Many of the prosthesis-related complications can be prevented or their impact minimized through optimal prosthesis selection in the individual patient and careful medical management and follow-up after implantation.
3. Introduction
The introduction of valve replacement surgery in the
early 1960s has dramatically improved the outcome of
patients with valvular heart disease.
Despite the improvements in prosthetic valve design
and surgical procedures , valve replacement does not
provide a definitive cure. Instead, native valve disease
is traded for “prosthetic valve disease”.
EVALUATION OF PROSTHERIC VALVE
FUNCTION-METHODS AND CLINICAL UTILITY
4. Introduction
After a valve is replaced, the prognosis for the patient
is highly correlated with the function of the
prosthetic valve like-
hemodynamics,
durability,
thrombogenicity.
Thus, early diagnosis of a prosthetic valve disorder is
crucial for reducing morbidity and mortality.
EVALUATION OF PROSTHERIC VALVE
FUNCTION-METHODS AND CLINICAL UTILITY
5. Introduction
Symptoms of prosthetic valve dysfunction may be non
specific, making it difficult to differentiate the effects of
prosthetic valve dysfunction from
ventricular dysfunction,
pulmonary hypertension,
the pathology of the remaining native valves,
no cardiac conditions.
Although physical examination can alert clinicians to the
presence of significant prosthetic valve dysfunction,
diagnostic methods are often needed to assess the
function of the prosthesis.
EVALUATION OF PROSTHERIC VALVE
FUNCTION-METHODS AND CLINICAL UTILITY
6. Types of prosthetic valves
Prosthetic Valves are classified as tissue or
mechanical
Tissue:
• Made of biologic tissue from an animal (bioprosthesis
or heterograft) or human (homograft or autograft)
source
Mechanical
Made of non biologic material (pyrolitic carbon,
polymeric silicone substances, or titanium)
Blood flow characteristics, hemodynamics, durability,
and thromboembolic tendency vary depending on the
type and sizeEVALUATION OF PROSTHERIC VALVE characteristics of
of the prosthesis and
the patient FUNCTION-METHODS AND CLINICAL UTILITY
8. Mechanical Valves
Extremely durable with overall survival rates of 94%
at 10 years
Primary structural abnormalities are rare
Most malfunctions are secondary to perivalvular leak
and thrombosis
Chronic anticoagulation required in all
With adequate anticoagulation, rate of thrombosis is
0.6% to 1.8% per patient-year for bileaflet valves.
EVALUATION OF PROSTHERIC VALVE
FUNCTION-METHODS AND CLINICAL UTILITY
9. Biological Valves
Stented bioprostheses
Primary mechanical failure at 10 years is 15-20%
Preferred in patients over age 70
Subject to progressive calcific degeneration & failure
after 6-8 years
Stentless bioprostheses
Absence of stent & sewing cuff allow implantation of
larger valve for given annular size->greater EOA
Uses the patient’s own aortic root as the stent,
absorbing the stress induced during the cardiac cycle
EVALUATION OF PROSTHERIC VALVE
FUNCTION-METHODS AND CLINICAL UTILITY
10. Biologic Valves Continued
Homografts
Harvested from cadaveric human hearts
Advantages: resistance to infection, lack of need for
anticoagulation, excellent hemodynamic profile (in
smaller aortic root sizes)
More difficult surgical procedure limits its use
Autograft
Ross Procedure
EVALUATION OF PROSTHERIC VALVE
FUNCTION-METHODS AND CLINICAL UTILITY
11. Desired valves
Mechanical valves - preferred in young patients
who have a life expectancy of more than 10 to 15 years
who require long-term anticoagulant therapy for other
reasons (e.g., atrial fibrillation).
Bioprosthetic valves
Preferred in patients who are elderly
Have a life expectancy of less than 10 to 15 years
who cannot take long-term anticoagulant therapy
A bileaflet-tilting-disk or homograft prosthesis is most
suitable for a patient with a small valvular annulus in
whom a prosthesis with the largest possible effective
orifice area is desired.OF PROSTHERIC VALVE
EVALUATION
FUNCTION-METHODS AND CLINICAL UTILITY
12. Algorithm for choice of prosthetic
heart valve
EVALUATION OF PROSTHERIC VALVE
FUNCTION-METHODS AND CLINICAL UTILITY
13. Approach to prosthetic valve
function assesment
CLINICAL INFORMATION &CLINICAL EXAMINATION
IMAGING OF THE VALVES
CXR
2D echocardiography
TEE
3D echo
CineFluoro
CT
Cardiac catheterisation
EVALUATION OF PROSTHERIC VALVE
FUNCTION-METHODS AND CLINICAL UTILITY
15. HISTORY
Subtle symptoms of cardiac failure or neurologic
events can be clues to serious valve dysfunction.
