Abstract

Dilated cardiomyopathy is characterized by an increase in ventricular size and impairment of ventricular function. Most cases are believed to be sporadic, and familial dilated cardiomyopathy is usually considered to be a rare and distinct disorder. We studied the proportion of cases of idiopathic dilated cardiomyopathy that were familial in a large sequential series of patients whose first-degree relatives were investigated regardless of whether these relatives had cardiac symptoms.