Download or read book Mathematical Modelling of Intracellular Ca2 Alternans in Atrial and Ventricular Myocytes written by Qince Li and published by . This book was released on 2012 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Mathematically Modelling the Electrical Activity of the Heart written by Andrew J. Pullan and published by World Scientific. This book was released on 2005 with total page 446 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book on modelling the electrical activity of the heart is an attempt to describe continuum based modelling of cardiac electrical activity from the cell level to the body surface (the forward problem), and back again (the inverse problem). Background anatomy and physiology is covered briefly to provide a suitable context for understanding the detailed modelling that is presented herein. The questions of what is mathematical modelling and why one would want to use mathematical modelling are addressed to give some perspective to the philosophy behind our approach. Our view of mathematical modelling is broad ? it is not simply about obtaining a solution to a set of mathematical equations, but includes some material on aspects such as experimental and clinical validation.
Download or read book Mathematical Modeling of Calcium Handling Dysfunctions Leading to Atrial Fibrillation written by Nikolina Krizanec and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The aim of this master s thesis is to study the basic cardiac cellular electrophysiology in order to understand and examine the role of SK3 channels. Among the many channels present in an atrial myocyte, SK3 channels are activated by calcium, providing the circulation of the intracellular calcium. A well established mathematical model, the Grandi model, forms the basis of the simulations presented in this project. First, to study the effect of the SK current, a modification of the atrial myocyte model is done. Secondly, the model is calibrated according to experimental results. Lastly, we study the effect of the SK currents to avoid spontaneous calcium release induced depolarizations. Numerical simulations of the whole-cell atrial myocyte performed in this project confirmed the anti arrhythmic behaviour of the SK current, that counteracts the effect of spontaneous calcium release. This effect is, however, not large and, therefore, does not seem to support the, development of SK channel blockers as a new therapeutic strategy in the treatment of atrial fibrillation, as has been suggested in the literature.
Download or read book Mathematical Modelling of Intracellular Calcium Oscillations and Waves in Cardiac Cells written by Yinshui Fan and published by . This book was released on 1997 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Biophysical Modelling of the Genesis of Alternans InCardiac Intracellular Ca2 Handling written by Tao Tao and published by . This book was released on 2008 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Cardiac mechanical alternans are believed to be associated with intracellular Ca2 + alternans. However, the mechanisms underlying the genesis of intracellular Ca2 + alternans are unclear. Experimental studies have shown that alternans of systolic Ca2 + under voltage clamp can be produced either by partially inhibiting the Ca2+ release mechanism or by applying small depolarising pulses. In each case the alternans relied on the appearance of propagating waves of Ca2 + release. The aim of the work in this thesis is to develop a theoretical model to understand the mechanisms underlying how the beat-to-beat alternation in the amplitude of the systolic Ca2+ transient is produced. A mathematical model of intracellular Ca2 + handling for a ventricular cardiac cell was developed as a spatially extended object, which is discretized by a group of coupled elements. Each element contains L-type and T-type Ca2 + channels, a subspace into which Ca2 + release takes place, a cytoplasmic space and sarcoplasmic reticulum (SR) release channels (RyR) and uptake sites (SERCA). Inter-element coupling is via Ca2 + diffusion between neighbouring subspaces and cytoplasm spaces. Small depolarising pulses were simulated by a sequence of step changes of cell membrane potential (20 mV) with random block on the L-type channels. Partial inhibition of the release mechanism is mimicked by applying a random reduction of the open probability of the RyR in response to a full stimulation by L type Ca2 + channels. In both cases the simulations are consistent with experimental observations and show that Ca2 + alternans can be generated and sustained through alternation of SR Ca2+ content produced by the propagating wave of Ca2 + release. However, the presented model has certain limitations. In the model, the property of L-type Ca2 + channel is described as an average effect of global current in a cardiac cell, rather than the total current of a large population of unitary L-type Ca2 + current, which is directly associated with the testing potential and which is a very important part of Ca2 + induced Ca2 + release (CICR). To conquer the limitation, an improved version of the Ca2 + handling model was developed by incorporating stochastic unitary L-type Ca2 + channels into the previous model. The improved model has a more biophysically detailed Ca2 + handling model, which can not only simulate proper unitary L-type Ca2 + influx but also produce a good quality of global L-type Ca2 + current. Like the old model the new stochastic model produced the global and regional alternans of Ca2 + transients observed in previous experimental studies as well, and agreed the key role of SR Ca2 + content to genesis of cardiac Ca2 + alternans. The study in this thesis provided novel insights into understanding the mechanisms underlying the genesis of intracellular Ca2 + alternans. In addition, the simulation study of effects of volatile anesthesics on rat ventricle has also been included in this thesis, and is presented in Appendix 1.
