Global cardiac function: mechano-energetico-informatics.
This review on the global cardiac function covers cardiac mechanics, energetics, and informatics that I have developed with my collaborators over the last 30 years in Japan and USA. We first established E(max) (end-systolic maximum elastance or pressure/volume ratio) as a new index of ventricular contractility using canine hearts. We then expanded the E(max) concept to PVA (systolic pressure-volume area consisting of external mechanical work and mechanical potential energy) as an innovative measure of total mechanical energy of ventricular contraction and discovered it to be a reliable determinant of ventricular energetics or O(2) consumption (V(O(2))). We have discovered that E(max) shifts the V(O(2))-PVA relation and the E(max) dependency (O(2) cost of E(max)) varies among different pathophysiological hearts. We also searched for the basis of E(max) in crossbridge behavior information contained in an X-ray diffraction of papillary muscle. Recently, we established a new integrative analysis to estimate total Ca(2+) recruited for excitation-contraction coupling in a beating heart using the E(max)-PVA-V(O(2)) information. These global, mechano-energetico-informatic approaches seem to facilitate better understanding of cardiac function, as required in the present post-genomic era when more physiomic knowledge is required not only in cardiac function but also in all other physiologic functions.
Suga
Hiroyuki
H
National Cardiovascular Center (NCVC), Research Institute, 5-7-1 Fujishirodai, Suita, Osaka 565-8565, Japan. hsuga@ri.ncvc.go.jp
D000818:Animals; D001783:Blood Flow Velocity; D001794:Blood Pressure; D002118:Calcium / Q000502:physiology*; D004548:Elasticity; D004734:Energy Metabolism / Q000502:physiology*; D006321:Heart / Q000502:physiology*; D006801:Humans; D008955:Models, Cardiovascular; D009200:Myocardial Contraction / Q000502:physiology*; D009218:Myosins / Q000502:physiology; D010101:Oxygen Consumption / Q000502:physiology; D010210:Papillary Muscles / Q000502:physiology; D016276:Ventricular Function
D009218:Myosins; D002118:Calcium