A uworld question : in both HOCM and aortic stenosis : LV mass is increased … cavity size is decreased .relaxation is decreased .Why it states that EF in HOCM is unchanged but EF in aortic stenosis is decreased ? What’s the difference ? Aren’t both Hfpef ?Any idea ?
Ejection fraction is the fraction of blood that got into the left heart that gets ejected. In HOCM, the problem is a diastolic dysfunction because the left ventricle can’t dilate enough to accommodate enough blood during diastole due to low compliance. But the systolic function of the left ventricle is still intact… As such, the ejection fraction during systole is intact but the ventricular filling during diastole is reduced…
While in Aortic stenosis, there is obstruction to blood outflow from the left ventricle, as such, the left ventricle can’t pump out enough blood because of the obstruction which increases the afterload… As such, the ejection fraction is reduced because of the obstruction to outward flow…
There is no such obstruction to outward flow in HOCM