Aortic Stenosis and Regurgitation

gorlin equation

used by Cath lab to assess for AS, measures pressure gradients and cardiac output

components of aortic stenosis waveforms

- CW

- multiple windows

- log the best window

- crisp envelop

- peak velocity

- max and mean pressure gradient

severe AS mean gradient

> or equal to 40 mmhg

continuity equation

.785 x LVOT D2 x LVOT VTI / AV VTI

SV equation

.785 x LVOT D2 x VTI

where do you measure LVOT diameter?

measure at leaflet insertion points

typical diameter for LVOT

around 2 cm

who might have a larger LVOT diameter ?

larger patients or patients with BAV

how many times should you measure a normal LVOT?

x3

how many times should you measure an LVOT with arrhythmia?

x5

what is the greatest source for error between monographers?

LVOT diameter measurements

LVOT diameter challenges

calcium deposit and septal bulge

what technique do you use to obtain LVOT velocity?

use PW and walk it

what should you do if your LVOT velocity is greater than your aortic velocity?

move further from valve

windows used with PEDOFF

apical 4, right parasternal, SSN

when a patient has an arrhythmia, how many consecutive waveforms should you take?

5-10

aortic valve index

AVA/BSA

units for aortic valve index

cm/m2

dimensionless ratio or index

LVOT VTI or velocity/AV VTI or velocity

mild dimensionless ratio

> or equal to .5

moderate dimensionless ratio

.25-.5

severe dimensionless ratio

< or equal to .25

when would you use dimensionless index

if you can't assess for LVOT diameter

planimetry best suited for

TEE

what view do you use planimetry

PSAX aortic level

doppler derived AVA is ____________ valve area, planimetry is an ______________ valve area

functional, anatomic

low flow low gradient equation

SV/BSA

what can low output/EF create?

low gradients making the AS underestimated

indication of low flow state

< 35 mL/m2

dobutamine

drug used instead of treadmill for stress echo

AV velocity severe classification

> or equal to 4 m/sec

Mean P gradient severe classification

> or equal to 40 mmhg

AVA severe classification

< 1 cm2

dimensionless index severe classification

< .25

in PLAX, which cusp is on the top and which is on the bottom

right cusp on top, non cusp on bottom

in TEE, which cusps are on the top and bottom?

non on top, right on bottom

what is TEE used for?

to assess valve anatomy and how disease looks

aortic stenosis

progressive aortic valve narrowing and secondary LVH

what is the gold standard for aortic stenosis

echo

AS effect on the LV

increased LV systolic pressure, decreased systolic aortic pressure

what is the compensatory/secondary response of the LV with AS

hypertrophy

what comes after hypertrophy of the LV

dilation

what grade is usually associated with aortic stenosis

grade 1 - thickened, stiff, impaired relaxation

normal AVA

3-4 cm2

symptoms of significant AS

SOB, angina, syncope

AS etiology

senile, congential, rheumatic

what is the male to female ratio for AS

2:1

characteristics of senile AS

-calcified

-sclerosis

-thick and stiff leaflets

-mitral annular calcification

what ages is senile seen in?

50-80 years

characteristics of rheumatic AS

-scarring and thickening

-strikes MV first

-only rheumatic if MV is involved

-results in commissural fusion

characteristics of congenital BAV AS

-fusion of leaflets

-BAV most common congenital defect

-1-2% of population are BAV

-50-75% of replacements are from BAV

-eccentric closure line

-raphe

-football shape in PSAX in systole

-doming in PLAX in systole

-most common fusion is L and R cusps

coarctation and BAV relationship

more likely finding a BAV in a patient with a coarct, then finding a coarct with a BAV

main finding of a coarctation on an ultrasound

spectral broadening

what is the method of choice for valvular regurgitation

echo and doppler

what are the etiologies of aortic regurgitation

- valve degeneration

- infective endocarditis

- genetic

- trauma

what is the main genetic disorder found with aortic regurgitation?

marfan syndrome

what will you see with Marfan syndrome on an ultrasound?

effacement of ST junction = giant aortic root and aorta

likelihood of MR

70-80%

Likelihood of TR

80-90%

likelihood of PR

70-80%

likelihood of AR

5%

average value of LVOT

1.7-2.2 cm

average value for sinus of valsalva

2-3.7 cm

average value for ST junction

2-3.6 cm

average value for ascending aorta

2-3.4 cm

wall stress

force on myocardial fibers that pulls them apart; energy is expended in opposing that force

equation for wall stress

P x r / 2h

what is the law associated with wall stress?

Law of La Place

wall stress and oxygen demand relationship

direct

wall stress and pressure relationship

direct

wall stress and radius relationship

direct

wall stress and thickness relationship

inverse

wall stress with a dilated LV

increase stress

wall stress with hypertrophy

decrease stress

what etiologies of AR are chronic

degenerative and congenital

what etiologies of AR are acute

trauma

Acute AR

abrupt LV volume overload in an LV that has not had time to adapt, excessive preload

what can acute AR cause?

pulmonary edema

chronic AR

LV enlargement and increased LV compliance

AR complications

- LVEDP increase

- symptoms of fatigue and dyspnea

- LVE can lead to MR

- LV systolic dysfunction

- patients can be asymptomatic until further along

BNP

B-type natriuretic peptide

what is BNP used for

indication of heart failure

what is the normal BNP level

less than 100

Austin flint murmur and wide pulse pressure

Aortic regurgitation

how to get wide pulse pressure

more than 100 number difference between diastolic and systolic pressures or if you double the diastolic pressure, it will still be less than the systolic pressure

main ways to diagnose AR

spectral and color doppler

what does the slope of an AR CW indicate?

pressure difference between aorta and LV

The AR peak velocity

at least 4 m/sec

the steeper the AR slope...

the worse the regurg

mild pressure 1/2 time for AR

>500 ssec

moderate pressure 1/2 time for AR

200-500 msec

severe pressure 1/2 time for AR

<200 msec

what does severe AR do to diastolic function

can produce diastolic dysfunction

AR on m-mode

fluttering with closure line, incomplete closure of valve leaflets during diastole, fluttering of the AMVL, no A wave

greater risk of pulmonary edema?

acute AR

how does high LVEDP affect pressure half time

shortens it

regurgitant volume equation

SV(incompetent) - SV(competent)

regurgitant fraction equation

SV(incompetent) - SV(competent) / SV(incompetent)

vena contracta

smallest width shown in PLAX

vena contracta severe measurement

> .6 cm