ScholarRX: Aortic Disease

Question 1

what is aortic stenosis?

Answer 1

a condition in which there is a narrow left ventricular outflow tract caused by failure of the aortic valve to open up completely

aortic stenosis occurs when the aortic valve leaflets become stiff and unable to fully open, making it difficult for the heart to pump blood out to the rest of the body.

the heart has to work harder to pump blood through this tight opening to deliver blood to the rest of the body

if the restriction of blood from the LV becomes severe enough, it can lead to heart failure because there will be a lack of oxygen and nutrients to the body

Question 2

what causes aortic stenosis?

Answer 2

the stiffening of the aortic valve leaflets, which is triggered by inflammation, has three
main causes:

1. degenerative calcification, seen with aging;
2. congenital bicuspid valve (born with two leaflets instead of three)
3. rheumatic heart disease.

Question 3

what’s the difference between aortic sclerosis and aortic stenosis?

Answer 3

over time, inflammation causes the aortic valve to scar, thicken, and eventually calcify and stiffen

aortic sclerosis results when calcification and thickening of the aortic valve happens without any restriction of blood flow from the left ventricle

in contrast, aortic stenosis is characterized by obstructed blood flow

aortic sclerosis eventually leads to aortic stenosis

Question 4

what are the risk factors for aortic stenosis?

Answer 4

1. old age
2. male sex
3. smoking
4. HTN
5. high LDL levels
6. DM

these risk factors are the same as those for coronary artery disease

Question 5

what is coronary artery disease?

Answer 5

CAD occurs when plaque builds up in the arteries that feed the heart muscle, narrowing the arteries and eventually cutting off blood flow to the heart muscle

Question 6

what is a congenital biscupid aortic valve?

Answer 6

bicuspid aortic valve is the most common congenital malformation of the aortic valve and is present in 1%‐2% of the population

the two leaflets of the bicuspid valve are not able to hold up as well to the normal wear and tear on the aortic valve and tend to calcify more easily than a normal, tricuspid valve

aortic stenosis due to a bicuspid valve develops at an earlier age, in the 40s or 50s, rather than the older age (>70‐80 years) associated with degenerative aortic stenosis

Question 7

what is an aortic aneurysm?

Answer 7

dilation of the aortic root which is associated with a biscupid aortic valve

this is like the stretching of a balloon and puts the aorta at risk of dissection or rupture

when a bicuspid valve is identified, the patient should also be screened for aortic root aneurysm

Question 8

what is rheumatic heart disease?

Answer 8

the result of an autoimmune disease called rheumatic fever, which is caused by an infection with the bacteria Streptococcus pyogenes

if the strep infection is left untreated, it allows the body to create antibodies to a surface protein on the bacteria (M protein) that mimics a protein present on the lining of the heart

this in turn directs the body’s immune system to attack the lining of the heart, causing inflammation and scarring of the valves of the heart, most commonly the mitral and aortic valves

Question 9

what are the symptoms of aortic stenosis?

Answer 9

1. angina
2. syncope
3. dyspnea
4. heart failure

survival starts to decrease with the onset of symptoms ):

Question 10

what causes angina in aortic stenosis? what is the prognosis?

Answer 10

it is caused by decreased blood flow through the coronary arteries to the myocardium

angina occurs because the coronary arteries open from the aorta directly after the aortic valve

decreased flow from the left ventricle through the stenotic valve leads to decreased coronary blood flow and angina

patients with angina have an average 5‐year survival

Question 11

what causes syncope in aortic stenosis? what is the prognosis?

Answer 11

it’s due to transient decrease of blood flow to the brain, again because of the tight stenotic valve

these patients have an average 3‐year survival

Question 12

what causes dyspnea in aortic stenosis? what is the prognosis?

Answer 12

this is a symptom of heart failure!!

it occurs because the pressure load on the ventricle eventually causes it to hypertrophy and then causes the muscle to weaken

this leads to backup of fluid into the lungs, dyspnea, and even pulmonary edema

these patients have an average 2‐year survival

Question 13

what is the main sign associated with aortic stenosis?

Answer 13

because patients are often asymptomatic, it’s likely that AS will be discovered on a routine exam or during a check for another condition

the main sign associated with AS is a systolic crescendo‐decrescendo murmur

the intensity of the murmur changes with how much blood flow is going through the aortic valve –> ↓ aortic blood flow = quieter murmur, ↑ aortic blood flow = louder murmur

Question 14

how does the murmur heard with aortic stenosis change?

Answer 14

the intensity of the murmur changes with how much blood flow is going through the aortic valve:

amount of blood flowing through the aortic valve depends on the position of the patient

the murmur will become quieter when the patient bears down (Valsalva) or stands because both lead to less blood flow through the aortic valve

the murmur will become louder when the patient squats because this leads to more blood flow through the aortic valve

Question 15

what is pulses parvus et trades?

Answer 15

delayed and dulled pulse felt in the carotid arteries of the neck

Question 16

what are some signs of heart failure that can be see during a PE in a patient with aortic stenosis?

