The aim of a study published in Emergency was to evaluate the prevalence of ST segment changes in lead aVR, and its association with the outcome of these patients. This retrospective cross sectional study analyzed medical profiles of 288 patients admitted to the emergency department with a final diagnosis of myocardial infarction (MI), in a 4-year period. Among these, 79.2% were males. It was found that 58.3% patients exhibited ST segment changes. On the other hand, no significant relationship could be established between presence of ST changes in lead aVR with infarct location, number of vessels involved, and ejection fraction on admission. However, ST elevation ≥ 1 mv in lead aVR had a significant correlation with mortality. Sensitivity, specificity, positive and negative predictive values and positive and negative likelihood ratios of ST elevation ≥ 1 for prediction of in-hospital mortality were 41.66, 91.53, 31.25, 94.44, 0.45, and 0.05, respectively. In summary, it was stated that the prevalence of ST segment changes in lead aVR was estimated to be 58.3%. There was no significant relationship between these changes and the number of vessels involved in angiography, infarct location and cardiac ejection fraction. Whereas, the presence of ST elevation ≥ 1 in lead aVR was associated with eight-fold increase in the risk of in-hospital mortality.