scholarly journals Drift of Scroll Waves in a Mathematical Model of a Heterogeneous Human Heart Left Ventricle

Mathematics ◽  
2020 ◽  
Vol 8 (5) ◽  
pp. 776
Author(s):  
Sergey Pravdin ◽  
Pavel Konovalov ◽  
Hans Dierckx ◽  
Olga Solovyova ◽  
Alexander V. Panfilov
Keyword(s):  
Left Ventricle ◽  
Homogeneous Model ◽  
Heterogeneous Model ◽  
Wave Dynamics ◽  
Ventricular Cells ◽  
Large Heterogeneity ◽  
Scroll Wave ◽  
Spatio Temporal ◽  
Human Left Ventricle ◽  
Transmural Heterogeneity

Rotating spiral waves of electrical excitation underlie many dangerous cardiac arrhythmias. The heterogeneity of myocardium is one of the factors that affects the dynamics of such waves. In this paper, we present results of our simulations for scroll wave dynamics in a heterogeneous model of the human left ventricle with analytical anatomically based representation of the geometry and anisotropy. We used a set of 18 coupled differential equations developed by ten Tusscher and Panfilov (TP06 model) which describes human ventricular cells based on their measured biophysical properties. We found that apicobasal heterogeneity dramatically changes the scroll wave dynamics. In the homogeneous model, the scroll wave annihilates at the base, but the moderate heterogeneity causes the wave to move to the apex and then continuously rotates around it. The rotation speed increased with the degree of the heterogeneity. However, for large heterogeneity, we observed formation of additional wavebreaks and the onset of complex spatio-temporal patterns. Transmural heterogeneity did not change the dynamics and decreased the lifetime of the scroll wave with an increase in heterogeneity. Results of our numerical experiments show that the apex may be a preferable location of the scroll wave, which may be important for development of clinical interventions.

scholarly journals A Mathematical Spline-Based Model of Cardiac Left Ventricle Anatomy and Morphology

2016 ◽  
Author(s):  
Sergei Pravdin
Keyword(s):  
Left Ventricle ◽  
Reaction Diffusion ◽  
Diffusion Problem ◽  
Clinical Applications ◽  
Dynamics Simulation ◽  
Heart Activity ◽  
Wave Dynamics ◽  
Symmetrical Model ◽  
Scroll Wave ◽  
Cardiac Left Ventricle

Computer simulation of normal and diseased human heart activity requires a 3D anatomical model of the myocardium, including myofibres. For clinical applications, such a model has to be constructed based on routine methods of cardiac visualisation such as sonography. Symmetrical models are shown to be too rigid, so an analytical non-symmetrical model with enough flexibility is necessary. Based on previously made anatomical models of the left ventricle, we propose a new, much more flexible spline-based analytical model. The model is fully described and verified based on DT-MRI data. We show a way to construct it on the basis of sonography data. To use this model in further physiological simulations, we propose a numerical method to utilise finite differences in solving the reaction-diffusion problem together with an example of scroll wave dynamics simulation.

scholarly journals A Mathematical Spline-Based Model of Cardiac Left Ventricle Anatomy and Morphology

2016 ◽  
Author(s):  
Sergei Pravdin
Keyword(s):  
Left Ventricle ◽  
Reaction Diffusion ◽  
Diffusion Problem ◽  
Clinical Applications ◽  
Dynamics Simulation ◽  
Heart Activity ◽  
Wave Dynamics ◽  
Symmetrical Model ◽  
Scroll Wave ◽  
Cardiac Left Ventricle

Computer simulation of normal and diseased human heart activity requires a 3D anatomical model of the myocardium, including myofibres. For clinical applications, such a model has to be constructed based on routine methods of cardiac visualisation such as sonography. Symmetrical models are shown to be too rigid, so an analytical non-symmetrical model with enough flexibility is necessary. Based on previously made anatomical models of the left ventricle, we propose a new, much more flexible spline-based analytical model. The model is fully described and verified against DT-MRI data. We show a way to construct it on the basis of sonography data. To use this model in further physiological simulations, we propose a numerical method to utilise finite differences in solving the reaction-diffusion problem together with an example of scroll wave dynamics simulation.

The study of scroll wave dynamics in personalized models of the left ventricle of the human heart

2016 ◽  
Vol 31 (5) ◽  
Author(s):  
Konstantin S. Ushenin ◽  
Sergei F. Pravdin ◽  
Yuliya S. Alueva ◽  
Tatyana V. Chumarnaya ◽  
Olga E. Solovyova
Keyword(s):  
Left Ventricle ◽  
Human Heart ◽  
Ultrasound Examination ◽  
Left Ventricular ◽  
Left Ventricular Cavity ◽  
Wave Dynamics ◽  
Wave Drift ◽  
Starting Point ◽  
First Results ◽  
Scroll Wave

AbstractThis paper presents first results on the dynamics of filaments of scroll waves of myocardium excitation obtained for personalized models of the left ventricle of the human heart. The paper describes a mathematical model of the left ventricle of the human heart and its electrical activity, numerical methods for the model calculation within the framework of computer implementation, and also the method of personalization of the model according to data of ultrasound examination. We found that regardless of the starting point of wave the filaments of wave drift along a spiral to the attractor located near the apex of the ventricle. The attractor position was essentially different in models constructed from the data of patients without identified pathology and those for patients with an increased left ventricular cavity.

