HOCM and other things Flashcards
Why does hypertrophic cardiomyopathy cause problems?
LV systolic function is vigorous, but thickened muscle is stiff
Stiff muscle –> impaired relaxation –> high diastolic pressures –> heart failure
Is the hypertrophy in hypertrophic cardiomyopathy symmetric or asymmetric?
Asymmetric, usually focused in septum (asymmetric septal hypertrophy, ASH)
How do the muscle fibers appear in hypertrophic cardiomyopathy?
Myocardial fiber disarray
What proteins are usually mutated in hypertrophic cardiomyopathy?
Sarcomeric proteins
Are all cases of hypertrophic cardiomyopathy obstructive?
NO, some are non-obstructive
What are the symptoms of hypertrophic obstructive cardiomyopathy (HOCM)?
Same as aortic stenosis
- Angina
- Syncope
- Heart failure
What causes the obstruction of the aorta in HOCM?
Anterior leaflet of the mitral valve gets pushed toward outflow tract
Hypertorphied septum means that the edge of the outflow tract is closer to the leaflet, so when it gets pushed over, can essentially obstruct the outflow
What is the movement of the mitral valve in HOCM called?
SAM = systolic anterior motion of the mitral valve
Anterior leaflet bulges toward septum and obstructs flow during systole
What type of murmur will be heard in HOCM?
High velocity flow murmur, crescendo-decrescendo, just like in aortic stenosis
What will occur to the murmur heard in HOCM when contractility is increased?
Murmur will increase in intensity
Increasing contraction brings septum closer to the leaflet, obstructing flow even more
What will occur to the murmur heard in HOCM when preload (volume) is increased?
Murmur will decrease in intensity
Increased volume will make heart bigger, bringing septum further from leaflet, reducing the obstruction of flow
What two classic maneuvers can be used to differentiate the HOCM murmur from aortic stenosis murmur?
Valsalva
Squat
If patient has HOCM, what will happen to the murmur when they Valsalva?
Valsalva will decrease volume back to heart, bringing septum closer to leaflet, increasing obstruction of flow
Murmur will increase in intensity
If patient has aortic stenosis, what will happen to the murmur when they Valsalva?
Valsalva will decrease volume back to heart, decreasing flow across stenotic aorta
Murmur will decrease in intensity
If patient has HOCM, what will happen to the murmur when they squat?
Squat will increase volume back to heart, bringing septum further from leaflet, decreasing obstruction of flow
Murmur will decrease in intensity
