QRS Score at Presentation Electrocardiogram Is Correlated With Infarct Size and Mortality in ST-Segment Elevation Myocardial Infarction Patients Undergoing Primary Percutaneous Coronary Intervention

BACKGROUND In ST-segment elevation myocardial infarction (STEMI), QRS score at presentation ECG may reflect the progression of infarction and facilitate prediction of the degree of myocardial salvage achieved by reperfusion therapy.Methods and Results:Admission electrocardiogram (ECG) was studied in 2,607 patients with STEMI undergoing primary percutaneous coronary intervention (PCI) within 24 h of symptom onset. Patients were classified into 3 groups according to QRS score: low (0-3, n=1,227), intermediate (4-7, n=810), and high (≥8, n=570). An increase of infarct size estimated by median peak creatine phosphokinase was observed as QRS score increased (low score, 1,836 IU/L; inter-quartile range (IQR), 979-3,190 IU/L; intermediate score, 2,488 IU/L; IQR, 1,126-4,640 IU/L; high score, 3,454 IU/L; IQR, 1,759-5,639 IU/L; P