Search results for "geometry."
showing 10 items of 4386 documents
Disturbed glucose metabolism and left ventricular geometry in the general population – results from the Gutenberg health study
2020
Abstract Background Prediabetes and type 2 diabetes mellitus (T2DM) have been demonstrated to alter left ventricular geometry and promote left ventricular (LV) hypertrophy (LVH). However, the impact of impaired glucose metabolism on cardiac structure is still not completely understood and controversially discussed. Purpose To investigate the impact of prediabetes and T2DM on left ventricular geometry and their potential interaction with LVH in the prediction of survival. Methods Data from the Gutenberg Health Study (N=15,010) – a population-based study with highly standardized phenotyping – were analysed. Information was obtained from computer-assisted personal interviews, medical-technical…
Magnetic resonance in isolated noncompaction of the ventricular myocardium
2010
Abstract Non-compaction of the ventricular myocardium (LCVM) is a rare disorder of myocardial morphogenesis usually diagnosed in paediatric age. The diagnosis was echocardiographically made on the basis of a reported spongeous/compacted ratio >2 in one or more segments of the left ventricle during the diastolic period. We aimed to test the diagnostic accuracy of cardiovascular magnetic resonance (CMR) imaging in distinguishing pathological left ventricular non-compaction. Methods We collected a consecutive series of 8 patients, 5 males and 3 females, with a mean age of 14.9 years with non-compaction of left ventricular myocardium. All patients were admitted in our divisions of cardiology. I…
Disturbed Glucose Metabolism and Left Ventricular Geometry in the General Population
2021
Background: This study sought to investigate the prevalence and clinical outcome of left ventricular (LV) geometry in prediabetes and type 2 diabetes mellitus (T2DM) and the impact of glucose metabolism on the incidence of left ventricular hypertrophy (LVH). Methods: 15,010 subjects (35–74 years) of the population-based Gutenberg Health Study were categorized into euglycemia, prediabetes, and T2DM according to clinical and metabolic (HbA1c) information. Clinical outcome was assessed via structured follow-up. Results: The study comprised 12,121 individuals with euglycemia (81.6%), 1415 with prediabetes (9.5%), and 1316 with T2DM (8.9%). Prevalence of LVH increased from euglycemia (10.2%) ove…
The Relationship between the Transforming Growth Factor β1 T29C Gene Polymorphism and Left Ventricular Geometry and Function in Hypertensive Subjects
2009
The distribution of the T29C TGFβ1 gene polymorphism was analyzed in 198 hypertensives with left ventricular hypertrophy (LVH) and in 235 hypertensives without LVH. Circulating TGFβ1 levels, procollagen type III levels, microalbuminuria, and left ventricular geometry and function were evaluated in all the hypertensives with LVH subgrouped according to T29C TGFβ1 gene polymorphism. Circulating TGFβ1 was evaluated by ELISA technique, procollagen type III by a specific radioimmunoassay, microalbuminuria by radioimmunoassay, and left ventricular geometry and function by echocardiography. All groups were comparable for gender, age, and sex. Regarding T29C TGFβ1 gene polymorphism, prevalence of T…
Abstract P153: Early Changes in Left-Atrial and Left-Ventricular Geometry and Function in Women After Preeclampsia as Detected by Cardiac Magnetic Re…
2019
Objectives: Preeclampsia (PE), the leading cause of maternal and neonatal morbidity and mortality, is associated with an increased long-term risk for cardiovascular disease (CVD). We aimed to characterize myocardium and investigate potential functional and structural cardiac alterations in asymptomatic women after PE using cardiovascular magnetic resonance (CMR) imaging. Methods and Results: We performed a post-pregnancy case-control study (clinicaltrials.gov ID: NCT03313063). In total, 22 cases and 23 controls were recruited. Participants were matched by age, BMI and parity. Hemodynamic and morphologic characteristics of the myocardium were assessed using established and innovative CMR te…
On one-dimensionality of metric measure spaces
2019
In this paper, we prove that a metric measure space which has at least one open set isometric to an interval, and for which the (possibly non-unique) optimal transport map exists from any absolutely continuous measure to an arbitrary measure, is a one-dimensional manifold (possibly with boundary). As an immediate corollary we obtain that if a metric measure space is a very strict $CD(K,N)$ -space or an essentially non-branching $MCP(K,N)$-space with some open set isometric to an interval, then it is a one-dimensional manifold. We also obtain the same conclusion for a metric measure space which has a point in which the Gromov-Hausdorff tangent is unique and isometric to the real line, and fo…
Mappings of finite distortion between metric measure spaces
2015
We establish the basic analytic properties of mappings of finite distortion between proper Ahlfors regular metric measure spaces that support a ( 1 , 1 ) (1,1) -Poincaré inequality. As applications, we prove that under certain integrability assumption for the distortion function, the branch set of a mapping of finite distortion between generalized n n -manifolds of type A A has zero Hausdorff n n -measure.
Non-branching geodesics and optimal maps in strong CD(K,∞) -spaces
2014
We prove that in metric measure spaces where the entropy functional is Kconvex along every Wasserstein geodesic any optimal transport between two absolutely continuous measures with finite second moments lives on a non-branching set of geodesics. As a corollary we obtain that in these spaces there exists only one optimal transport plan between any two absolutely continuous measures with finite second moments and this plan is given by a map. The results are applicable in metric measure spaces having Riemannian Ricci curvature bounded below, and in particular they hold also for Gromov-Hausdorff limits of Riemannian manifolds with Ricci curvature bounded from below by some constant. peerReview…
Uniformization of two-dimensional metric surfaces
2014
We establish uniformization results for metric spaces that are homeomorphic to the Euclidean plane or sphere and have locally finite Hausdorff 2-measure. Applying the geometric definition of quasiconformality, we give a necessary and sufficient condition for such spaces to be QC equivalent to the Euclidean plane, disk, or sphere. Moreover, we show that if such a QC parametrization exists, then the dilatation can be bounded by 2. As an application, we show that the Euclidean upper bound for measures of balls is a sufficient condition for the existence of a 2-QC parametrization. This result gives a new approach to the Bonk-Kleiner theorem on parametrizations of Ahlfors 2-regular spheres by qu…
An EEMD Aided Comparison of Time Histories and Its Application in Vehicle Safety
2017
In the context of signal processing, the comparison of time histories is required for different purposes, especially for the model validation of vehicle safety. Most of the existing metrics focus on the mathematical value only. Therefore, they suffer the measuring errors, disturbance, and uncertainties and can hardly achieve a stable result with a clear physical interpretation. This paper proposes a novel scheme of time histories comparison to be used in vehicle safety analysis. More specifically, each signal for comparison is decomposed into a trend signal and several intrinsic mode functions (IMFs) by ensemble empirical mode decomposition. The trend signals reflect the general variation a…