Prosthetic Valves II
John N. Hamaty, DO, FACC, FACOI
Question 1
For each of the following four images, the valve shown is:
A. Bileaflet mechanical valve
B. Mechanical valve, unknown type
C. Stented prosthetic valve
D. Stentless bioprosthetic valve
E. Normal native valve
Answer – 1A
Stented bioprosthetic valve
This is a zoomed image of an aortic valve
prosthesis in the parasternal short-axis view in
an 82 year old woman who underwent valve
replacement for severe aortic stenosis 4 years
ago. Three struts of the valve are seen at the
perimeter of the valve with thin leaflets between
the struts, consistent with the typical appearance
of a bioprosthetic stented aortic valve.
Answer – 1B
Mechanical Valve, Unknown Type
This apical 4-chamber view shows a
mechanical mitral valve with extensive
reverberations and shadowing distal to the
valve, obscuring the LA in an 85 year old
woman who had undergone valve surgery
10 years ago. The exact valve type cannot
be discerned on this still frame image, but
it is most likely a “low-profile” valve
(bileaflet or single tilting disc) rather than a
ball and cage valve, which protrudes
further into the LV cavity.
Answer – 1C
Bileaflet mechanical valve
Answer – 1D
Stentless bioprosthetic valve
This TEE image recorded in the 2-chamber
plane (note the image plane rotation angle and
the LA appendage) shows the typical appearance
of a bileaflet mechanical valve. The disks are
closed in systole, forming a “tent-shaped”
closure within the sewing ring. Distal to the
valve the LV is obscured by shadowing from the
sewing ring and reverberations from the valve
disks. The small dense echo on the atrial side of
the medial aspect of the sewing ring most likely
is a valve suture.
This zoomed parasternal long-axis diastolic image
of the aortic valve might be mistaken for a normal
appearance of the aortic valve leaflets. However,
there is increase echodensity in the paravalvular
region, both anteriorly and posteriorly, consistent
with the extra tissue of a stentless bioprosthetic
valve. This image emphasizes the importance of
complete and correct clinical information for
interpretation of echocardiographic data, as this
patient was known to have a stentless aortic
bioprosthesis.
Question 2
This 44 year old male presented for evaluation of atypical chest pain. He had undergone aortic valve replacement
for aortic regurgitation 8 years ago with placement of a 27 mm stented bioprosthetic valve. A post-operative
echocardiogram demonstrated an aortic velocity of 2.4 m/s, mean transaortic gradient of 19 mmHg, and valve
area of 1.5cm2 . Data from the current study are shown in the figure below.
Measure the aortic valve velocity and calculate the maximum transaortic gradient and valve area.
Answer 2
Aortic Velocity -Maximum gradient
Aortic valve area
3.0 m/s
36 mmHg
1.1cm2
The aortic velocity shown is about 3.0 m/s, corresponding to a maximum transaortic pressure gradient of 4(3)2 or
36 mmHg. Calculation of mean gradient requires averaging the instantaneous pressure gradients over the systolic
ejection period, so this maximum gradient cannot be compared directly with the baseline postoperative mean
gradient. However, aortic velocity has increased from 2.4 to 3.0 m/s suggesting possible early prosthetic valve
stenosis. This is a central flow orifice valve with anatomy similar to a native aortic valve so continuity equation valve
area can be calculated. The measured LV outflow tract diameter (LVOTD), not the implanted valve size, should be
used in the valve area calculation.
Thus, in this example, LV outflow tract cross-sectional area (CSALVOT) is:
CSA LVOT = πr2 = 3.14(2.3/2)2=4.15cm2
Aortic valve area (AVA), then is:
AVA = CSA LVOT x VTILVOT / VAo
= 4.15CM2 X (18CM/68CM) = 1.1CM2
Answer 2 – Continued
For a quicker valve area calculation, maximum LV outflow tract and aortic velocities can be substituted for
velocity-time integrals:
AVA = CSA LVOT x VLVOT / VAo
= 4.15CM2 X (0.8M/S/3.0M/S) = 1.1CM2
These findings suggest there has been a decrease in functional aortic valve area compared with
the early postoperative study, which is consistent with early calcific degeneration of a 10 year
old bioprosthetic valve in a young patient. However, this degree of stenosis is unlikely to
account for symptoms of chest pain so that the evaluation for other causes is appropriate
Question 3
A 43 year old woman with aortic valve replacement 20 years ago for congenital aortic stenosis presents for routine
follow-up. She is asymptomatic and physically active with no exercise limitation , but no previous echocardiogram
are available. A systolic murmur is noted on examination and the echocardiogram shows the following doppler
data.
