Examinations
Examinations
AST is an intracellular enzyme involved in amino acid metabolism. It plays a role in diagnosing liver, heart, and skeletal muscle damage. In cells, there are two isomers of AST: mitochondrial and cytoplasmic. Two-thirds of total AST activity is located in mitochondria, while one-third is in the cytoplasm. AST activity in the myocardium is 10,000 times higher than in the blood, making it one of the most rapidly increasing markers during a heart attack. ALT, in contrast, shows only slight elevation during a heart attack, which causes the De Ritis ratio (AST/ALT ratio) to increase significantly.
In liver cell damage, AST levels rise along with ALT; however, ALT is considered more specific to the liver. AST levels may increase up to 8 times in progressive muscular dystrophy and dermatomyositis but remain normal in other muscle pathologies.
- The test requires a blood sample taken from a vein.
- The analysis should be performed after 8–14 hours of fasting.
- It can also be done 4 hours after a light meal.
- Avoid high emotional stress and physical activity before the test.
- Differential diagnosis of myocardial infarction and other heart muscle disorders
- Liver diseases
- Skeletal muscle pathologies
- Monitoring the effects of medications
Increased AST Levels
- Myocardial infarction
- Acute rheumatic carditis
- Pulmonary artery thromboembolism
- Heart surgery
- Hepatitis of various etiologies (viral, alcohol, toxic)
- Angina attacks
- Cholestasis
- Skeletal muscle injuries
- Myopathy
- Acute pancreatitis
- Liver cancer
Decreased AST Levels
- Severe necrotic processes and liver degeneration
- Vitamin B6 deficiency