The cardiomyopathies. A pathophysiologic approach to therapeutic management
"Cardiomyopathies" are a disparate group of myocardial disorders, usually of unknown or obscure origin, characterized by systolic or diastolic myocardial dysfunction but involving conditions of widely divergent pathophysiology. For purposes of devising appropriate clinical management, a useful classification scheme can be created with reference to the type of pathophysiologic abnormality exhibited. On this basis, three major types can be identified: (1) congestive (poor systolic function, normal diastolic function, left ventricular dilatation without the expected degree of compensatory hypertrophy), (2) hypertrophic (supernormal systolic function, subnormal diastolic function, and pronounced left ventricular hypertrophy, usually asymmetric, without dilatation), and (3) restrictive (normal or near-normal systolic function and subnormal diastolic function, usually mild symmetrical left ventricular, without dilatation). Noninvasive identification of these pathophysiologic features can be useful in optimizing management programs.