A. Exercise treadmill testing
B. Transesophageal echocardiography
C. Calculate continuity equation valve area
D. Chest computed tomographic imaging
E. LV strain rate imaging
Answer 3
3–D
This is a doppler recording of transaortic flow based on the presence of prominent valve
opening and closing clicks, an ejection type velocity curve, and the time of flow relative to
the QRS signal. The triangular shape of the signal suggests normal valve function because
stenotic valves usually have a more rounded systolic curve with a late peaking maximum
velocity. However, the velocity of 4.3 m/s is much greater than expected for this valve
type. This high velocity most likely is due to low acceleration in the central slit-like orifice
of the bileaflet valve with pressure recovery distally resulting in only a modest valve
gradient. The denser signal within the aortic curve supports this possibility of valve
thrombosis or pannus formation limited disk excursion must be excluded by direct
visualization of leaflet motion. Simple fluoroscopy can be used to evaluate mechanical disk
motion with careful adjustment of imaging angle to visualize the leaflets. However, chest
computer tomographic imaging showed normal valve function in this patient. Exercise
treadmill testing can be helpful to clarify symptoms status with native or prosthetic alve
stenosis but is not needed in this asymptomatic patient. TEE might provide better images of
the posterior aspects of the prosthetic valve, but shadowing and reverberations would now
obscure the anterior valve structures, making it difficult6 to exclude prosthetic valve
stenosis. The continuity equation valve area will be falsely reduced if the apparent aortic
velocity is recorded from the small central flow orifice. LV strain rate imaging allows
detection of early LV dysfunction when aortic valve disease is present but would not be
helpful for evaluation of valve function in this patient
Question 4
This 88 year old woman presented with worsening heart failure and hemoptysis. She had undergone bioprosthetic
mitral valve replacement 12 years ago for severe mitral stenosis with an early postoperative baseline
echocardiogram that showed normal LV and RV size and function, normal prosthetic valve function, and a
pulmonary systolic pressure of 40 mmHg. On exam now she has a blood pressure of 100/70 mmHg, heart rate of
74 bpm with an irregular pulse, jugular venous pressure of 20cm H2O, distant heart sounds and bilateral
pulmonary rales. The following doppler tracings were recorded on the current study.
The most likely cause of her current symptoms is:
A. Pulmonary embolus
B. LV systolic dysfunction
C. Severe mitral regurgitation
D. Rheumatic aortic valve disease
E. Mitral stenosis
Answer 4
E – Mitral Stenosis
These doppler recordings show a high velocity tricuspid regurgitant jet, consistent with pulmonary hypertension,
and a transmitral flow signal consistent with an elevated transmitral gradient and small valve area. The tricuspid
regurgitant signal is identified based on systolic flow with a long flow period relative to the QRS and with the
typical rapid, followed by slow, rate of rise in velocity with a late peaking curve. The transmitral flow curve is in
diastole with a typical passive flow pattern or an early diastolic peak and linear fall off in velocity through diastole.
Atrial fibrillation is present with no discernable A-velocity. The slow diastolic decline in velocity is consistent with
mitral stenosis.
Pulmonary embolus might be associated with pulmonary hypertension, but transmitral flow would be normal.
LV systolic dysfunction would result in a reduce dP/dt on the mitral regurgitant velocity signal, which is not shown
here. Severe mitral regurgitation would result in an increased antegrade transmitral velocity, but the diastolic
slope would be steep.
Rheumatic aortic valve disease is present in about a third of patients with rheumatic valve disease, and the mitral
stenosis signal appears similar in shape to aortic regurgitation. However, diastolic velocities are lower across the
mitral valve compared with the aortic valve; with a diastolic blood pressure of 70 mmHg, the initial diastolic
velocity for aortic regurgitation would be about 4 m/s.
Question 5
88 year old with worsening heart failure and hemoptysis. Bioprosthetic mitral valve replacement 12 years ago for
severe mitral stenosis. Baseline echocardiogram that showed normal LV and RV size and function
normal prosthetic valve function. Pulmonary systolic pressure of 40 mmHg
Current Exam:
Blood pressure of 100/70 mmHg
Heart rate of 74 bpm with an irregular pulse
Jugular venous pressure of 20cm H2O
Distant heart sounds
Bilateral pulmonary rales.
