Diagnosis of viral cardiomyopathy by analysis of peripheral blood?

Polymerase chain reaction testing has become an important tool in assessing the role of virus in inflammatory cardiomyopathies, including fulminant myocarditis, lymphocytic myocarditis, peripartum cardiomyopathy, unknown cause or idiopathic dilated cardiomyopathy, and acute myocarditis of suspected viral etiology. While this tool has been traditionally reserved for application to endomyocardial biopsy tissue, there is increasing evidence that it may also be helpful in the study of peripheral blood samples, particularly during the viremic phase when there may also be IgM antibodies present against one or more of the cardiotropic viruses.