[Contribution of the electrocardiogram to the diagnosis of localization and extension of coronary lesions in patients with acute myocardial infarct].
With the purpose of evaluating the contribution of the ECG to the localization and extension of coronary artery lesions, 85 patients with the first acute myocardial infarction treated with thrombolysis, 79 males and 6 females (mean age 53.9 years), were studied, and the ECG changes at 3.5 and 24 hours correlated with the coronary angiographic findings before discharge. Patients were divided in two groups--Group A with anterior infarction (48 pts) and Group B with inferior infarction (37 pts).


RESULTS
A) Returning of the ST downslope to baseline in inferior and anterior leads, respectively in anterior and inferior infarction at 24 h ECG, excluded associated LAD or RCA/CX lesions with a sensitivity (S) of 93% and 87% and aspecificity (E) of 60% and 58%, with a positive predictive value (PPV) of 62% and 77% and a negative predictive value of 86% and 85% respectively. All patients with anterior infarction had LAD stenosis. B) ST upslope bigger than 5 mm in V2-V3 or its presence in D-I or aVL associated to any precordial leads, diagnosed proximal LAD lesions with S of 82% and 73% and E of 75% and 73% respectively. The left axis deviation was present in 6 of 7 patients and pointed to proximal lesion. C) In Group B patients, RCA lesion was related to ST downslope in D-I, S = 77%, E = 37.5%, PVV = 80% and NPV = 33.5%, and the proximal localization (ratio between ST downslope in V2 and ST upslope in aVF) inferior to 0.5 mm with S and NPV = 80% and E and PPV = 100%. The presence of an isoelectrical ST in D-I in association with ST upslope in V5-V6 is related to CX with S and NPV = 100%, E = 85% and PPV = 25%. In conclusion, these results suggest that a careful analysis of ECG changes in patients with first acute myocardial infarction, can provide important information regarding the infarct related artery, localization of the stenosis and the presence of associated coronary artery disease, with implications in the risk stratification before hospital discharge.
Farto e Abreu
P
P
Serviço de Cardiologia, Hospital de Santa Cruz.
Gil
V
V
Silva
J A
JA
Gomes
R S
RS
D000328:Adult; D000368:Aged; D017023:Coronary Angiography; D004562:Electrocardiography; D005260:Female; D006321:Heart / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000145:classification / Q000175:diagnosis* / Q000503:physiopathology
Contribuição do electrocardiograma para o diagnóstico da localização e extensão das lesões coronárias em doentes com enfarte agudo do miocárdio.