Relation of sarcomere lengths to filling pressures in normal and hypertrophied hearts

The sarcomere lengths at the inner, middle and outer layer of the ventricular wall were computed with the aid of a simulated static pressure volume curve of the left ventricle. By assuming the Young's modulus as a linear function of pressure, a good fit was obtained between the computed sarcomere lengths and the values reported in the literature. A length- tension diagram constructed from data reported for the papillary muscle was used to predict the peak contractile tension in the middle layer. The results indicate that in simulated hypertrophy the peak tension is developed at a higher level of the filling pressure and the peak tension is maintained through a wider range of filling pressure. Supported by a research fellowship and research grant from The Canadian Heart Foundation.