PATHOLOGICAL IMPLICATIONS OF RESTORED POSITIVE T-WAVE AND PERSISTENT NEGATIVE T-WAVE AFTER Q-WAVE MYOCARDIAL-INFARCTION

Objectives. We sought to study the pathologic implications of restored positive T waves and persistent negative T waves in the chronic stage of Q wave myocardial infarction. Background. Some inverted T waves (c oronary T waves) become positive after acute myocardial infarction; ot hers retain their negative T wave component fur a long time, The patho logic implications of the difference between restored positive T waves and persistent negative T waves in leads with Q waves has not, until now, been given much careful study. Methods. Of 17 patients with anter ior or anteroseptal myocardial infarction confirmed by autopsy, 8 (gro up P) had positive and 9 (group N) had negative T waves in precordial leads with Q waves greater than or equal to 1 year after the onset of myocardial infarction. The appearance and extent of the infarct area a nd the degree of coronary artery stenosis were evaluated in both group s. Results, At autopsy, seven of eight patients in group P had nontran smural fibrotic changes in the anteroseptal or anterior nail, However, seven of nine patients in group N had a transmural myocardial infarct ion consisting of only a thin fibrotic layer in the anteroseptal or an terior wall, The left anterior descending coronary artery showed 75% s tenosis in I patient in each group but > 90% stenosis in the remaining 15 patients, Conclusions. Persistent negative T waves in leads with Q waves in the chronic stage of myocardial infarction indicate the pres ence of a transmural infarct ion with a thin fibrotic layer, whereas p ositive T waves indicate a nontransmural infarct containing viable myo cardium within the layer.