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Atrial fibrillation (AF) consequences on the heart valve dynamics are usually studied along with a valvular disfunction or disease, since in medical monitoring the two pathologies are often concomitant. Aim of the present work is to study,…

Fluid Dynamics · Physics 2015-10-27 Stefania Scarsoglio , Carlo Camporeale , Andrea Guala , Luca Ridolfi

We consider a dissipative vector field which is represented by a nearly-integrable Hamiltonian flow to which a non symplectic force is added, so that the phase space volume is not preserved. The vector field depends upon two parameters,…

Dynamical Systems · Mathematics 2012-02-13 Alessandra Celletti , Christoph Lhotka

We developed a novel patient-specific computational model for the numerical simulation of ventricular electromechanics in patients with ischemic cardiomyopathy (ICM). This model reproduces the activity both in sinus rhythm (SR) and in…

Valvular heart diseases are growing concern in impoverished parts of the world, such as Southern-Africa, claiming more than 31 % of total deaths related to cardiovascular diseases. The ability to model the effects of regurgitant and…

Medical Physics · Physics 2022-04-11 Ryno Laubscher , Jacques Liebenberg , Philip Herbst

Lumped method (Electrical analogy) is a quick and easy way to model human cardiovascular system. In this paper Lumped method is used for simulating a complete model. It describes a 36-vessel model and cardiac system of human body with…

The three dimensional harmonic oscillator model including a cranking term is used for an energy variational calculation. Energy minima are found under variation of the three oscillator frequencies determining the shape of the system for…

Nuclear Theory · Physics 2009-11-07 W. D. Heiss , R. G. Nazmitdinov

Assuming that a constant potential energy function has meaning for a dissipated harmonic oscillator, then an important issue is the time dependence of the turning points. Turning point studies demonstrate that the common model of external…

Classical Physics · Physics 2007-05-23 Randall D. Peters

A minimalistic model of the half-center oscillator is proposed. Within it, we consider dynamics of two excitable neurons interacting by means of the excitatory coupling. In the parameter space of the model, we identify the regions of…

Dynamical Systems · Mathematics 2021-03-02 A. G. Korotkov , T. A. Levanova , M. A. Zaks , G. V. Osipov

The left ventricular end-systolic pressure-volume relationship (ESPVr) is a key indicator of cardiac contractility. Despite its established importance, several studies suggested that the mechanical mode of contraction, such as isovolumetric…

Medical Physics · Physics 2024-11-12 Francesco Regazzoni , Corrado Poggesi , Cecilia Ferrantini

Recent studies in mammalian hearts show that left ventricular wall thickening is an important mechanism for systolic ejection and that during contraction the cardiac muscle develops significant stresses in the muscular cross-fiber…

Analysis of PDEs · Mathematics 2008-12-04 Christian Bourdarias , Stéphane Gerbi , Jacques Ohayon

Two crucial factors for accurate numerical simulations of cardiac electromechanics, which are also essential to reproduce the synchronous activity of the heart, are: i) accounting for the interaction between the heart and the circulatory…

Patients at high risk for sudden death often exhibit complex heart rhythms in which abnormal heartbeats are interspersed with normal heartbeats. We analyze such a complex rhythm in a single patient over a 12-hour period and show that the…

Left Ventricular Hypertrophy (LVH) is a major cardiovascular risk factor, linked to heart failure, arrhythmia, and sudden cardiac death, often resulting from chronic stress like hypertension. Electrocardiography (ECG), while varying in…

Signal Processing · Electrical Eng. & Systems 2024-11-14 Wei Tang , Kangning Cui , Raymond H. Chan , Jean-Michel Morel

We present a novel mathematical model that simulates myocardial blood perfusion by embedding multiscale and multiphysics features. Our model incorporates cardiac electrophysiology, active and passive mechanics, hemodynamics, reduced valve…

Computational Engineering, Finance, and Science · Computer Science 2023-03-27 Alberto Zingaro , Christian Vergara , Luca Dede' , Francesco Regazzoni , Alfio Quarteroni

Experiments that discuss influence of noise to H. Seidel and H. Herzel dynamics model of human cardiovascular system are presented. Noise is introduced by considering stochastic delays in response to the sympathetic system. It appears that…

Tissues and Organs · Quantitative Biology 2007-05-23 Aleksandra Dudkowska , Danuta Makowiec

Normal human heart rate shows complex fluctuations in time, which is natural, since heart rate is controlled by a large number of different feedback control loops. These unpredictable fluctuations have been shown to display fractal…

Medical Physics · Physics 2009-11-07 Tom A. Kuusela , Tony Shepherd , Jarmo Hietarinta

We discuss open problems related to the stochastic modeling of cardiac function. The work is based on an experimental investigation of the dynamics of heart rate variability (HRV) in the absence of respiratory perturbations. We consider…

Biological Physics · Physics 2015-05-14 I. A. Khovanov , N. A. Khovanova , P. V. E. McClintock , A. Stefanovska

Arrhythmias are potentially fatal disruptions to the normal heart rhythm, but their underlying dynamics is still poorly understood. Theoretical modeling is an important tool to fill this gap. Typical studies often employ detailed…

Tissues and Organs · Quantitative Biology 2022-03-08 R. V. Stenzinger , M. H. R. Tragtenberg

Isolated post-capillary pulmonary hypertension (Ipc-PH) occurs due to left heart failure, which contributes to 1 out of every 9 deaths in the United States. In some patients, through unknown mechanisms, Ipc-PH transitions to combined…

Tissues and Organs · Quantitative Biology 2021-03-11 Michelle A. Bartolo , M. Umar Qureshi , Mitchel J. Colebank , Naomi C. Chesler , Mette S. Olufsen

This brief article accompanies a fluid dynamics video presenting the results of a large-eddy simulation of the flow in a realistic left heart. The left heart geometry, from the pulmonary veins to the aortic root, is extracted from medical…

Fluid Dynamics · Physics 2013-10-14 Christophe Chnafa , Simon Mendez , Franck Nicoud