[Heart diagnosis using m-mode-echography. Continuous registration of transverse left-ventricular internal diameters. IV. Patients with coronary artery disease (author's transl)].

"Relative Cross-sectional area Differences" (RCD) and "Relative mean Velocity of Contraction" (RVC) can precisely be determined by means of impulse-reflected ultrasound. They are highly invariant under physiological conditions and closely related to the degree of non-ischemic myocardial disorders. To evaluate the diagnostic information of these parameters in coronary artery disease (CAD), echocardiographic examinations were performed on 105 subjects. The results were compared with the angiocardiographically determined ejection fraction and with minimal cardiac transit times. The heart-dynamic data were grouped according to the manifestation of CAD and correlated to each other. Furthermore the parameter's capability in identifying differences in hemodynamics in normals and in patients with CAD was tested. In more than 90 per cent of patients with CAD, RCD and RVC exceeded the normal range. For clinical diagnosis the results lead to certain limitations in the validity of the echocardiographic parameters. In cases of infarction localized at the apex and in myocardial aneurysmas, RCD and RVC reflect the function of the whole myocardium, not the ejection fraction of the left ventricle. In those cases of infarction of the posterior or posterolateral wall, the value of RCD and RVC could not be verified. If infarction occurs at other localizations (septum, anterior wall), RCD and RVC show the degree of reduced myocardial function without any limitation.