Starling's Law of the Heart Revisited

ISBN-13: 9789401070843 / Angielski / Miękka / 2011 / 168 str.

Henk Keurs; M. I. M. Noble

Opis

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.

Spis treści

1. The contribution of myofibrillar properties to the sarcomere length-force relationship of cardiac muscle.- Appendix (Sarcoplasmic reticulum calcium release).- 2. The mechanism of the length-tension relation in cardiac muscle of Rana Catesbeiana.- 3. Intracellular calcium concentration following length changes in mammalian cardiac muscle.- 4. Some dynamic effects of length and isotonic motion on cardiac sarcomere shortening.- 5. The relation between contraction dynamics and the intracellular calcium transient in mammalian cardiac muscle.- 6. The effects of sarcomere length on force and velocity of shortening in cardiac muscle.- 7. Similarity and dissimilarity between muscle force-length relationship and ventricular pressure-volume relationship.- 8. The importance of the geometry of the heart to the pump.- 9. Cardiac pump function and ventricular dimensions.- 10. The pressure-volume relationship of the intact heart.- Index of Subjects.