Aspartate aminotransferase is mainly found in the heart and liver, and its elevated index suggests cardiac or hepatic impairment. Aspartate aminotransferase has two isoenzymes, cytoplasmic and mitochondrial, and the cytoplasmic type is usually elevated at the beginning of the less severe injury, and the mitochondrial type is elevated in the case of severe injury or necrosis. 1. Impairment of cardiac function: elevated aspartate aminotransferase, especially mitochondrial type, may indicate acute myocardial infarction, myocarditis, pericarditis, rheumatic cardiac valvular disease and so on. 2. Liver function impairment: elevated aspartate aminotransferase may also indicate acute hepatitis, cirrhosis, viral hepatitis, liver abscess, liver tumor, etc. If the aspartate aminotransferase test result is abnormal, it is recommended to consult a doctor in time to make a clear diagnosis with the help of a doctor and carry out targeted treatment or therapy.