[Coronary thrombolytic therapy in acute myocardial infarction: time dependence of beneficial effects assessed by two-dimensional echocardiography].

Abstract

To elucidate the effects of coronary thrombolytic therapy in acute myocardial infarction, we observed serially the degree of left ventricular (LV) wall motion immediately after on day 1, and on days 7, 14, 21 and 28 after thrombolytic therapy, in 22 patients with acute anteroseptal myocardial infarction. Base-line coronary arteriography revealed significant lesions in the proximal portions of the left anterior descending artery of all the patients. The patients were categorized according to results of thrombolytic therapy as Group I-a: seven patients with spontaneous or successful recanalization within three hours of onset of chest pain; Group I-b: nine patients with successful recanalization between three and seven hours, with a mean of 4.8 hours from onset; and Group II: six patients in whom thrombolytic therapy was unsuccessful and infarct-related vessels remained totally occluded. The LV wall motion index (WMI) was defined as the sum of point scores for the degrees of regional wall motion at nine segments on serial two-dimensional echocardiograms, and used for quantitative assessments of LV function. Results were as follows: On day 1, immediately after thrombolytic therapy, the WMI of Group I-a was smaller than that of Group II. However, there was no significant difference between Groups I-a and I-b and between Groups I-b and II. These findings suggest that LV function cannot be recovered immediately after recanalization of occluded arteries unless recanalization occurs exceptionally early. Percent improvement of the WMI from days 1 to 28 in Group I-a, 65 +/- 14%, was significantly greater than that in Group I-b, 31 +/- 18%. However, Group II did not show significant improvement in the WMI. The WMI in Group I-a decreased significantly from days 1 to 7 (9.0 +/- 1.6 vs 7.1 +/- 1.8, p less than 0.05); whereas, the WMI in Group I-b showed no significant decrease until day 21. On day 1, the regional wall motion of the antero-apical wall was akinetic or dyskinetic in all patients studied. On day 28, it improved in six of seven patients in Group I-a, while it remained akinetic or dyskinetic in all patients in Groups I-b and II.(ABSTRACT TRUNCATED AT 400 WORDS)