Poor R Wave Progression 例における陳旧性前壁梗塞の鑑別―体表面心臓電位図による検討―

The clinical usefulness of the body surface maps (maps) to discriminate old anterior myocardial infarction (OAMI) in patients whose ECG showed poor R wave progression (PRWP) was examined. The maps of 60 patients with PRWP, including 33 cases of OAMI and 27 without myocardial infarction (non-MI) were recorded. The multivariate stepwise discriminant analysis elucidated that 5 leads (G4, C3, J5, B3, A5) of the QRST area map would contribute to the discrimination of OAMI from non-MI, and the the formula z=-6.0×G4+26.8×C3+9.1×J5-14.0×B3-9.0×A5-1.1(unit : 0.1mVS), using these parameters two groups were separated with a sensitivity of 90.9% and a specificity of 96.3%. The discriminating performance using 5 leads (G4, H2, H4, L6, M5)of the QRS area map and 5 leads (G5, G2, H4, L5, M5) of the Q20 map gave a sensitivity of 90.9%, and 93.9%, and specificity of 96.3%, and 92.6%, respectively. Furthermore, for formula was applied to 26 new consecutive patients with PRWP for evaluating this formula. The indicies obrained from the QRST area map gave the best results, and provided a sensitivity of 85.7% and a specificity of 100%. In the pattern of the QRST area map, the existence of the regions less than-20μVS can fairly identify the OAMI (sensitivity 87.9%, specificity 85.2%). These findings suggest that the mathematical models obtained from the result of map analysis, especially QRST area maps, are useful to discriminate OAMI among the cases with PRWP.

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