Enzymes are chemicals that help control different reactions in your body. There are many blood enzyme tests. This section focuses on blood enzyme tests used to check for heart attack. These include creatine kinase (CK) and troponin tests.

Creatine Kinase
When muscle or heart cells are injured, CK (a blood product) leaks out, and its levels in your blood rise. There are different types of CK. CK-MB is released when the heart muscle is damaged. High CK levels can mean that you've had muscle damage in your body. High levels of CK-MB can mean that you've had a heart attack. Doctors order CK tests (such as CK-MB) when patients have chest pain or other heart attack signs and symptoms.

Troponin
This is a muscle protein that helps your muscles contract. Blood levels of troponin rise when you have a heart attack. For this reason, doctors often order troponin tests along with CK-MB tests when patients have chest pain or other heart attack signs and symptoms.