Inflammation of the heart muscle - blood tests
introduction
Blood values in the case of an inflammation of the heart muscle give the doctor an opportunity to assess what is going on in the body. The heart as an internal organ cannot be viewed directly, but only indirectly checked for its condition. However, a combination of certain laboratory parameters gives clues or very strong clues as to the underlying disease in the body. An unequivocal diagnosis cannot be ensured on the basis of the blood values alone, but the probability of a correct diagnosis can be increased further and further by combining blood values with other examination methods.
Read about this too How do you recognize myocarditis?
Can you have myocarditis if your blood values are normal?
Heart muscle inflammation despite normal values is definitely possible, although very unlikely. As is so often the case, a principle of medicine applies here that can be applied almost everywhere: there is nothing that does not exist. As already described, some increases in blood values only occur with a certain time delay, whereas some can only be measured in pathological concentrations in a relatively short time window.
Which blood values indicate a heart muscle inflammation?
As one can already see from the term heart muscle inflammation, a reliable diagnosis needs blood values that reflect both the inflammation and the affected organ in the body, i.e. the heart. The most heart-specific blood value currently available for diagnostics is troponin I. This protein is usually almost completely absent in the blood, so that an increased occurrence in the patient's blood is always in need of clarification. However, the troponin is only detectable in the blood 3-6 hours after the damage to the heart muscle cells, which is why blood is always drawn twice with an interval of at least four hours if a heart disease is suspected. The two most distinctive values to detect inflammation are the white blood cell count and the value of the C reactive protein (CRP for short). The white blood cell count is part of every small blood count and, if it is increased, provides a very strong indication of inflammation. The determination of the CRP, on the other hand, does not belong to the small blood count, but is considered a very meaningful value, the level of which allows conclusions to be drawn about the reason for the inflammation or infection.
In order to be able to use the white blood cell count to estimate what could be the cause of the myocardial inflammation, however, the various components of the white blood cells must be determined, for which a separate blood test is also required.
Troponin T / I
Troponins are another protein from muscle cells, whereby the isoform troponin I and troponin T are heart muscle-specific. An increase in troponins in the blood can be detected three to six hours after the damage to the heart muscle cells, with the maximum concentration only being reached after about four days. Troponin I and T are regarded as the most specific markers for cardiac muscle damage and are determined several times in the course of a cardiac problem in order to be able to estimate the course of the concentration. In addition, the level of the troponin concentration correlates with the patient's disease prognosis.
Read more on this topic at: Troponin
C-reactive protein (CRP)
C-reactive protein (CRP) is a protein synthesized by the body and made by the liver. Scientifically it has been found that the CRP value increases after about 6 hours in the course of an inflammation. The exact connection between inflammation and increased production has not yet been clarified. However, almost every inflammation is accompanied by an increase in CRP, so this value is very reliable, but cannot provide any information about the location of the inflammation. In the case of bacterial infections, the increase in the CRP value is significantly higher than in the case of viral inflammation. The normal value is below 1mg / dL.
Read more about C-reactive protein below CRP value.
Creatine kinase
Creatine kinase is a protein that occurs in all body muscles and is released into the blood when these muscle cells are damaged. Today we know three different forms of creatine kinase, of which the heart muscle-specific CK-MB can be determined individually. But the total mass of creatine kinase in the blood can also be determined and is primarily an indicator of damage to muscle tissue. Which tissue is affected can only be determined with an accurate determination of the various forms of creatine kinase.
More information can be found here: The creatine kinase
CK MB
Creatine kinase-MB (CK-MB) is a subgroup of creatine kinases. The proportion of CK-MB in the heart muscle is proportionally the greatest, so that it is only released into the blood when there is damage to heart muscle tissue, which ensures a detectable increase . This value is therefore relatively heart-specific and is included as standard in the diagnosis of heart muscle damage.
Lactate dehydrogenase
Lactate dehydrogenase is an enzyme that is found in almost all body cells and plays a role in the energy production process from sugars. An increased value of the LDH stands for an increased cell death in the body. Using the enzyme, however, it is not possible to localize the point at which cells die. The normal range for lactate dehydrogenase is between 260 and 500 units per liter, i.e. units per liter of blood plasma.
Glutamate Oxaloacetate Transaminase (GOT)
Glutamate oxaloacetate transaminase is another protein that is found in certain cells in the body, namely in liver cells as well as in heart and skeletal muscle cells. An increase in the GOT value or the ASAT value (ASAT is used synonymously for GOT) is therefore not a specific indicator of myocardial inflammation, but it can be an indication to examine further heart-specific blood values.
White blood cells
The so-called white blood cells are typically increased in all types of inflammation. Depending on the cause of the inflammation, different fractions of white blood cells are increased. While bacterial inflammation of the heart muscle (myocardites) causes an increase in granulocytes, viruses increase the number of lymphocytes. The normal range for white blood cells is between 4000 and 10,000 per mm³ or µl.
Read more about this under White blood cells.
Erythrocyte sedimentation rate (ESR)
The rate of sedimentation of the blood cells (ESR for short) measures within one and after two hours by how much the blood cell components decrease. The speed of this lowering is then determined.
It is also an inflammation marker that is elevated when there is an inflammatory process in the body. The advantage of the ESR determination is that the blood does not have to be sent to a special laboratory, but can also be collected in any doctor's practice that has the appropriate blood collection tubes. The disadvantage of the sedimentation rate, however, is that the normal value covers a relatively broad spectrum and is therefore very unspecific.
Determination of virus types
Virus serology is a type of screening test for the presence of certain types of virus in the patient's blood. Since infectious myocarditis is viral in about 50% of cases, this test can be used if the cause of the myocarditis cannot be clearly identified. The most common viruses are Coxsackie viruses, but influenza viruses can also be responsible for an infectious heart muscle inflammation.
Detection of auto-antibodies
A detection of auto-antibodies can be a further explanation for the origin of the heart muscle inflammation (myocarditis). In the sense of a so-called autoimmune disease, these antibodies are directed against the body's own structures. So the body is subconsciously harming itself. There are a number of antibodies that the blood can be tested for. In relative terms, autoimmune diseases are rather rare as a cause of myocardial inflammation and should only be considered if the condition cannot really be explained otherwise, as these examinations are very cost-intensive.
Read more on the subject here Autoimmune disease.