EVALUATION OF PROSTHERIC VALVE
FUNCTION-METHODS AND CLINICAL UTILITY
16. CLINICAL INFORMATION
Clinical data including reason for the study and the
patient’s symptoms
Type & size of replacement valve,
date of surgery
Patient’s height, weight, and BSA should be recorded
to assess whether prosthesis-patient mismatch (PPM)
is present
BP & HR
HR particularly important in mitral and tricuspid
evaluations because the mean gradient is dependent on
the diastolic filling period
EVALUATION OF PROSTHERIC VALVE
FUNCTION-METHODS AND CLINICAL UTILITY
20. CXR
chest x-ray are not performed on a routine basis in
the absence of a specific indication.
It can be helpful in identification of valve type if
information about valve is not available.
EVALUATION OF PROSTHERIC VALVE
FUNCTION-METHODS AND CLINICAL UTILITY
21. The location of the cardiac
valves is best determined
on the lateral radiograph.
A line is drawn on the
lateral radiograph from
the carina to the cardiac
apex.
The pulmonic and aortic
valves generally sit above
this line and the tricuspid
and mitral valves sit below
this line.
So me time s the ao rtic ro o t
can be infe rio rly displace d
which will shift the ao rtic
valve be lo w this line . OF PROSTHERIC VALVE
EVALUATION
FUNCTION-METHODS AND CLINICAL UTILITY
23. For further localization
prosthetic valves involves
drawing a second line
which is perpendicular to
the patient's upright
position which bisects the
cardiac silouette.
The aortic valve projects
in the upper quadrant, the
mitral valve in the lower
quadrant ,the tricuspid
valve in the anterior
quadrant and pulmonary
valve in the superior
portion of the posterior
quadrant
EVALUATION OF PROSTHERIC VALVE
FUNCTION-METHODS AND CLINICAL UTILITY
24. On the frontal chest
radiograph ( AP or PA ) -
longitudinal line through the
mid sternal body. draw a
perpendicular line dividing
the heart horizontally.
The aortic valve -
intersection of these two
lines.
The mitral valve - lower
left quadrant (patient’s left).
The tricuspid valve - lower
right corner (the patient's
right)
The pulmonic valve- upper
left corner (the patient's OF PROSTHERIC VALVE This method is less reproducible
EVALUATION
left).
FUNCTION-METHODS AND CLINICAL UTILITY
25. Patients with cardiac valves often have chamber
enlargement and cardiac rotation which can displace
the positions of the valves as well as create difficulty
when drawing lines through the cardiac silouette.
These rules are meant as a guideline to better localize
cardiac valves although they do not always work.
EVALUATION OF PROSTHERIC VALVE
FUNCTION-METHODS AND CLINICAL UTILITY
26. Some bioprosthetic valves have components that
determine the direction of flow which helps
localize the valve prosthesis.
If the direction of flow is from
inferior to superior – likely aortic valve.
superior to inferior- likely a mitral valve.
EVALUATION OF PROSTHERIC VALVE
FUNCTION-METHODS AND CLINICAL UTILITY
28. Radiologic Identification
Starr-Edwards caged
ball valve
Radiopaque base ring
Radiopaque cage
Silastic ball impregnated
with barium that is
mildly radiopaque (but
not in all models)
EVALUATION OF PROSTHERIC VALVE
FUNCTION-METHODS AND CLINICAL UTILITY
29. Appearance of
CarboMedics prosthesis
on plain radiography.
EVALUATION OF PROSTHERIC VALVE
FUNCTION-METHODS AND CLINICAL UTILITY
30. Echo Imaging of Prosthetic Valves
EVALUATION OF PROSTHERIC VALVE
FUNCTION-METHODS AND CLINICAL UTILITY
31. TIMING OF ECHO CARDIOGRAPHIC
FOLLOW-UP
Ideally, a baseline postoperative transthoracic
echocardiography(TTE) study should be performed
3-12weeks after surgery, when the
chest wound has healed,
ventricular function has improved, and
anaemia with its associated hyperdynamic state has
resolved.
EVALUATION OF PROSTHERIC VALVE
FUNCTION-METHODS AND CLINICAL UTILITY
32. Bioprosthetic valves Annual echocardiography is
recommended after the first 5years,
Mechanical valves, routine annual echocardiography is
not indicated in the absence of a change in clinical
status.
EVALUATION OF PROSTHERIC VALVE
FUNCTION-METHODS AND CLINICAL UTILITY
33. challenges in echocardiography
The high reflectance leads to
shadowing
Reverberations
multiple echocardiographic windows must be used to fully
interrogate the areas around prosthetic valves.
transesophageal echocardiography is necessary to provide
a thorough examination.
