Understanding the CK-MB Blood Test: Calculation & Significance

CK-MB is an abbreviation for the Creatine Kinase-MB blood test. Levels of CK-MB in your blood rise when there is injury to the heart muscle. The higher the level of CK-MB, the more damage there has probably been. The CK-MB lab test is part of a group of tests that examine cardiac enzymes. Following a heart attack, these enzymes will increase. The CK-MB ratio is calculated through a simple mathematical equation. This ratio indicates how much muscle damage is related specifically to the heart muscle, as opposed to other muscles in the body.

Things You'll Need

• CK laboratory value
• CK-MB laboratory value

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Instructions

• 1

  Obtain your CK value from laboratory test results. This number reflects the level of creatine kinase, which is an enzyme found in all muscles, not just the heart muscle. Therefore, elevated CK values could be caused by damage to any muscle in your body.

• 2

  Obtain your CK-MB level from laboratory test results. The CK-MB is a more specific indicator of damage to the heart muscle alone.

• 3

  Divide the CK-MB value by the CK value to obtain the CK-MB ratio. Multiply your answer by 100 to obtain a percentage.

• 4

  Compare the percentage with standard laboratory reference ranges. If your CK-MB percentage is higher than 3 percent, cardiac damage is most likely present.