The behavior of the weakening and failing myocardium
- 31 Downloads
Use of an electrical model of the left ventricle of the heart and the arterial system permits analysis of the changes which take place as the capacity of the myocardium for generation of force decreases. The model is simple in structure, and its construction and practical testing would not be difficult. It demonstrates that, as the heart muscle weakens, the peak of intracardiac force occurs later in systole, and the difference between the intracardiac pressure and the aortic pressure in the second half of systole is much greater than for the normal heart. The feedback mechanisms which are proposed to affect myocardial contractility would affect this compensation for cardiac weakening. Indices to categorize the behavior of the normal, compensated though weakened, and decompensated myocardium are proposed.
KeywordsNormal Heart Myocardial Contractility Aortic Pressure Electrical Model Force Decrease
Unable to display preview. Download preview PDF.
- Defares, J. G., J. J. Osborn and H. H. Hara. 1965. “On the Theory of the Cardiovascular System”.Bull. Math. Biophys.,27, Special Issue, 71–83.Google Scholar
- Friedberg, C. K. 1956.Diseases of the Heart. Philadelphia: W. B. Saunders Co.Google Scholar
- Goodyer, A. V. N., M. J. Goodkind and A. B. Landry. 1962. “Ventricular Response to a Pressure Load. Left Ventricular Function Curves in Intact Animal”.Circulation Research,10, 885–896.Google Scholar
- Harvey, R. M., W. M. Smith, J. O. Parker and M. I. Ferrer. 1962. “The Response of the Abnormal Heart to Exercise”.Circulation,26, 341–362.Google Scholar
- Ross, J. Jr. and E. Braunwald. 1964. “The Study of Left Ventricular Function in Man by Increasing Resistance to Ventricular Ejection with Angiotensin”.Circulation,29, 739–749.Google Scholar
- Roston, S. 1962. “Blood Pressure and the Cardiovascular System”.Ann. N.Y. Acad. Sci.,96, 962–974.Google Scholar
- — 1966. “Control of the Contractility of the Myocardium in a Feedback System”.Bull. Math. Biophys.,28, 195–205.Google Scholar