title: Clinical implications of anterior S-T segment depression in patients with acute inferior myocardial infarction.
abstract: To assess various factors associated with anterior S-T segment depression during acute inferior myocardial infarction, 47 consecutive patients with electrocardiographic evidence of a first transmural inferior infarction were studied prospectively with radionuclide ventriculography an average of 7.3 hours (range 2.9 to 15.3) after the onset of symptoms. Thirty-nine patients (Group I) had anterior S-T depression in the initial electrocardiogram and 8 (Group II) did not have such "reciprocal" changes. There was no difference between the two groups in left ventricular end-diastolic or end-diastolic volume index or left ventricular ejection fraction. Stroke volume index was greater in Group I than in Group II. There were no group differences in left ventricular total or regional wall motion scores. A weak correlation existed between the quantities (mV) or inferior S-T segment elevation and reciprocal S-T depression. No relation between anterior S-T segment depression and the left ventricular end-diastolic volume index could be demonstrated; the extent of left ventricular apical and right ventricular wall motion abnormalities, both frequently associated with inferior infarction, did not correlate with the quantity of anterior S-T depression. These data show that anterior S-T segment depression occurs commonly during the early evolution of transmural inferior infarction, is not generally a marker of functionally significant anterior ischemia and cannot be used to predict left ventricular function in individual patients. Anterior S-T segment depression may be determined by reciprocal mechanisms.
mesh_terms: D006328:Cardiac Catheterization; D004796:Clinical Enzyme Tests; D003402:Creatine Kinase / Q000097:blood; D004562:Electrocardiography; D006352:Heart Ventricles / Q000000981:diagnostic imaging / Q000503:physiopathology; D006801:Humans; D007527:Isoenzymes; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000503:physiopathology; D011446:Prospective Studies; D011877:Radionuclide Imaging; D013670:Sodium Pertechnetate Tc 99m; D013318:Stroke Volume; D013667:Technetium
chemical_list: D007527:Isoenzymes; D013667:Technetium; D013670:Sodium Pertechnetate Tc 99m; D003402:Creatine Kinase