Does echocardiography detect structural and functional abnormalities in genetically affected subjects with familial hypertrophic cardiomyopathy without overt left ventricular hypertrophy compared to nonaffected relatives?
Genetically affected subjects with familial hypertrophic cardiomyopathy but without overt left ventricular hypertrophy exhibit subtle echocardiographic structural and functional modifications, indicating a continuous phenotypic spectrum.
AIMS: It is not known whether the apparent normality of echocardiographic examination results, in subjects bearing a mutation for hypertrophic cardiomyopathy but without ultrasonic left ventricular hypertrophy, is due to incomplete phenotypic expression, or inaccurate echocardiographic criteria. The aim of this study was to search for echocardiographic abnormalities in these patients. METHODS AND RESULTS: Echocardiography was performed in 100 subjects from two families with a mutation in the beta-MHC (720) or My-BPC (714) genes. We compared genetically affected subjects with an apparently normal left ventricle (thickness or = 18 years) were considered; (3) a subanalysis of Family 714 (13 patients, 25 normals matched for sex, age and height) showed the same trends. CONCLUSION: In familial hypertrophic cardiomyopathy, genetically affected subjects with an apparently normal heart by echocardiography show slight ultrasonic structural and functional left ventricular modifications, suggesting that the phenotype of the disease is a continuous spectrum from normal structure to typical hypertrophy.
Albert Hagège (Sun,) studied this question.