Determination of Myocardial Material Properties by Optimization
The previous chapter includes a computationally efficient strain energy function for describing the three-dimensional relationship between stress and strain in passive myocardial material properties, the material parameters of which were formally optimized using left ventricular pressure and epicardial strain measurements in a cylindrical model. Results from such a model are confined at best to the equatorial region of the left ventricle. A finite element model of the entire left ventricle is required to determine regional variations in myocardial material properties. The most important or at least interesting finding from such a study is that myocardial contractility in the (border zone) region adjacent to a myocardial infarction is much less than (typically only half) that in regions remote from the myocardial infarction. This finding has been confirmed with active stress measurements in skinned muscle fibers dissected from these regions. This chapter is concerned with brief descriptions of the studies from our laboratory that have led up to our current knowledge concerning regional variations of myocardial contractility in infarcted left ventricles.
KeywordsLeft Ventricle Root Mean Square Error Finite Element Model Border Zone Radial Strain
This research was supported by a grant from the Whitaker Foundation (Dr. Guccione) and National Institutes of Health grant 5R01 HL077921 (Dr. Guccione).
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