How is the diagnosis?
Medical history suggestive of the condition. At the medical examination, it is classic heart failure signs bulging veins on his neck and crackles over the lungs.
Damage to heart muscle cells gives rise to certain blood tests (cardiac enzyme such as CK-MB and troponin-I) which is also elevated in myocardial infarction. The difference is that the heart muscle inflammation keeps these blood samples is increased further. Viral and bacterial tests can confirm that the patient has recently had or have a viral or bacterial infection. ECG may show transient light rhythm with extra strokes. Life threatening arrhythmias may occur late or early in the course.
Radiographs of the chest may show diffuse enlargement of the heart shadow and fluid in the lungs. Echocardiography will immediately determine the severity and can judge the hearts pumping function. Other imaging modalities are rarely used in suspected acute myocarditis, but MRI is shown to be beneficial in some cases.
Diagnosis can be confirmed in difficult cases by taking a tissue sample (biopsy) of heart muscle tissue. The disadvantage is that inflammatory changes may be patchy in the heart, and it is not certain that the sample is taken from the inflamed tissue. Such sampling is not entirely harmless.