1. BCLT 403: ECHOCARDIOGRAPHY
PRESENTEDBY:
FARHEEN ANSARI (B.Sc. in cardiology lab. Tech. 4TH SEM)
TOPICS:
POST MITRAL VALVE REPLACEMENT
POST AORTIC VALVE REPLACEMENT
PROSTHETIC VALVE MALFUNCTION

2. CONTENTS:
INTRODUCTION
TYPES OF REPLACEMENT VALVES:
DESIRED VALVES
BASIC PRINCIPLES OF THE ECHOCARDIOGRAPHIC EXAMINATION OF
PROSTHETIC VALVES:
 Two dimensional echocardiography
 Doppler echocardiography
- Color flow mapping

3. CONTENTS:
 POST MITRAL VALVE REPLACEMENT:
 Echo assessment
 Echo findings
 Is there evidence of obstruction?
 POST AORTIC VALVE REPLACEMENT:
 Echo assessment
 Echo findings
 is there evidence of obstruction?
 COMPLICATIONS OF PROSTHETIC VALVES:
 Prosthetic dysfunction
 REFERENCES

4. INTRODUCTION
 The introduction of valve replacement surgery in the early 1960s has dramatically improved
the outcome of patients with Valvular heart disease.
 By their design, almost all replacement valves are obstructive compared with normal native
valves.
 Minor regurgitation through the prosthetic valve is usually normal and the pattern differs
between the types of valve.
 The mechanical parts make imaging hard because of artefact and also the effects of
shielding.
 Despite the improvement in prosthetic valve design and surgical procedures, valve
replacement does not provide a definitive cure.

5. TYPES OF REPLACEMENT VALVES:
Replacement valves are either MECHANICAL or BIOLOGICAL.

6. DESIRED VALVES:
 The most frequently implanted biological types are those made from animal tissue,
‘xenografts’ usually made from pig aorticvalves or bovine pericardium.
 The most frequently implanted mechanical valve now is the Bileafletmechanical valve but
tilting discvalves are still used.
 An important new class of valve is the transcatheter valve(TAVI). There are many available or
in production but the most commonly implanted are the Edwards SAPIEN (Fig. G) and the
Medtronic CoreValve (Fig. H).

7. DESIRED VALVES CONTINUED…
MECHANICAL VALVE
 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)
BIOPROSTHETICVALVE
 Preferred in patients who are elderly:
 Who have a life expectancy of less than 10
to 15 years.
 Who cannot take long term anticoagulant
therapy.

8. BASIC PRINCIPLES OF THE
ECHOCARDIOGRAPHIC EXAMINATION
OF PROSTHETIC VALVES:

9.  TWO- DIMENSIONAL ECHOCARDIOGRAPHY
 Prosthetic valves should be imaged from multiple windows and angles to overcome the problem of
acoustic shadowing that occurs owing to the highly reflective components inherent in many of these
valves.
 Nonstandard windows and angles are often required to avoid imaging artifacts. On TTE, LV
function is readily evaluated, but the left atrium is often obscured for imaging and Doppler
interrogation..
 The opening and closing of the mechanical valve disks or bioprosthetic cusps must be evaluated.

10.  DOPPLER ECHOCARDIOGRAPHY
 The Doppler examination includes CF, PW, and CW Doppler examinations. Each method
contributes toward qualifying and quantifying flow patterns of both normal and abnormally
functioning prosthetic valves.
 The principles and rationale in utilizing Doppler techniques to qualify, measure, and
quantify blood flow velocities, pressure gradients, and effective valve orifice areas of
prosthetic valves are similar to that of native valves.
 However, the “normal” flow profiles of prosthetic valve are NOT assumed to be equal to that
of normal functioning native valves.

11. • COLOR FLOW MAPPING
 Paravalvular regurgitation is not uncommon and results from a combination of surgical
technique and the condition of the native annulus.
 The severity of prosthetic valve regurgitation is graded by criteria similar to that used for the
native valve.
 Although paravalvular regurgitation is always abnormal, small jets are often imaged on CF
Doppler immediately after valve implantation in the operating room. To be clinically and
hemodynamically insignificant, these jets should be small in comparison with the total
circumference of the sewing ring they originate from. Many frequently resolve shortly after
reversal of heparinization.

12. POST-MITRAL VALVE
REPLACEMENT
Biological cusps and mechanical leaflets are more easily imaged in mitral position than
replacement valves in the aortic position.

