Hypertrophic cardiomyopathy

Hypertrophic cardiomyopathy (HCM) is characterized by a hypertrophied left ventricle, defined as diastolic wall thickness 15mm or more, without any identifiable cause such as hypertension or valvular disease.
Normal ventricular septal measurement is 8-12 mm.
Usually there is asymmetric thickening of the wall most prominently involving the ventricular septum without abnormal enlargement of the ventricular cavities.
It is a genetic myocardial disorder with a prevalence of 1:500.

HCM with narrow left ventricular outflow tract (yellow arrow), systolic anterior motion of anterior leaflet of mitral valve (blue arrow) and mitral regurgitation (red arrow).