Aortic Regurgitation Flashcards
What are 4 groups of mechanisms that cause aortic incompetence (AI)?
Cuspal abnormalities, aortic root dilation, aortic root distortion, loss of commissural support
Cuspal abnormalities includes what four things?
Congenital abnormalities, rheumatic aortic valve disease, aortic valve prolapse, infective endocarditis
What are some examples of congenital abnormalities?
Bicuspid or quadricuspid AV
What is quadricuspid AV associated with?
Anomalous coronary artery origin
What is rheumatic AV disease associated with?
Aortic stenosis, mitral regurgitation, and mitral stenosis
What is aortic bacterial endocarditis?
When vegetation destroys the AV
What does aortic root dilation do?
Prevents normal leaflet coaptation during diastole which leads to AR
What are six causes of aortic dilation?
- Systemic hypertension
- Atherosclerosis
- Connective tissue disorders
- Bicuspid AV
- Sinus of valsalva aneurysms
- Idiopathic dilation
What happens with aortic root distortion?
Root becomes distorted due to inflammatory process
Which inflammatory processes can lead to aortic root distortion?
Ankylosing spondylitis, takayasu’s arteritis, rheumatoid arthritis
Loss of commissural support may occur with what three things?
Ventricular septal defects, aortic dissections, aortic trauma
What are causes of acute severe AI?
Trauma, infective endocarditis, aortic dissection
How does acute sever AI affect filling pressures?
They will be increased, especially LVEDp
How does acute-severe AI increase EDP?
Regurg volume leaks back into the LV as well as the normal blood flow from the LA. Since it happens suddenly, the LV has not had time to stretch to accomodate for extra volume, therefore increasing pressure dramatically.
Acute-severe AI may cause the early closure of the MV, why?
LV pressure rises faster than normal
What would the filling pressures look like in someone with chronic-severe AI?
Normal or slightly elevated
With chronic-severe AI, LV chamber size increases over time due to stretching. This may lead to what through the AV?
Increased forward volume
Why would filling pressures appear normal in someone with chronic-severe AI?
Chamber sizes have had time to increase to accommodate for more volume
In chronic-severe AI, the LV mass will increase, known as what kind of hypertrophy?
Eccentric
What is one of the most common causes of acute severe AI?
Infective endocaditis
What is an infective endocarditis?
Hypermobile mass on the underside of the AV
The width of the vena contracta is less influenced by what?
Loading conditions
What is jet height/LVOT ratio?
Measurement of jet height (LVOT level jet alias measurement in PLAX) divided by the LVOT
What is is mild and severe jet height/LVOT ratio?
Mild = < 25%
Severe = ≥65%
What is jet area/LVOT area ratio?
Trace of jet circle divided by trace of AV root circle in PSAX
What is considered to be a mild and severe jet area/LVOT area ratio?
Mild = <5%
Severe = > 60%
What is considered a mild vena contracta?
<3 mm
What is considered a severe vena contracta?
≥6 mm
What would a bright signal indicate in terms of a waveform for AI?
More significant AI
If flow reversal is seen in the abdominal aorta, what does this usually indicate?
Severe AI
What does a steep slope indicate with pressure half time?
Severe regurg
What are the mild, mod and severe pressure half time values?
Mild: >500 ms
Mod: 200-500
Severe: < 200
Why does severe AI have a steeper slope?
AI causes pressure in LV to rise faster than normal, this causes the pressure gradient between the LV and AO to drop faster = steeper slope.
The stroke volume of a regurgitant valve will be higher than what?
The stroke volume of a normal valve
How can you get regurgitant volume from stroke volume?
SV difference between a competent valve and a regurgitant valve.
What is a quantitative method to assess AI?
PISA
What does PISA stand for?
Proximal isovelocity surface area
What is the formula for regurgitant volume?
RV = SVcompvalve - SVregurgvalve
Or
RV = CSAcv x VTIcv - CSArv x VTIrv
What are the mild and severe values for regurg volume?
Mild < 30 mL
Severe >60 mL
What is the AV regurgitant fraction?
RF(Ao) = ((SV(av) - SV(pv)) ÷ SV(av)) X 100
What is considered a mild regurgitant fraction?
<30%
What is considered a severe regurgitant fraction?
> 50%
What are two ways AI can affect the mitral valve?
- AML doming (seen in PSAX)
2. AML flutter
What two things diagnose severe AI off the bat?
- Vena contracta >6mm
2. Reversal in desc Ao