Numerical simulation of pulsatile blood flow in the human left ventricle

2007 ◽  
Vol 55 (S 1) ◽  
Author(s):  
W Schiller ◽  
K Spiegel ◽  
T Schmid ◽  
H Rudorf ◽  
S Flacke ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Blood Flow ◽  
Left Ventricle ◽  
Pulsatile Blood Flow ◽  
Human Left Ventricle

scholarly journals Simultaneous Endocardial Mapping in the Human Left Ventricle Using a Noncontact Catheter

Circulation ◽  
1998 ◽  
Vol 98 (9) ◽  
pp. 887-898 ◽  
Author(s):  
Richard J. Schilling ◽  
Nicholas S. Peters ◽  
D. Wyn Davies
Keyword(s):  
Left Ventricle ◽  
Endocardial Mapping ◽  
Human Left Ventricle

Human left ventricle transcriptome signatures and signalling pathways in patients with high and low intramyocardial lipid

2021 ◽  
Vol 331 ◽  
pp. e41
Author(s):  
J.P. Hobkirk ◽  
A. Burska ◽  
Y. Haqzad ◽  
A. Gemmink ◽  
S. Carroll ◽  
...  
Keyword(s):  
Left Ventricle ◽  
Signalling Pathways ◽  
Human Left Ventricle

Combining static and dynamic environmental factors at various scales to predict shallow landsliding in South Tyrol, Italy – The Proslide project

2021 ◽  
Author(s):  
Robin Kohrs ◽  
 Lotte de Vugt ◽  
Thomas Zieher ◽  
Alice Crespi ◽  
Mattia Rossi ◽  
...  
Keyword(s):  
Regional Scale ◽  
Remote Sensing Data ◽  
Predisposing Factors ◽  
Physical Models ◽  
Data Driven ◽  
Catchment Scale ◽  
Heterogeneous Model ◽  
South Tyrol ◽  
Daily Precipitation Data ◽  
Spatio Temporal

<p>Shallow landslides in alpine environments can constitute a serious threat to the exposed elements. The spatio-temporal occurrence of such slope movements is controlled by a combination of predisposing factors (e.g. topography), preparatory factors (e.g. wet periods, snow melting) and landslide triggers (e.g. heavy precipitation events).  </p><p>For large study areas, landslide assessments frequently focus either on the static predisposing factors to estimate landslide susceptibility using data-driven procedures, or exclusively on the triggering events to derive empirical rainfall thresholds. For smaller areas, dynamic physical models can reasonably be parameterized to simultaneously account for static and dynamic landslide controls.  </p><p>The recently accepted Proslide project aims to develop and test methods with the potential to improve the predictability of landslides for the Italian province of South Tyrol. It is envisaged to account for a variety of innovative input data at multiple spatio-temporal scales. In this context, we seek to exploit remote sensing data for the spatio-temporal description of landslide controlling factors (e.g. precipitation RADAR; satellite soil moisture) and to develop models that allow an integration of heterogeneous model inputs using both, data-driven approaches (regional scale) and physically-based models (catchment scale). This contribution presents the core ideas and methodical framework behind the Proslide project and its very first results (e.g. relationships between landslide observations and gridded daily precipitation data at regional scale). </p>

Capillary network structure does not affect theoretical analysis of glomerular size selectivity

1995 ◽  
Vol 268 (5) ◽  
pp. F972-F979
Author(s):  
A. Remuzzi ◽  
B. Ene-Iordache
Keyword(s):  
Pressure Drop ◽  
Homogeneous Model ◽  
Wistar Rat ◽  
Size Selectivity ◽  
Membrane Pore ◽  
Heterogeneous Model ◽  
Glomerular Size ◽  
The Difference ◽  
Membrane Pore Size ◽  
Log Normal

Anatomical studies have demonstrated that the glomerular capillaries are complex and heterogeneous networks. Conventional models of glomerular size selectivity, however, are based on the assumption of simplified geometries. We developed a theoretical model of glomerular size-selective function based on the geometric data obtained in a previous reconstruction of a glomerular network from a normal Munich-Wistar rat. This heterogeneous model was compared with the homogeneous model conventionally used to calculate membrane selective parameters from the fractional clearance of two test solutes, neutral dextran and Ficoll. For both models we assumed a hypothetical log-normal distribution of pore sizes and calculated optimal membrane pore-size parameters using previously published values of fractional clearances. The difference between the sieving coefficients calculated with the two models was negligible, never exceeding 5.5%. Since the homogeneous model does not consider the pressure drop along the glomerular capillary, we also computed fractional clearances with the homogeneous model, assuming the same pressure drop as in the heterogeneous one. The differences in computed fractional clearances using the homogeneous model with and without a pressure drop were less than 1.2%. We concluded that models based on identical capillary networks can therefore be used for interpreting sieving coefficients for macromolecules.

The effect of upright tilt on the volume of the failing human left ventricle

1975 ◽  
Vol 90 (6) ◽  
pp. 735-743 ◽  
Author(s):  
Miltiadis A. Stefadouros ◽  
Manfouz El Shahawy ◽  
Frieda Stefadouros ◽  
A.Calhoun Witham
Keyword(s):  
Left Ventricle ◽  
Human Left Ventricle ◽  
Upright Tilt
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