Myocarditis, or inflammation of the heart muscle, is a type of cardiomyopathy that occurs as a rare complication of an infection, usually caused by a virus. In mild cases, the only symptoms may be slight chest pain, shortness of breath, and a rapid pulse. In more severe cases, such as those caused by diphtheria, myocarditis can lead to heart failure, third-degree heart block, or death.
Myocarditis is usually caused by a virus, for which there is no specific treatment. The doctor will recommend complete rest. In some cases, a doctor will prescribe a corticosteroid drug to reduce inflammation.