Aortic Valve Disease Exam #2 Flashcards
2D and M-mode measurements are good for assessing what in regards to AS?
assessing its PRESENCE
NOT
its severity (it is unreliable for severity)
m-mode from SAX to assess AS can be unreliable. True or False do you need to see all 3 cusps or is just 2 ok
ALL 3!
also can’t be any wall motion or septal wall abnormalities
lastly, decreased SV can affect cusp separation
TTE Planimetry is unreliable to assess AS as well. Many factors can affect your assessment such as (3)
- not imaging at max stenosis
- not being parallel
- heavy calcification, acoustic shadowing, and reverb artifact may obscure cusps
this measurement can ONLY be obtained in cath lab
peak to peak av gradient (LV peak pressure and peak aortic pressure)
this measurement is usually lower (by as much as ________mmHg) than the peak instantaneous gradient. *hint its the only measurement that can only be obtained in cath lab
30 mmHg!
peak to peak av gradient
4xV2squared solves for what
it is the SIMPLIFIED Bernoulli equation used to calculate PEAK INSTANTANEOUS GRADIENT
*use only if LVOT or V1 value is LESS THAN 1.5 m/sec
If the LVOT velocity is greater than OR EQUAL TO 1.5 m/sec, use this equation to solve for PEAK INSTANTANEOUS AV GRADIENT
4x (V2 squared - V1 squared)
What pressure constitutes SEVERE AS (give peak gradient value and mean gradient value)
peak value is 80mmHg
mean value is 50mmHg
Peak gradient and peak instantaneous gradient are the same thing TRUE OR FALSE
TRUE
measures stroke distance
velocity time integral
stoke distance is what exactly?
it is the distance that the column of blood travels past the LVOT or AoV during one cardiac cycle
why is the continuity equation used? for what type of patients?
it is used to calculate AVA or aortic valve area. It is used to calculate AVA instead of peak and mean gradient IN PATIENTS WITH LOW CARDIAC OUTPUT!!!!
mean and peak gradient are not reliable in low cardiac patients
What could cause a low pressure gradient even if a patient had severe AS
significant MR could cause AoV peak velocity to be underestimated (one of many things)
With these conditions AI, Anemia, Pregnancy… they could do what and cause an error in what
cause an err0r in PG calculation (INCREASE FLOW RATES) across the aorta
continuity equation is effective in calculating what in patients with what? *providing there is no what?
calculating effective valve area in low cardiac output state
*providing NO VSD is present!!!
when you are measuring LVOT diameter, make sure you are parallel to what
parallel to AORTIC VALVE PLANE
when do you measure the LVOT diameter (what point during cardiac cycle)
MID-SYSTOLE
window to view the LVOT should be from where. there are 2
apical 5 chamber view and apical long view
what’s the advantage of a non imaging probe
higher sensitivity and better access between rib spaces
3 Doppler abnormalities that all occur in ______ that make timing and waveform key to identify when using a non imaging probe
aortic stenosis
mitral regurgitation
tricuspid regurgitation
jets mistaken for AS
sub aortic obstruction
mitral regurgitation
tricuspid regurgitation
ventricular septal defect
pulmonic artery stenosis
peripheral vascular stenosis
An MR jet is _______in comparison to an AS jet
peak velocity is higher (longer duration)
MR usually GREATER than 4 to 5 m/s
the velocity of tricuspid regurgitation usually displays
RESPIRATORY VARIATION
Situation: you’re having trouble measuring an LVOT diameter… this is impeding you from obtaining an accurate continuity equation…. what measurement should you use now?
DI or dimensionless index
AKA
VELOCITY RATIO
It is INDEPENDENT of CO (measurement)
DI
Dimensionless Index
aka
Velocity Ratio
DI =
VTILVOT / VTIA
AoV index =
AVA/BSA
severity of aortic sclerosis (just memorize moderate… that way anything above is severe and anything below is normal) *these are average calculations
(all moderate severity measurements)
peak velocity: 3.0 - 4.0 m/s
mean gradient: 20 - 40 mmHg
ava: 1.0 - 1.5 cm2
indexed ava: 0.60 - 0.85
velocity ratio: 0.25 - 0.50
auscultations…
aortic regurgitation is 1.
aortic stenosis is 2.
- heard at LEFT parasternal border.
high-pitched diastolic decrescendo blowing murmur - heard at the RIGHT sternal border
harsh systolic ejection murmur
may radiate up the carotids
crescendo-decrescendo in shape
AI is
AR
Aortic Insufficiency or Aortic Regurgitation
this is the most common cause of ao root dilatation in the elderly
chronic and poorly controlled HTN
what is a complication of AR aka AI?
LVVO with LVE
left ventricular volume overload with left ventricular enlargement
left ventricular pressure overload
decreased left ventricular systolic function (if disease has progressed)
increased risk of SBE and veggies
Acute AI looks like
end diastolic volumes increase but LV can’t dilate rapidly
elevated LA pressure
pulmonary edema
tachycardia
tachycardia caused by increase afterload which leads to decreased stroke volume
myocardial ischemia
premature closure of mv on m-mode and diastolic MR
symptoms: dyspnea, lower extremity edema - maybe….?
chronic aortic insufficiency
surgical intervention for LVDdiastole (mm), LVDsystole (mm), and FS (%)
LVDdiastole if greater than 70mm
LVDsystole if greater than 50mm
Fractional shortening if less than 30%
the AR jet/LVOT diameter may not be reliable if (2)
AI jet is eccentric
AI jet doesn’t have circular cross-sectional shape
LVOT area is difficult to trace… you can simplify this with an equation though! easy… just measure the LVOT diameter. then plug in this equation
LVOTdiameter squared, then multiply by .785
THAT EQUALS THE LVOT AREA!
