標準12誘導心電図を用いた急性心筋梗塞における左室機能の評価

Electorocardiographic evaluation of left ventricular function in acute myocardial infarction

　急性心筋梗塞では，左室機能を早期に評価することがきわめて重要であり，多くの努力がなされている^1〜4）。そのうち，最も普遍的で簡便な検査法である心電図から左室機能を評価する試みが，Selvester^5）らによって提唱され，核医学的手法による左室駆出率との対比検討が行われてきた。

　今回，我々は，標準12誘導心電図から種々のパラメータを設定し，^99mTC心室造影法から得られた左室全体駆出率と比較検討し，救急患者のベッドサイドにおける左室機能の評価法として，実用にたえる知見を得た。

The object of this study is to evaluate left ventricular function in patients with acute myocardial infarction (AMI) by 12 lead electorocardiography (ECG). The subject of this study was 84 patients with definite transmural AMI diagnosed from typical chest pain, elevation of serum CPK (MB), and evolutional ECG changes. There were 66 men and 18 women with mean age of 60. These patients were devided into subgroups according to the location of AMI : anterior=group A and inferior=group I and the presence or absence of heart failure: group F and group N, res-pectively. Eight parameters seemed suggesting the size of AMI (4th day after attack) served for this study : ECG scoring system proposed by Palmeri (QRS score, New Eng J Med 1982), sum of Rwave proposed by Askezani (ΣR, Am J Med 1978), sum of amplitude and duration of Q wave (ΣQ, DQ), ST elevation (ΣE), and ST depression (ΣD), and number of coronary T wave and Q vaves (NT, NQ). These parameters were compared with left ventricular ejec-tion fraction (LVEF) obtained from ECG gated equi-librium radionuclide ventriculography (RNVG). Sig-nificant positive relationship was noted among LVEF and QRS score (all groups), NQ (group A, group N), ΣR (group N), ΣD (group I), (each p<0. 001). Especially, close correlation was noted between LVEF and QRS score; r=0.63 with group A, r=-0.77 with group I, r=-0.77 with group N and r=-0.61 with group F (each p<O.001). Moreover QRS score≧ 5 suggesting LVEF<35% and in group A and ER<5 indicating LVEF <45%. In conclusion, QRS score is a noninvasive and useful parameter estimating left ventricular function at the bedside of patients with AMI.