Hypertrophic cardiomyopathy, a family of diseases with genetic and nongenetic causes, occurs throughout the world. It is characterized by morphologically diverse patterns of left ventricular hypertrophy that range from marked diffuse thickening of the ventricular septum and left ventricular free wall to focal hypertrophy of the apical region. An association between hepatitis C virus infection and cardiomyopathies and myocarditis was recently found [1-4].

In our study, 11 of 70 (15.7%) patients with hypertrophic cardiomyopathy (mean age of the 70 patients, 57.7 years) were positive for hepatitis C virus antibody compared with 25 of 1039 (2.4%) volunteer blood donors (age range, 50 to 59 years) (P < 0.001). Of these 11 patients, 5 were men and 6 were women (mean age, 59.7 years [range, 50 to 71 years]). Three patients had a history of mild hypertension and 1 had a family history of hypertrophic cardiomyopathy. Symptoms consisted of chest pain in 2 patients, shortness of breath with exertion in 4 patients, and palpitation in 2 patients. Two patients had a history of chronic hepatitis, and the others had no known risk factors for hepatitis C virus infection, such as a history of intravenous drug use and previous blood transfusions. Mildly elevated serum aminotransferase levels were noted in 6 patients. Hepatitis C virus RNA was found in the hearts of all 6 of these patients, and negative strands of hepatitis C virus RNA were found in the hearts of 2 of the 6 patients. Because negative RNA molecules are considered intermediaries in the replication of the hepatitis C virus genome, the detection of negative strands of hepatitis C virus in the heart suggests that hepatitis C virus replicates in the heart.

Of the 11 infected patients with hypertrophic cardiomyopathy, 6 had ace-of-spade-shaped deformities of the left ventricle that indicated apical hypertrophy. Apical hypertrophic cardiomyopathy was originally described by Sakamoto and colleagues [5] as a morphologic variant of the disease in which hypertrophy primarily affects the apical region of the left ventricle. Our study suggests that hepatitis C virus infection may be associated with apical and other forms of hypertrophic cardiomyopathy.