Aortic Stenosis

Question 1

normal aortic valve: structure? normal opening size?

Answer 1

three leaflets of roughly equal size. ~3 cm squared

Question 2

3 causes of aortic stenosis

Answer 2

degenerative, aka senile. bicuspid (congenital defect). rheumatic.

Question 3

most common type of AS? other names? usually shows up at what age? what causes is and speeds it up?

Answer 3

calcific aka senile aortic stenosis. after age 65. wear and tear on normal valve = fibrosis and calcification of leaflets = stenosis. faster with other risk factors for atherosclerosis like hypertension, high cholesterol

Question 4

stenosis is when valve area is what size

Answer 4

<1.5 cm squared

Question 5

calcific aortic valve: calcification is mostly where?

Answer 5

on the leaflet; the free edges are mostly spared

Question 6

bicuspid aortic valve: prevalence? caused? name of fusion line?

Answer 6

1-2% population, fairly common. usually from congenital fusion of 2 aortic leaflets (usually R + L cusps). fusion line = raphe

Question 7

most common cause of AS <65 yo

Answer 7

bicuspid aortic valve

Question 8

rheumatic aortic stenosis: prevalence? almost always has? where is the damage?

Answer 8

<25% of AS cases; almost always has associated mitral disease. fusion of commissures and calcification of leaflets –> edges are damaged, unlike in the other causes

Question 9

what is the consequence of AS in terms of pressure

Answer 9

you need markedly higher LV pressures to drive blood across the stenotic AV = high pressure gradient from LV to aorta

Question 10

AS hemodynamics curve (ventricular and aortic)

Answer 10

ventricular pressure increased a lot, aortic pressure slower to rise. in diastole, LV pressure is high too because it’s stiff

Question 11

type of LV hypertrophy in AS

Answer 11

concentric aka thicker, no change in heart overall size, no dilation (reduces size of cavity)

Question 12

benefits of LVH in AS?

Answer 12

higher thickness, lower radius so counterbalances the increase in LV pressure (recall wall tension = LVP X R / T) so there isn’t a huge increase in wall tension

Question 13

consequences of LVH in AS?

Answer 13

concentric hypertrophy = muscle more stiff aka harder to fill. LA pressures have to increase to drive blood into the LV. more muscle also means more blood required

Question 14

atrial kick and LVH?

Answer 14

LV stiffer in diastole so you need higher LA pressure –> atrial kick becomes more important, now provides > 25% of LV filling (vs less that 15% before)

Question 15

AS hemodynamics curve (atrial)

Answer 15

during systole, it’s still the same. in diastole, it is higher because you need higher LA pressures since LV is stiff. atrial kick also higher pressure

Question 16

in end stage AS, what is the pressure in the LV like? this causes?

Answer 16

really high LV pressure so really high LV wall tension = high afterload. eventually LV systolic function decreases, can’t empty fully and will dilate = decompensation

Question 17

what is a very ominous sign in AS? it’s usually associated with?

Answer 17

dilation (bc that means LV past the point of compensation). usually associated with heart failure signs.

Question 18

end stage AS: what happens to LV? LA?

Answer 18

LV size has increased, and its diastolic pressure is also high. LA size and pressure have increased

Question 19

natural history of AS

Answer 19

long asymptomatic phase (with a low but real risk of sudden death ~1-5%), but once symptoms develop a very malignant course (2-5y to death).

Question 20

aortic stenosis is a ___ story?

Answer 20

SAD: syncope, angina, dyspnea