Answer 16

1. S3 or S4 gallop (an extra heart sound heard on heart exam)
2. atrial fibrillation (an irregular heart rhythm)
3. a larger and more lateral point of maximal impulse, or PMI (the point where the
   heart hits the chest wall)
4. crackles heard on lung exam
5. jugular venous distention, or JVD (bulging of the jugular veins in the neck)
6. peripheral edema (fluid buildup in the extremities)

Question 17

what is the effect of aortic stenosis on blood flow and the left ventricle?

Answer 17

instead of pumping blood through a wide‐open valve, the LV has to pump through a tight, narrowed valve

this pressure load on the LV causes left ventricular hypertrophy over time and eventually may lead to weakening of the heart muscle due to fatigue

damage to the heart muscle can be irreversible, which is one of the reasons patients with AS should be treated before the LV is affected

Question 18

what does it mean that patients with severe aortic stenosis are preload dependent?

Answer 18

the LV is trying to pump blood through the pinhole‐sized opening of the stenotic aortic valve and to do so the LV needs enough pressure, but it also needs enough fluid, like a full tank

the pressure and volume flowing through the right side of the heart are controlled by the tone of the venous blood vessels and if these veins dilate, they can hold a lot of fluid but it will also decrease the forward pressure into the LV

so anything that drops the preload by dilating the veins can be potentially dangerous for patients with severe AS

so do NOT give nitroglycerin because it dilates blood vessels –> this is tricky because it’s usually given to patients in the ER who present with chest pain…

Question 19

how do you diagnose aortic stenosis?

Answer 19

1. echocardiogram

this is the preferred test and will usually show
thickening and calcification of the aortic valve along with any malformation of the valve

2. doppler echocardiography

used to determine the amount of flow through the aortic valve and the pressure
gradient between the left ventricle and the aorta caused by the narrowed
valve

3. left and right heart catheterization

this is the confirmatory gold standard test if the Doppler
echocardiogram is indeterminate, but the patient is having symptoms of AS.

Question 20

how do we treat aortic stenosis?

Answer 20

if a patient with severe AS is asymptomatic, watchful waiting with repeat echocardiograms is recommended

however, once patients develop symptoms, their survival decreases

therefore, the ideal moment for surgical intervention is the day before the patient develops symptoms –> of course, that’s
impossible in practice, but it illustrates the point that finding the right timing for surgery is a delicate balance

aortic stenosis is not conventionally treatable with medications, although blood pressure control is recommended.

Question 21

what is the only definite treatment for patients with symptomatic aortic stenosis?

Answer 21

valve replacement

Question 22

A 45‐year‐old man from the United States presents to clinic with shortness of breath
and a feeling like he’s going to pass out when he runs. Listening to his heart reveals a
crescendo‐decrescendo systolic murmur radiating to the carotids, and
echocardiogram finds thickening and calcification (sclerosis) of the aortic valve.
What else is most likely be found on echocardiogram?

A. Aortic valve with one leaflet

B. Aortic valve with three leaflets

C. Aortic valve with three leaflets and mitral valve sclerosis

D. Aortic valve with two leaflets

E. Vegetations on the aortic leaflets

Answer 22

D. Aortic valve with two leaflets

AS is not a very common diagnosis in middle‐aged patients, and there is most likely some kind of malformation of his aortic valve to allow this sclerosis to happen at such an early age

If our patient were found to have three aortic valve leaflets and sclerosis of the mitral valve this would suggest a history of rheumatic heart disease

Question 23

You are listening to the heart sounds of a patient with severe AS. As you listen, you
feel the carotid arteries in the neck of the patient. What do you most likely feel?

A. Carotid pulses that happen after the heartbeat and feel weak

B. Carotid pulses that happen before the heartbeat

C. Carotid pulses that happen with the heartbeat

D. Carotid pulses that happen with the heartbeat and also have a humming feeling
to them

E. Carotid pulses that happen with the heartbeat and are very strong

Answer 23

A. Carotid pulses that happen after the heartbeat and feel weak

this is pulsus parvus et tardus

Question 24

A 78‐year‐old man with severe aortic stenosis presents to the emergency room
complaining of chest pain. Which of the following medications should not be
prescribed?

A. Nitroglycerin

B. Diuretic

C. β‐Blocker

D. Calcium channel blocker

Answer 24

A. Nitroglycerin

it decreases preload by causing vasodilation

in severe AS, patients are preload dependent, and dropping the preload with nitroglycerin (even though chest pain is typically treated with this medicine) could cause cardiovascular collapse

Question 25

What findings indicate a patient needs aortic valve replacement?

A. Mild AS on echocardiogram and swelling of the legs

B. Moderate AS on echocardiogram, no symptoms, and no other heart problems

C. Severe AS on echocardiogram and no symptoms at rest or on exercise stress
testing

D. Severe AS on echocardiogram and shortness of breath at rest

E. Severe AS on echocardiogram, no symptoms, and a fever of 103.0°F

Answer 25

D. Severe AS on echocardiogram and shortness of breath at rest