Résumé
Cardiac electrophysiology is a branch of cardiology and basic science focusing on the electrical activities of the heart. The term is usually used in clinical context, to describe studies of such phenomena by invasive (intracardiac) catheter recording of spontaneous activity as well as of cardiac responses to programmed electrical stimulation - clinical cardiac electrophysiology. However, cardiac electrophysiology also encompasses basic research and translational research components. Specialists studying cardiac electrophysiology, either clinically or solely through research, are known as cardiac electrophysiologists. Electrophysiological (EP) studies are performed to assess complex arrhythmias, elucidate symptoms, evaluate abnormal electrocardiograms, assess risk of developing arrhythmias in the future, and design treatment. These procedures include therapeutic methods (typically radiofrequency ablation, or cryoablation) in addition to diagnostic and prognostic procedures. Other therapeutic modalities used in this field include antiarrhythmic drug therapy and implantation of pacemakers, implantable cardioverter-defibrillators and cardiac resynchronisation therapy devices. Electrophysiology study The cardiac electrophysiology (EP) study typically measures the response of myocardium to programmed electrical stimulation (PES) on specific pharmacological regimens in order to assess the likelihood that the regimen will successfully prevent potentially fatal sustained ventricular tachycardia (VT) or ventricular fibrillation VF (VF) in the future. Sometimes a series of EP study drug trials must be conducted to enable the cardiologist to select the one regimen for long-term treatment that best prevents or slows the development of VT or VF following PES. Such studies may also be conducted in the presence of a newly implanted or newly replaced cardiac pacemaker or ICD. A specialist in cardiac electrophysiology is known as an electrophysiologist, or "heart electrician" in layman' terms.
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Publications associées (2)

Mathematical modeling and numerical simulation of excitation-contraction phenomena in the heart

In this Master thesis we aim at studying some physiological and computational aspects of the excitation-contraction mechanisms in the heart muscle. This phenomenon exhibits many complexities at different spatio-temporal scales. The relevance and applicability of several recent phenomenological and physiologically detailed ionic models will be assessed. The choice of the treated models is based on an equilibrium between results that manage to reproduce correctly the complexity of the cardiac electrophysiology and a weak computational cost in order to solve the large set of ODEs which describe the dynamics of that ionic model. The preferred models include a large part of the more recent electrophysiological discoveries and understandings (e.g. L-type calcium and ryanodine channels) in order to reproduce at best the electrical conduction in the human cardiac tissue based on different experimental or computational measurements. According to these previous remarks, we will perform a thorough testing and quantitative comparison of these models and mechanical activation mechanisms in the framework of the LifeV finite element library. In a second step, a recent model for the description of crossbridge dynamics will be implemented. The importance of using good ionic models makes sense to identify correctly the possible influence on the muscle mechanics activation, which enable the heart to pump blood throughout the entire circulatory system.
2013

Phenomenological and physiological approaches in the study of cardiac alternans: Theoretical background, mathematical modeling and numerical simulations

This project presents the theoretical background in electrophysiology that is used as a basis in the development of numerical methods for the simulation of heart’s electrical activity. We discuss the mathematical models currently used in cardiac electrophysiology research to simulate the propagation of an action potential wave, and then focus on the description of the ionic currents. This study allows us to anticipate the numerical model sensitivity with regard to the discretization, with the aim of recovering the physiological behaviors of the tissue (i.e. conduction velocity, electrical restitution, etc). Thereafter, we introduce the pseudo-ECG signal reconstruction method from the action potential map. This leads us to examine the approximation of such a signal using the finite element basis coming from the discretization of the monodomain equations. We discuss then a particular cardiac rhythm disorder: action potential alternans. In a second step, we perform an extended simulation study in order to validate the previous numerical methods. We carefully check the convergence of the conduction velocity with respect to the mesh size, and we bring out the advantage of phenomenological approach in terms of electrical restitutions and computational cost. We reproduce typical rhythm disorders and show that the pseudo-ECG signal is able to detect them. Finally, we discuss the influence of anisotropy in cardiac wave propagation and alternans development, characterizing the effect of fibers direction and pacing site in the resulting spatio-temporal distribution.
2013
Concepts associés (16)
Cardiac electrophysiology
Cardiac electrophysiology is a branch of cardiology and basic science focusing on the electrical activities of the heart. The term is usually used in clinical context, to describe studies of such phenomena by invasive (intracardiac) catheter recording of spontaneous activity as well as of cardiac responses to programmed electrical stimulation - clinical cardiac electrophysiology. However, cardiac electrophysiology also encompasses basic research and translational research components.
Trouble du rythme cardiaque
Les troubles du rythme cardiaque ou arythmies sont une famille de maladies cardiaques. Un rythme sinusal correspond au rythme cardiaque normal, c'est-à-dire piloté par le nœud sinusal avec conservation de la séquence « contraction des oreillettes »-« contraction des ventricules ». Un trouble du rythme correspond donc à un rythme cardiaque non sinusal : on parle de « tachycardie » lorsque la fréquence cardiaque est rapide ; et de « bradycardie » lorsque la fréquence cardiaque est lente.
Resynchronisation cardiaque
vignette|Stimulateur cardiaque posé pour une resynchronisation cardiaque. La resynchronisation cardiaque est une technique de traitement de l'insuffisance cardiaque par pose d'un stimulateur cardiaque spécial permettant la délivrance d'une stimulation électrique simultanée sur plusieurs points des ventricules. Elle est appelée également stimulation multisite. Cette fonction de resynchronisation peut être couplée à une fonction de défibrillateur automatique implantable, donnant un défibrillateur multi site.
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Cours associés (4)
NX-421: Neural signals and signal processing
Understanding, processing, and analysis of signals and images obtained from the central and peripheral nervous system
EE-512: Applied biomedical signal processing
The goal of this course is twofold: (1) to introduce physiological basis, signal acquisition solutions (sensors) and state-of-the-art signal processing techniques, and (2) to propose concrete examples
BIO-377: Physiology by systems
Le but est de connaitre et comprendre le fonctionnement des systèmes cardiovasculaire, urinaire, respiratoire, digestif, ainsi que du métabolisme de base et sa régulation afin de déveloper une réflect
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MOOCs associés (4)
Simulation Neurocience
Learn how to digitally reconstruct a single neuron to better study the biological mechanisms of brain function, behaviour and disease.
Simulation Neurocience
Learn how to digitally reconstruct a single neuron to better study the biological mechanisms of brain function, behaviour and disease.
Simulation Neurocience
Learn how to digitally reconstruct a single neuron to better study the biological mechanisms of brain function, behaviour and disease.
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