[Idiopathic cardiomyopathy--pathogenesis].

Etiology of hypertrophic cardiomyopathy and dilated cardiomyopathy has been thought to be different. In fact, most of the mutations of the genes of sarcomere were shown to be associated with hypertrophic cardiomyopathy. However, the same mutations of the genes such as mitochondria, dystrophin or actin have been reported in both the patients with hypertrophic and dilated cardiomyopathy. Recently, the importance of hepatitis C virus infection was noted in patients with cardiomyopathy, and the virus may also cause both hypertrophic and dilated cardiomyopathy. Therefore, the unknown factors may define the phenotype of cardiomyopathy. Increased expression of cytokines and nitric oxide has been shown and is being increasing recognized as important factors in the pathogenesis of cardiomyopathy.