[Myocarditis].

Myocarditis is an inflammatory disease of the cardiac muscle caused by intramyocardial infiltration of immunocompetent cells following any kind of cardiac injury. Classic myocarditis mainly occurs by the host's immune response against organisms that cause common infectious illnesses, as a manifestation of hypersensitivity or as toxic reaction to drug administration. Chronic inflammatory events may survive successful clearance of initial cardiotoxic agents, be triggered or amplified by autoimmunologic processes, or develop in the context of systemic diseases. In many cases, however, the cause of inflammatory changes, which may spread from a focus or be diffused throughout the cardiac muscle, remains unclear. Since clinical and histologic classification criteria of myocarditis alone are unsuitable for a clinically useful classification of inflammatory cardiac muscle disease, only the combination of clinical and histologic methods with immunohistochemical characterization of the inflammatory process and molecular biology virus detection ensure a reliable diagnosis and subsequent indication of specific treatment options.