Search results for " STIFFNESS"
showing 10 items of 299 documents
Influence of age and sex on aortic distensibility assessed by MRI in healthy subjects
2010
International audience; Abstract: Magnetic resonance imaging (MRI) is particularly well adapted to the evaluation of aortic distensibility. The calculation of this parameter, based on the change in vessel cross-sectional area per unit change in blood pressure, requires precise delineation of the aortic wall on a series of cine-MR images. Firstly, the study consisted in validating a new automatic method to assess aortic elasticity. Secondly, aortic distensibility was studied for the ascending and descending thoracic aortas in 26 healthy subjects. Two homogeneous groups were available to evaluate the influence of sex and age (with an age limit value of 35 years). The automatic postprocessing …
Relationship of Metabolic Syndrome With Pulse Pressure in Patients With Essential Hypertension
2006
BACKGROUND: Pulse pressure is largely dependent on arterial stiffness. Recent studies have documented reduced large artery compliance in nondiabetic subjects with metabolic syndrome (MS). The aim of our study was to analyze, in a group of patients with essential hypertension and without diabetes mellitus, the influence of MS on clinic and 24-h pulse pressures. METHODS: A total of 528 hypertensive subjects, aged 18 to 72 years, who were free of cardiovascular and renal diseases were enrolled. Of the subjects, 41% had MS. In all subjects routine blood chemistry, echocardiographic examination, and 24-h ambulatory blood pressure monitoring were performed. RESULTS: When compared with subjects wi…
Ambulatory Arterial Stiffness Index (AASI) is Unable to Estimate Arterial Stiffness of Hypertensive Subjects: Role of Nocturnal Dipping of Blood Pres…
2018
BACKGROUND: Ambulatory Arterial Stiffness Index (AASI) has been proposed as an indirect and simpler method to estimate the Arterial Stiffness (AS). AASI, calculated from a set of data collected during a 24-hours ambulatory blood pressure monitoring (ABPM), is defined as 1 minus the regression slope of diastolic on systolic blood pressure (BP) values. For a given increase in diastolic BP, the increase in systolic BP is smaller in a compliant compared to a stiff artery; the stiffer the arterial tree, the closer AASI is to 1. AASI was demonstrated to predict cardiovascular mortality, cerebrovascular events and to be associated with target organ damage. Taking into account the almost complete a…
Two-stage multi-Gaussian fitting of conduit artery photoplethysmography waveform during induced unilateral hemodynamic events.
2014
Photoplethysmography (PPG) is an optical technique with high diagnostic potential, yet clinical applications remain underdeveloped. Standardization of signal recording and quantification of waveform are essential prerequisites for broader clinical use. The aim of this study was to utilize a two-stage multi-Gaussian fitting technique in order to examine the parameters of conduit artery PPG waveform recorded during increasing the unilateral regional vascular resistance (RVR). This study was conducted on 14 young and healthy volunteers; various external compressions (ECs) were performed by inflating a tight cuff at 0, 40, 80, and 200 mmHg, while registering femoral PPG (wavelength 880 nm), dia…
Measurement of the local aortic stiffness by a non-invasive bioelectrical impedance technique.
2011
International audience; Aortic stiffness measurement is well recognized as an independent predictor of cardiovascular mortality and morbidity. Recently, a simple method has been proposed for the evaluation of the local aortic stiffness (AoStiff) using a non-invasive bioelectrical impedance (BI) technique. This approach relies on a novel interpretation of the arterial stiffness where AoStiff is computed from the measurement of two new BI variables: (1) the local aortic flow resistance (AoRes) exerted by the drag forces onto the flow; (2) the local aortic wall distensibility (AoDist). Herein, we propose to detail and compare these three indices with the reference pulse wave velocity (PWV) mea…
Validity criteria for the diagnosis of fatty liver by M probe-based controlled attenuation parameter.
2017
Background & Aims Controlled attenuation parameter (CAP) can be performed together with liver stiffness measurement (LSM) by transient elastography (TE) and is often used to diagnose fatty liver. We aimed to define the validity criteria of CAP. Methods CAP was measured by the M probe prior to liver biopsy in 754 consecutive patients with different liver diseases at three centers in Europe and Hong Kong (derivation cohort, n = 340; validation cohort, n = 414; 101 chronic hepatitis B, 154 chronic hepatitis C, 349 non-alcoholic fatty liver disease, 37 autoimmune hepatitis, 49 cholestatic liver disease, 64 others; 277 F3-4; age 52 ± 14; body mass index 27.2 ± 5.3 kg/m2). The primary outco…
Noninvasive peripheral vascular function and atrial fibrillation in the general population.
2019
Background Arterial stiffness is a strong predictor of atrial fibrillation in the community. Whether noninvasively measured conduit artery function and peripheral vascular reactivity are related to atrial fibrillation remains unknown. Methods and results In 15 010 individuals of the population-based Gutenberg Health Study, mean age 55 ± 11 years, 50.5% men, we determined noninvasive vascular function by flow-mediated dilation (FMD) and peripheral arterial tonometry (PAT) in relation to manifest atrial fibrillation (N = 466). Patients with atrial fibrillation exhibited a higher mean brachial artery diameter [4.81 mm (4.17, 5.33) in atrial fibrillation vs. 4.31 mm (3.67, 4.93)] and baseline p…
Inverse Relationship Between Ambulatory Arterial Stiffness Index and Glomerular Filtration Rate in Arterial Hypertension
2007
BACKGROUND: Arterial stiffness and mild-to-moderate renal dysfunction are predictors of cardiovascular (CV) morbidity and mortality. Recently, the ambulatory arterial stiffness index (AASI) has been proposed as a surrogate index of arterial stiffness. It has been associated with an enhanced risk of stroke. The aim of our study was to assess the relationship between AASI and glomerular filtration rate (GFR) in a group of hypertensive patients with no CV complications. METHODS: A total of 143 untreated hypertensive subjects (mean age: 44 +/- 12 years; men 57%), with serum creatinine <1.5 mg/dl, were enrolled. AASI was calculated as one minus the regression slope of diastolic on systolic blood…
Domains of Physical Activity in Relation to Stiffness Index in the General Population.
2021
Background Regular exercise training represents an important modifier of arterial stiffness (AS). Therefore, sex‐specific relations between domains of physical activity (PA; commuting, domestic, and leisure‐time PA, including active sport and occupational PA) with AS were investigated. Methods and Results Stiffness index by digital photoplethysmography was investigated in 12 650 subjects from the GHS (Gutenberg Health Study). Self‐reported PA was evaluated by the “Short Questionnaire to Assess Health‐Enhancing Physical Activity” and reported as activity score peer week, being a combined measure of duration, frequency, and intensity of PA. Multivariable linear regression analysis demonstrat…
Variability of the Dynamic Stiffness of Foot Joints: Effect of Gait Speed
2019
Background:Comparison of dynamic stiffness of foot joints was previously proposed to investigate pathologic situations with changes in the properties of muscle and passive structures. Samples must be controlled to reduce the variability within groups being compared, which may arise from different sources, such as gait speed or Foot Posture Index (FPI).Methods:Variability in the measurement of the dynamic stiffness of ankle, midtarsal, and metatarsophalangeal joints was studied in a controlled sample of healthy men with normal FPI, and the effect of gait speed was analyzed. In experiment 1, dynamic stiffnesses were obtained in three sessions, five trials per session, for each participant, ta…