BASIC CONSIDERATION: Hypertrophic cardiomyopathy is defined as a primary myocardial disease associated with a hypertrophic non-dilated left ventricle with no other heart or systemic disease that might lead to hypertrophy of the left ventricle. The leading symptoms are effort-associated angina and dyspnea, rapid fatigue, dizziness and syncope.The hemodynamic situation is characterized by a hyperdynamic systole and impaired diastole and left-ventricular filling. In the obstructive form, hypertrophy of the basal septum and an anteriorly moving mitral valve during systole result in an end-systolic reduction in the cross-section of the outflow tract associated with considerable intraventricular pressure gradients. Disturbances in the myocardial calcium metabolism are presently suspected to be causally involved in the diastolic function impairment.