For stented valves-ultrasound beam aligned parallel to
flow to avoid the shadowing effects of the stents and
sewing ring.
EVALUATION OF PROSTHERIC VALVE
FUNCTION-METHODS AND CLINICAL UTILITY
35. The concept of pressure recovery
EVALUATION OF PROSTHERIC VALVE
FUNCTION-METHODS AND CLINICAL UTILITY
36. The primary goals of 2D echo
Valves should be imaged from multiple views, with
attention to
determine the specific type of prosthesis,
confirm the opening and closing motion of the
occluding mechanism,
confirm stability of the sewing ring(abnormal rocking
motion )
Presence of leaflet calcification or abnormal echo density
attached to the sewing ring, occluder, leaflets, stents, or
cage such as vegetations and thrombi
EVALUATION OF PROSTHERIC VALVE
FUNCTION-METHODS AND CLINICAL UTILITY
37. Primary goals of 2D echo
(cont)
Calculate valve gradient
Calculate effective orifice area
Confirm normal blood flow patterns
Detection of pathologic transvalvular and
paravalvular regurgitation.
EVALUATION OF PROSTHERIC VALVE
FUNCTION-METHODS AND CLINICAL UTILITY
38. Starr-Edwards mitral prosthesis is shown. A: During systole, the poppet is
seated within the sewing ring (arrows). B: During diastole, the poppet moves
forward into the cageEVALUATION OF PROSTHERIC VALVE
(arrows), allowing blood flow around the occluder.
FUNCTION-METHODS AND CLINICAL UTILITY
39. St. Jude mitral prosthesis is demonstrated. A: During systole, the hemidisks are
shown in the closed position (arrows). B: During diastole, the two disks are
recorded in the open position (arrows).
EVALUATION OF PROSTHERIC VALVE
FUNCTION-METHODS AND CLINICAL UTILITY
40. St. Jude aortic prosthesis is demonstrated. The sewing ring is indicated
by the arrows. The walls of the aortic root (Ao) often obscure the
motion of the disks.
EVALUATION OF PROSTHERIC VALVE
FUNCTION-METHODS AND CLINICAL UTILITY
41. M-Mode
M-Mode echocardiography enables better evaluation
of valve movements and corresponding time intervals
and recognition of quick movements and fibrillations.
EVALUATION OF PROSTHERIC VALVE
FUNCTION-METHODS AND CLINICAL UTILITY
43. For bioprostheses, evidence of leaflet degeneration
can be recognized as
leaflet thickening (cusps >3 mm in thickness)-
earliest sign
calcification (bright echoes of the cusps),
tear (flail cusp).
Prosthetic valve dehiscence is characterized by a
rocking motion of the entire prosthesis.
An annular abscess may be recognized as an
echolucent, irregularly shaped area adjacent to the
sewing ring of the prosthetic valve.
EVALUATION OF PROSTHERIC VALVE
FUNCTION-METHODS AND CLINICAL UTILITY
44. Assessment of Flow Characteristics
of Prosthetic Valves
Normal functioning mechanical prosthetic valves
cause:
some obstruction to blood flow
closure backflow (necessary to close the valve)
leakage backflow (after valve closure)
The extent of normal obstruction and leakage of prosthetic
valves depends on prosthetic valve design
EVALUATION OF PROSTHERIC VALVE
FUNCTION-METHODS AND CLINICAL UTILITY
45. Valve type Flow Characteristics
Ball-in-cage prosthetic valve (Starr- much obstruction and little leakage.
Edwards, Edwards Lifescience)
Tilting disc prosthetic valve (Björk- less obstruction and more leakage.
Shiley; Omniscience; Medtronic Hall)
Bileaflet prosthetic valves (St. Jude Less obstruction and more leakage.
Medical; Sorin Bicarbon; Carbomedics)
Bioprostheses. little or no leakage
Homografts, pulmonary autografts, and almost unobstructive to blood flow.
unstented bioprosthetic valves
(Medtronic Freestyle,
Toronto, Ontario, Canada)
Stented bioprostheses (leaflets obstructive to flow.
suspended within a frame)
EVALUATION OF PROSTHERIC VALVE
FUNCTION-METHODS AND CLINICAL UTILITY
46. Dopplar interogation
EVALUATION OF PROSTHERIC VALVE
FUNCTION-METHODS AND CLINICAL UTILITY
47. color flow imaging is
often helpful to define
the location and
direction of the various
flow patterns.
pulsed and continuous
wave Doppler imaging
can be oriented to
quantify flow velocity.
Whenever velocity is higher than expected,
consider the possibility of pressure recovery.
