Postgraduate medical journal
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Cardiomyopathies are defined as 'heart muscle diseases of unknown cause' and classified into hypertrophic, dilated and restrictive types, respectively. Hypertrophic cardiomyopathy is notable for massive ventricular hypertrophy without obvious cause, impaired diastolic and systolic function, a tendency for sudden death and a familial propensity. Dilated cardiomyopathy by contrast, demonstrates severe systolic failure progressing to congestive heart failure, with usually no familial tendency. ⋯ Amyloid heart disease occupies a place intermediate between cardiomyopathies and specific heart muscle diseases. The major features of the above conditions are described and current and future advances noted. Examples are the identification of the gene probably responsible for hypertrophic cardiomyopathy located on chromosome 14, and the identification of virus RNA particles in the myocardium in both myocarditis and in dilated cardiomyopathy, which strengthens the growing evidence suggesting that some cases of dilated cardiomyopathy may be due to previous myocarditis.