IS CONTRACTILITY DEPRESSED IN THE FAILING HUMAN HEART

Is contractility depressed in the failing human heart? The question mu st be approached in a stringent manner. Myocardium from failing human hearts has been shown to generate normal physiological force under the ideal conditions of low stimulation and an adequate energy supply. Ne vertheless, even when subjected to physiologically conducive condition s, failing myocardium experiences a slowed relaxation, adversely affec ting the diastolic properties of the heart. In addition, experiments h ave shown that increasing the contraction rates of failing hearts clea rly results in lowered force and pressure evolution. This information indicates a decrease in contractile reserve in both a systolic and dia stolic sense. Not surprisingly, the term end-stage heart failure becom es questionable when applied to myocardium obtained from patients unde rgoing cardiac transplantation. A number of studies involve such myoca rdium from feasible regions of the heart perfused within ideal physiol ogical conditions yielding, at times, nonfailing performance. Therefor e, it becomes imperative to bear in mind the role of such myocardium w ithin the framework of the entire diseased heart.