Precordial T-wave polarity changes in acute inferior infarction. A poor indicator of associated disease of the left anterior descending coronary artery.

T-wave polarity in V1 to V3 was examined in 70 patients with acute inferior wall myocardial infarctions (IWMI) as an indicator of significant disease in the left anterior descending coronary artery (LAD). Fifty-three percent (37/70) had precordial T-wave inversions, and of these 38 percent (14/37) had angiographically significant LAD disease. Conversely, 47 percent (33/70) had upright T waves in V1 to V3, and of these, 52 percent (17/33) had significant LAD disease. Likewise, 41 percent of the patients with ST segment depression in V1 to V3 had significant LAD disease, while 50 percent of those with isoelectric ST segments were similarly affected. Finally only 39 percent of those patients with both precordial ST segment depression and T-wave inversion had significant LAD disease. We conclude that neither anterior ST depression, T-wave inversion, nor a combination of both is a sensitive or specific indicator of LAD disease in patients with acute IWMI.