Evaluation of different electrocardiographic scores (QRS score) for estimating the ejection fraction of the left ventricle after acute myocardial infarct

Abstract We calculated the QRS score using both the simplified Selvester's method and the Hills' one, extended to the 12 standard leads, from the electrocardiograms registered on the fifth and thirtieth day from the ischemic event from 50 infarcted patients whose radionuclide left ventricular ejection fraction was known. The analysis of our results showed a very good correlation existing between the early and the late scores (r = 0.91 Hillis's method) as well as the equivalence of the two methods as witnessed by a correlation coefficient of 0.86 on the fifth day electrocardiogram and of 0.84 on the thirtieth day E.C.G. However the correlation between QRS score and left ventricular ejection fraction was quite weak ranging from -0.36 to -0.48 depending upon the method and the moment selected for the acquisition of the data. Even the attempt to correctly select patients with a higher risk identifying a QRS score able to predict a reduced left ventricular ejection fraction (i.e. less than 40%) failed because of the low sensitivity and specificity of the method. We therefore believe that the QRS score or, at least the simplified one, is not useful to assess the residual left ventricular function after a myocardial infarction and its use should be reduced to the evaluation of the infarct size.