Track 7: Aortic Regurgitation

Question 1

Name some causes of AR

Answer 1

Rheumatic
Bicuspid
Dilated aortic root
Endocarditis

Question 2

Although less common than other valvular abnormalities, why is it crucial to dx AR?

Answer 2

Causes severe volume overload on the LV and if left untreated can lead to severe HF and LV dysfunction

The LV is often able to compensate quite well, so despite dilitation occurring the pt may remain asx for years-decades

Question 3

Briefly describe the hemodynamic changes that occur in the cardiac cycle with AR

Answer 3

During diastole there is significant blood flow from aorta back into left ventricle
During ventricular contraction there is a very high preload at left ventricle and large stroke volume
LV systolic pressure will be much higher than normal

During diastole marked drop in aortic pressure as blood regurgitates back to LV
Marked rise in systolic aortic pressure as huge preload is ejected into aorta
(This is why we see a wide pulse pressure)

Question 4

Explain the hemodynamics seen at the aorta in AR

Answer 4

• High systolic pressure
• Low diastolic pressure
• “Wide pulse pressure”

Question 5

Describe the AR murmur

Answer 5

Onset of S2 then high pitched diastolic decrescendo murmur (at RUSB in the case of root dilatation and LUSB in the case of primary valvular abnormality)
Small sytolic murmur d/t high flow going through the aortic valve

Question 6

Describe the changes to the LV and aorta in AR

Answer 6

Volume overload leads to greatly dilated LV
May see aortic dilitation as well
*Note patient’s can remain asx for some time (years to decades) as the ventricle is able to compensate

Question 7

High pitched diastolic decrescendo murmur
Short systolic ejection murmur

Name the murmur.
What is another key physical exam finding

Answer 7

AR

Very high systolic pressure and low diastolic pressure (palpate carotid or obtain blood pressure) “wide pulse pressure” “Bounding pulses”

Question 8

Briefly describe the natural history of AR

Answer 8

Patient may remain asx for years-decades
LV is very good at accomadating fluid overload and will dilate accordingly
Eventually however the extent of dilation will result in irreversible fibrosis and we will see a depression of EF (prognosis slighly decresed at this time)
Once sxs develop (prognosis decreases significantly)

Question 9

What are the 2 indicators for poor prognosis in AR?

Answer 9

Drop in EF (slight decrease in prognosis)
Development of sxs (significant decrease in prognosis)

Question 10

In contrast to other valvular pathologies, what is unique about severe AR

Answer 10

Patient can live with severe aortic regurgitation for years-decades in which the ventricle will continue to enlarge and the patient will be asx and feel quite well
Don’t want to operate just when LV starts to dilate

Question 11

Define severe AR

Answer 11

> 50% regurgitant fraction

Question 12

Definitive intervention options for AR

Answer 12

SAVR
If concomittant aortic root dilitation, replacement of the aorta OR combined aorta/valve conduit

Question 13

Optimal timing for intervention for AR

Answer 13

1 Onset of sxs

#2 Once EF starts to drop (< 55%)
#3 Massive significant aortic dilitation