Regulation of Cardiac Contractility

Regulation of Cardiac Contractility PDF Author: R. John Solaro
Publisher: Biota Publishing
ISBN: 1615041753
Category : Medical
Languages : en
Pages : 46

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Book Description
Contractility describes the relative ability of the heart to eject a stroke volume (SV) at a given prevailing afterload (arterial pressure) and preload (end-diastolic volume; EDV). Various measures of contractility are related to the fraction as the SV/EDV or the ejection fraction, and the dynamics of ejection as determined from maximum pressure rise in the ventricles or arteries or from aortic flow velocities determined by echocardiography. At the cellular level, the ultimate determinant of contractility is the relative tension generation and shortening capability of the molecular motors (myosin cross-bridges) of the sarcomeres as determined by the rates and extent of Ca activation, the turnover kinetics of the cross-bridges, and the relative Ca responsiveness of the sarcomeres. Engagement of the regulatory signaling cascades controlling contractility occurs with occupancy and signal transduction by receptors for neurohumors of the autonomic nervous system as well as growth and stress signaling pathways. Contractility is also determined by the prevailing conditions of pH, temperature, and redox state. Short-term control of contractility is fully expressed during exercise. In long-term responses to stresses on the heart, contractility is modified by cellular remodeling and altered signaling that may compensate for a time but which ultimately may fail, leading to disorders.

Regulation of Cardiac Contractility

Regulation of Cardiac Contractility PDF Author: R. John Solaro
Publisher: Biota Publishing
ISBN: 1615041753
Category : Medical
Languages : en
Pages : 46

Get Book

Book Description
Contractility describes the relative ability of the heart to eject a stroke volume (SV) at a given prevailing afterload (arterial pressure) and preload (end-diastolic volume; EDV). Various measures of contractility are related to the fraction as the SV/EDV or the ejection fraction, and the dynamics of ejection as determined from maximum pressure rise in the ventricles or arteries or from aortic flow velocities determined by echocardiography. At the cellular level, the ultimate determinant of contractility is the relative tension generation and shortening capability of the molecular motors (myosin cross-bridges) of the sarcomeres as determined by the rates and extent of Ca activation, the turnover kinetics of the cross-bridges, and the relative Ca responsiveness of the sarcomeres. Engagement of the regulatory signaling cascades controlling contractility occurs with occupancy and signal transduction by receptors for neurohumors of the autonomic nervous system as well as growth and stress signaling pathways. Contractility is also determined by the prevailing conditions of pH, temperature, and redox state. Short-term control of contractility is fully expressed during exercise. In long-term responses to stresses on the heart, contractility is modified by cellular remodeling and altered signaling that may compensate for a time but which ultimately may fail, leading to disorders.

Regulation of Cardiac Contractility

Regulation of Cardiac Contractility PDF Author: R. John Solaro
Publisher: Morgan & Claypool Publishers
ISBN: 1615041745
Category : Medical
Languages : en
Pages : 47

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Book Description
Contractility describes the relative ability of the heart to eject a stroke volume (SV) at a given prevailing afterload (arterial pressure) and preload (end-diastolic volume; EDV). Various measures of contractility are related to the fraction as the SV/EDV or the ejection fraction, and the dynamics of ejection as determined from maximum pressure rise in the ventricles or arteries or from aortic flow velocities determined by echocardiography. At the cellular level, the ultimate determinant of contractility is the relative tension generation and shortening capability of the molecular motors (myosin cross-bridges) of the sarcomeres as determined by the rates and extent of Ca activation, the turnover kinetics of the cross-bridges, and the relative Ca responsiveness of the sarcomeres. Engagement of the regulatory signaling cascades controlling contractility occurs with occupancy and signal transduction by receptors for neurohumors of the autonomic nervous system as well as growth and stress signaling pathways. Contractility is also determined by the prevailing conditions of pH, temperature, and redox state. Short-term control of contractility is fully expressed during exercise. In long-term responses to stresses on the heart, contractility is modified by cellular remodeling and altered signaling that may compensate for a time but which ultimately may fail, leading to disorders. Table of Contents: Introduction: Contractility and the Integrative Biology of the Myocardium / Control of Contractility Is at the Cellular Level of Organization / Left Ventricular Diastolic and Systolic Pressure, Ejection, and Relaxation Reflect Sarcomeric Mechanical Properties / Integration of Sarcomere Mechanics with Cardiac Function Clarifies the Meaning of Preload, Afterload, and Contractility / Pressure Volume Loops Provide a Quantification of Contractility / Phosphorylations of Regulatory Proteins in Excitation Contraction Coupling Modify Contractility by Controlling Cellular Ca + Fluxes, the Response of the Myofilaments to Ca +, and the Kinetics of the Cross-Bridge Cycle / Contractility May Be Altered by a Variety of Mechanisms Not Involving a Prominent Role for the Autonomic Nervous System / Cardiac Function Curves Provide a Compact Graphical Representation of Regulation of CO and SV / Heart Failure as a Failure of Contractility / References

