What does it mean when creatine kinase MB is elevated but total creatine kinase is normal?

Under normal circumstances, elevated creatine kinase-MB (CK-MB) with normal total creatine kinase levels may be caused by intense exercise, pregnancy, myocarditis, acute myocardial ischemia, or acute myocardial infarction. If discomfort occurs, it is recommended to seek medical attention promptly. The specific analysis is as follows:

1. Intense Exercise

During intense physical activity, muscle tissues are strongly stimulated, which may cause CK-MB to be released from muscle cells into the bloodstream, leading to elevated CK-MB levels. This phenomenon is usually temporary and does not significantly affect total creatine kinase levels. It is recommended to rest appropriately and avoid consecutive high-intensity exercise.

2. Pregnancy

During pregnancy, physiological changes in the mother's body may lead to a slight increase in CK-MB. However, this typically does not raise clinical concern, as total creatine kinase remains within the normal range. Regular prenatal checkups are advised to monitor maternal and fetal health, along with following medical guidance for proper pregnancy management.

3. Myocarditis

Bacterial infections may trigger myocarditis, and the resulting inflammatory response can lead to the release of CK-MB into the blood, causing elevated CK-MB levels. However, since myocarditis may only affect a portion of heart muscle cells, total creatine kinase levels may remain normal. Symptoms may include chest pain and shortness of breath. It is recommended to follow a physician’s guidance and use medications such as Guanxin Danshen Dropping Pills, Wenxin Granules, or Ribavirin Granules for treatment.

4. Acute Myocardial Ischemia

When heart muscle cells suffer from oxygen deprivation, acute myocardial ischemia may occur, leading to the release of large amounts of CK-MB into the bloodstream and resulting in elevated CK-MB levels. Depending on the severity and duration of ischemia, total creatine kinase levels may remain normal. Symptoms may include chest tightness and shortness of breath. Under medical supervision, medications such as Warfarin Sodium Tablets, Aspirin Enteric-coated Sustained-release Tablets, or Clopidogrel Hydrogen Sulfate Tablets may be prescribed.

5. Acute Myocardial Infarction

Excessive fatigue or emotional stress may lead to acute myocardial infarction, causing a rapid release of large amounts of CK-MB into the blood and resulting in elevated CK-MB levels. Since the infarction may be localized to a specific area, total creatine kinase levels might remain normal. Common symptoms include chest tightness and a sense of impending doom. Treatment should follow medical advice and may include medications such as Heparin Sodium Injection, Lidocaine Hydrochloride Injection, or Dopamine Hydrochloride Injection.

In daily life, appropriate physical exercise can be increased to enhance physical strength and boost immune function.