13. ECHO ASSESSMENT:
 Note the transducer position where the optimal Doppler signal was obtained so it may be
used for follow-up studies (most often the apical or para-apical position)
 The valve leaflets should be visualized and their mobility noted.
 Determine the peak velocity; a peak velocity > 2. 5 m/sec may indicate stenosis or significant
regurgitation.
 Determine the pressure half-time; a PHT > 180 ms may be abnormal.
 Determine the mitral valve area by the continuity equation.
 Determine the mean pressure gradient; a mean pressure gradient > 10 mm Hg may be
abnormal.
 Determine the presence and severity of mitral regurgitation

14. ECHO FINDINGS:
2-D PLAX VIEW:
 For mechanical valves, imaging perpendicular to the leaflets will allow one to see the opening and closing
by noting the leaflet edges. Imaging parallel to the valve leaflets is not likely to visualize the leaflet edges
opening and closing.
 The aortic root may be thickened as a result of hematoma [a solid swelling of clotted blood within the tissues]
and edema after the insertion of a stentless valve as an inclusion inside the aortic root.
 A major consideration in the evaluation of prosthetic mitral valve function by echocardiography is the
effect of acoustic shadowing by the prosthesis on assessment of MR. This problem is worse with
mechanical valves than with bioprosthetic valves.
 Some appearances which are normal but can cause confusion are: bubbles in the LV, which occur with all
types of valve but especially Bileaflet mechanical valves (caused by aggregations of red cells as a result of
sheer stresses at the leaflet edge as it closes).

15. 2-D PSAX VIEW:
 The short-axis view at the level of the prosthesis allows visualization of the leaflet excursion and
sewing ring of a bioprosthetic mitral valve.
 For mechanical valves, the short-axis view is limited by acoustic shadowing of the posterior
aspect of the valve sewing ring.
APICAL VIEW:
 The apical views allow visualization of leaflet excursion for both bioprosthetic and mechanical
valve prostheses.
 Apical views may allow the detection of thrombus or pannus that might limit leaflet excursion.

16. DOPPLER:
 the mitral valve prosthesis may obscure(conceal) portions of the left atrium and its posterior wall.
This may prevent detection of small degrees of MR or make it difficult to determine the precise origin
of an MR jet.
 Color mapping filling the orifice in all views
during diastole is a useful corroboration of
normal opening.
Figure 1: Normal functioning bioprosthetic valve
in the mitral position.

17. IS THERE EVIDENCE OF OBSTRUCTION?
 Most information for the diagnosis of obstruction is found from imaging and colour flow
mapping. Compare measured peak velocity and mean gradient with normal values.
 Pressure half-time does not reflect orifice area in normally-functioning prosthetic mitral valves.
However, the pressure half-time lengthens significantly when the valve becomes obstructed.

18. POST-AORTIC VALVE
REPLACEMENT

19. ECHO ASSESSMENT:
 Note the transducer position where the optimal Doppler signal was obtained so it may be used
for follow-up studies (most often the apical or right parasternal position)
 The valve leaflets should be visualized and their mobility noted.
 Determine the peak velocity.
 Determine the mean pressure gradient; a mean pressure gradient > 25 mm Hg may be
abnormal.
 Determine the aortic valve area using the continuity equation
 Determine the velocity ratio
 Determine the presence and severity of aortic insufficiency

20. ECHO FINDINGS:
2-D & M- MODE:
 In patients with aortic prostheses, measurements of the aortic root and ascending aorta are
recommended.
 The cusps should be thin and move freely through an arc of about 90o.
 Rocking of the valve is a sign of dehiscence and is seldom(rarely) seen in a normal valve.
 Valves should be imaged from multiple views, with particular attention to the following:
 the opening and closing motion of the moving parts of the prosthesis;
 the presence of leaflet calcifications or abnormal echo density attached to the sewing ring,
occluder, leaflets, stents, or cage; and
 On M-mode, mechanical leaflets often flutter slightly.

21. DOPPLER:
 All windows should be used but the site of the jet is usually most easily seen in PLAX view
 Doppler velocity recordings across normal prosthetic valves usually resemble those of mild
native aortic stenosis, with a maximal velocity usually >2 m/s
 In all types of valves, colour should fill the orifice in all planes during systole.
 Normal physiological regurgitation through the valveoccurs in all mechanical valves and,
depending on the design, can occur during closing or after closure or throughout diastole
(Fig. 2).
 To establish whether the regurgitation is normal or pathological it is necessary to determine
its origin and grade and whether there is thickening of the cusps.

