This is called “systolic anterior motion” of the mitral valve or SAM. Mitral regurgitation can result and contribute to congestive heart failure symptoms in the setting of HOCM.

Mitral regurgitation (MR) is the term used for (abnormal) systolic retrograde ... of the mitral valve process. It usually radiates to the axilla and back — due to anterior leaflet disease ...

The diagnosis of HCM was excluded by echocardiography in 819 (98%) on the basis of an LV wall thickness <12 mm, absence of systolic anterior motion of the anterior mitral valve leaflet causing LV ...