Exams and Tests

Myocarditis is usually suspected based on the patient's story and physical exam. Cardiac imaging tests can help confirm the presence of myocarditis and the extent of the inflammation. These may include:

• Electrocardiogram (ECG) to measure the electrical activity of the heart and detect any abnormal heart rhythms
• Chest X-ray to show pictures of the heart, lungs, airways, and bones
• Echocardiogram to take a closer look at the structures of the heart and its pumping function
• Heart MRI to look at the structure of the heart and and for signs of inflammation or injury

Blood tests can also help diagnose myocarditis. These may include tests to check for:

• Damage to the heart tissue (troponin) or other muscle tissue in the body (creatinine kinase, or CK)
• High levels of inflammation in the body, such as C-reactive protein (CRP) or erythrocyte sedimentation rate (ESR or SED rate)
• Infection, which may include a complete blood count (CBC) and blood cultures to see if the infection is in the bloodstream
• Liver and kidney function

A biopsy to take a piece of tissue from the heart and examine it is the most definitive way to detect myocarditis. Because there are risks associated with this procedure, it is usually reserved for patients in whom a diagnosis using the heart tissue itself would help to define the best treatment approach. The risks and benefits should be discussed as part of the decision-making process.