A method of analyzing regional myocardial function: mean wall stress-area strain relationship.

We introduce a new method of defining regional work of the ventricle and evaluating regional myocardial function using the relationship between mean wall stress (sigma) and the natural logarithm of the reciprocal of wall thickness (ln (1/H)). The sigma-ln (1/H) relationship was studied during pressure loading, contractility change, volume loading and the development of ischemia in ten anesthetized dogs. The validity of our method is discussed. At the time of cardiac catheterization, our method was applied to three human subjects: one with a normal heart, one with anterior acute myocardial infarction, and one with inferior acute myocardial infarction. The functioning state of a region of the ventricular wall was evaluated quantitatively by the amount of regional work per stroke.