The 18-lead ECG is commonly used in patients with acute myocardial infarction, especially in patients with suspected acute posterior wall and right ventricular myocardial infarction. 18-lead ECG has 6 additional leads compared to the conventional ECG, and the 6 leads correspond to the right ventricle and posterior wall of the heart. This helps the physician to better detect the occurrence of posterior wall and right ventricular myocardial infarction and guides the physician’s judgment of the offender’s vascularity. In most hospitals, there is no special machine to do 18-lead ECG, but a 12-lead ECG is done first, and then the chest leads are rearranged and the two are combined into an 18-lead ECG.