Background: This study shows that the arterial longitudinal impedance constitutes a hemodynamic parameter of interest for performance characterization of large arteries in normal condition as well as in pathological situations. For this purpose, we solved the Navier-Stokes equations for an incompressible flow using the finite element analysis method and the Arbitrary Lagrangian Eulerian (ALE) formulation. The mathematical model assumes a two-dimensional flow and takes into account the nonlinear terms in the equations of fluid motion that express the convective acceleration, as well as the nonlinear deformation of the arterial wall. Several numerical simulations of the blood flow in large vessels have been performed to study the propagation along an arterial vessel of a pressure gradient pulse and a rate flow pulse. These simulations include various deformations of the wall artery leading to parietal displacements ranging from 0 (rigid wall) to 15% (very elastic wall) in order to consider physiological and pathological cases.
Results: The results show significant changes of the rate flow and the pressure gradient wave as a function of aosc, the relative variation in the radius of the artery over a cardiac cycle. These changes are notable beyond a critical value of aosc equal to 0.05. This critical value is also found in the evolution of the longitudinal impedance. So, above a variation of radius of 5%, the convective acceleration, created by the fluid-wall interactions, have an influence on the flow detectable on the longitudinal impedance.
Conclusions: The interpretation of the evolution of the longitudinal impedance shows that it could be a mean to test the performance of large arteries and can contribute to the diagnosis of parietal lesions of large arteries. For a blood vessel with a wall displacement higher than 5% similar to those of large arteries like the aorta, the longitudinal impedance is substantially greater than that obtained in the absence of wall displacement. This study also explains the effects of convective acceleration, on the shape of the decline of the pressure gradient wave and shows that they should not be neglected when the variation in radius is greater than 5%.
Download full-text PDF |
Source |
|---|---|
| http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3442960 | PMC |
| http://dx.doi.org/10.1186/1753-4631-6-2 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Inhibition of nitric oxide synthase transforms carotid occlusion-mediated benign oligemia into large cerebral infarction.
Theranostics
January 2025
Department of neurology, Dongguk University Ilsan Hospital, Goyang 10326, Republic of Korea.
It remains unclear why unilateral proximal carotid artery occlusion (UCAO) causes benign oligemia in mice, yet leads to various outcomes (asymptomatic-to-death) in humans. We hypothesized that inhibition of nitric oxide synthase (NOS) both transforms UCAO-mediated oligemia into full infarction and expands pre-existing infarction. Using 900 mice, we i) investigated stroke-related effects of UCAO with/without intraperitoneal administration of the NOS inhibitor (NOSi) N-nitro-L-arginine methyl ester (L-NAME, 400 mg/kg); ii) examined the rescue effect of the NO-donor, molsidomine (200 mg/kg at 30 minutes); and iii) tested the impact of antiplatelet medications.
View Article and Find Full Text PDFTrends and cost structure of drug-based secondary prevention of ischemic strokes.
Neurol Res Pract
January 2025
Goethe University Frankfurt, University Hospital, Department of Neurology, Schleusenweg 2-16, 60528, Frankfurt am Main, Germany.
Background: Advances in secondary stroke prevention, including direct oral anticoagulants (DOACs), dual antiplatelet therapies (DAPT), and cardiovascular risk management, have changed costs over the past decade. This study aimed to evaluate annual treatment costs and trends in drug-based secondary prophylaxis after ischemic strokes.
Methods: Annual treatment costs were evaluated using the net costs per defined daily dosage (DDD) of discharge medications for ischemic stroke patients treated in 2020 at the University Hospital Frankfurt, Germany.
Phenotyping atherosclerotic plaque and perivascular adipose tissue: signalling pathways and clinical biomarkers in atherosclerosis.
Nat Rev Cardiol
January 2025
Department of Biomedical Sciences, and Department of Medicine, Cedars-Sinai Medical Center, Biomedical Imaging Research Institute, Los Angeles, CA, USA.
Computed tomography coronary angiography provides a non-invasive evaluation of coronary artery disease that includes phenotyping of atherosclerotic plaques and the surrounding perivascular adipose tissue (PVAT). Image analysis techniques have been developed to quantify atherosclerotic plaque burden and morphology as well as the associated PVAT attenuation, and emerging radiomic approaches can add further contextual information. PVAT attenuation might provide a novel measure of vascular health that could be indicative of the pathogenetic processes implicated in atherosclerosis such as inflammation, fibrosis or increased vascularity.
View Article and Find Full Text PDFImpact of Complications on Survival Outcomes in Different Temporary Mechanical Circulatory Support Techniques: A Large Retrospective Cohort Study of Cardiac Surgical and Non-surgical Patients.
J Heart Lung Transplant
December 2024
DZHK (German Centre for Cardiovascular Research), Partner Site Berlin, 13353 Berlin, Germany; Deutsches Herzzentrum der Charité, Department of Cardiothoracic and Vascular Surgery, Berlin, Germany. Charité-Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Charitéplatz 1, 10117 Berlin, Germany.
Background: Temporary mechanical circulatory support (tMCS) devices have become a standard treatment option in cardiogenic shock but are associated with high complication rates. This study analyzes common complications associated with modern tMCS devices and their impact on mortality depending on the tMCS approach.
Methods: We conducted a retrospective single-center analysis of patients with all-cause cardiogenic shock treated with veno-arterial extracorporeal life support, microaxial flow pump, and a combination of both (ECMELLA).
Drug-Coated Balloons versus Drug-Eluting Stents for the Treatment of De Novo Coronary Artery Disease: A Meta-Analysis of Randomized Controlled Trials.
Rev Cardiovasc Med
December 2024
Department of Cardiology, Beijing Anzhen Hospital, Capital Medical University, 100069 Beijing, China.
Background: Because of the limitations in new-generation drug-eluting stents (DES), treatments advocating for non-stents with a drug-coated balloon (DCB) is now of great interest. Here, we conducted a meta-analysis to testify whether a DCB was more effective and safer than a DES in treating de novo coronary artery disease (CAD).
Methods: We searched PubMed, Embase, Cochrane Library, and Web of Science to obtain high-quality trials comparing DCB with DES for the treatment of de novo CAD.
Want AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!