Aortic Stenosis 2

Question 1

reason for syncope in AS

Answer 1

LV is already pumping at maximal cardiac output. so if body demands a higher output, and it decreases vascular resistance like in exercise: decrease BP = decreased brain perfusion = syncope

Question 2

syncope: any stimulus that ____ can cause it. examples?

Answer 2

any stimulus that tends to decrease vascular resistance or decrease LV filling: exercise, BP lowering drugs. severe dehydration, bleeding

Question 3

angina: what?

Answer 3

discomfort (squeezing, crushing, aching) usually in chest and maybe throat, jaw, arms, upper stomach

Question 4

angina is brought on by?

Answer 4

lack of O2 in cardiac tissue aka myocardial ischemia. usually from exertion bc you need more O2

Question 5

coronary blood flow depends on? coronary perfusion pressure = ?

Answer 5

on pressure driving blood from aorta to inner layer of LV myocardium. CPP = aortic pressure = LV pressure

Question 6

coronary blood flow: systole and diastole?

Answer 6

in systole, LVP ~ AoP so no flow. coronary perfusion is mostly in diastole

Question 7

AS: angina and increased demand?

Answer 7

increased blood flow demand because AS means you have higher LV systolic pressure = increased cardiac work. LVH = more cardiac tissue to perfuse

Question 8

AS: angina and decreased supply?

Answer 8

decreased aortic pressure and higher LV diastolic pressure = decreased perfusion pressure. AS also often associated w/ coronary blockages

Question 9

AS: cause of dyspnea?

Answer 9

high LV diastolic pressures eventually lead to higher LA then pulmonary pressures = dyspnea

Question 10

AS and dyspnea: what happens when LV decompensates?

Answer 10

huge increase in LV diastolic pressure, so huge increase in LA pressure esp if A fib = overt heart failure

Question 11

importance of symptoms in survival

Answer 11

50% mortality: angina = 5 years. syncope = 3. heart failure = 2. A fib = 0.5

Question 12

aortic stenosis physical: BP? HR? apex?

Answer 12

BP rarely very high, but usually normal. HR normal unless A fib. apex in normal position (b/c concentric hypertrophy) unless LV decompensates and dilates = displaced apex

Question 13

carotid pulse findings?

Answer 13

low and slow pulse: aortic pressure rises slowly so low volume, slow upstroke. might also be associated with vibration that you can feel “carotid shudder”

Question 14

apical impulse findings?

Answer 14

sustained aka lasts >1/2 of systole. this is because LVH = longer LV ejection time

Question 15

heart sounds in AS

Answer 15

decreased or absent S2 intensity, A2 is delayed (paradoxical splitting). hear an S4 from atrial kick emptying into stiff LV

Question 16

murmur in AS? loudest where? radiation?

Answer 16

diamond shaped aka crescendo decrescendo murmur, mid or late peaking murmur between S1 and S2 (during systole). later peak = more severe. loudest over aortic area, radiates into carotids and down into apex.

Question 17

ECG findings in AS? echocardiogram findings?

Answer 17

LVH signs common, might also see LA enlargement. echo is the method of choice: visualize leaflets, LV size/thickness/function, look at aortic valve area

Question 18

drug therapy for AS?

Answer 18

there are none

Question 19

preventing complications of AS

Answer 19

no antibiotics needed before dental work, maintain good dental hygiene. careful follow up of asymptomatic patients. avoid extreme exertion

Question 20

only definitive treatment for AS? effectiveness? downside?

Answer 20

valve replacement. good long term results, bad LVs will improve. stroke and infection risk