EVALUATION OF PROSTHETIC VALVE FUNCTION - CCE(CARDIOLOGY) - 18.03.2023

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foreign

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Research Center Ahmedabad I will be

discussing on evaluation of prosthetic

valve function we'll focus mainly on

echocardiographic evaluation so the

introduction of valve replacement

surgery in the early 1960 improved the

outcome of patients with valvular heart

disease but despite these improvements

in well design and function it is often

said that it is only the replacement of

a native wild disease with prosthetic

wild disease so after a while we replace

the prognosis of patient depends on the

hemodynamics of the valve the durability

of while and the thrombogenicity of the

well so early diagnosis of prosthetic

World dysfunction is essential for

reducing patients morbidity what we

actually look for in a how the

prosthetic dysfunction presents to us

depends uh depends a lot on the

ventricular function the pulmonary

hypertension of the patient the

pathology of the remaining native oil

disease and also a certain non-cardiac

conditions like any condition improving

the ah

exaggerating the cardiac output of the

patient like anemia or say thyroid

disorders

the types of prosthetic was that we have

are tissue and mechanical Wells tissue

wise are biological tissues that come

from an animal that could be heterograft

or it could come from humans that could

be homographed or an autographed Source

otherwise mechanical Wells are

non-biologic it they are often made of

pyrolytic carbon polymeric silicon

substances or titanium

here we have a few examples of the

valves that are available a bilifred

valve as seen in figure a is a Saint

Jude well otherwise the single tilting

disc as seen in B is a Medtronic hole a

cage wall while like a star adverse is

also available these are the types of

mechanical one and amongst biologic well

we have stented wells like porcine

zenograft or pericardial xenograft also

they can be stainless grafts like

porcine xenograft pericardial xenograft

and homographs or they could be

percutaneous expandable over balloon or

self-expandable

mechanical valves are more durable they

have a survival rate of 94 percent and

biological are usually have a failure

rate of 15 to 20 percent at 10 years

so we uh we reached to approach to

prostatic valve uh function assessment

uh routine yearly follow-up visits are

recommended for any patient who has

undergone a vital valvular replacement

uh the basic idea comes from Clinical

information first is always the patient

symptoms we look for the type and size

of the prosthetic valve the date of the

surgery and certain vitals

echocardiographically a valve should be

made from multiple use with attention to

determine the specific type of processes

the opening and closing of the occluder

the stability of the sewing ring and the

presence of leaflet calcification

abnormal Eco density attached to the

sewing rig occluded leaflet stent

circuits such as vegetations and thrombi

we calculate the valve gradient we

calculate the effective orifice area we

confirm the normal blood flow patterns

and we detect pathologic transferular

and parallel regurgitation

in uh

figure eight is seen in a systole you

can see the properties seated between

the sewing ring and in figure bit is

seen in diastole where the puppet moves

out forward in the cage here we see a

Saint Jude processes material processes

in C2 here again in Sicily the

hemidiscus seen in a closed position and

in diastrally we can appreciate the

movement of the opening of the two discs

of the valve

so for Bio prosthesis the evidence of

leaflet degeneration comes from a

thickening of the cusp which is the

earliest and occurs thickness more than

3 mm is considered significant also

calcification tear or dehiscence is

characterized by rocking motion of the

prosthesis

so normal functioning mechanical

prosthetic well have some obstruction to

blood flow they have a closing back flow

and a leakage backflow

prosthetic well that is the star Edwards

well has more obstruction and less

leakage as compared to a tilting disc

well or a bile the Wiley flat valve has

a lesser obstruction and more leakage

similarly in BIO processes there is

there is less leakage

criteria to quantify uh prosthetic wire

stenosis have been given and effective

verifies area which is considered normal

for uh for aortic position it is normal

it is more than 1.2 for mitral it is

more than uh two uh square millimeter

and significant stenosis is considered

when the orifice area at the mitral

valve is less than one and at aortic

valve area when it is less than 0.8

is calculated by continued equation

continuity equation is ah given by the

effective orifice area which is equal to

the uh cross sectional area at the for

for supposing the effective orify series

to be calculated at the aortic well then

we see the cross sectional area of the

lvot multiplied with the velocity time

integral of the lvot and divide it with

the velocity time integral of the

prosthetic aortic valve

so accordingly here we have a example of

the shape the cross sectional area of

the lvot is seen in the para paristernal

long axis View ah if we get the diameter

of the lvot from this view we multiply

it with 0.785 because that is uh the

cross sectional area a cross sectional

area of a circle is given by pi R square

accordingly it is pi d square by 4 Pi by

4 is 0.785 multiplied by D Square gives

you a cross sectional area of the lvot

so aortic valve area can be calculated

by having the cross sectional area of

the lvot we multiply it with the

velocity time integral of the lvot which

