Molecular diagnosis of the viral component in cardiomyopathies: pathophysiological, clinical and therapeutic implications

Background: Myocarditis is defined as the inflammation of myocardium associated with cardiac dysfunction. Despite this clear-cut definition, diagnosis and etiologic treatment continue to create considerable debate. Viral infections are frequent causes of myocarditis and there is evidence that persistent viral infection is associated with poor prognosis in different subtypes of cardiomyopathy. Objective: To review methods for diagnosis of viral myocarditis and present the use of polymerase chain reaction (PCR)–based protocols for evaluating viral infection in myocarditis/cardiomyopathies. Methods: A review of published literature. Results/conclusion: There is increasing evidence that PCR-based protocols can provide reliable molecular evidence for the presence of viral infection in myocardium. Thus application of molecular techniques will allow collection and analysis of more information on the epidemiology of viral cardiomyopathies, patient risk stratification and appropriate medical treatment.