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Concept

Résistance vasculaire

Publications associées (31)

Novel theory and potential applications of central diastolic pressure decay time constant

Nikolaos Stergiopoulos, Vasiliki Bikia, Georgios Rovas, Sokratis Anagnostopoulos

Central aortic diastolic pressure decay time constant ( ) is according to the two-element Windkessel model equal to the product of total peripheral resistance (R) times total arterial compliance (C ). As such, it is related to arterial stiffness, which has ...

2024

The Impact of Left Ventricular Performance and Afterload on the Evaluation of Aortic Valve Stenosis: A 1D Mathematical Modeling Approach

Nikolaos Stergiopoulos

The transaortic valvular pressure gradient (TPG) plays a central role in decision-making for patients suffering from severe aortic stenosis. However, the flow-dependence nature of the TPG makes the diagnosis of aortic stenosis challenging since the markers ...

MDPI2023

Modulation of Pulsatile Left Ventricular Afterload by Renal Denervation in Heart Failure With Preserved Ejection Fraction

Nikolaos Stergiopoulos, Stamatia Zoi Pagoulatou

Background:Arterial stiffening contributes to hemodynamic derangements in heart failure with preserved ejection fraction (HFpEF). We sought to investigate the impact of renal denervation on pulsatile left ventricular loading in patients with HFpEF and hype ...

Lippincott Williams & Wilkins2023

Cardiac output estimated from an uncalibrated radial blood pressure waveform: validation in an in-silico-generated population

Nikolaos Stergiopoulos, Vasiliki Bikia, Georgios Rovas

Background: Cardiac output is essential for patient management in critically ill patients. The state-of-the-art for cardiac output monitoring bears limitations that pertain to the invasive nature of the method, high costs, and associated complications. Hen ...

FRONTIERS MEDIA SA2023

A comprehensive mathematical model for cardiac perfusion

Alfio Quarteroni, Francesco Regazzoni, Christian Vergara

The aim of this paper is to introduce a new mathematical model that simulates myocardial blood perfusion that accounts for multiscale and multiphysics features. Our model incorporates cardiac electrophysiology, active and passive mechanics, hemodynamics, v ...

Nature Portfolio2023

Rapid low-cost hyperspectral imaging system for quantitative assessment of infantile hemangioma

Viktor Vorobev

Hemangioma, the predominant benign tumor occurring in infancy, exhibits a wide range of prognoses and associated outcomes. The accurate determination of prognosis through noninvasive imaging modalities holds essential importance in enabling effective perso ...

Wiley-V C H Verlag Gmbh2023

p-Aminobenzamidine attenuates cardiovascular dysfunctions in spontaneously hypertensive rats

Nikolaos Stergiopoulos

Aims:Diminazene aceturate, a putative ACE2 activator, is susceptible to cleavage resulting in the formation of paminobenzamidine (PAB). This study aimed to investigate the effects of PAB in addressing cardiovascular dysfunctions in spontaneously hypertensi ...

PERGAMON-ELSEVIER SCIENCE LTD2022

Assessment of Stiffness of Large to Small Arteries in Multistage Renal Disease Model: A Numerical Study

Nikolaos Stergiopoulos, Vasiliki Bikia

Arterial stiffness (AS), as assessed via pulse wave velocity (PWV), is a major biomarker for cardiovascular risk assessment in patients with chronic kidney disease (CKD). However, the mechanisms responsible for the changes in PWV in the presence of kidney ...

FRONTIERS MEDIA SA2022

Effect of Lower Limb vs. Abdominal Compression on Mobility in Orthostatic Hypotension: A Single-Blinded, Randomized, Controlled, Cross-Over Pilot Study in Parkinson's Disease

Kamiar Aminian, Arash Atrsaei

Background: Orthostatic hypotension (OH) in Parkinson's disease (PD) is frequent and associated with impairments in quality of life and reduced activities of daily living. Abdominal binders (AB) and compression stockings (CS) have been shown to be effectiv ...

IOS PRESS2022

Prognostic Implications of the Novel Pulmonary Hypertension Definition in Patients with Aortic Stenosis after Transcatheter Valve Replacement

Nikolaos Stergiopoulos, Vasiliki Bikia, Georgios Rovas, Stamatia Zoi Pagoulatou

Introduction: Pulmonary hypertension (PH), traditionally defined as a mean pulmonary artery pressure (PAP) >= 25 mmHg, is associated with poor outcomes in patients undergoing a transcatheter aortic valve replacement (TAVR) for severe aortic stenosis (AS). ...

