心筋硬塞の心電図に関する研究

第1報 特殊誘導, 特に心筋硬塞診断上の限界値について

抄録

In many cases, the posterior wall infarction shows no abnormality of diagnostic significance on the electrocardiograms taken by the conventional 12 different methods of leads. A number of special methods have appeared with an intention of improving the diagnostic value for myocardial infarction, but most of them unfortunately are deficient of their scrutinization on normal individuals and accordingly their normal limits have not been confirmed as yet.
In the present study, normal limits and availability of those special methods of lead were investigated on 222 normal individuals, 121 of non-infarct and on 23 of posterior wall infarction.
1. With dorsal unipolar lead, Q/R 0.25 can be regarded as the limit of V₇ for the diagnosis of infarction, but as Q/R of V₈ and V₉ show a figure over 0.4-0.5 in the absence of infarction, the value of this method for the diagnosis of infarction is small.
2. With Sdd lead, it was found to have supplementary diagnostic value in the diagnosis of the posterior wall infarction provided that the voltage of QRS (not the difference of low voltage) and the direction P wave (positive) are taken into consideration when Q/R gives a figure over 0.4.
3. D lead of Nehb was recognized to have supplementary diagnostic value, sometimes, when Q/R 0.4 is taken as its limit.
4. V_E, V_EO and V_o can hay Q/R 0.25 as their limit and especially V_o was found to have the diagnostic value in the diagnosis of posterior wall infarction.