EVALUATION OF PROSTHERIC VALVE
FUNCTION-METHODS AND CLINICAL UTILITY
48. Challenges in doppler interogation
variability of flow
through and around the
different prostheses
Some prosthetic valves
have more than one
orifice and,
consequently, a complex
flow profile
EVALUATION OF PROSTHERIC VALVE
FUNCTION-METHODS AND CLINICAL UTILITY
49. Challenges in doppler interogation
Because the signal-to-noise ratio for Doppler imaging
is lower compared with two-dimensional
echocardiographic imaging, the shadowing effect is
even more pronounced and the ability to record a
Doppler signal behind a prosthetic valve is very
limited
Multiple views m be used to fullyinterrogate the regurgitant signal.
ust
EVALUATION OF PROSTHERIC VALVE
FUNCTION-METHODS AND CLINICAL UTILITY
50. Primary goals of dopplar
interogation
ASSESMENT OF OBSTRUCTION OF
PROSTHETIC VALVE
DETECTION AND QUANTIFICATION OF
PROSTHETIC VALVE REGURGITATION
EVALUATION OF PROSTHERIC VALVE
FUNCTION-METHODS AND CLINICAL UTILITY
51. Doppler Assessment of Obstruction
of Prosthetic Valves
Quantitative parameters of prosthetic valve function
Trans prosthetic flow velocity & pressure gradients,
valve EOA,
Doppler velocity index(DVI).
EVALUATION OF PROSTHERIC VALVE
FUNCTION-METHODS AND CLINICAL UTILITY
52. Effective orifice area(EOA)
Continuity equation
EOA PrAV = (CSA LVO x VTI LVO) / VTI PrAV
EVALUATION OF PROSTHERIC VALVE
FUNCTION-METHODS AND CLINICAL UTILITY
55. EOA of mitral prostheses:
Pressure half time may be useful if it is significantly
delayed or shows significant lengthening from one
follow-up visit to the other despite similar heart rates.
continuity equation using the stroke volume
measured in the LVOT. However, this method cannot
be applied when there is more than mild concomitant
mitral or aortic regurgitation.
o better for bioprosthetic valves and single tilting disc
mechanical valves.
o underestimation of EOA in case bileaflet valves.
EVALUATION OF PROSTHERIC VALVE
FUNCTION-METHODS AND CLINICAL UTILITY
57. PPM
PPM occurs when the EOA of the prosthesis is too
small in relation to the patient's body size, resulting
in abnormally high postoperative gradients.
EOA indexed to the patient’ s body surface area
. PPM AORTIC MITRAL
Insignificant >0.85 cm2/m2. >1.20 cm²/m²
moderate 0.65and0.85cm2/m2. 0.9-1.20 cm²/m²
severe <0.65 cm2/m2. <0.90 cm²/m²
EVALUATION OF PROSTHERIC VALVE
FUNCTION-METHODS AND CLINICAL UTILITY
58. Transprosthetic jet contour and
acceleration time
AT/ET > 0.4
AT and AT/ET, angle-independent parameters.
EVALUATION OF PROSTHERIC VALVE
FUNCTION-METHODS AND CLINICAL UTILITY
60. Doppler velocity index
Dimensionless ratio of the proximal flow velocity in
the LVOT to the flow velocity through the aortic
prosthesis
DVI=VLVOT/VPrAv
• Time velocity time integrals may also be used in
Place of peak velocities
DVI= TVILVOT /TVIPrAv
• Prosthetic mitral valves, the DVI is calculated by
DVI=TVIPrMv/TVILVOT
EVALUATION OF PROSTHERIC VALVE
FUNCTION-METHODS AND CLINICAL UTILITY
61. DVI had a sensitivity, specificity, positive and negative predictive values,
and accuracy of 59%, 100%, 100%, 88%, and 90%, respectively.
EVALUATION OF PROSTHERIC VALVE
FUNCTION-METHODS AND CLINICAL UTILITY
63. IMPORTENCE
DVI can be helpful to screen for valve
dysfunction, particularly when the
Crosssectional area of the LVO tract cannot be
obtained
Valve size is not known.
EVALUATION OF PROSTHERIC VALVE
FUNCTION-METHODS AND CLINICAL UTILITY
64. Transprosthetic velocity and gradient
• The flow is
eccentric - monoleaflet valves multi-windows examination
three separate jets - bileaflet valves
Localised high velocity may be recorded by
continuous wave(CW) Doppler
Interrogation through the smaller central
orifice of the bileaflet mechanical prostheses
overestimation of gradient
EVALUATION OF PROSTHERIC VALVE
FUNCTION-METHODS AND CLINICAL UTILITY
67. Highvelocity or gradient alone is not proof of intrinsic
prosthetic obstruction and may be secondary to
prosthesis patient mismatch (PPM),
high flow conditions,
prosthetic valve regurgitation, or
localised high central jet velocity in bileaflet
mechanical valves.
