Myocarditis is the inflammation of myocardium, the heart muscle. It is caused due to infection by viruses and pathogen like Borrelia burgdorferi. Inflammation of the heart muscle usually results because certain regions of the pathogen may be similar to the protein myosin present in the heart muscle. As a result, the immune system attacks the protein.
Common symptoms include chest pain, fever, sweating, difficulty in breathing, irregular heartbeat and upper respiratory tract infections.