Viral Myocarditis: Clinical and Paraclinical Diagnosis

Myocarditis is an inflammatory disease of the myocardium, that can be produced by a multitude of infectious or noninfectious agents. The incidence rate of the disease is between 10 to 22 per 100,000 individuals. Among the infectious causes, viruses are considered to be the most frequent pathogens. Regarding the clinical presentation, viral myocarditis may have a wide variety of manifestations, ranging from asymptomatic disease to chest pain, myalgia, fatigue, heart failure, arrhythmias and, in some cases, sudden death. A definitive diagnosis of viral myocarditis involves histological evidence for myocarditis associated with positive viral polymerase chain reaction (PCR). Endomyocardial biopsy represents the gold standard for diagnosis; in the absence of histological, immunologic and immunohistochemical criteria, a definitive diagnosis cannot be established.