The purpose of this brief communication is to emphasize that serious errors can occur when the interpreter of electrocardiograms simply identifies, but does not understand, the mechanism responsible for ST-segment elevated myocardial infarction or non-ST-segment elevated myocardial infarction. Such interpretive errors may, in turn, lead to the incorrect treatment of myocardial infarction. In addition, errors of omission are made when the interpreter states what is not present (non-ST-segment elevated myocardial infarction) rather than stating what is present in the electrocardiogram. Finally, the real question is, why does properly used thrombolytic therapy or angioplasty rejuvenate injured myocytes that are located in the epicardium but do not rejuvenate injured myocytes located in the subendocardial area?