Early diagnosis is key to preventing long-term heart damage. After a physical examination, your doctor might order one or more tests to confirm that you have myocarditis and determine its severity. Tests might include:
- Electrocardiogram (ECG). This noninvasive test shows your heart's electrical patterns and can detect abnormal rhythms.
- Chest X-ray. An X-ray image shows the size and shape of your heart, as well as whether you have fluid in or around the heart that might indicate heart failure.
- MRI. Cardiac MRI will show your heart's size, shape and structure. This test can show signs of inflammation of the heart muscle.
- Echocardiogram. Sound waves create moving images of the beating heart. An echocardiogram might detect enlargement of your heart, poor pumping function, valve problems, a clot within the heart or fluid around your heart.
- Blood tests. These measure white and red blood cell counts, as well as levels of certain enzymes that indicate damage to your heart muscle. Blood tests can also detect antibodies against viruses and other organisms that might indicate a myocarditis-related infection.
- Cardiac catheterization and endomyocardial biopsy. A small tube (catheter) is inserted into a vein in your leg or neck and threaded into your heart. In some cases, doctors use a special instrument to remove a tiny sample of heart muscle tissue (biopsy) for analysis in the lab to check for inflammation or infection.