Using the above data from question 4, calculate the following:
1. Pulmonary systolic pressure:_____________________________________
2. Mitral valve area:_____________________________________________
Answer 5
Pulmonary systolic pressure
Mitral valve area
79mmHg
0.6cm2
The tricuspid regurgitant velocity is 4.0 m/s, reflecting a RV-RA systolic pressure difference of 64 mmHg. Images
of the inferior vena cava are not provided to estimate RA pressure; the central venous pressure was estimated to be
about 20cm H2O (or 15mmhg) based on physical examination of the neck veins. The conversion factor for units of
pressure is 1.36cm H2O for each mmHg. Thus, adding RA pressure to the RV-RA pressure difference, the estimated
pulmonary systolic pressure is 79 mmHg.
With this bioprosthetic valve, mitral valve area is calculated from the mitral pressure half-time (T ½ ), as for native
mitral valve stenosis. One the first beat, the peak transmitral velocity is 2.3 m/s, corresponding to an instantaneous
pressure gradient of 21 mmHg. The T ½ is measured on the time axis from this point to the point on the diastolic
deceleration slope where the pressure drop is half the initial gradient. A pressure gradient of 11 mmHg
corresponds to a velocity of 1.66 m/s. Finding this point on the doppler signal, drawing a vertical line to the time
axis, and then measuring the time interval from peak velocity to this point, provides a T ½ of 370 ms. Mitral valve
area is 220/ t ½ or 6.cm2. These findings are consistent with severe prosthetic mitral stenosis. Although tissue
valve durability usually is longer in older patients, at surgery the bioprosthetic valve was severely calcified with
restricted leaflet motion.
Question 6
In the patient with this echocardiographic image which of the following clinical findings is most likely present?
A.
B.
C.
D.
Elevated reticulocyte
Diastolic murmur
S4 gallop
Thrombocytopenia
Answer 6
A – Elevated reticulocyte count
This is a TEE 2-chamber view of a patient with a mechanical valve prosthesis showing an eccentric paravalvular
mitral regurgitant jet. Paravalvular mitral regurgitation can cause hemolysis resulting in an elevated
reticulocyte count. Most often, hemolysis is well tolerated and the patient is able to maintain a relatively
normal red blood cell count, although sometimes vitamin and iron supplementation. Rarely is surgical or
percutaneous intervention needed to close the paravalvular leak unless there also is a large volume regurgitant
flow. This patient likely has a systolic (not diastolic) murmur. A wide pulse pressure is typical for aortic , not
mitral regurgitation. An S4 gallop will not be present because the electrocardiogram shows atrial fibrillation.
The platelet count should be normal, although blood clotting likely is abnormal due to warfarin anticoagulation
for a mechanical valve and atrial fibrillation.
Question 7
This doppler tracing obtained in a patient with prior valve surgery is consistent with all of the following EXCEPT:
A.
B.
C.
D.
Aortic stenosis
Aortic regurgitation
Mitral stenosis
Mitral regurgitation
Answer 7
D – Mitral regurgitation
This cw doppler tracing shows a systolic ejection fraction velocity
below the baseline (recorded from the apex) with a maximum
velocity about 3 m/s consistent with mild aortic stenosis or without a
prosthetic aortic valve. In diastole, mild aortic regurgitation is seen
with a signal that starts with aortic valve closure and extends to aortic
valve opening, with a maximum early diastolic velocity about 3.5 m/s
and passive diastolic deceleration with a flat slope. Overlapping with
the aortic regurgitant signal is a denser diastolic signal; that has a time
delay between aortic closure and onset of flow, consistent with
isovolumic relaxation period, indicating that this is transmitral flow.
The peak velocity over 2 m/s and slightly prolonged deceleration
slope suggest mild mitral stenosis or q prosthetic mitral valve , as was
the case in this patient. There should be a time interval between the
end of transmitral flow and aortic ejection, but this finding is
obscured by a poor signal-to-noise ration. There is no atrial
contribution to LV diastolic filling because this is a ventricular paced
rhythm (see electrocardiogram) and the atrial rhythm likely is atrial
fibrillation. This tracing does not show evidence of mitral
regurgitation; a different doppler beam is needed for better evaluation
of mitral valve function.
