PREDICTION AT THE INFARCT-RELATED ARTERY IN ACUTE MYOCARDIAL-INFARCTION BY A SCORING SYSTEM USING SUMMARY ST-SEGMENT AND T-WAVE CHANGES

We developed a scoring system to predict the artery responsible for an acute myocardial infarction (AMI) using ST-segment and T-wave changes on the initial electrocardiogram (ECG) using data from 228 patients ( development set) with symptoms compatible with AMI and tested in a sim ilar group of 223 patients (test set) from the Thrombolysis and Angiop lasty in Myocardial Infarction (TAMI-5) Trial. Using stepwise logistic regression we were able to accurately predict the left anterior desce nding (LAD), right, or left circumflex (LC) coronary artery as the inf arct-related artery using 2 variables: (1) the summation of the ST-seg ment elevation in leads V-1 to V-4; and (2) the summation of the T-wav e negativity in leads I, aVL, and V-5 In the development set, these 2 variables demonstrated respective sensitivity and specificity of: 98% and 90% for LAD lesions, 82% and 85% for right narrowings, and 82% and 84% for LC narrowings. In the test set, the sensitivity and specifici ty were 97% and 95% for LAD lesions, 85% and 86% for right lesions, an d 73% and 60% for LC coronary artery lesions. Information easily obtai ned on the ECG can accurately predict the likelihood of the LAD, right , or LC artery as the infarct-related artery, This may be useful in th e decision to administer thrombolytic treatment.