Download or read book Ion Channel Regulation in the Pathophysiology of Atrial Fibrillation written by Birce Onal and published by . This book was released on 2017 with total page 139 pages. Available in PDF, EPUB and Kindle. Book excerpt: Atrial fibrillation (AF) affects 2.5 million people per year in the U.S., and is associated with high morbidity and mortality. Both electrical and structural remodeling on the cardiac cell- and tissue-level contribute to AF, but the precise molecular pathways that lead to atrial fibrillation pathogenesis are not well understood. Mathematical modelling is ideally suited to understand the molecular basis of cardiac arrhythmias by allowing simulation of complex biological systems based on integrated data from individual populations of ion channels. A cross-platform multi-threaded graphical user interface LongQt was developed for advanced computational cardiac electrophysiology studies in sinoatrial, atrial, and ventricular cells to help bridge the gap between experimental and theoretical techniques in cardiac electrophysiology. A method of parameter sensitivity analysis is discussed to help define the contribution of individual ion channels to cell membrane excitability and action potential properties. Finally, a computational model of the human atrial cell was used to determine the mechanism for increased susceptibility to arrhythmogenic events in patients with defects in Ca2+/calmodulin-dependent protein kinase signaling pathways. An atrial computational model was extended to explore CaMKII activation of late sodium current (INa,L) and phosphorylation of downstream targets (L-type Ca2+ channel, phospholamban, ryanodine receptor). Both LongQt and the method of parameter sensitivity analysis were used to help identify the cellular pathway responsible for disrupted ion homeostasis and afterdepolarizations in atrial cells. Intracellular Ca2+ and Na+ accumulation, increased phosphorylation of RyR2 by CaMKII, and abnormal Ca2+ dynamics [e.g. beat-to-beat alteration (alternans)], and afterdepolarizations (early and late phase) was observed in mathematical models of the atrial cell with constitutive increase in INa,L, compared to wildtype control. These simulations define roles for previously unexplored ion channel regulation of CaMKII-mediated INa,L in the context of atrial fibrillation. Although INa,L is
Download or read book ATP and the Heart written by Joanne S. Ingwall and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 272 pages. Available in PDF, EPUB and Kindle. Book excerpt: ATP plays a central role in the two leading causes of cardiac morbidity and mortality in the western world: ischemia and heart failure. We are in our infancy applying what is known about biology and chemistry of ATP toward developing effective therapies for these diseases. In this volume, the current understanding of the chemistry and biology of ATP specifically in the cardiomyocyte is presented. New insights into ATP have been gleaned using biophysical techniques allowing dynamic measurement of chemical events in the intact beating heart and using new animal models in which cardiac proteins are either over expressed, deleted or harbor specific mutations. This book provides a summary of the basic understanding and includes illustrations of why ATP and the Heart is important to both the clinician and scientist.
Download or read book Integrative Computational Modeling of Calcium Handling and Cardiac Arrhythmias written by Henry Sutanto and published by Henry Sutanto. This book was released on 2021-01-01 with total page 350 pages. Available in PDF, EPUB and Kindle. Book excerpt: Cardiomyocyte calcium handling is a major determinant of excitation-contraction coupling. Alterations in one or more calcium-handling proteins may induce arrhythmias through the formation of ectopic activity, direct and indirect ion-channel regulation, and structural remodeling. Due to the complex and tight interactions between calcium and other molecules within a cardiomyocyte, it remains experimentally challenging to study the exact contributions of calcium-handling abnormalities to arrhythmogenesis. Multiscale computational studies performed in close collaboration with laboratory experiments create new opportunities to unravel the mechanisms of arrhythmogenesis. This thesis describes the roles of integrative computational modeling in unraveling the arrhythmogenic consequences of calcium-handling abnormalities.
Download or read book Nanodomain Regulation of Muscle Physiology and Alterations in Disease written by Niall Macquaide and published by Frontiers Media SA. This book was released on 2023-01-03 with total page 202 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Simulating Normal and Arrhythmic Dynamics From Sub Cellular to Tissue and Organ Level written by Hans Dierckx and published by Frontiers Media SA. This book was released on 2019-10-04 with total page 276 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Biopacemaking written by J.A.E Spaan and published by Springer Science & Business Media. This book was released on 2007-08-08 with total page 190 pages. Available in PDF, EPUB and Kindle. Book excerpt: The development of a bio-engineered pacemaker is of substantial clinical and also scientific interest because it promises to overcome several limitations of electronic pacemakers. Moreover it may answer the longstanding question of whether the complex structure of the sinus node is indeed a prerequisite for reliable pacemaking, or simpler structures might work as well. This book gives an overview of the current state-of-the-art of creating a bio-engineered pacemaker. It shows the approaches to develop of genetic and cell-based engineering methods suitable to implement them with safety and stability. It also illuminates the problems that need to be solved before bio-pacemaking can be considered for clinical use.