Increased heart rate.
EVALUATION OF PROSTHERIC VALVE
FUNCTION-METHODS AND CLINICAL UTILITY
68. Algorithm for interpreting abnormally high transprosthetic pressure gradients
EVALUATION OF PROSTHERIC VALVE
FUNCTION-METHODS AND CLINICAL UTILITY
72. DETECTION AND QUANTIFICATION OF
PROSTHETIC VALVE REGURGITATION
• Physiologic Regurgitation.
closure backflow (necessary to close the valve)
leakage backflow (after valve closure)- washing jets
o short in duration
o narrow
o symmetrical
o homogenous
Pathologic Prosthetic Regurgitation.
EVALUATION OF PROSTHERIC VALVE
FUNCTION-METHODS AND CLINICAL UTILITY
73. Homogeneous in color, with aliasing mostly confined to the base of the jet
EVALUATION OF PROSTHERIC VALVE
FUNCTION-METHODS AND CLINICAL UTILITY
74. Pathologic Prosthetic Regurgitation
Pathologic regurgitation is either
central Pathologic jets tend to be high velocity,
paravalvular. intense, broad, and highly aliased.
Most pathologic central valvular regurgitation is seen
with biologic valves, whereas paravalvular regurgita-
tion is seen with either valve type and is frequently
the site of regurgitation in mechanical valves.
EVALUATION OF PROSTHERIC VALVE
FUNCTION-METHODS AND CLINICAL UTILITY
82. Thrombus and Pannus
In one surgical study of 112 obstructed mechanical
valves,
pannus formation was the underlying cause in
11 percent of valves,
pannus formation in combination with thrombus was
present in 12 percent,
thrombus alone was the etiology in the remaining
cases.
EVALUATION OF PROSTHERIC VALVE
FUNCTION-METHODS AND CLINICAL UTILITY
83. Distinction between thrombus and
pannus
Thrombus Large,
mobile,
less echo-dense,
associated with spontaneous contrast,
INR<2.5
Pannus Small
firmly fixed (minimal mobility) to the valve apparatus
highly echogenic, (fibrous composition)
common in aortic position
Para valve jet suggests pannus
EVALUATION OF PROSTHERIC VALVE
FUNCTION-METHODS AND CLINICAL UTILITY
88. Abnormal echoes
Abnormal echoes that may be found in patients with
prosthetic valves are
spontaneous echo contrast (SEC),
microbubbles or cavitations, strands,
sutures,
vegetations,
thrombus.
EVALUATION OF PROSTHERIC VALVE
FUNCTION-METHODS AND CLINICAL UTILITY
89. Spontaneous echo contrast (SEC)is defined as smoke-
like echoes.
SEC is caused by increased red cell aggregation that
occurs in slow flow, for example, because of a
low cardiac output,
severe left atrial dilatation,
atrial fibrillation, or
pathologic obstruction of a mitral prosthesis.
The prevalence of SEC is 7% to 53%.
EVALUATION OF PROSTHERIC VALVE
FUNCTION-METHODS AND CLINICAL UTILITY
90. Microbubbles are characterized by a discontinuous
stream of rounded, strongly echogenic, fast moving
transient echoes
Microbubbles occur at the inflow zone of the valve
when flow velocity and pressure suddenly drop at the
time of prosthetic valve closing, but may also be seen
during valve opening.
Microbubbles are probably due to carbon dioxide
degassing.
EVALUATION OF PROSTHERIC VALVE
FUNCTION-METHODS AND CLINICAL UTILITY
91. Kaymaz et al
75% of the normal bileaflet valves compared with 39%
of the tilting-disk valves.
In prosthetic valves with thrombotic obstruction,
microbubbles were found in only 6% , whereas they
reappeared after successful thrombolytic treatment
with relief of valvular obstruction in 69%
Microbubbles are not found in bioprosthetic valves.
EVALUATION OF PROSTHERIC VALVE
FUNCTION-METHODS AND CLINICAL UTILITY
92. Strands are thin, mildly echogenic, filamentous
structures that are several mm long and move
independently from the prosthesis.
They are often visible intermittently during the car-
diac cycle but recur at the same site.
They are usually located at the inflow side of the
prosthetic valve
Strands are found in 6% to 45% of patients.
Have a fibrinous or a collagenous composition.
EVALUATION OF PROSTHERIC VALVE
FUNCTION-METHODS AND CLINICAL UTILITY
93. Sutures are defined as linear, thick, bright, multiple,
evenly spaced, usually immobile echoes seen at the
periphery of the sewing ring of a prosthetic valve;
They may be mobile when loose or unusually long.
