Clinically, creatine kinase (CK) is often elevated alone, and myocardial infarction is ruled out through various cardiac examinations. At this time, clinicians need to consider from many aspects and make reasonable treatment to avoid misdiagnosis and mistreatment and delay the illness.
There are many reasons for the increase of creatine kinase.
CK mainly exists in skeletal muscle, brain and myocardium. Under normal circumstances, most of CK is located in muscle cells, and the increase of CK in blood generally indicates that muscle injury has occurred or is occurring.
The increase of CK can be seen in many diseases:
1. The level of CK began to increase 2-4 hours after the acute attack of myocardial infarction, peaked at 12-48 hours, and returned to normal in 2-4 days. The degree of CK increase was basically consistent with the degree of myocardial injury. Therefore, CK can be used for the early diagnosis of acute myocardial infarction, especially for the diagnosis of myocardial ischemia and subendocardial myocardial infarction, and its sensitivity is higher than other enzyme markers. After thrombolytic therapy for myocardial infarction restored the blood flow of occluded vessels, the peak time of CK was advanced. Dynamic detection of CK changes is helpful to observe the condition and evaluate the prognosis.
2. Various myopathy (such as progressive muscular dystrophy, viral myocarditis, polymyositis, crush syndrome and other serious muscle injuries) or postoperative serum CK increased.
3. When cerebrovascular diseases, acute brain injuries, alcoholism, generalized convulsions and seizures occur, serum CK will increase. When myxoedema occurs in hypothyroidism, CK level will also increase.
Evaluation of neuromuscular diseases
CK detection plays an important role in the diagnosis and evaluation of neuromuscular diseases.
1. Suspected myopathy can be diagnosed early before other symptoms appear.
2. It is helpful to judge whether the symptoms of myasthenia come from muscle tissue itself or abnormal nerve function.
3. Various myopathy can be distinguished, such as muscular dystrophy and congenital myopathy.
4. It can be used to detect the "carriers" of neuromuscular diseases, especially the gene carriers of Duchenne muscular dystrophy. "carriers" with genetic defects will not show any symptoms themselves, but their offspring may become patients.
5. Monitor the course of some diseases (mainly inflammatory myopathy) with fluctuating conditions, or make clear the acute injury period of some metabolic myopathy.
Asymptomatic hyperccreatine kinase anemia
Chronic CK elevation is called hyperkalemia, which is occasionally seen in normal people. In 1980, Rowland called hypercapnia without clinical and histopathological evidence of neuromuscular diseases idiopathic hypercapnia.
For hypercalcemia patients with clinical symptoms of neuromuscular diseases, a definite diagnosis can generally be made by carrying out various related examinations. Those who meet the following conditions belong to asymptomatic hyperkalemia: ① occasionally found elevated serum CK; (2) Persistent high potassium for at least 3 months; ③ Mild nonspecific symptoms (occasionally mild myalgia) are asymptomatic or only found at the time of treatment; ④ No family history of neuromuscular diseases; ⑤ Lack of clinical manifestations of neuromuscular diseases related to hyperkalemia; ⑥ No heart disease (CK-MB and ECG are normal); ⑦ hypercck (malignant tumor, alcoholism and drug abuse, systemic metabolic diseases, infection, malignant hyperthermia, thyroid and parathyroid diseases, blood system diseases, pregnancy, drug side effects, etc.) is not caused by other reasons. ).
For patients diagnosed as asymptomatic hypertonia, the following tests should be performed to clarify the reasons: ① nervous system examination, especially muscle strength examination; ② CK determination of family members; ③ Blood lactic acid test, including basic state, forearm ischemia and exercise; ④ Electromyography of needle electrode; ⑤ Muscle biopsy: routine histology, various histochemical staining, immunohistochemical staining and electron microscopy were performed on the specimens.
If the results of the above system examination are still negative, it can be considered as idiopathic hyperkalemia.