is calculated by getting the pulse wave

Doppler at the lvot in apical four

chamber View

also we need the velocity time integral

of the aortic valve which is obtained by

get ah getting the continuous wave

Doppler of the aortic valve at ah in a

particle four chamber

so if I an effective area for mitral

values uh is obtained by a pressure half

time which is a significant delay in it

shows or a lengthening of the pressure

half time shows that the mitral valve

area is stenosed

also for a prosthetic aortic well we

depend on the acceleration time divided

by ejection time of the patient so the

counter of the aortic valve at the level

of the aortic valve obtained in a

particle 4 chamber ah by continuous uh

continuous velocity Doppler gives us the

acceleration time which is the time from

onset to the peak of the uh aortic valve

Contour that is the acceleration time as

shown here

Doppler velocity index is a

dimensionless ratio of the proximal flow

velocity to the flow velocity distal to

the prosthetic valve

so transport static velocity and

gradient is to be assessed a rise in

gradient such as prosthetic valve

dysfunction which can be because of

obstruction or regurgitation ah in a

normal prosthetic well we can get

because of patient prosthetic mismatch

High cardiac output States or pressure

recovery phenomena

so prosthetic patient mismatch it is

considered a significant or severe when

at erotic area the patient prosthetic

mismatch is less than 0.65 Square

centimeter per square millimeter and for

mitral it is less than 0.9 Square

centimeter per square millimeter so this

is the basic flowchart that we should

know at the time of uh when a patient of

with signs and symptoms suggesting

erotic prosthetic while stenosis uh

presence to us a normal normal V Max

Less Than 3 or if the mean increase in

Delta p is less than 20 uh if the

effective modifies area at the aortic

valve is more than 1.2 or index series

more than 0.85 Square centimeter per

square meter if DVI is more than equal

to 0.35

acceleration time is less than 80 or 80

upon LV it is less than 0.32 everything

says it's a normally functioning

prosthetic valve any abnormal wire

structure basically V Max more than four

a rise in Delta P more than 35 from the

previous uh on follow-up

on follow-up increase more than 20

effective orifice area less than 0.8

acceleration time more than 100 or L 80

upon 80 more than 0.37 suggests

significant stenosis anything in between

needs to be evaluated

for evaluation for example uh when the

peak prosthetic aortic velocities about

more than three meters per second uh the

first DVI has to be seen if DVI is more

than 0.3 and the counter of the jet of

the jet at the aortic valve is less than

100 it is normally appearing triangular

in shape then it is a normally

functioning prosthetic well we have to

look for the indexed effective orifice

area if it is normal it has to be a high

flow otherwise we'll get a PPM

when DVI is less than ah sorry when DVA

is more than 0.3 and acceleration time

is more than 100 then prosthetic aortic

valve stenosis with sub-value are

narrowing

is implicated when DVI is less than 0.25

and acceleration time is more than 100

such as prosthetic aortic valve stenosis

similarly for mitral valve the normal uh

parameters of the valve include a V Max

less than 1.9 a mean Delta pre mean

gradient less than five across the valve

increasing gradient on follow-up less

than three millimeter of mercury

effective modifies area more than two

index refers area more than 1.2 Square

centimeter per square meter DVI of less

than 2.2 and pressure half time of less

than 130 abnormal values that suggest

significant stenosis are V Max more than

2.5 mean uh gradient more than 10

increase in gradient more than 5 from

previous follow-up effective verifies

area less than one DVI more than 2.5 and

pressure half time of more than 200.

other things that we distinguish on an

echo for functioning of a prosthetic

valve include a thrombus and a penis a

thrombus is a large mobile less

equivalent structure it is associated

with spontaneous ecogenic contrast it is

usually associated when the INR is

therapeutic less than 2.5 whereas the

panus is a small firmly fixed uh firmly

fixed structure to the valve apparatus

it has a higher echogenicity and it has

a higher association with paralleloget

abnormally goes on uh on ecogenic

structures include spontaneous Eco

contrast micro bubbles or cavitation

strands vegetations and thrombus a

spontaneous Eco contrast this was a

smoke like ecos they are caused by

increased Red Cell aggregation in in

slow flow in low cardiac output uh

severe left atrial dilatation atrial

fibrillation and pathological

obstruction of mitral valve prosthesis

the prevalence is about seven percent to

53 percent and micro bubbles are

characterized by stream of rounded

strongly ecogenic fast moving transient

ecos they occur in in inflow zone of the

valve when the flow velocity and

pressure suddenly drop at the time of

prosthetic while closure and they are

not found in bioprostatic Wells

so here we have a

example we will just see a case of a

patient offers himmatlal thakur who

presented with acute pulmonary edema in

emergency there was no history of drug

non-compliance he had history of first

cabg with AVR uh done before five years

with normal ejection fraction his heart

rate was 116 blood pressure was 90 by

60. on examination he did not have a

quick sum

to decode and was suggestive of V Max of

4.4 mean gradient of 50 a rounded a

corner of Z DVI of 0.22 and 80 upon 80

of more than

0.5.4 so this was suggestive of

uh or take well prosthetic stenosis

thank you