ABSTRACT
CLASSIFICATION The traditional cardiomyopathy classifi cation, based on gross morphology and the principal form of functional cardiac impairment, is to divide the cardiomyopathies into the dilated, hypertrophic, and restrictive phenotypes (Fig. 9.1). The cardinal features of the dilated forms are multichamber dilation with marked impairment of systolic function, as well as reduced diastolic function. The features of the hypertrophic forms are atrial dilatation, marked left ventricular (LV) muscle hypertrophy with vigorous systolic function, impaired ventricular diastolic relaxation and compliance, and a small LV volume (1,2). Restrictive cardiomyopathy is characterized by normal ventricular size, relatively preserved systolic function, marked biatrial enlargement, and severe diastolic dysfunction. While descriptively useful, this grouping has been revised in the light of advances in clinical genetics.
