[Significance of the early maximal negative T wave in acute anterior myocardial infarction].

The significance of the early maximal negative T wave on electrocardiography was evaluated in 74 patients with initial acute anterior myocardial infarction (MI) admitted within 6 hours of onset. The relationship between the negative T wave and the severity of MI, as assessed by MI size and left ventricular dysfunction, was investigated. Serial electrocardiography, maximal creatine phosphokinase (CKmax), total myocardial perfusion index by thallium-201 single photon emission computed tomography myocardial scintigraphy, and left ventricular ejection fraction (LVEF) by technetium-99m scintigraphy were obtained. The amplitude of maximal negative T wave (NTmax) was observed between 4 and 96 hours after the onset (mean 46.3 +/- 19.3 hours). NTmax was significantly correlated with CKmax-1 (r = 0.613, p < 0.001) and with LVEF (r = 0.542, p < 0.002). Patients were divided into 3 groups based on NTmax: the deep negative T (DNT: NTmax > or = 10 mm) group, intermediate negative T (INT: 4 mm < or = NTmax < 10 mm) group and shallow negative T (SNT: NTmax < 4 mm) group. Compared with the SNT group, the DNT group revealed smaller CKmax (p < 0.05), more reduced LVEF and myocardial perfusion index (p < 0.05, respectively). The INT group had intermediate values. Serial electrocardiography of the DNT group showed the reappearance of R waves in leads V1-V4, normalization of the ST segment, and relatively early appearance of terminal T wave inversion (p < 0.05, respectively). NTmax reflects the infarct size, and is a clinically simple and useful parameter to estimate the severity of acute anterior myocardial infarction.