Increased myoglobin is one of the three items of myocardial infarction, and if it is accompanied by significant ST-segment elevation on the ECG, acute myocardial infarction is considered and emergency coronary angiography with stenting is recommended. Myoglobin can be elevated within two hours in patients with myocardial infarction, while troponin takes until 4-6 hours to change. Only if myoglobin is elevated with ST-segment elevation, emergency coronary angiography is recommended. If myoglobin is elevated with significant ST-segment depression on the ECG, a repeat infarct triple test is recommended after 4-6 hours. If there is an increase in troponin, non-ST-segment elevation myocardial infarction should be considered and treated with anticoagulation, antiplatelet and coronary dilation. In addition, increased myoglobin, excessive strenuous exercise and muscle spasm may also be suggested.