[Diagnosis of transient acute myocardial ischemia in man by M-mode echocardiography (author's transl)].
Under basal conditions the echocardiographic findings in anginal patients (pts.) without previous myocardial infarction appears usually normal. Consequently, the usefulness of the ultrasounds evaluation in angina pectoris has been commonly considered poor and the utilization of this technique in coronary artery disease has been restricted to the detection of myocardial infarction in its acute phase or to its chronic mechanical alterations. The purpose of this study was to assess the possibility offered by M-mode echocardiography to detect changes caused by transient myocardial ischemia at rest in man, in view of the possible diagnostic application of this technique. The reported results were obtained from 25 ischemic attacks (13 spontaneous and 12 ergonovine induced) with ST segment elevation or pseudonormalization of a basally negative T wave at rest. The semiautomatic computerized analysis of echocardiograms continuously recorded during these attacks showed a reduction of motion and of systolic thickening, accompanied by a diastolic thinning of the wall involved by the ischemia. These changes occur very early: they appear few seconds before ECG changes and are accompanied by a reduction of contraction and relaxation dP/dt and precede the onset of chest pain; moreover, they are followed by an increase in left ventricular internal diameters. In conclusion M-mode echocardiography is a sensitive technique capable to detect transient myocardial ischemia in the course of spontaneous or induced angina with ST segment elevation or positivity of negative T wave. This approach could be helpful in the diagnostic evaluation of patients with atypical chest pain and/or aspecific ECG changes and it can be complementary to other non invasive techniques such dynamic ECG and nuclear cardiology techniques.
PubMed Abstracts
PubMed Abstracts