Question 8
A 71 year old female presented for a second opinion regarding possible aortic patient-prosthesis mismatch. She
had undergone a 19 mm pericardial bioprosthetic valve replacement 2 years ago but continued to have symptoms
of atypical chest pain. On physical examination she is an older anxious woman with a blood pressure of
120/80mmHg, pulse of 72 bpm, body surface area of 1.9cm2, and an aortic ejection murmur but no evidence of
heart failure. Echocardiography shows a normal-appearing prosthetic valve with the following doppler data shown
in the image below.
The most likely diagnosis in this patient is:
A. No prosthetic valve dysfunction
B. Prosthetic valve stenosis
C. Prosthetic valve regurgitation
D. Patient-prosthesis mismatch
Answer 8
D – Patient prosthesis mismatch
The doppler data show an aortic velocity of 3.0 m/s with an LV outflow tract diameter of only 1.5cm and LV outflow
tract velocity of 1.4 m/s. The circular LV outflow tract cross-sectional area (CSA) is 1.77 cm2. Aortic valve area
calculated with the continuity equation is:
AVA = CSA LVOT x VLVOT / VAo
= 1.77CM2 X (1.4M/S/3.0 M/S) = 0.8CM2
When indexed for body size:
AVA = 0.8 CM2 / 1.9 M2 = 0.42 CM2/M2
These data are consistent with severe patient-prosthesis mismatch, defined as a prosthetic aortic valve indexed area
less than 0.65 cm2/ m2. The reason for patient-prosthetic mismatch is the very small LVOT. Ideally, patientprosthesis mismatch is avoided by calculating the expected valve area divided by body size before valve implantation if
the expected valve area is too small, an alternate valve choice or an aortic root enlarging procedure can be considered.
Once patient prosthesis mismatch is present, decision making is more difficult because correction would require
another surgical procedure. Both short and long term outcomes are worse when patient-prosthesis is present, but the
increase in late mortality is seen only in patients younger than age 70, patients with a body mass index less than 30
kg/m2, and those with LV systolic, dysfunction (ejection fraction < 50%).
Answer 8 – Continued
This patient is older than 70, she has normal LV function and is not clear that her symptoms are related to her valve
size. Her BMI is 26 kg/m2, so she may benefit from weight reduction. In addition, her transvalvular mean gradient is
only 14mmHg and the LV outflow to aortic velocity ration is only 1.4/3.0=0.47, neither of which support a
significant hemodynamic effect from the small valve prosthesis. Thus, although she clearly meets the definition for
patient-prosthesis mismatch, there is no evidence for significant stenosis or regurgitation. In any case, this patient has
declined further interventions and continues to do well with medical therapy.
Question 9
Match each of the following diagnostic issues with the most useful imaging modality
1. Prosthetic aortic valve function
A. Transthoracic 2D imaging
2. Prosthetic mitral valve function
B. Transthoracic Doppler
3. Aortic graft pseudoaneurysm
C. TEE 2D imaging
4. Aneurysm of the aortic-mitral
intervavlular fibrosa
D. TEE Doppler
5. Aortic valve paravalvular abscess
6. Bioprosthetic tricuspid valve
vegetation
7. LV function with a mechanical
mitral valve
E. Chest computed tomographic
imaging
Answer 9
1. Prosthetic aortic valve function:
2. Prosthetic mitral valve function:
3. Aortic graft pseudoaneurysm:
4. Aneurysm of the aortic-mitral intervalvular fibrosa:
5. Aortic valve paravalvular abscess:
6. Bioprosthetic tricuspid valve vegetation:
7. LV function with a mechanical mitral valve:
B – Transthoracic doppler
D – TEE Doppler
E – Cardiac CT imaging
C –TEE 2D imaging
A – Transthoracic 2D imaging
A – Transthoracic 2D imaging
A –Transthoracic 2D imaging
Evaluation of a patient with suspected prosthetic valve dysfunction often requires both transthoracic and TEE
imaging. Transthoracic imaging is optimal for measurement of LV volumes and ejection fraction because the LV
often is foreshortened on TEE and may be shadowed by the mitral or aortic valve prosthesis. Transthoracic
imaging usually is preferred for a bioprosthetic tricuspid valve because this valve is anterior in the chest and thus
well seen from this approach. However, TEE imaging maybe needed is transthoracic images are suboptimal.
Transthoracic doppler is the best approach for evaluation of prosthetic aortic valve function because the doppler
beam can be aligned from an apical window parallel with transvalvular flow and aortic regurgitation can be
evaluated in both parasternal and apical views. In contrast, on TEE, alignment of the doppler beam with
transaortic flow is problematic and evaluation of regurgitation is limited by shadowing of the LV outflow tract by
the prosthetic valve.
