aortic regurgitation Flashcards
epidemiology
much less common than aortic stenosis or mitral valve disease
usually only trace or mild
incidence increases w/ age
Causes
- insufficiency of congenitally anomalous bicuspid valve
- endocarditis
- chronic rheumatic valve deformation
- dilation of aortic valve ring by aortic aneurysm or dissection
if half of pt’s SV is falling back into LV and pt can only compensate by increasing SV 20%, to 120mL…
How much is pumped into the aorta?
60mL pumped out
if half of pt’s SV is falling back into LV and pt can only compensate by increasing SV 20%, to 120mL..
What volume is left from last systole?
50mL
if half of pt’s SV is falling back into LV and pt can only compensate by increasing SV 20%, to 120mL…
How much fluid falls back into left ventricle?
60mL
if half of pt’s SV is falling back into LV and pt can only compensate by increasing SV 20%, to 120mL…
what volume is from the left atrium?
60mL
decreased from the normal 100mL b/c venous return is decreased
if half of pt’s SV is falling back into LV and pt can only compensate by increasing SV 20%, to 120mL…
What would the End-Diastolic Pressure be (if situation is acute?)?
around 50mmHg
Higher than the normal 10mmHg
if half of pt’s SV is falling back into LV and pt can only compensate by increasing SV 20%, to 120mL…
What would the End-diastolic volume be?
170 mL
Consequences of acute
increased LV diastolic pressure (hasn’t had time to dilate and accommodate)
- ->increased left atrial pressure
- ->pulmonary congestion and edema
- ->dyspnea
Treatment of severe acute AR
surgical valve replacement (surgical emergency)
Chronic AR consequences
dilation of LV w/ increased muscle mass
–>inccreased compliance and less elevated LV diastolic pressure
pt. may be able to double SV to compensate for half of SV falling back into ventricle
chronic compensated aortic regurgitation:
If SV is 200mL…
What volume is pumped into aorta?
100mL
chronic compensated aortic regurgitation:
If SV is 200mL…
normal amount left in LV at end of systole
50mL
chronic compensated aortic regurgitation:
If SV is 200mL…
volume from left atrium?
100mL
chronic compensated aortic regurgitation:
If SV is 200mL…
volume that falls back into LV from aorta?
100mL
chronic compensated aortic regurgitation:
If SV is 200mL…
EDV?
250mL
chronic compensated aortic regurgitation:
If SV is 200mL…
End diastolic pressure?
about 12mmHg
chronic compensated aortic regurgitation:
If SV is 200mL…ejection fraction?
80%
SV/EDV
How can chronic AR become decompensated?
diastolic BP falls b/c of blood leaking backward…
–heart gets coronary blood supply during diastole via coronary ostia just above aortic valve…
if coronary perfusion lowered sufficiently
–>decompensation
Decompensation of chronic AR…
heart might only be able to pump out 150mL SV instead of 200.
If pt still losing half of SV back into ventricle, forward SV is then only 75mL (REMEMBER: clinical manifestations of HF)
may lead to:
- -if pt retains enough fluid, addition of LA volume to LV EDV might increase from 100 to 175mL…yielding LV EDV of 300mL
- ->and ED pressure of 25mmHg
Symptoms of decompensated aortic regurgitation
fatigue
decreased exercise tolerance
dyspnea
Signs of decompensated AR
diastolic decrescendo murmur (sometimes w/ a blowing quality)
hyperdynamic bounding
rapidly collapsing pulse (Corrigan pulse)
head-bobbing w/ eauch pulse (de Musset sign)
multiple other eponymic signs
characteristic of aortic regurgitation
wide pulse pressure due to increased systolic and decreased diastolic pressure from the abnormally large amount of blood ejected into aorta in systole and back leak into LV in diastole
Treatment of choice for symptomatic AR
aortic valve replacement
