A family with cardiomyopathy

A family in which six members of three generations had cardiomyopathy is described. In two affected patients Adams-Stokes attacks developed and implantation of an artificial pacemaker was required. The mode of inheritance conformed to transmission by a dominant gene with variable expressivity and incomplete penetrance. Investigation of serum enzymes demonstrated significantly increased activity of lactic dehydrogenase, alpha hydroxybutyric dehydrogenase, aldolase, glutamic oxaloacetic transaminase and creatine phosphokinase in all the affected male subjects. In the affected female subjects, only slight deviations from normal enzyme activity were observed. Heterogeneity of the condition designated as familial cardiomyopathy is suggested by the observation that in a second family with this disorder normal serum enzyme activity was found in all subjects.