A New Method of Analyzing Regional Myocardial Function of the Ventricle
We introduce a new method of defining regional work and regional elastic modulus of the myocardium of the ventricular wall using the relationship between mean wall stress (σ) and the natural logarithm of reciprocal of wall thickness (ln(1/H)). The area surrounded by the loop described by the σ-ln (1/H) relationship during a cardiac cycle-is equal to regional work per unit volume of myocardium per stroke. The slope of the σ-ln (1/H) relationship corresponds to Young’s modulus of an incompressible Hookean material. The end-systolic σ-ln(1/H) data point moves on a rectilinear line during pre-and afterloadings. The slope of this line is not affected by alterations in pre-and afterloads, but changes singnificantly due to the changes in the contractile state. Therefore, the slope can be regarded as the normalized Emax, i.e., a normalized index of myocardial contractility index of myocardial contractility.
KeywordsVentricular Wall Wall Stress Aortic Constriction Wall Tension Contractile State
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