Today, with the help of modern echocardiographic techniques we are able not only to describe the characteristic changes when a HOCM is present and to determine the intracavitary pressure gradient, but also recognize the functional irregularities typical for the HOCM. Thus, the methodical progress of the echocardiography has essentially enlarged our knowledge about the pathophysiology of this clinical picture. Today, the echocardiography is the method of choice for the diagnostics of the HOCM and for the judgment of the functional consequences of therapeutic interventions.