Cardiomyopathies are a group of diseases that affect the heart muscle and can be classified into different types including dilated, hypertrophic, restrictive and arrhythmogenic right ventricular cardiomyopathy. Hypertrophic cardiomyopathy is a genetic condition that causes abnormal thickening of the heart muscle. The document discusses different types of cardiomyopathies and mentions hypertrophic cardiomyopathy as a familial condition that results in abnormal thickening of the heart muscle.