[Clinical significance of calcium sensitizer].

Oral inotropes did not always improve mortality of the patients with heart failure partly because of possible direct toxic effects of these agents on myocytes, exacerbating arrhythmias, enhancing neurohormonal activity. Ca(2 +) sensitizers such as pimobendan and levosimendan was expected to improve even mortality of the patients with heart failure through increasing cardiac contractility without a rise in intracellular calcium. However, the trials using these agents disappoint our expectations. We need the development of the agents which has more specific effect of Ca(2 +) sensitizing and the selection of the patients who will receive the benefits of Ca(2 +) sensitizers.