- The cardiomyopathies refers to a grouping of diseases which result in primary morphological derangements of the myocardium and excludes morphological changes due to other well-defined cardiac disease processes such as valvular, ischemic, hypertensive, or congenital heart diseases. Although the root cause of some cardiomyopathies are heritable genetic lesions, their etiological basis is diverse and often unknown. Therefore, the cardiomyopathies should not be considered a specific set of etiopathogenic entities but rather a generic grouping of diseases defined by their morphological sequelae which likely arise from primary defects of the myocardium. Three basic patterns of cardiomyopathies have been described: Dilated, hypertrophic, and restrictive. Although these diseases possess different morphological characteristics and evolve differently over time, their end result is often heart failure.