Electrocardiographic evolution after Q-wave anterior myocardial infarction: Correlations between QRS score and changes in left ventricular perfusion and function

Background. In the thrombolytic era, conflicting data have been reported on the usefulness of the QRS score in estimating the amount of left ventricul ar (LV) damage after acute myocardial infarction (MI). Methods and Results. We correlated the QRS score with the extent of LV hypo perfusion and ejection fraction (EF) in 95 consecutive male patients with a first anterior Q-wave MI; the 6-month evolution of QRS score and changes i n LV perfusion and function were also compared. The Selvester-Wagner QRS sc ore was computed from the digitized 12-lead electrocardiogram, both at pred ischarge and 6 months later; at the same time, resting sestamibi first-pass ventriculography and single photon emission computed tomography imaging we re performed. A reduction in QRS score occurred at 6 months (6.7 +/-3.4 vs 7.8 +/-2.9 at predischarge; P<.001); the perfusion defect extent also decre ased (P<.01), and LV EF improved (P<.05). At predischarge, no correlation w as found between QRS score and hypoperfusion extent or EF; in contrast, a w eak correlation was observed 6 months later (r=0.55; P<.001; and r=0.48; P< .01, respectively). QRS score changes from predischarge to 6 months showed limited accuracy in predicting clinically meaningful changes of perfusion o r EF (receiver operating characteristic area under the curve, 0.58 and 0.61 , respectively). Thrombolytic therapy did not influence the relationship be tween QRS score and scintigraphic findings. Conclusions. In patients with recent anterior Q-wave MI, QRS scoring showed a weak, delayed correlation with the amount of LV damage, as estimated by radionuclide techniques. Spontaneous changes in QRS score from predischarge to 6 months seem to be of limited value in identifying patients with late improvement in LV perfusion and function.