Diagnosis | Heart muscle inflammation

Diagnosis

In order to confirm the diagnosis “heart muscle inflammation”, various examinations may be necessary:

• Anamnesis: First, the patient is asked about his current complaints and his previous medical history. In the foreground here are, for example, recently experienced flu-like infections or fever attacks
• Resting ECG: deviations can be an indication of myocarditis
• Blood tests: Typical are e.g. increased inflammation values and special heart muscle enzymes
• Echocardiography: Reduced heart function can be made visible
• Imaging techniques: X-ray or heart MRI provide an overview of the extent of the inflammation
• Biopsy: In particularly severe cases, a tiny tissue sample from the heart may be necessary

In many cases, inflammation of the heart muscle leads to increased levels of inflammation in the blood. These include CRP (C-reactive protein), BSG (blood cell sedimentation rate) and leukocytes (white blood cells).

However, the values mentioned do not necessarily have to be elevated! Conversely, elevated inflammation values alone do not constitute sufficient evidence for a diagnosis. Furthermore, the levels of CRP, BSG and leukocytes do not reflect the severity of myocardial inflammation.

Particularly in the initial phase, an increase in cardiac enzymes in the blood can still frequently be measured: If the heart muscle is damaged by, for example, an inflammation, it releases increased amounts of the enzyme creatine kinase-MB (CK-MB). However, the enzyme creatine kinase is also found in other forms, including the brain and skeletal muscle. To be able to make a more precise statement, the troponin T/1 concentration in the blood is therefore often measured.

Troponin-T/1 is a protein that is normally found inside heart muscle cells. If the cells are damaged, it is released into the blood and can be detected there. Recently, so-called myocardial antibodies can also be determined in suspected cases of heart muscle inflammation.

These are small, endogenous proteins that can be detected, especially in cases of viral causes. In addition, the blood can be examined for individual, disease-causing viruses (e.g. Coxsackie A+B, influenza A+B, adeno-, hepatitis-, herpes-, or polio viruses). By means of an electrocardiogram (ECG), statements can be made about rhythm, activity, frequency and type of location of the heart.

In principle, any type of rhythm disturbance can occur in the case of heart muscle inflammation, depending on which part of the heart is affected. They are therefore also referred to as non-specific. Observable changes in the ECG may include, for example

• Supraventricular extrasystoles: Beats outside or in addition to the normal heart rhythm, originating in the atrium
• Ventricular extrasystoles: Beats outside or in addition to the normal heart rhythm
• Tachycardia: Heart rate over 100 beats/minute
• Arrhythmias: Atrial fibrillation, v-fib.

  Characteristic is an irregular, usually too fast (tachycardic) heartbeat. Depending on where the cause of the irregular frequency lies, a distinction is made between ventricular and atrial fibrillation

• T-shaft lowering, ST-segment changes: If the T-wave or ST segment changes in the ECG, this may be an indication of reduced blood flow (ischemia) in parts of the heart

An MRI of the heart is particularly suitable for characterizing the severity of myocardial inflammation. First indications are wall movement disorders and restrictions of the pump function.

By means of an MRI, the contractile force, i.e. the force with which the heart muscles contract, can be displayed. This provides valuable information about the functioning of the muscles. The more restricted the pump function is, the greater the inflammation of the heart muscle. A further assessment of myocardial inflammation can be made by imaging a cardiac edema. This water retention is also particularly well visible on the MRI