The document provides criteria for diagnosing ST-elevation myocardial infarction (STEMI) on electrocardiogram (ECG). It lists cut-off values for ST elevation in different leads used to identify STEMI based on the patient's age, sex and lead location. It cautions that baseline ECG abnormalities like left bundle branch block (LBBB) could obscure interpretation and provides examples of STEMI in different heart locations identified by affected leads on ECG.