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Ventricular diseases can be defined as congenital or acquired disorders of the myocardium which cause ventricular dysfunction. This chapter primarily focuses on salient, clinical, and echocardiographic features of cardiomyopathies, but also includes discussion of other ventricular pathologies such as myocarditis and ventricular rupture.
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Cardiomyopathies represent a heterogeneous group of pathological diseases of the myocardium caused by electromechanical dysfunction of the heart (Figure 21-1) but does not include myocardial dysfunction secondary to valvular heart disease, systemic hypertension, congenital heart disease, and atherosclerosis. Cardiomyopathy often leads to progressive heart failure with symptoms of shortness of breath, fatigue, cough, orthopnea, and paroxysmal nocturnal dyspnea and is associated with significant morbidity and mortality.
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Cardiomyopathies are actually the result of genetic mutations with significant phenotypic and genetic heterogeneity. The crossover of some cardiomyopathies into different subcategories means that different classifications are proposed by various organizations (Table 21-1).1,2
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Primary cardiomyopathies (genetic, nongenetic, acquired) are those confined to heart muscle, while secondary cardiomyopathies exhibit myocardial involvement as part of systemic disorders (Table 21-2). Mutant proteins in cardiomyocytes affect the contractile apparatus, which affects cardiac function and may cause sudden cardiac death and heart failure.3
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