Publications related to Intra-aortic balloon pump

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

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

A novel soft cardiac assist device based on a dielectric elastomer augmented aorta: An in vivo study

Yves Perriard, Yoan René Cyrille Civet, Thomas Guillaume Martinez, Francesco Clavica, Armando Matthieu Walter, Jonathan André Jean-Marie Chavanne, Silje Ekroll Jahren, Lorenzo Ferrari

Although heart transplant is the preferred solution for patients suffering from heart failures, cardiac assist devices remain key substitute therapies. Among them, aortic augmentation using dielectric elastomer actuators (DEAs) might be an alternative tech ...

2022

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

Nikolaos Stergiopoulos, Georgios Rovas, Vasiliki Bikia, 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

Noninvasive estimation of aortic hemodynamics and cardiac contractility using machine learning

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

Cardiac and aortic characteristics are crucial for cardiovascular disease detection. However, noninvasive estimation of aortic hemodynamics and cardiac contractility is still challenging. This paper investigated the potential of estimating aortic systolic ...

Nature Research2020

Ventricular response regularity in atrial fibrillation and its relationship to successful catheter ablation

Jean-Marc Vesin, Adrian Luca, Etienne Pruvot

Atrial rate is known to modulate ventricular response during atrial fibrillation (AF). The resulting pulse irregularity translates into widely varying inter-beat intervals (IBIs) extracted from recorded surface electrocardiogram (ECG) activity. In AF, the ...

IEEE2020

Swirl number based transposition of flow-induced mechanical stresses from reduced scale to full-size Francis turbine runners

François Avellan, Christian Landry, Arthur Tristan Favrel, Keita Yamamoto, Joao Gomes Pereira Junior

At part load conditions, Francis turbines are subject to the emergence of a hydrodynamic instability in their draft tube, referred to as precessing vortex rope. It induces pressure pulsations in the water passages at the precession frequency of the vortex, ...

2020

On the importance of the nonuniform aortic stiffening in the hemodynamics of physiological aging

Nikolaos Stergiopoulos, Bram Trachet, Vasiliki Bikia, Stamatia Zoi Pagoulatou

Mathematical models of the arterial tree constitute a valuable tool to investigate the hemodynamics of aging and pathology. Rendering such models as patient specific could allow for the assessment of central hemodynamic variables of clinical interest. Howe ...

AMER PHYSIOLOGICAL SOC2019

The onset of cardiovascular disease in mice: an image-based, computational-experimental approach

Lydia Aslanidou

In a number of cardiovascular diseases, the paucity of longitudinal human data hinders our understanding of disease evolution and forestalls the discovery of new therapeutic strategies. We therefore heavily rely on animal models to elucidate the mechanisms ...

EPFL2019

Propagation-based phase-contrast synchrotron imaging of aortic dissection in mice: from individual elastic lamella to 3D analysis

Nikolaos Stergiopoulos, Lydia Aslanidou, Bram Trachet, Marco Stampanoni, Patrick Segers

In order to show the advantage and potential of propagation-based phase-contrast synchrotron imaging in vascular pathology research, we analyzed aortic medial ruptures in BAPN/AngII-infused mice, a mouse model for aortic dissection. Ascending and thoraco-a ...

Nature Research2018

A computational fluid-structure interaction analysis of coronary Y-grafts

Alfio Quarteroni, Christian Vergara

Coronary artery disease is one of the leading causes of death worldwide. The stenotic coronary vessels are generally treated with coronary artery bypass grafts (CABGs), which can be either arterial (internal mammary artery, radial artery) or venous (saphen ...

Elsevier Sci Ltd2017

Computational comparison of aortic root stresses in presence of stentless and stented aortic valve bio-prostheses

Alfio Quarteroni, Christian Vergara, Elena Faggiano

We provide a computational comparison of the performance of stentless and stented aortic prostheses, in terms of aortic root displacements and internal stresses. To this aim, we consider three real patients; for each of them, we draw the two prostheses con ...

Taylor & Francis Ltd2017

Single breath-hold 3D measurement of left atrial volume using compressed sensing cardiovascular magnetic resonance and a non-model-based reconstruction approach

Nikolaos Stergiopoulos, Orestis Vardoulis, Janine Schwitter

Background: Left atrial (LA) dilatation is associated with a large variety of cardiac diseases. Current cardiovascular magnetic resonance (CMR) strategies to measure LA volumes are based on multi-breath-hold multi-slice acquisitions, which are time-consumi ...

Taylor & Francis2015

Novel non-invasive techniques for hemodynamic monitoring

Orestis Vardoulis

The monitoring of hemodynamic parameters is crucial for optimal patient management and treatment. However, established methods are often invasive and possibly inapplicable to sensitive age groups. Novel, non-invasive techniques have the potential to transf ...

EPFL2014

The effect of continuous positive airway pressure on total cerebral blood flow in healthy awake volunteers

Nikolaos Stergiopoulos, Bryn Andrew Martin

Continuous positive airway pressure (CPAP) is the gold standard treatment for obstructive sleep apnea. However, the physiologic impact of CPAP on cerebral blood flow (CBF) is not well established. Ultrasound can be used to estimate CBF, but there is no wid ...

Springer-Verlag2013

On the Estimation of Total Arterial Compliance from Aortic Pulse Wave Velocity

Nikolaos Stergiopoulos, Orestis Vardoulis

Total arterial compliance (C (T)) is a main determinant of cardiac afterload, left ventricular function and arterio-ventricular coupling. C (T) is physiologically more relevant than regional aortic stiffness. However, direct, in vivo, non-invasive, measure ...

Springer US2012

Contribution of Left and Right Atrial Appendage Activities to ECG Fibrillation Waves

Jean-Marc Vesin, Andréa Buttu, Etienne Pruvot

It was recently shown that atrial fibrillation (AF) waves on chest lead V1 adequately reflect right atrial appendage (RAA) activity during long standing persistent AF (pers-AF). The contribution of the left atrial (LA) activity to chest leads AF waves, how ...

2012

Impact of Aortic Grafts on Arterial Pressure: A Computational Fluid Dynamics Study

Nikolaos Stergiopoulos, Philippe Reymond, Orestis Vardoulis, Bryn Andrew Martin, Eline Coppens

Objective: Vascular prostheses currently used in vascular surgery do not have the same mechanical properties as human arteries. This computational study analyses the mechanisms by which grafts, placed in the ascending aorta (proximal) and descending aorta ...

Elsevier2011

Modélisation mécanique de fils pour la simulation chirurgicale

Lindo Robert Duratti

Minimally Invasive Surgery (MIS) represents one of the major progresses in surgery in the last decade. In general, it is based on the application of small body-cuts through which instruments are inserted into the patient's body allowing the surgeon to carr ...

EPFL2008

Model-based inferences for clinical applications of the ECG

Doctor Macchi reported on the progress of an animal model study of electric propagation initiated by electric stimuli. Doctor Oostendorp first gave an introduction to the inverse problem of cardiac activation time mapping (ATM), the determination of the de ...

Elsevier2007

Optimization of the treatment of hydrocephalus by the non-invasive measurement of the intra-cranial pressure

Alec Ginggen

This thesis work aims to optimize the treatment of hydrocephalus. It consists of two distinct objectives: the optimization of the diagnosis of patients implanted with a shunt system for the derivation of cerebro-spinal fluid (CSF) and the optimization of t ...

EPFL2007