Publications associées à Insuffisance mitrale

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

Cardiovascular monitoring system

Marco Mattavelli, Catherine Dehollain, Diego Ruben Barrettino, Kerim Türe, Mustafa Besirli

A cardiovascular monitoring system for measuring at least cardiac output comprises an implantable unit (2) configured for placement in a section of artery of a patient and a portable external unit (1) configured for mounting against or close to a patient's ...

2022

Impact of atrial fibrillation on left atrium haemodynamics: A computational fluid dynamics study

Alfio Quarteroni, Luca Dede'

We analyse the haemodynamics of the left atrium, highlighting differences between healthy individuals and patients affected by atrial fibrillation. The computational study is based on patient-specific geometries of the left atria to simulate blood flow dyn ...

PERGAMON-ELSEVIER SCIENCE LTD2022

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

Nikolaos Stergiopoulos, Georgios Rovas, Vasiliki Bikia, 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

AI-Based Estimation of End-Systolic Elastance From Arm-Pressure and Systolic Time Intervals

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

Left ventricular end-systolic elastance (Ees) is a major determinant of cardiac systolic function and ventricular-arterial interaction. Previous methods for the Ees estimation require the use of the echocardiographic ejection fraction (EF). However, given ...

2021

An image-based computational hemodynamics study of the Systolic Anterior Motion of the mitral valve

Alfio Quarteroni, Luca Dede', Christian Vergara, Marco Fedele

Systolic Anterior Motion (SAM) of the mitral valve - often associated with Hypertrophic Obstructive Cardiomyopathy (HOCM) - is a cardiac pathology in which a functional subaortic stenosis is induced during systole by the mitral leaflets partially obstructi ...

PERGAMON-ELSEVIER SCIENCE LTD2020

Design optimization of Miniature Magnetorheological Valves with Self-Sensing Capabilities Used for a Wearable Medical Application

Yves Perriard, Yoan René Cyrille Civet, Sofia Lydia Ntella, Minh Trung Duöng

Magnetorheological (MR) fluids are materials characterized as “intelligent” since their rheological properties may be controlled by the excitation of an external magnetic field. The application of the latter brings the fluid from a liquid to a semi-solid s ...

IEEE2020

Acute effects of transcatheter aortic valve replacement on the ventricular-aortic interaction

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

Transcatheter aortic valve replacement (TAVR) is increasingly used to treat severe aortic stenosis (AS) patients. However, little is known regarding the direct effect of TAVR on the ventricular-aortic interaction. In the present study, we aimed to investig ...

AMER PHYSIOLOGICAL SOC2020

Computational fluid dynamics of blood flow in an idealized left human heart

Alfio Quarteroni, Filippo Menghini

We construct an idealized computational model of the left human heart for the study of the blood flow dynamics in the left atrium and ventricle. We solve the Navier-Stokes equations in the ALE formulation and we prescribe the left heart wall displacement b ...

Wiley2019

Fluid dynamics of an idealized left ventricle: the extended Nitsche's method for the treatment of heart valves as mixed time varying boundary conditions

Alfio Quarteroni, Anna Tagliabue

In this work, we study the blood flow dynamics in idealized left ventricles (LV) of the human heart modelled by the Navier-Stokes equations with mixed time varying boundary conditions. The latter are introduced for simulating the functioning of the aortic ...

Wiley2017

A patient-specific aortic valve model based on moving resistive immersed implicit surfaces

Alfio Quarteroni, Elena Faggiano, Marco Fedele

In this paper, we propose a full computational framework to simulate the hemodynamics in the aorta including the valve. Closed and open valve surfaces, as well as the lumen aorta, are reconstructed directly from medical images using new ad hoc algorithms, ...

Springer Heidelberg2017

Experimental study of atrial fibrillation cycle length during rapid atrial septal pacing

Jean-Marc Vesin, Adrian Luca, Sasan Yazdani

Computer model-based simulations have shown that rapid stimulation at 60-100% of atrial fibrillation cycle length (AFCL) from a ring of electrodes located around the septum may induce local capture in both atria for most AF dynamics. The present study aims ...

2017

Identification of Abnormal Heart Sounds

Jean-Marc Vesin, Sasan Yazdani, Silas Schlatter, Seyyed Abbas Atyabi

As a part of 2016 Physionet/CinC callenge, this work aims at the detection of abnormal phonocardiogram (PCG) recordings. Heart sound signal analysis has been an active research topic over the past decades with various studies such as heart sound segmentati ...

2016

Ascending Aortic Aneurysm in Angiotensin II–Infused Mice: Formation, Progression, and the Role of Focal Dissections

Nikolaos Stergiopoulos, Lydia Aslanidou, Jessica Sordet, Bram Trachet, Alessandra Piersigilli, Patrick Segers

Objective To understand the anatomy and physiology of ascending aortic aneurysms in angiotensin II-infused ApoE(-/-) mice. Approach and Results We combined an extensive in vivo imaging protocol (high-frequency ultrasound and contrast-enhanced microcomputed ...

2016

How to prevent venous cannula orifice obstruction during extracorporeal circulation

Julien Favre

Venous cannula orifice obstruction is an underestimated problem during augmented cardiopulmonary bypass (CPB), which can potentially be reduced with redesigned, virtually wall-less cannula designs versus traditional percutaneous control venous cannulas. A ...

Sage Publications Ltd2015

Performance Comparison of Ultrasound-Based Methods to Assess Aortic Diameter and Stiffness in Normal and Aneurysmal Mice

Nikolaos Stergiopoulos, Bram Trachet, Patrick Segers

Objective Several ultrasound-based methods are currently used to assess aortic diameter, circumferential strain and stiffness in mice, but none of them is flawless and a gold standard is lacking. We aimed to assess the validity and sensitivity of these met ...

Public Library Science2015

Helical flows and asymmetry of blood jet in dilated ascending aorta with normally functioning bicuspid valve

Alfio Quarteroni, Christian Vergara, Elena Faggiano

Bicuspid aortic valve (BAV) is associated with aortic dilatation and aneurysm. Several studies evidenced an eccentric systolic flow in ascending aorta associated with increased wall shear stresses (WSS) and the occurrence of an helical systolic flow. This ...

Springer Heidelberg2013

Off-the-shelf human decellularized tissue-engineered heart valves in a non-human primate model

Peter Modregger, Marco Stampanoni, Chad Brokopp

Heart valve tissue engineering based on decellularized xenogenic or allogenic starter matrices has shown promising first clinical results. However, the availability of healthy homologous donor valves is limited and xenogenic materials are associated with i ...

Elsevier2013

Time course of flow-induced adaptation of carotid artery biomechanical properties, structure and zero-stress state in the arteriovenous shunt

Nikolaos Stergiopoulos

Numerous studies have provided evidence of diameter adaptation secondary to flow-overload. but with ambiguous findings vis a vis other morphological parameters and information on the biomechanical aspects of arterial adaptation is rather incomplete. We exa ...

2012

Ventricle Equilibrium Position in Healthy and Normal Pressure Hydrocephalus Brains Using an Analytical Model

Jean-Marie Drezet, Bryn Andrew Martin, Kamal Shahim

The driving force that causes enlargement of the ventricles remains unclear in case of normal pressure hydrocephalus (NPH). Both healthy and NPH brain conditions are characterized by a low transparenchymal pressure drop, typically 1 mm Hg. The present pape ...

2012