EVALUATION OF PROSTHERIC VALVE
FUNCTION-METHODS AND CLINICAL UTILITY
94. TEE
Careful alignment of the transducer is essential to
fully display leaflet motion as comprehensively as
possible.
Multiplane imaging should be done at a minimum of
every 30˚from 0–180˚.
EVALUATION OF PROSTHERIC VALVE
FUNCTION-METHODS AND CLINICAL UTILITY
95. TEE evaluation immediately after valve replacement
1. Verify that all leaflets or occluders move normally.
2. Verify the absence of paravalvular regurgitation.
3. Verify that there is no left ventricular outflow tract
obstruction by struts or subvalvular apparatus.
TEE diagnosis of prosthetic valve dysfunction
1. Identification of prosthetic valve type.
2. Detection and quantification of transvalvular or
paravalvular regurgitation.
3. Detection of annular dehiscence.
4. Detection of vegetations consistent with endocarditis.
5. Detection of thrombosis or pannus formation on the
valve.
6. Detection and quantification of valve stenosis.
7. Detection of tissue degeneration or calcification.
EVALUATION OF PROSTHERIC VALVE
FUNCTION-METHODS AND CLINICAL UTILITY
96. TEE
Higher-resolution image than TTE
Proximity of the oesophagus to the heart .
Size of vegetation defined more precisely
Absence of interference with lungs and ribs, a very detailed image can
be obtained of the atrial side
of the mitral valve prosthesis and especially the posterior part of the
aortic prosthesis.
Peri annular complications indicating a locally uncontrolled
infection (abscesses, dehiscence, fistulas) detected earlier.
EVALUATION OF PROSTHERIC VALVE
FUNCTION-METHODS AND CLINICAL UTILITY
97. limitation -inability to detect aortic prosthetic-valve
obstruction or regurgitation, especially when a mitral
prosthesis is present.
EVALUATION OF PROSTHERIC VALVE
FUNCTION-METHODS AND CLINICAL UTILITY
98. CONSIDERATIONS IN TAVI
The echocardiographic evaluation of TAVI is , in
most ways same as that for surgically implanted
valves
But 2 areas of chalenges are
Caluculation of EOA
Quantification of post TAVI AR
EVALUATION OF PROSTHERIC VALVE
FUNCTION-METHODS AND CLINICAL UTILITY
99. CONSIDERATIONS IN TAVI
LVOT diameter and velocity should be measured
immediately proximal to the apical border of the
stent.
However, if the border of the stent sits low in the
LVOT, which may occur more frequently with self-
expandable prostheses (such as the CoreValve), it may
be preferable to measure the LVOT diameter and
velocity within the proximal portion of the stent at
approximately 5-10 mm below the bioprosthetic valve
leaflets.
EVALUATION OF PROSTHERIC VALVE
FUNCTION-METHODS AND CLINICAL UTILITY
100. CONSIDERATIONS IN TAVI
Paravalvular regurgitation is more common following
transcatheter aortic valve implantation versus
standard valve replacement– 30-80% with 5-
14%being moderate or severe.
EVALUATION OF PROSTHERIC VALVE
FUNCTION-METHODS AND CLINICAL UTILITY
101. CONSIDERATIONS IN TAVI
Delayed migration and embolisation of the prosthesis
have been reported following transcatheter valve
implantation.
The distance between the ventricular end of the
prosthesis stent and the hinge point of the mitral
valve measured in the parasternal long axis view can
be used to monitor the position of the prosthesis
during follow-up.
EVALUATION OF PROSTHERIC VALVE
FUNCTION-METHODS AND CLINICAL UTILITY
102. Considerations for Intraoperative
Patients
TEE and epicardial and epiaortic ultrasound
TEE remains the most widely used
American Society of Anesthesiologists has recommended
intraoperative TEE as a category II indication in patients
undergoing valve surgery
Current ACC & AHApractice guidelines recommend
TEE as a class 1 indication for patients undergoing valve
replacement with stentless xenograft, homograft, or
autograft valves.
EVALUATION OF PROSTHERIC VALVE
FUNCTION-METHODS AND CLINICAL UTILITY
103. Considerations for Intraoperative
Patients
Multiple echocardiographic views are obtained to
determine
Appropriate movement of valve leaflets,
Color flow Doppler should exclude the presence of
paravalvular leaks
• Immediate surgical attention
Any regurgitation that is graded moderate or severe,
‘Stuck’’ mechanical valve leaflets,
Valve dehiscence,
Dysfunction of adjacent valves
EVALUATION OF PROSTHERIC VALVE
FUNCTION-METHODS AND CLINICAL UTILITY
104. Stress Echocardiography in Evaluating
Prosthetic Valve Function
Stress echocardiography should be considered in
patients with exertional symptoms for which the
diagnosis is not clear.