Download or read book Mathematical Modeling of Cardiovascular Systems From Physiology to the Clinic written by Julius Guccione and published by Frontiers Media SA. This book was released on 2020-01-13 with total page 289 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Role of Calcium Handling in Heart Failure and Heart Failure Associated Arrhythmias written by Elisabetta Cerbai and published by Frontiers Media SA. This book was released on 2019-05-15 with total page 191 pages. Available in PDF, EPUB and Kindle. Book excerpt: Under normal, healthy conditions, the contraction of cardiac myocytes, leading to the pump function of this organ, is driven by calcium-dependent mechanisms. Entry of calcium into the myocyte during the cardiac action potential causes activation of the ryanodine receptors and release of calcium from the sarcoplasmic reticulum. This process termed calcium-induced calcium release is essential for excitation-contraction coupling and enables each action potential to be transduced into a mechanical event. Indeed, in healthy myocytes, the calcium concentration in the cytosol of is elevated approximately 10-fold from a resting level of ∼100 nM to ∼1 μM. This process is finely orchestrated by a number of key proteins, which can be specifically regulated by various pathways depending on the oxygen demand. Furthermore, the specific structure of the myocyte allows certain calcium-dependent processes to be compartmentalised, increasing the efficiency and safety of this regulation. Heart failure is a common, costly, and life-threatening condition. In 2015, for example, it affected around 40 million people globally. In patients with heart failure, the risk of sudden cardiac death and arrhythmias increases substantially. Cellular remodelling and alterations in calcium handling, which appear to contribute to the arrhythmogenic burden in heart failure, have been extensively reported. However, a number of unanswered questions remain, and each new study - while continuing to shed light on this subject - raises additional novel questions. This current compendium of articles covers a number of aspects and comprehensively reviews current knowledge and perspectives regarding the link between calcium handling, arrhythmias and heart failure providing at the same time insights that may lead to novel therapeutic options for the future.
Download or read book Multi Scale Computational Cardiology written by Ling Xia and published by Frontiers Media SA. This book was released on 2022-03-07 with total page 153 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Cardiac Repolarization written by Ihor Gussak and published by Springer Science & Business Media. This book was released on 2003-03-13 with total page 549 pages. Available in PDF, EPUB and Kindle. Book excerpt: A comprehensive review of all the latest developments in cardiac electrophysiology, focusing on both the clinical and experimental aspects of ventricular repolarization, including newly discovered clinical repolarization syndromes, electrocardiographic phenomena, and their correlation with the most recent advances in basic science. The authors illuminate the basic electrophysiologic, molecular, and pharmacologic mechanisms underlying ventricular repolarization, relate them to specific disease conditions, and examine the future of antiarrhythmic drug development based on both molecular and electrophysiological properties. They also fully review the clinical presentation and management of specific cardiac repolarization conditions.
Download or read book Modeling and Simulating Cardiac Electrical Activity written by David J. Christini and published by . This book was released on 2020 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides a thorough introduction to the topic of mathematical modeling of electrical activity in the heart, from molecular details of ionic channel dynamics to clinically derived patient-specific models. It discusses how cellular ionic models are formulated, introduces commonly used models and explains why there are so many different models available. The chapters cover modeling of the intracellular calcium handling that underlies cellular contraction as well as modeling molecular-level details of cardiac ion channels, and also focus on specialized topics such as cardiomyocyte energetics and signalling pathways. It is an excellent resource for experienced and specialised researchers in the field, but also biological scientists with a limited background in mathematical modelling and computational methods. Part of Biophysical Society-IOP series.
Download or read book Comprehensive Biophysics written by and published by Academic Press. This book was released on 2012-04-12 with total page 3533 pages. Available in PDF, EPUB and Kindle. Book excerpt: Biophysics is a rapidly-evolving interdisciplinary science that applies theories and methods of the physical sciences to questions of biology. Biophysics encompasses many disciplines, including physics, chemistry, mathematics, biology, biochemistry, medicine, pharmacology, physiology, and neuroscience, and it is essential that scientists working in these varied fields are able to understand each other's research. Comprehensive Biophysics, Nine Volume Set will help bridge that communication gap. Written by a team of researchers at the forefront of their respective fields, under the guidance of Chief Editor Edward Egelman, Comprehensive Biophysics, Nine Volume Set provides definitive introductions to a broad array of topics, uniting different areas of biophysics research - from the physical techniques for studying macromolecular structure to protein folding, muscle and molecular motors, cell biophysics, bioenergetics and more. The result is this comprehensive scientific resource - a valuable tool both for helping researchers come to grips quickly with material from related biophysics fields outside their areas of expertise, and for reinforcing their existing knowledge. Biophysical research today encompasses many areas of biology. These studies do not necessarily share a unique identifying factor. This work unites the different areas of research and allows users, regardless of their background, to navigate through the most essential concepts with ease, saving them time and vastly improving their understanding The field of biophysics counts several journals that are directly and indirectly concerned with the field. There is no reference work that encompasses the entire field and unites the different areas of research through deep foundational reviews. Comprehensive Biophysics fills this vacuum, being a definitive work on biophysics. It will help users apply context to the diverse journal literature offering, and aid them in identifying areas for further research Chief Editor Edward Egelman (E-I-C, Biophysical Journal) has assembled an impressive, world-class team of Volume Editors and Contributing Authors. Each chapter has been painstakingly reviewed and checked for consistent high quality. The result is an authoritative overview which ties the literature together and provides the user with a reliable background information and citation resource
