The electrocardiogram (ECG) remains the most accessible and inexpensive diagnostic tool to evaluate the patient presenting with symptoms suggestive of acute myocardial ischemia. It plays a crucial role in decision making about the aggressiveness of therapy especially in relation to reperfusion therapy, because such therapy has resulted in a considerable reduction in mortality from acute myocardial infarction. Several factors play a role in the amount of myocardial tissue that can be salvaged by reperfusion therapy, such as the time interval between onset of coronary occlusion and reperfusion,...