Regulation of Cardiac Contractility

Regulation of Cardiac Contractility PDF Author: R. John Solaro
Publisher: Morgan & Claypool Publishers
ISBN: 1615041745
Category : Medical
Languages : en
Pages : 47

Get Book

Book Description
Contractility describes the relative ability of the heart to eject a stroke volume (SV) at a given prevailing afterload (arterial pressure) and preload (end-diastolic volume; EDV). Various measures of contractility are related to the fraction as the SV/EDV or the ejection fraction, and the dynamics of ejection as determined from maximum pressure rise in the ventricles or arteries or from aortic flow velocities determined by echocardiography. At the cellular level, the ultimate determinant of contractility is the relative tension generation and shortening capability of the molecular motors (myosin cross-bridges) of the sarcomeres as determined by the rates and extent of Ca activation, the turnover kinetics of the cross-bridges, and the relative Ca responsiveness of the sarcomeres. Engagement of the regulatory signaling cascades controlling contractility occurs with occupancy and signal transduction by receptors for neurohumors of the autonomic nervous system as well as growth and stress signaling pathways. Contractility is also determined by the prevailing conditions of pH, temperature, and redox state. Short-term control of contractility is fully expressed during exercise. In long-term responses to stresses on the heart, contractility is modified by cellular remodeling and altered signaling that may compensate for a time but which ultimately may fail, leading to disorders. Table of Contents: Introduction: Contractility and the Integrative Biology of the Myocardium / Control of Contractility Is at the Cellular Level of Organization / Left Ventricular Diastolic and Systolic Pressure, Ejection, and Relaxation Reflect Sarcomeric Mechanical Properties / Integration of Sarcomere Mechanics with Cardiac Function Clarifies the Meaning of Preload, Afterload, and Contractility / Pressure Volume Loops Provide a Quantification of Contractility / Phosphorylations of Regulatory Proteins in Excitation Contraction Coupling Modify Contractility by Controlling Cellular Ca + Fluxes, the Response of the Myofilaments to Ca +, and the Kinetics of the Cross-Bridge Cycle / Contractility May Be Altered by a Variety of Mechanisms Not Involving a Prominent Role for the Autonomic Nervous System / Cardiac Function Curves Provide a Compact Graphical Representation of Regulation of CO and SV / Heart Failure as a Failure of Contractility / References

Excitation-Contraction Coupling and Cardiac Contractile Force

Excitation-Contraction Coupling and Cardiac Contractile Force PDF Author: Donald Bers
Publisher: Springer Science & Business Media
ISBN: 940100658X
Category : Medical
Languages : en
Pages : 427

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Book Description
How is the heartbeat generated? What controls the strength of contraction of heart muscle? What are the links between cardiac structure and function? How does our understanding of skeletal and smooth muscle and non-muscle cells influence our thinking about force development in the heart? Are there important species differences in how contraction is regulated in the heart? How do the new molecular data fit together in understanding the heart beat? What goes wrong in ischemia, hypertrophy, and heart failure? This book paints a modern `portrait' of how the heart works and in this picture the author shows a close-up of the structural, biochemical, and physiological links between excitation and contraction. The author takes the reader through a series of important, interrelated topics with great clarity and continuity and also includes many useful illustrations and tables. The book starts by considering the cellular structures involved in excitation-contraction coupling and then described the characteristics of the myofilaments as the end effector of excitation-contraction coupling. A general scheme of calcium regulation is described and the possible sources and sinks of calcium are discussed in simple, but quantitative terms. The cardiac action potential and its many underlying currents are reviewed. Then the characteristics of some key calcium transport systems (calcium channels, sodium/calcium exchange and SR calcium uptake and release) are discussed in detail. This is then built into a more integrated picture of calcium regulation in succeeding chapters by detailed discussions of excitation-calcium coupling mechanisms (in skeletal, cardiac, and smooth muscle), the interplay between calcium regulatory processes, and finally mechanisms of cardiac inotropy, calcium overload, and dysfunction (e.g., ischemia, hypertrophy, and heart failure). Excitation-Contraction Coupling and Cardiac Contractile Force – Second Edition is an invaluable source of information for anyone who is interested in how the heart beat is controlled and especially suited for students of the cardiovascular system at all levels from medical/graduate students through senior investigators in related fields.

