CPK Isoenzymes Test

CPK values help to diagnose muscle injuries. CPK consists of 3 different enzymes that gives an idea about the exact source of muscle injury. 

• CPK-MB that measures the injury to the cardiac muscles like in case of a heart attack or myocarditis.
• CPK- BB that measures lung or brain injury. 
• CPK-MM that measures the skeletal muscle injury like in polymyositis or severe muscle injuries or surgeries.

In case of a heart attack, CPK values peak after few hours which helps to know the approximate time of the attack.

cpk isoenzymes test measures the level of various components of Creatinine Phosphokinase (CPK) in the blood like CPK-MM, CPK-MB and CPK-BB.

The test measures the different forms of CPK Isoenzymes in the bloodstream. 

CPK isoenzymes test requires a blood sample. A tourniquet (elastic) band is placed tightly on the upper arm. The patient is then asked to make a fist. This helps in the build-up of blood filling the veins. The skin is disinfected before needle insertion and the blood sample is collected in vacutainer. 

healthcare provider will take your blood sample. An elastic band gets tightly tied to the upper arm. You have to tighten your fist. Your skin gets disinfected with cotton soaked in alcohol. The healthcare provider inserts the needle into your vein just above your elbow to collect your blood. The blood will then gets poured into a serum separator tube. You may feel a prick when the needle enters and exits your vein. The healthcare provider then puts clean cotton over the punctured area. The provider will ask you to fold your elbow and hold it for a minute or two. Then a tiny bandaid is used to cover the punctured wound

High levels of CPK-MB  along with other parameters are indicative of a myocardial infarction (heart attack). These levels peak after 3-6 hours and if no further injury, return to normal within 24-48 hours.
High CPK-BB levels may indicate brain injuries or lung damage (pulmonary infarction).
High CPK-MM may occur due to skeletal muscle injuries and muscle disorders.

There is no preparation required for the CPK Isoenzymes test.

Total CPK Isozymes gets measured in mcg/L. The ranges are mentioned below.

CPK Isozymes Total:

Normal: 10 to 120 mcg/L

Severely high: More than 5000 IU/L

CPK Total in males:

Normal range: 39 to 308 U/L

CPK Total in females:

Normal range: 26 to 192 U/L

Creatinine phosphokinase - MB helps in the diagnosis of a recent heart attack.

Conditions that may require CPK Isoenzymes test are as follows:

• Heart attack
• Chest pain
• Heart muscle damage
• Muscular tissue damage
• Inflammatory disease of the skin and muscles
• Inflammatory disease causing muscular weakness
• Over-exercising
• Prolonged seizures
• Certain medications

If your doctor predicts a heart condition, another test that may be ordered along with CPK Isoenzymes is:

• Troponin test:

Troponin is a type of protein present in the heart muscle.

When your heart gets damaged, Troponin gets released into the bloodstream. The Troponin test measures the levels of Troponin T and Troponin I in your bloodstream, thus indicating heart muscle damage.

Creatine Phosphokinase Test

CPK Enzyme Test with Fractions (%)

Creatine Kinase with Isoenzymes

CPK-MM

CPK-BB

CPK-MB