[Effect of calcium on the diastolic phases in healthy persons and in patients with cardiac insufficiency].

Variations in the duration of diastolic phases under acute calcium loading were studied in normal subjects and patients with heart failure, using left ventricular apexcardiography (ACG). Certain changes in diastolic phases were revealed in patients with heart failure as compared to normal subjects, which corresponded to the severity of heart failure. The phase of isometric relaxation as well as those of rapid and slow filling showed the most dynamic variation. The calcium test brought out differences in the effects of calcium on normal and affected myocardium. The established variations may be due to changes in mechanisms of calcium fixation in and the elimination from sarcoplasmatic reticulum.