Cardiac enzyme tests are done in hospitals and doctors' offices, not at home, as WebMD explains. These tests, which measure enzymes in the heart to determine the extent of any damage, involve drawing blood and are typically repeated many times across several hours.
High levels of the enzyme creatine kinase, as well as of the protein troponin, indicate potential damage to the heart. Doctors often perform cardiac enzyme tests to determine if a heart attack is occurring or is likely to occur in the near future, according to WebMD. Because many other factors, including medications taken or the existence of other diseases, can affect the test results, doctors must always evaluate cardiac enzyme tests in the light of other test findings and symptoms.