Etiological diagnosis of viral heart disease.

Myocarditis is a relatively common complication of viral infections and for example enteroviruses, influenza-viruses and adenoviruses are found in association with this disease. However, in many clinical myocarditis cases the etiology remains unknown when the present routine methods are used for viral diagnosis. The availability of myocardial biopsy samples has now made it possible to analyse the presence of viruses and viral components directly in the heart muscle. In particular the molecular methods, in situ hybridization and polymerase chain reaction (PCR), have recently given promising results. Furthermore, the use of these methods is casting new light in the viral etiology of idiopathic dilated cardiomyopathy.