CK-MB (Creatine Kinase - Muscle Brain)

The CK-MB (Creatine Kinase - Muscle Brain) test is used to identify whether a patient has experienced a recent myocardial infarction (heart attack). Since CK-MB is an enzyme found mostly in heart muscle cells, its presence in the bloodstream serves as a specific cardiac marker that rises when the heart is damaged. It is particularly helpful for clinicians because it begins to increase within 4 to 6 hours of a heart injury and typically returns to normal within 48 to 72 hours. This specific timeline allows doctors to not only diagnose an initial heart attack but also to detect a re-infarction (a second heart attack) occurring shortly after the first, which other markers might miss.