Value of the terminal QRS distortion in the admission electrocardiogram compared to several clinical and electrocardiographs parameters in predicting myocardial infarction size, and final scar size

ABSTRACT

The major determinants of short and long-term prognosis after myocardial infarction [MI] are MI size as well as the final scar size. Clinical and electrocardiographic [ECG], admission variables were studied in 60 consecutive patients admitted with their first acute anterior ST-segment elevation MI of <6 hours duration. Predischarge low-dose dobutamine stress echo was done to the patients unless contraindicated to measure MI size [Resting wall motion score index; WMSI] and final scar size [low-dose WMSI]. Out of the 19 variables studied only 4 variables were significant univariate predictors of both MI size and scar size; QRS distortion, higher Killip class, number of leads with ST segment elevation and Selvester score. Other 3 variables predicted only MI size; history of chronic stable angina, sum of ST elevation, and maximum creatinine kinase level. Of the admission variables, the multivariate predictors of larger MI size were QRS distortion and higher baseline Killip class. For scar size the only multivariate predictor was Killip class. The pre-discharge multivariate model added Selvester score to the above admission variables as a significant multivariable predictor to both MI and scar sizes. The presence of QRS distortion in the admission ECG can independently predict large MI ALT but not essentially a large final scar size. Both can be independently predicted by the admission Killip class as well as by Selvester score in the predischarge ECG