Dobutamine and supine bicycle exercise are most
commonly used.
Treadmill exercise provides additional information
about exercise capacity but is less frequently used
because the recording of the valve hemodynamics is
after completion of exercise, when the
hemodynamics may rapidly return to baseline.
EVALUATION OF PROSTHERIC VALVE
FUNCTION-METHODS AND CLINICAL UTILITY
105. Stress Echocardiography(cont)
Prosthetic Aortic Valves
Guide to significant obstruction would be similar to
that for native valves, such as a rise in mean gradient
>15 mm Hg with stress.
Prosthetic Mitral Valves
Obstruction or PPM is likely if the mean gradient
rises > 18 mm Hg after exercise, even when the
resting mean gradient is normal.
EVALUATION OF PROSTHERIC VALVE
FUNCTION-METHODS AND CLINICAL UTILITY
106. RT-3D TEE
Excellent spacial imaging
Ease of use
Enables enface viewing(surgical view)
adds to the available information provided by
traditional imaging modalities.
EVALUATION OF PROSTHERIC VALVE
FUNCTION-METHODS AND CLINICAL UTILITY
107. Limitations of 3D echo
poor visualization of anterior cardiac structures,
poor temporal resolution,
poor image quality in patients with arrhythmias
tissue dropout
EVALUATION OF PROSTHERIC VALVE
FUNCTION-METHODS AND CLINICAL UTILITY
110. Cinefluoroscopy
Structural integrity
Motion of the disc or poppet
Excessive tilt ("rocking") of the base ring - partial
dehiscence of the valve
Aortic valve prosthesis - RAO caudal
- LAO cranial
Mitral valve prosthesis - RAO cranial .
EVALUATION OF PROSTHERIC VALVE
FUNCTION-METHODS AND CLINICAL UTILITY
111. Fluoroscopy of a normally functioning CarboMedics
bileaflet prosthesis in mitral position
A=opening angle B=closing angle
EVALUATION OF PROSTHERIC VALVE
FUNCTION-METHODS AND CLINICAL
UTILITY
112. St. Jude medical
bileaflet valve
Mildly radiopaque
leaflets are best seen
when viewed on end
Seen as radiopaque
lines when the leaflets
are fully open
Base ring is not
visualized on most
models
EVALUATION OF PROSTHERIC VALVE
FUNCTION-METHODS AND CLINICAL UTILITY
113. MULTISLICE CT
Because of its high temporal and spatial resolution,
MDCT has recently shown good potential in
assessing prosthetic valve disorders.
to evaluate the prosthetic valve motion in various
planes, with a focus on leaflet motion and on the
residual opening angle between leaflets.
EVALUATION OF PROSTHERIC VALVE
FUNCTION-METHODS AND CLINICAL UTILITY
114. The residual
openingangle, the angle
between two leaflets when
fully opened, is measured
using the plane
perpendicular to the two
leaflets
Normal limit (≤ 20°)
• For a single-leaflet
prosthetic valve, the
maximal opening angle is
recorded. EVALUATION OF PROSTHERIC VALVE
FUNCTION-METHODS AND CLINICAL UTILITY
115. Special attention is also
paid to the relationship
between the suture ring and
the surrounding valve
annulus for detecting
thrombosis,
paravalvular leak (suture
loosening),
pannus,
pseudoaneurysm formation.
EVALUATION OF PROSTHERIC VALVE
FUNCTION-METHODS AND CLINICAL UTILITY
118. Thrombolysis impact
EVALUATION OF PROSTHERIC VALVE
FUNCTION-METHODS AND CLINICAL UTILITY
119. MDCT
In IE MDCT clarify the extent of the damage to the
valve and paravalvular region to provide the surgeon
the information required for débridement and a redo
of the valve replacement.
EVALUATION OF PROSTHERIC VALVE
FUNCTION-METHODS AND CLINICAL UTILITY
120. Cardiac Catheterization
measure the transvalvular pressure gradient, from
which the EOA can be calculated –Gorlin formula.
can visualize and quantify valvular or paravalvular
regurgitation by Contrast injection.
In clinical practice, it is not commonly performed.
Crossing a prosthetic valve with a catheter should not
be attempted in mechanical valves because of
limitations and possible complications.
Tissue valves can be crossed with a catheter easily,
but a degenerative, calcified bioprosthesis is friable,
and leaflet rupture with acute severe regurgitation is
possible.
