Histological diagnosis of right ventricular dysplasia: a role for electron microscopy?

Right ventricular dysplasia is a rare cardiomyopathy predominantly involving the right ventricle. We report eight cases studied with light and electron microscopy. By light microscopy, we found the typical replacement of myocardium with mature adipose tissue where only scattered degenerated myocytes wrapped in thin fibrous sheets are seen. Electron microscopy shows abnormal intercalated discs in both the right and left ventricles: intercalated discs are attenuated and flattened with decreased Z band material (desmin). These changes, not previously reported, may be useful for diagnosing ARVD.