[Relation of the impedance cardiogram to the course of myocardial contraction].

53 patients with coronary heart disease were investigated synchronously by means of impedance and angiocardiography combined with the measurement of the pressure in the aorta and the left ventricle. In these cases relatively close correlations were found between the stroke volumes and systolic time intervals, determined by the two methods, as well as between the ejection fraction on the one hand and the parameter dz/dt max on the other. The pressures, measured invasively, do not correlate significantly with the impedance cardiography parameters. With help of the relations found it is possible to coordinate the changes of the thoracic impedance curve depending on the heart action with the various phases of the left-ventricular volume change.