EVALUATION OF PROSTHERIC VALVE
FUNCTION-METHODS AND CLINICAL UTILITY
121. TAKE HOME
Many of the prosthesis-related complications can be
prevented or their impact minimized through optimal
prosthesis selection in the individual patient and
careful medical management and follow-up after
implantation.
EVALUATION OF PROSTHERIC VALVE
FUNCTION-METHODS AND CLINICAL UTILITY
mechanical valves can be quite difficult to assess with two-dimensional echocardiography. Although gross abnormalities can be detected, more subtle changes are often missed, especially with transthoracic imaging.
M-Mode image of a Bileaflet prosthetic valve -- leaflets form two parallel lines while open, disappearing when closed
measurementis often difficult because of the reverberations and artefactscausedbythe prosthesisstentorsewing ring
usually requires a position 0.5 to 1 cm below the sewing ring (toward the apex)
Schematic representation of the concept of the DVI. Velocity across the prosthesis is accelerated through the jet from the LVO tract. DVI is the ratio velocity in the LVO (Vlvo)to that of the jet (Vjet )
DVI is always less than unity, because velocity will always accelerate through the prosthesis. A DVI < 0.25 is highly suggestive of significant valve obstruction. Similar to EOA, DVI is not affected by high flow conditions through the valve, including AR, whereas blood velocity and gradient across the valve are.
Localized high gradient in a mitral bileaflet valve. A, Visualization of lateral (narrow arrow) and central (large arrow) jets on color Doppler image. B, C, Two Doppler envelopes are superimposed. The highest one, which presumably reflects the velocity within the central orifice, yields a value of peak gradient of 21 mm Hg, whereas the smallest one (lateral orifices) provides a gradient of 12 mm Hg.
Examples of bileaflet, single-leaflet, and caged-ball mechanical valves and their transesophageal echocardiographic char-acteristics taken in the mitral position in diastole(middle)and in systole(right). The arrows in diastole point to the occluder mechanism of the valve and in systole to the characteristic physiologic regurgitation observed with each valve. Videos 1 to 6 show the motion and color flow patterns seen with these valves Starr-Edwards valve, there is a typical small closing volume and usually little or no truetransvalvular regurgitation single tilting disc valves have both types of regurgitation, but the pattern may vary: the Bjork-Shiley valve has small jets located just inside the sewing ring, where the closed disc meets the housing, while the Medtronic Hall valve has these same jets plus a single large jet through a central hole in the disc The bileaflet valves typically have multiple jets located just inside the sewing ring, where the closed leaflets meet the housing, and centrally, where the closed bileaflets meet each other
The white or black arrows indicate the regurgitant jet(s). (A, B) Transoesophageal echocardiographic (TOE) views of normal physiological regurgitant jets (thin white arrows; A and B) and paravalvular regurgitant jets (thick white arrows; B) in mitral bileaflet mechanical valves
(G) TTE short axis view of a mild paravalvular regurgitation (one single jet occupying<10% of circumference) in a stented aortic bioprosthetic valve. (H) TOE short axis view of a severe paravalvular regurgitation (two jets occupying>20% of circumference) in a transcatheter bioprosthetic aortic valve
Pannus formation on a St Jude Medical valve prosthesis in the aortic position as depicted by TEE. The mass is highly echogenic and corresponds to the pathology of the pannus at surgery
Prosthetic St Jude Medical valve thrombosis in the mitral position(arrow)obstructing and immobilizing one of the leaflets of the valve. After thrombolysis, leaflet mobility is restored, and the mean gradient (Gr) is significantly decreased.
De-gassing involves separation of the gas contained in the water (or blood). In the case of a tran-sient drop in pressure, the gas separates out be-fore redissolving in the water when normal pressure is re-established.
ie, the atrial side of a mitral pros-thesis or the ventricular side of an aortic pros-thesis Strands have been found to be more common in patients undergoing TEE for evalu-ation of the source of embolism than in patients examined for other reasons the thera-peutic implications of prosthetic valve-associat-ed strands remain unclear. Importantly, if strands consist of collagen, aggressive thera-peutic anticoagulation is not likely to com-pletely eliminate their embolic potential
Real-time three-dimensional transesophageal echocardiography of a normal mechanical mitral valve visualized from the left atrium with the leafletsin systole (A) and in diastole (B).
Real-time three-dimensional transesophageal echocardiography of a bioprosthetic mitral valve with vegetation on the atrial side of the leaflet as visualized from the left atrium (A) and left ventricle (B). In image B, the struts of the bioprosthetic valve are clearly visible. Black arrow points to the vegetation
Long-axis view of left ventricular outflow tract (LVOT) perpendicular to prosthetic valve leaflets in systolic phase shows residual opening angle (dashed lines) is 19°, which is still within normal limit (≤ 20°)