[Heart diagnostics using M-mode echography. Continuing registration of transverse internal left ventricular diameters. II. Determination in patients with myocardial insufficiency with special reference to ischemic heart disease].

Relative Cross-sectional area Differences (RCD) and Relative mean Velocity of Contraction (RVC) are easily, quickly and precisely determined by means of impulse-reflected ultrasound. They were recognized to be highly invariant under physiological conditions and thus were considered as sensitively regulated heart-dynamic-parameters. (his paper reports about a total of 395 examinations on patients with myocardial disease and on normal subjects. Various pathogenic factors are included excepting patients with myocardial infarction. In all subgroups there is a decrease of RCD and RVC with increasing degrees of cardiac disease. Correlating the angiocardiographically determined left-ventricular ejection fraction with both parameters, they show a significant linear relationship. Even in clinically latent myocardial disease the echocardiographic parameters are defnitely reduced. Small changes of myocardial function, e.g. under digoxin and in different degrees of uremic heart disease with uremic cardiomyopathy, can be recognized by RCD and RVC under exclusion of extracardiac factors. Physical tests during exercise confirm the observed trends. The typical changes of the echocardiographic parameters in myocardial disease, permitting a sharp discrimination of pathologic values with their small physiological variability, identify RCD and RVC as sensitive parameters of the mechanical function of the myocardium in the range of validity that was examined. The described properties and the lack of discomfort to the patient suggest a number of important indications of this method.