites. The aim of this study is to describe the association between the longitudinal displacement of the carotid arterial wall and cardiovascular risk factors, among which periodontal disease. Some 126 Indigenous Australians with periodontal disease, an emerging risk factor, and 27 healthy age- and sex-matched non-indigenous control subjects had high-resolution ultrasound scans of the common carotid artery. Carotid intima-media thickness and arterial wall 2-D motion were then assessed using our method in ultrasound B-mode sequences. Carotid longitudinal displacement was markedly lower in the periodontal disease group than the control group (geometric mean (IQR): 0.15 mm (0.13) vs. 0.42 mm (0.30), respectively; p < 0.0001), independent of cardiovascular risk factors, cross-sectional distensibility and carotid intima-media thickness (p < 0.0001). A multivariable model indicated that the strongest correlates of carotid longitudinal displacement in adults with periodontal disease were age (β-coefficient = −.235, p = .03), waist (β-coefficient = −.357, p = 0.001), and pulse pressure (β-coefficient = .175, p = 0.07), independent of other cardiovascular risk factors, cross-sectional distensibility and pulse wave velocity. Carotid longitudinal displacement, estimated with our approach, is impaired in the periodontal disease group, independent of established cardiovascular risk factors and other noninvasive measures of arterial stiffness, and may represent an important marker of cardiovascular risk.

Effects of the left ventricular assist device on the compliance and distensibility of the carotid artery

We investigated the impact of continuous-flow left ventricular assist devices (LVAD) on the carotid elastic properties. Carotid artery parameters (diameter distensibility (DD), cross-sectional distensibility (CSD), diameter compliance (DC), cross-sectional compliance (CSC), and incremental elastic modulus (IEM)) were measured in a cross-sectional study using a standard ultrasound with a 10-MHz linear array probe. Measurements (mean ± SEM) were made in separate groups at various clinical time points: prior to LVAD surgery (baseline; 13 male/3 female; age 48 ± 3 years), 1 week following LVAD placement (acute; 12 male/2 female; age 47 ± 3 years), approximately 24 weeks following LVAD surgery (chronic; 13 male/2 female; age 52 ± 3 years), and in a group of healthy subjects (controls; 9 male/1 female; age 51 ± 4 years). Distensibility properties were lower (P < 0.05) in the acute (DD 2.3 % ± 0.4 %; CSD 4.7 % ± 0.8 %) and chronic (DD 2.2 % ± 0.4 %; CSD 4.5 ± 0.9 %) compared with the baseline (DD 5.9 % ± 0.7 %; CSD 12.2 % ± 1.5 %) and control (DD 5.8 % ± 0.6 %; CSD 11.9 % ± 1.3 %) groups. Compliance properties were lower (P < 0.05) in the chronic (DC 4.4 ± 0.7 mm/mmHg × 10(-3); CSC 1.2 ± 0.2 mmHg(-1) × 10(-3)) compared with acute (DC 9.0 ± 1.6 mm/mmHg × 10(-3); CSC 2.6 ± 0.4 mmHg(-1) × 10(-3)) and baseline (DC 11.1 ± 1.1 mm/mmHg × 10(-3); CSC 3.3 ± 0.4 mmHg(-1) × 10(-3)) groups. The compliance properties in the control (DC 8.3 ± 0.8 mm/mmHg × 10(-3); CSC 2.4 ± 0.2 mmHg(-1) × 10(-3)) group were not different from any of the patient groups. The IEM was higher (P < 0.05) in the chronic (6908 ± 1269 mmHg) compared with acute (2739 ± 412 mmHg), baseline (1849 ± 177 mmHg), and control (2349 ± 241 mmHg) groups. Chronic continuous-flow LVAD support is associated with lower carotid artery compliance and distensibility, which may place further strain on the left ventricle.

Normal values of aortic dimensions, distensibility and pulse wave velocity in children and young adults

Background Aortic enlargement and impaired bioelasticity is a focus of interest in several cardiac and non-cardiac diseases as it can lead to severe cardiovascular complications. Assessment of aortic anatomy and bioelasticity, namely aortic distensibility and pulse wave velocity (PWV), by cardiovascular magnetic resonance imaging (CMR) is accurate and reproducible and can help to identify anatomical and functional abnormalities of the aorta. However, normal CMR values for healthy children and young adults are lacking. Methods Seventy-one heart-healthy subjects (mean age 16.4 ± 7.6 y, range 2.3 - 28.3 y) were examined using a 3.0-T CMR scanner. Aortic cross-sectional areas and aortic distensibility were measured at four positions of the thoracic aorta. PWV was assessed from aortic phase-contrast flow measurements in a segment which includes the aorta between the ascending aorta and the proximal descending aorta. Reference percentile curves for aortic cross-sectional areas, aortic distensibility and PWV were computed with the Lambda-Mu-Sigma method by Cole. Results Aortic areas, aortic distensibility and PWV (aortic crosssectional areas: r= 0.8 to 0.9, p<0.001; aortic distensibility r= -0.43 to -0.62, p<0.001; PWV: r= 0.25 to 0.32, p= 0.047 to 0.009) correlated with height, weight, body surface area, and age. There were no significant sex differences. Percentile curves for aortic cross-sectional areas, aortic distensibility and PWV according to age are presented (Figure: Example of reference percentiles for PWV in the aortic arch). Conclusions This study provides percentile curves for cross-sectional areas, distensibility and PWV of the thoracic aorta in children and young adolescents between their 3rd and 29th year of life. These data may serve as a reference for the early detection of pathological changes of the aorta in various cardiovascular diseases. Funding None.

The assessment of relationship between bone mineral density and arterial stiffness in turkish women

The aim of this study was to investigate the correlation between bone mineral density (BMD) and arterial stiffness as a preclinical atherosclerosis criterion. Carotid and femoral artery Doppler ultrasonography and arterial stiffness measurements were performed on 113 female patients referred for BMD measurements. The cross-sectional compliance and cross-sectional distensibility of the carotid artery were positively correlated with the BMD of the Ward's triangle, the femoral neck, and the lower femoral neck; and the Ward's triangle, respectively. A negative correlation was found between the intima-media thickness of the femoral artery and the femoral elastic modulus with the BMD of L1, L12, L13, and L23; and the BMD of L1, L3, L13, L24, L34, the femoral neck, the lower femoral neck, and Ward's triangle, respectively. The cross-sectional compliance and cross-sectional distensibility of the femoral artery were positively correlated with the BMD of the femoral neck, upper femoral neck, lower femoral neck, Ward's triangle; and the BMD of the total femur and Ward's triangle, respectively. The arterial stiffness measurements in women are correlated with BMD, regardless of age and other demographic factors.