Module 5 : Aortic Valve Regurgitation Flashcards
what is another name for aortic regurgitation
- aortic insufficiency/ incompetence
definition of AI
- blood moves backward through the AV from aorta to the left ventricle
4 groups of mechanisms that can cause AI
- cusps abnormalities
- aortic root dilation
- aortic root distortion
- loss of commissural support
4 causes of cuspal abnormalities
- congenital abnormalities
- rheumatic aortic valve disease
- aortic valve prolapse
- infective endocarditis
3 types of congenital abnormalities
- bicuspid AV and quadrucuspid AV
- quadricuspid AV is extremely rare
- quad is also associated with anomalous coronary artery origin
rheumatic AV disease characteristics
- cusp tissue is infiltrated with fibrous tissue causing them to shorten
- prevents cusps apposition easing to AI
what is rheumatic disease also associated with
- aortic stenosis
- mitral regurge
- mitral stenosis
aortic valve prolapse characteristics
- defined as cusp leaflet tips displaced below the valve ring
- may be due to myxomatous degeneration fo the valve due to rheumatic heart disease
- occur secondary to aortic root dilation or trauma
aortic bacterial endocarditis characteristics
- vegetation destroys the AV
- cause perforation of cusps
what is aortic root dilation
- prevents normal leaflet computation during diastole which leads to AR
6 causes of aortic root dilation
- systemic hypertension
- atherosclerosis
- connective tissue disorders (marfans)
- bicuspid AV
- sinus of valsalva aneurysms
- idiopathic dilation
what is aortic root distortion
- root becomes distorted due to inflammatory process
what is aortic root distortion related to what 3 things
- Ankylosing spondylitis
- takayasu’s artitis
- rheutmoid arthritis
3 things that loss of commissural support may occur with
- ventricular septal defects
- aortic dissections
- aortic trauma
+ motor vehicle accident
+ fall from great height
+ blow to the chest
causes of acute-severe AI
- trauma
- infective endocarditis
- aortic dissection
what does acute - sever AI causes what
- increase in filling pressure mainly end diastolic pressure
how does acute - severe AI cause increase filling pressure
- regurgitant volume leaks back into the LV as well as the normal blood flow from the LA
- because it is acute the LV has not had time to stretch to accommodate the extra volume
- LVEDP increases dramatically
- cause early closure of MV (filling from both LA and AR jet)
chronic - severe AI characteristics
- filling pressures may be normal or slightly elevated
- RV caused the LV chamber volume to increase over time due to stretching
- may lead to increased forward volume through the AV
- volume entering the LV has increased from the RV but the chamber has dilated to try to accommodate it
- leads to near normal filling pressures
- LV mall will increase
- LV may start to fail at which time the LVEDP will increase
6 symptoms of AI
- dizziness
- syncope
- fatigue
- SOBOE
- CHF signs
- auscultation
+ murmur
+ S3 and S4
complications with AI
- increased LV and LA size from pressure overload
+ pulmonary venous congestion
+ pulmonary edema
+ right heart failure
+ systemic venous congestion and edema - embolization
+ sudden death
4 jobs for echo with AI
- determine etiology = congential, degenerative, rheumatic
- assess LV size and function
+ acute AI = filling pressure increased
+ chronic AI = has the dilated LV started to decompensated - measure aortic dimension
+ where is the aortic root dilated
+ annulus, sinus, STJ or ascending - estimate severity of AI
+ quantitative and semi quantitative
determining the etiology - quadracuspid AV
- diagnosis made is PSAX view
- look for X or + sign
- rare
bicuspid AV and AI
- jet is eccentric (off to one side)
- ascending AO may be dilated
- AI severity is progressive
- younger patients have mild AI
- gets worse as patient ages and aortic root dilates
- can lead to chronic and severe AI
infective endocarditis and AI
- one of the most common causes of acute and severe AI
- hypermobile mass on UNDERSIDE of AV
- different echo characteristics than surrounding tissue
- causes AI by the infection destroying one or more of cusps
VSD and AI
- membranous VSD’s are located just on the LV side of the AV
- can affect the supporting structure of the aortic root leading to AI
aortic root dilation and AI
- dilates the aortic root will not allow the cusps to close tight
aortic dissection and AI
- dissection in the proximal portion of the aorta will cause some AI
3 AI assessment methods
- 2D assessment
- color doppler assessment
- spectral doppler assessment
2D assessment metod
- LV size
- LV thickness
- LV function
- aortic root measurements
color doppler assessement method
- jet height ratio
- jet area ratio
- vena contracta
spectral doppler assessment
- AI jet intensity
- flow reversal
- AI pressure half time
- regurgitant volume
- regurgitant fraction
- effective regurgitant orifice area
2D assessment of LV size, wall thickness, function
- with chronic volume overload such as significant AI = the LV progressively dilates
- the LV will dilate until ultimately fails
- LV start to look more spherical
- ** measure LVEDD and LVESD and EF
- calculate LV mass and assess for eccentric hypertrophy
2D assessment - aortic root measurements
- leading to leading edge
- measure perpendicular to central aortic axis
- reduce gain/ TGC with zoom
what is jet height
- JH
- slightly on the LVOT side of the AV
- not as accurate for severity of AI with eccentric jets
what is vena contracta width
- VC W
- width of venal contract is less influenced by loading conditions
- measure at most narrow point
- use zoom to measure
jet height / LVOT diameter
- ratio between AI jet height diameter and LVOT diameter
mild jet height / LVOT ratio
< 25%
severe jet height / LVOT ratio
> /= 65%
jet area / LVOT area ratio
- performed at PSAX AV zoom
- measure within 1cm of vena contracta
- estimates regurgitant orifice area
- may be over or underestimated based on direction of jet
mild jet area / LVOT area ratio
< 5%
moderate jet area / LVOT area ratio
5-56%
severe jet area / LVOT area ratio
> 60%
AI vena contracta
- aka vena contracta zone
- slightly smaller than jet diameter at valve
- preformed in PLAX with zoom
- narrowing of jet on LV side
- best for single central jets
mild AI vena contracta
< 3mm
severe AI vena contracta
> /= 6mm
what is AI jet intensity
- density/brightness of AI jet is proportional to number of RBC moving in unison
- brighter signal = more significant AI
flow reversal in aorta from SSN
- use color to visualize flow
- PW in descending ao
- look for retrograde flow in descending ao
- should be holo diastolic
what grade of AI is it if abd ao is reversed
severe
what is pressure half time
- PHT or P 1/2
- the time it takes for the pressure to reduce by half of original
- measures deceleration rate
what is the pressure alf time determined by
- pressure gradient
steep slope more or less severe
more
mild AI PHT
> 500ms
moderate AI PHT
200-500ms
severe AI PHT
< 200ms
mild RV amount
< 30ml
severe RV amount
> 60ml
what is the PISA method to assess AI
- proximal is-velocity surface area method
- measure mushroom cap
what is the regurgitant fraction
- percentage of blood leaking back across the valve
RF for aortic valve equation
SVav - SVpv / SVav x 100
mild RF
< 30%
severe RF
> 50%
mild effective regurgitant orifice area (PISA)
< 0.1
severe effective regurgitant orifice area (PISA)
> /= 0.3
other AI findings in 2D and Mmode
- AML reverse doming / decreased AML excursion from AI jet
- AML flutter on Mmode
