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Serum Creatinine Phosphokinase Isoenzyme MB (CPK-MB)

Published: August 9, 2026Updated: August 16, 2026

This test measures a specific form of the enzyme creatine phosphokinase (CPK), which is found in heart muscle and some blood cells. It helps assess damage to heart tissue after events like a heart attack.

Quick summary

["CPK-MB helps identify heart muscle injury and guides treatment decisions."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
23703-2
Short code
CPV IgG Titr Ser
Synonyms
CPV IgG Titr Ser
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Ref low
8
Ref high
61
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
CPT
82977
SNOMED
3110003
Specimen volume
5 mL
Stability
Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
Hemolysis max
500
Lipemia max
1000
Icterus max
500
TAT
4–24 hours
Order
routine

What Is CPK-MB Used For?

CPK-MB is primarily used to diagnose and evaluate the extent of heart muscle damage caused by conditions like a heart attack (myocardial infarction). It can also help determine the severity of damage and monitor recovery. This test is often ordered alongside other cardiac markers like troponin.

How Is the Test Performed?

A blood sample is taken from a vein, usually in your arm. The sample is sent to a lab where it is analyzed to measure the CPK-MB isoenzyme levels. This process typically takes a few hours to complete.

What Are Common Results?

Results are usually reported in units per liter (U/L) or milligrams per deciliter (mg/dL), though reference ranges can vary by lab. Elevated levels of CPK-MB may indicate recent heart muscle injury.

When Might You Need This Test?

Your healthcare provider may recommend this test if you have symptoms like chest pain, shortness of breath, or other signs of heart problems. It may also be used during or after a heart attack, or in cases of suspected heart injury from conditions like a heart attack, heart surgery, or severe chest trauma.

Reference range

Adult males: 8-61 U/L; Adult females: 5-36 U/LN/A

Specimen: serum

No special preparation required. Avoid fatty meals before the test if possible.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

CPK-MB Isoenzyme

Frequently asked questions

How long does it take to get results from this test?
Results from CPK-MB tests are typically available within 24 to 48 hours, depending on lab processing times. Your healthcare provider will discuss the results with you once they are ready.
Can CPK-MB levels be affected by other conditions besides heart attacks?
Yes, CPK-MB levels can be elevated in other conditions, such as severe muscle damage (e.g., from strenuous exercise, muscle injuries, or certain medications). However, it is most specific for heart muscle injury when combined with other cardiac markers like troponin.
What should I do if my CPK-MB levels are elevated?
If your CPK-MB levels are elevated, your healthcare provider will review your symptoms, medical history, and other test results to determine the cause. Treatment may include medications to manage pain, improve heart function, or prevent further damage. Follow-up tests and monitoring may also be recommended to track recovery.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.

This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.

Medical Disclaimer

This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.

If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.

Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy