Starling S Law Of The Heart Revisited

H. E. D. J. TER KEURS & M. I. M. NOBLE The "Starling's Law of the Heart" and "The Frank-Starling Mechanism" have long been the cornerstone of cardiac mechanical physiology. It is often forgotten that Frank and Starling carried out fundamentally different exper iments. Frankl measured the isovolumic pressure developed by frog heart at different volumes. He therefore discovered the pressure-volume-volume rela tionship which depends directly on the force-length relationship of the 2 sarcomeres. Starling ,3 studied cardiac shortening as manifest by cardiac output and its relationship to end-diastolic conditions as manifest by right atrial pressure. Thus he was studying the ability of cardiac muscle to shorten more at a given load from a greater initial length. Starling in the promulga 4 tions of his law implied a common mechanism for these two phenomena and spoke of the "energy liberated" being a function of initial muscle fiber length. However, there has been much confusion about the interrelationship between the two different aspects studied by Frank and Starling. The 1960s saw the era of isolated cardiac muscle mechanics, beginning with 5 the paper of Abbott and Mommaerts. Whole muscle length-tension relations were equated with sarcomere-length-tension relations by fixation of muscle at a particular point on the curve and determination of sarcomere length by electronmicroscopy.

A comprehensive survey of recent advances is given in this Update. The wide spectrum of experimental and clinical investigations include the pathophysiologic, diagnostic and therapeutic aspects.

Molecular Control Mechanisms in Striated Muscle Contraction addresses the molecular mechanisms by which contraction of heart and skeletal muscles is regulated, as well as the modulation of these mechanisms by important (patho)physiological variables such as ionic composition of the myoplasm and phosphorylations of contractile and regulatory proteins. For the novice, this volume includes chapters that summarize current understanding of excitation-contraction coupling in striated muscles, as well as the compositions and structures myofibrillar thick and thin filaments. For the expert, this volume presents detailed pictures of current understanding of the mechanisms underlying the CA2+ regulation of contraction in heart and skeletal muscles and discusses important directions for future investigation.

With this volume of three essays, the authors want to create an opportunity for dialogue between different disciplines by taking a closer look at three cardio-physiological examples. In the essays presented, we will look at the exploration of different cardiological topics from the 20th century, all of which have contributed to a better understanding of certain aspects of cardiac activity. Not only do these insights provide a more complete picture of these cardiac phenomena, but it is also within this context that we can look for and into the patterns of regularities which govern this living organism. Our goal is to stimulate a dialogue on the philosophy of science in the spirit of Hans Reichenbach.

Prostheses, assistive systems, and rehabilitation systems are essential to increasing the quality of life for people with disabilities. Research and development over the last decade has resulted in enormous advances toward that goal-none more so than the development of intelligent systems and technologies. In the first truly comprehensive book addressing intelligent technologies for the disabled, top experts from around the world provide an overview of this dynamic, rapidly evolving field. They present state-of-the-art information on the latest, innovative technologies and their applications in various systems designed to better the lives of the disabled. From the underlying principles to the design, practical applications, and assessment of results, Intelligent Systems and Technologies in Rehabilitation Engineering offers broad, pragmatic coverage of the field. It incorporates the most recent advances in sensory and limb prostheses, myoelectric control systems, circulatory systems, assistive technologies, and applications of virtual reality. Rapid progress demands a concerted effort to keep up with the latest developments so they can begin to serve their purpose and improve the lives of the disabled. By incorporating details of the latest and most important advances into one volume, Intelligent Systems and Technologies in Rehabilitation Engineering makes that undertaking essentially effortless.

The objective of this book is to provide the researcher and clinician with the recent developments in the analysis and assessment of cardiovascular func tion. The chapters are organized into sections that correspond with the various anatomical levels of the cardiovascular system. To a large extent, recent focus on the cardiovascular system function has been directed at the molecular level to the near exclusion of the tissue and organ function. While this may be useful in developing new therapeutic drugs, it does not aid the cardiologist or surgeon, who routinely deal with patient symptoms. This book integrates the micro-level and organ-level function so that new infor mation may be assimilated into the cardiovascular system as a whole. Within each section, the chapters have been arranged to progress from recent theoretical developments, to experimental research, and finally to clinical applications. This approach facilitates the timely transfer of infor mation from basic research to the clinic. The strength of the analytical approach will be evident to the reader. The theoretical analysis offers guidance to experimental design and, in some cases, offers solutions where measurements are as yet unattainable. In moving from newly attained knowledge to clinical practice, this book emphasizes the noninvasive meth in the future as technological advances ods. Such methods are desirable occur and the trend towards early preventive diagnosis is sought. What follows are highlights of new developments covered in each section of the book.