Simulation and Imaging of the Cardiac System

Simulation and Imaging of the Cardiac System PDF Author: S. Sideman
Publisher: Springer Science & Business Media
ISBN: 9400949928
Category : Medical
Languages : en
Pages : 448

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Book Description
The ultrasound velocity tomography allows measurement of cardiac geometries for various phases in the cardiac cycle. The present tomograph makes reconstruc tions at intervals of 20 ms. Because of a lack of clear (intramural) landmarks (except the roots of the papillairy muscle), it is difficult to pinpoint spatial trajectories of particular points in the heart. Therefore, a second method was developed of injecting radiopaque markers in the heart and following their motion patterns during the cardiac cycle with help of a biplane X-ray equipment. The data obtained with both methods can be implemented in our finite element model of the heart to compute intramural stresses and strains. The results obtained sofar with the extended Darcy equation to account for the interaction of blood rheology and tissue mechanics look promising. Further testing with more sophisticated subjects than mentioned in Figure 9 is required before it will be implemented in our finite element model of the heart. We conclude that analysis of regional cardiac function, including regional myocardial blood flow, requires still a major research effort but the results obtained sofar justify, to our opinion, a continuation in this direction. Acknowledgement The authors acknowledge Dr. C. Borst and coworkers for doing the animal experiments and prof. Van Campen and dr. Grootenboer for their participation is some aspects of this work.

Cardiovascular Regulation

Cardiovascular Regulation PDF Author: David Jordan
Publisher: Ashgate Publishing
ISBN: 9781855780248
Category : Medical
Languages : en
Pages : 159

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Book Description
The Studies in Physiology series provides a concise introduction to developments in complex areas of physiology for a wide audience. Published on behalf of the Physiology Society, Cardiovascular Regulation provides an up-to-date account of our current understanding of the control of the cardiovascular system that is not covered by existing textbooks. Both students and lecturers of cardiovascular and exercise physiology, medicine, dentistry and biomedical sciences will find this book informative and easy to read. Each chapter has numerous summary boxes. 'Essential reading' suggestions provide additional reading for undergraduates and the suggestions for 'Further reading' cover the subject to postgraduate level.

Regulation of Coronary Blood Flow

Regulation of Coronary Blood Flow PDF Author: Michitoshi Inoue
Publisher: Springer Science & Business Media
ISBN: 4431683674
Category : Medical
Languages : en
Pages : 330

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Book Description
Research centering on blood flow in the heart continues to hold an important position, especially since a better understanding of the subject may help reduce the incidence of coronary arterial disease and heart attacks. This book summarizes recent advances in the field; it is the product of fruitful cooperation among international scientists who met in Japan in May, 1990 to discuss the regulation of coronary blood flow.

Physiology And Pharmacology of Cardio-Respiratory Control

Physiology And Pharmacology of Cardio-Respiratory Control PDF Author: Albert Dahan
Publisher: Springer
ISBN:
Category : Medical
Languages : en
Pages : 172

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Book Description
Comprises 22 contributions from the November 1997 symposium held at Leiden University Medical Center. The contributions are divided into sections on oxygen physiology, central chemoreception, breathing disorders in wakefulness and sleep, artificial ventilation, opioids and anesthetics, and modeling studies. Specific topics include the possible role of the carotid body responsible for hypoxic ventilatory decline in awake humans, end-tidal inspiratory activity and asthma, the physiological enigma of the congenital central hypoventilation syndrome, separate effects of respiratory stimuli and depressants on abdominal muscle action, and some theoretical consequences of a linear ventilatory response to both hypoxia and hypercapnia. Indexed by terms specific to each chapter. Annotation copyrighted by Book News, Inc., Portland, OR

Basic Physiology for Anaesthetists

Basic Physiology for Anaesthetists PDF Author: David Chambers
Publisher: Cambridge University Press
ISBN: 1108463991
Category : Medical
Languages : en
Pages : 469

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Book Description
Easily understood, up-to-date and clinically relevant, this book provides junior anaesthetists with an essential physiology resource.

Heart of the Matter

Heart of the Matter PDF Author: Cesare Terracciano
Publisher: Springer Nature
ISBN: 3030242196
Category : Science
Languages : en
Pages : 236

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Book Description
This textbook introduces readers to the scientific basics of cardiovascular medicine and biology. It covers not only developmental but also cellular and molecular aspects of normally functioning vasculature and the heart; importantly, it also addresses the mechanisms leading to and involved in specific cardiovascular diseases. Though the main emphasis is on novel therapies and potential therapeutic targets, specific controversial topics like cardiac remodeling and regenerative capacities are also addressed. All chapters were written by lecturers from the Imperial College London, in collaboration with their students from the College’s BSc Programme in Medical Sciences with Cardiovascular Science. Bridging the gap between clinics and basic biology, the book offers a valuable guide for medical students, and for Master and PhD students in Cardiovascular Biomedicine.