MDPI2022

The effect of left ventricular contractility on arterial hemodynamics: A model-based investigation

Nikolaos Stergiopoulos, Vasiliki Bikia, Georgios Rovas, Stamatia Zoi Pagoulatou

Ventricular-arterial coupling is a major determinant of cardiovascular performance, however, there are still inherent difficulties in distinguishing ventricular from vascular effects on arterial pulse phenotypes. In the present study, we employed an extens ...

2021

Determination of Aortic Characteristic Impedance and Total Arterial Compliance From Regional Pulse Wave Velocities Using Machine Learning: An in-silico Study

Nikolaos Stergiopoulos, Vasiliki Bikia, Georgios Rovas, Stamatia Zoi Pagoulatou

In-vivo assessment of aortic characteristic impedance (Zao) and total arterial compliance (CT) has been hampered by the need for either invasive or inconvenient and expensive methods to access simultaneous recordings of aortic pressure and flow, wall thick ...

2021

Apparatus for treating excess intraocular fluid having an elastic membrane

Nikolaos Stergiopoulos, Constantinos Stergiopulos

Apparatus and methods are provided for treating diseases that produce elevated intraocular pressures, such as glaucoma, wherein the device includes a housing shell defining a cavity between a first end and a second end of the housing shell, and an elastic ...

2021

On the assessment of arterial compliance from carotid pressure waveform

Nikolaos Stergiopoulos, Vasiliki Bikia, Georgios Rovas, Stamatia Zoi Pagoulatou

In a progressively aging population, it is of utmost importance to develop reliable, noninvasive, and cost-effective tools to estimate biomarkers that can be indicative of cardiovascular risk. Various pathophysiological conditions are associated to changes ...

AMER PHYSIOLOGICAL SOC2021

Non-invasive monitoring of key hemodynamical and cardiac parameters using physics-based modelling and artificial intelligence

Vasiliki Bikia

In a progressively aging population, it is of utmost importance to develop reliable, non-invasive, and cost-effective tools to estimate biomarkers that can be indicative of cardiovascular risk. Clinical parameters directly measured in the heart or the aort ...

EPFL2021

Shear force redistributions and resistance of slabs and wide beams

Aurelio Muttoni, Miguel Fernández Ruiz, Raffaele Cantone

Redistribution of shear forces in reinforced concrete members without shear reinforcement is a key aspect for the assessment of the shear capacity of wide beams and slabs. Such redistributions are due to the nonlinear response of reinforced concrete (both ...

2021

Distinct types of plexiform lesions identified by synchrotron-based phase-contrast micro-CT

Goran Lovric

In pulmonary arterial hypertension, plexiform lesions are associated with severe arterial obstruction and right ventricular failure. Exploring their structure and position is crucial for understanding the interplay between hemodynamics and vascular remodel ...

AMER PHYSIOLOGICAL SOC2021

Apelin-13 Protects Corpus Cavernosum Against Fibrosis Induced by High-Fat Diet in an MMP-Dependent Mechanism

Nikolaos Stergiopoulos, Rafaela Fernandes Da Silva, Mikaël Nils Sturny, Augusto Martins Lima, Maiia Bragina

Background: An increased fibrosis of the corpora cavernosa is a prevalent process that underlies most cases of erectile dysfunction. Apelin, an endogenous circulating peptide, has been documented as an important effector on cardiovascular homeostasis, cont ...

ELSEVIER SCI LTD2021

Implementation and Calibration of a Deep Neural Network to Predict Parameters of Left Ventricular Systolic Function Based on Pulmonary and Systemic Arterial Pressure Signals

Simone Deparis, Luca Pegolotti, Jean Bonnemain

The evaluation of cardiac contractility by the assessment of the ventricular systolic elastance function is clinically challenging and cannot be easily obtained at the bedside. In this work, we present a framework characterizing left ventricular systolic f ...

2020

Apparatus for treating excess intraocular fluid having an elastic membrane

Nikolaos Stergiopoulos, Constantinos Stergiopulos

A device (100) is provided for treating diseases that produce elevated intraocular pressures, such as glaucoma, wherein the device (100) includes a housing shell (101) defining a cavity (107) between a first end (102) and a second end (104) of the housing ...

2020