The predischarge electrocardiographic pattern in anterior acute myocardial infarction: Relation between evolutionary ST segment and T-wave configuration and prediction of myocardial infarct size and left ventricular systolic function by the QRS selvester score

Abstract

Left ventricular systolic function, determined mainly by final infarct size, has a major influence on prognosis after acute myocardial infarction (MI). It was found that infarct size and left ventricular ejection fraction can be predicted using the Selvester QRS-score in patients not receiving reperfusion therapy. We assessed whether the predischarge QRS-score can be used for estimating infarct size and left ventricular ejection fraction in 51 patients with a first anterior MI who had received reperfusion therapy and whether considering the configuration of the ST-segments and T-waves will increase the accuracy of these predictions. All patients had received reperfusion therapy and had predischarge resting 99mtTc-sestamibi scan. We determined the Selvester QRS score using the electrocardiograms performed on the same day of the scan. In addition, we divided the patients into 3 groups: A: isoelectric ST and negative T-waves (n=12); B: ST elevation (≥0.1 mV) and negative T-waves (n=23); and C:ST elevation (≥0.1 mV) and positive T-waves (n=16). The myocardial perfusion defect extent increased from group A to C (28.5±16.4%, 39.4±14.8%, and 45.3±15.8% in groups A, B, and C, respectively; P=.022). Similarly, the left ventricular ejection fraction decreased (41.7±11.6%, 38.4±8.1%, and 32.0±9.7%, respectively; P=.042) from group A to C. Overall, the correlation between the QRS-score and the myocardial perfusion defect extent (Rho=0.249; P=.08), and ejection fraction (Rho=−0.229; P=.11) was not good. A statistically significant correlation between the myocardial perfusion defect size and the ORS-score was found only in group A (Rho=0.599, P=.04). In patients with a first anterior myocardial infarction who underwent reperfusion therapy, the predischarge QRS-score is predictive of infarct size only in those in whom ST elevation resolved completely. In patients with residual ST elevation the Selvester QRS-score is inaccurate in predicting infarct size and left ventricular ejection fraction upon discharge.