There must only be a little or no _______ or _______ in order to measure aortic regurgitation volume which is used to grade what
little or no MR or subaortic obstruction, used to grade AI severity
(formula) regurgitant volume =
SVav - SVmv
greater than 60ml indicates severe AI
To calculate stroke volume use this formula
0.785 x VALVEdiametersquared x VTIofVALVE (pulsed wave, value will be in cm)
answer will be in cc’s so like 152 cc
Regurgitant volume and regurgitant fraction are used to measure
AI severity
(volume) RFav =
SVav - SVmv
all divided by
SVav
If regurgitant fraction is over ________%, it is severe.
50%
When measuring PLAX 2-D LVOT diameter, what part of cardiac cycle?
mid-systole
The optimal imaging view to obtain Doppler of LVOT and AoV is… from how many widows should you obtain Doppler of LVOT/AoV?
Apical is optimal view
AO velocities should be obtained from 2 windows… apical, rt parasternal, or suprasternal
VELOCITY RATIO
The third additional method is using the velocity ratio (also called dimensionless index). This method still measures the effective orifice area (EOA), which is the primary predictor of outcomes.
***VTILVOT divided by VTIAV
INDEXED CONTINUITY EQUATION
Using the same steps to calculate the AVA using the continuity equation, we can take it a step further to index the AVA by body surface area (BSA). This is beneficial in select patients:
Very large (tall) patients
Very small (petite) patients
AVA / BSA
AVA Planimetry
Parasternal Short Axis
TEE Preferred
Mid-Systole
Trace minimal orifice area
IF THEY OCCUR TOGETHER IN SAME PATIENT the peak _______ is always higher than the peak _______.
PEAK MR higher than PEAK AS
TR usually has __________ variation…
RESPIRATORY!
Remember what is immediately linked to the Right Atrium? The IVC… remember sniff test…? IVC collapses with inspiration etc etc
in grading severity of aortic sclerosis, you want these values to be bigger or smaller???
peak velocity?
mean gradient?
ava?
indexed ava?
velocity ratio?
peak velocity: smaller the better
mean gradient: smaller the better
ava: bigger the better
indexed ava: bigger the better
velocity ratio: bigger the better
The most common cause of ao root dilatation in the elderly is
chronic an poorly controlled HTN
Acute AI… think “flooding” of the heart… with fluid
end diastolic volumes increase/can’t dilate rapidly enough
elevated LA pressure
pulmonary edema
afterload increases which causes decreased SV
tachycardia due to low stroke volume… heart trying to keep up by squeezing faster since it is moving smaller units of blood
measure for LVOT area
.785 x (LVOTdiametersquared)
use if can’t trace LVOT area
if left ventricular diastolic pressure increases
a progressive drop in the CW AI velocities will result
for pressure half time and deceleration… the steeper the slope, the
more severe the AI is!
AI slope will be increased and severity of AI will be OVERESTIMATED if CW is
NOT within the AI jet throughout diastole
SVav - SVmv =
regurgitant volume!!!
> 60-65ml indicates severe AI
SVav - SVmv all divided by SVav = your regurgitant fraction which is a percentage answer
> 50% is severe
0-20% is normal
in the descending aorta, is it normal for there to be a reversal of flow?
yes! due to elastic recoil, small bit of back flow from smaller diameter descending to larger diameter descending
One major difference between rheumatic AS and calcific AS in terms of how it affects anatomy
Rheumatic AS: commissural fusion is present
Calcific AS: little to NO commissural fusion
During an echo exam, it’s important to assess ___________views for AS?
ALLLLLL VIEWS!!!!!!
When you record patient data such as BP, HR, age, weight, height… its important because any changes in these values affect the correlation to
CATH LAB DATA!!!
M-mode from SAX can be MORE accurate for assessing AS, but can be unreliable IF:
any abnormalities with the walls, only 2 of the 3 cusps are seen, or reduced SV reduces leaflet excursion, or asymmetrical septal hypertrophy
peak to peak av gradient vs peak instantaneous gradient… which is lower and why
peak to peak av gradient because is lower because it measures the difference between the pressure in the LV vs the pressure across the Aov, can be up to 30mmHg difference between instantaneous and peak to peak av measurements
the continuity equation is used to measure AVA since peak and mean gradients are thrown out (unreliable) with
LOW CARDIAC OUTPUT PATIENTS
Dimensionless Index is a great alternative measurement if you can’t get a good LVOT measurement when doing the continuity equation.. would probably work well for patients with
TRICK QUESTION… this measurement is INDEPENDENT OF CARDIAC OUTPUT!!!! :)
AR Jet Diameter to LVOT Diameter ratio
mild?
moderate?
severe?
mild <30%
moderate 30-50%
>50% severe
To grade AI severity… divide what
AR jet area/LVOT area
bc LVOT can be difficult to trace, measure LVOT diameter, then square it and multiply it by .785
That’s your LVOT area.
