Creatine phosphokinase - isoenzymes; Creatine kinase - isoenzymes; CK - isoenzymes; Heart attack - CPK; Crush - CPK DefinitionThe creatine phosphokinase (CPK) isoenzymes test measures the different forms of CPK in the blood. CPK is an enzyme found mainly in the heart, brain, and skeletal muscle. How the Test is PerformedA blood sample is needed. This may be taken from a vein. The test is called a venipuncture. If you are in the hospital, this test may be repeated over 2 or 3 days. A significant rise or fall in the total CPK or CPK isoenzymes can help your health care provider diagnose certain conditions. How to Prepare for the TestNo special preparation is needed in most cases. Tell your provider about all the medicines you are taking. Some drugs can interfere with test results. Drugs that can increase CPK measurements include the following:
This list is not all-inclusive. How the Test will FeelYou may feel slight pain when the needle is inserted to draw blood. Some people feel only a prick or stinging sensation. Afterward, there may be some throbbing. Why the Test is PerformedThis test is done if a CPK test shows that your total CPK level is elevated. CPK isoenzyme testing can help find the exact source of the damaged tissue. CPK is made of three slightly different substances:
What Abnormal Results MeanHigher-than-normal CPK-1 levels: Because CPK-1 is found mostly in the brain and lungs, injury to either of these areas can increase CPK-1 levels. Increased CPK-1 levels may be due to:
Higher-than-normal CPK-2 levels: CPK-2 levels rise 3 to 6 hours after a heart attack. If there is no further heart muscle damage, the level peaks at 12 to 24 hours and returns to normal 12 to 48 hours after tissue death. Increased CPK-2 levels may also be due to:
Higher-than-normal CPK-3 levels are most often a sign of muscle injury or muscle stress. They may be due to:
ConsiderationsFactors that can affect test results include cardiac catheterization, intramuscular injections, recent surgery, and vigorous and prolonged exercise or immobilization. Isoenzyme testing for specific conditions is about 90% accurate. ReferencesHabib G. Cardiology. In: Harward MP, ed. Medical Secrets. 6th ed. Philadelphia, PA: Elsevier; 2019:chap 4. Marshall WJ, Lapsley M, Day A, Shipman K. Plasma proteins and enzymes. In: Marshall WJ, Lapsley M, Day A, Shipman K, eds. Clinical Chemistry. 9th ed. St Louis, MO: Elsevier; 2021:chap 16. Panteghini M. Serum enzymes. In: Rifai N, Chiu RWK, Young I, Burnham CD, Wittwer CT, eds. Tietz Textbook of Laboratory Medicine. 7th ed. St Louis, MO: Elsevier; 2023:chap 32. Pincus MR, Carty RP. Clinical enzymology. In: McPherson RA, Pincus MR, eds. Henry's Clinical Diagnosis and Management by Laboratory Methods. 24th ed. Philadelphia, PA: Elsevier; 2022:chap 21. | |
| |
Review Date: 1/1/2023 Reviewed By: Michael A. Chen, MD, PhD, Associate Professor of Medicine, Division of Cardiology, Harborview Medical Center, University of Washington Medical School, Seattle, WA. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team. The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed medical professional should be consulted for diagnosis and treatment of any and all medical conditions. Links to other sites are provided for information only -- they do not constitute endorsements of those other sites. No warranty of any kind, either expressed or implied, is made as to the accuracy, reliability, timeliness, or correctness of any translations made by a third-party service of the information provided herein into any other language. © 1997- A.D.A.M., a business unit of Ebix, Inc. Any duplication or distribution of the information contained herein is strictly prohibited. | |
| |
Blood test
