Correlation between infarct-related coronary artery patency and predischarge electrocardiographic patterns in patients with first anterior myocardial infarction who received thrombolytic therapy

Abstract

The aim of this study was to investigate the correlation between the ST-segment and T-wave patterns in predischarge electrocardiogram and patency of left anterior descending coronary artery in patients with a first anterior myocardial infarction (AMI). One hundred and fifty-six of 175 consecutive patients who were admitted to our clinic between January 2000 and September 2002 due to a first episode of transmural AMI and who received thrombolytic therapy were enrolled. Coronary angiography was performed by the Judkins method on the 6th-10th day after the acute infarction. The corrected TIMI frame count (CTFC) was estimated according to the previously described method. According to the combination of the ST-segment and T-wave morphology on the day (6-10) of cardiac catheterization, patients were classified into four groups: group A, ST elevation <<0.1 mV and negative T waves; group B, ST elevation >or=0.1 mV and negative T waves; group C, ST elevation <<0.1 mV and positive T waves; and group D, ST elevation >or=0.1 mV and positive T waves. Of the 99 patients with negative T waves, 47 (48%) had CTFC <or=27, 32 (32%) CTFC between 27 and 40, 15 (15%) CTFC >or=40-100, and 5 (5%) CTFC >>100. Of the 57 patients with positive T waves, CTFC was <or=27 in 14 (25%), between 27 and 40 in 17 (30%), >or=40-100 in 11 (19%), and >>100 in 15 (26%) ( P << 0.001). From the 76 patients with an isoelectric ST segment, 38 (50%) had CTFC <or=27, 29 (38%) CTFC between 27 and 40, 8 (11%) CTFC >or=40-100, and 1 (1%) CTFC >>100. Of the 80 patients with an elevated ST segment, 23 (29%) had CTFC <or=27, 20 (25%) CTFC between 27 and 40, 18 (23%) CTFC >or=40-100, and 19 (23%) CTFC >>100 ( P << 0.001). Use of the combination of two electrocardiographic parameters (ST segment and T waves) also indicated that there were significant differences between groups A and D, and groups B and D ( P << 0.001 and P << 0.05, respectively). Development of an isoelectric ST segment with negative T waves may indicate a better degree of reperfusion after AMI. In contrast, patients in whom ST-segment elevation and positive T waves remain at discharge from the coronary care unit have a higher probability of a nonpatent left anterior descending artery.