In patients with a prosthetic mitral valve, the LA side of the prosthesis is shadowed on transthoracic imaging so
that the TEE is recommended whenever prosthetic mitral regurgitation is suspected. Similarly, TEE is much more
sensitive than paravalvular abscess because it allows imaging of the LA side of the aortic and mitral valve
prosthesis. Of course, an anteriorly located aortic paravalvular abscess may be seen on transthoracic imagine, but
absence of an anterior abscess does not exclude posterior annular infection. With involvement of structures
outside the narrow window provided by echocardiographic imaging, such as an aortic root pseudoaneurysm,
wide field imaging modalities, such as chest computed tomography, are recommended.
Question 10
The echocardiographic image below was obtained on the postoperative baseline study after bioprosthetic mitral
valve replacement. Which is the most likely diagnosis for the structure indicated by the arrow:
A.
B.
C.
D.
E.
Vegetation
Valve strut
Mitral valve
Ruptured papillary muscle
LC thrombus
Answer 10
C – Mitral valve
This image shows the native mitral valve chords and part of the mitral leaflet, which were retained at
the time of mitral valve replacement. Maintenance of mitral annular– papillary muscle continuity
helps prevent loss of LV systolic contractile function with surgical mitral valve replacement. Typically
the prosthetic valve is inserted centrally and the posterior leaflets and chords are left connected to the
papillary muscle behind the prosthetic valve sewing ring. The anterior leaflet may be partially retained
or may be resected, leaving freely mobile chordal remnants.
A mitral vegetation would be more likely on the LA side of the valve; infection of the sewing ring with
annual abscess formation instead of a typical vegetation is common with a prosthetic valve.
Valve struts are more uniform in appearance and do not protrude this far into the LV cavity.
A ruptured papillary muscle results in a disrupted muscle head moving freely in the LV, attached to the
mitral valve; normal attachments of the chords to the papillary muscle can be seen on this image .
An LV thrombus usually occurs in an area of regional dysfunction, often the apex, and is adherent to
the LV myocardium.
Question 11
This 75 year old man underwent surgical aortic valve repair 10 years ago for endocarditis resulting in
prolapse of the noncoronary cusp. He has done well postoperatively and has been followed annually
with echocardiograms showing mild to moderate residual aortic regurgitation. He now presents with a
cough, fatigue, and a low grade fever. On exam his blood pressure is 158/40 mmHg, pulse is 113 bpm
and irregular; bibasilar rales are present.
The doppler flow tracing below was recorded. The most likely new diagnosis in this patient is:
A.
B.
C.
D.
E.
Acute mitral regurgitation
Aortic to LA fistula
Severe pulmonary hypertension
Severe aortic stenosis
Patent ductus arteriosis
Answer 11
A – Acute mitral regurgitation
This doppler tracing shows a diastolic signal with a peak velocity and systolic slope consistent with known aortic
regurgitation The diastolic flow is directed away from the transducer, so the probe position likely is parasternal with a
posteriorly directed aortic regurgitant jet. In systole there is an ejection-type (rapid rise and fall with curved waveform) signal with a peak velocity about 5.5 m/s. This is most consistent with mitral regurgitation, given a systolic
blood pressure of 158 mmHg even with an LV pressure of 20mmHg., the Bernoulli equation indicates that velocity
should be at least 6 m/s if the intercept angle between the jet and ulatrasound beam was parallel. In this example, a
nonparallel intercept angle is most likely with the transducer in a parasternal position. The relatively rapid fall-off in
velocity in late systole suggests acute regurgitation with an elevated LV pressure. This patient had a mitral valve
vegetation with an adjacent leaflet perforation and blood cultures were positive for alpha-hemolytic Streptococcus.
With an aortic-to-LA fistula, high velocity continuous flow in systole and diastole would be seen reflecting the high
aortic-to-LV pressure difference. The typical valve velocity curves would not be seen.
Pulmonary hypertension cannot de diagnosed from these data; a tricuspid regurgitant jet would be longer in duration
and overlap with aortic regurgitation at the onset and end of flow.
If the systolic signal were due to aortic stenosis, a slight time interval before and after aortic regurgitation would be
seen corresponding to the isovolumic relaxation and contraction periods.
A patent ductus arteriosis would show continuous flow in the pulmonary artery with a lower velocity, reflecting the
pressure difference from the descending aorta to the pulmonary artery, and the distinct valve-type curves would not
be seen.