Post-infectious myocarditis is a condition where the symptoms of infectious myocarditis continue after the bacteria or virus causing the myocarditis has been removed from the body. A virus or bacterium causes disease-fighting cells to respond to the infection. These cells sometimes enter the heart and release chemicals that can damage the heart muscle and cause inflammation, resulting in myocarditis. As a result, the heart may become thick, swollen, and weak. If the myocarditis does not go away after the infection has been completely treated, the condition is called post-infectious myocarditis. Myocarditis may often have no symptoms, but some potential signs include shortness of breath, chest pain, swelling of the ankles, fatigue, and risk of heart failure. In order to prevent or treat post-infectious myocarditis, seek immediate medical attention if you have an infection.