22. 1. Doppler parameters of prosthetic aortic valve function:
Figure 2: Patterns of normal regurgitation.

23. IS THERE EVIDENCE OF OBSTRUCTION?
 The definitive signs of obstruction are thickened and immobile biological cusps or stuck
mechanical occlude.
 The disc or leaflets of an obstructed mechanical valve may be difficult to image parasternally,
but may be seen more easily from the apical 5-chamber and long-axis views.

24. COMPLICATIONS OF
PROSTHETIC VALVE

25. GENERAL POINTS OF 2D IMAGING OF
PROSTHETIC VALVES
 The presence of cusp thickening is usually an early sign of primary failure of a bioprosthetic valve.
 Failure of a disk to open will significantly reduce the prosthetic valve’s EOA (effective orifice area)
and thus result in increased pressure gradients across that valve.
 Failure to close properly will result in increased regurgitant flow.
 Incomplete closure of prosthetic valve leaflets can be due to pannus growth, infection, thrombus, or
suture materials around the sewing ring or the leaflets.
 Mechanisms of prosthetic valve dysfunction are both similar to and different from those of the
native valves.
 Subtle symptoms of cardiac failure and neurological events can be clues to serious valve dysfunction.

27. PROSTHETIC DYSFUNCTION:
 Structural failure:
 Any problem with the prosthetic valve structure either mechanical or bioprosthetic such as
ball or disc variance, thrombus, pannus, endocarditis.
 For bioprosthetic, evidence of leaflet degeneration can be recognized as:
- Leaflet thickening (cusps >3mm)
- Calcification (bright echoes of the cusps)
- Tear (flail cusps)
 Prosthetic dehiscence: it is characterized by the “rocking motion” of entire prosthesis.
 Thromboemboli:
 Although thrombus formation is frequently associated with valve obstruction,
regurgitation, or embolism, it may be an incidental finding during imaging.

28.  Obstruction: thrombus and pannus.
THROMBUS PANNUS
MORPHOLOGY - Larger mass than pannus (>2.8cm)
- Independent motion common
- Project into left atrium
- Grows centrifugally
- Small mass (<2.8cm)
- Mostly involves suture line
- Confined to the disc plane
- Grow beneath disc
CHRONOLOGY Occurs at any time (if late, usually associated with
pannus)
Minimum 12 months.
Commonly 5 years from date surgery.
ABNORMAL PROSTHETIC VALVE
MOTION BY TEE
more common in valves with thrombus Less common
DURATION OF SYMPTOMS obstruction due to thrombus is associated with a short
duration of symptoms and with a history of inadequate
anticoagulation
Comparatively, it is associated with longer duration
of symptoms
FREQUENCY mitral aortic
MOBILITY Independent motion common fixed
ECHO DENSITY (videointensity ratio) Less
<0.4
More
>0.7 (100% specific)
PREVALENCE more less

29.  Hemodynamic compromise:
 Prosthetic Stenosis:
• the initial suspicion of prosthetic valve stenosis may be the incidental finding of abnormally
high flow velocities detected during a routine examination.
• With increasing stenosis of the valve, a higher velocity and gradient are observed, with longer
duration of ejection and more delayed peaking of the velocity during systole.
• High gradients may be seen with normally functioning valves with a small size, increased stroke
volume, PPM, or valve obstruction. Conversely, a mildly elevated gradient in the setting of severe
LV dysfunction may indicate significant stenosis. Thus, the ability to distinguish malfunctioning
from normal prosthetic valves in high flow states on the basis of gradients alone may be difficult.
 Prosthetic Regurgitation:
• Mild regurgitation through a biological valve associated with a thickened cusp is an early sign of
primary failure especially if either the regurgitation or thickening increases on serial studies.
• Rocking of the replacement valve implies that there is a large paraprosthetic leak.

30.  Prosthetic endocarditis:
 Vegetations are usually irregularly shaped and can be recognized on echocardiography
as independently mobile structures of relatively low echogenicity.
 Vegetations in the setting of prosthetic valves tend to form in the valve ring area and
may spread to the leaflet of the prosthetic valve, stent, or occluder and impair the
opening and closing of the valve.
 Endocarditis may also lead to suture dehiscence and paravalvular regurgitation in all
prosthetic valves and to valve destruction in Bioprosthetic valves.
 Valve PPM(patient-prosthesis mismatch):
 This means that the valve is functioning normally but is too small for the patient.
 All xenografts have at least mild patient–prosthesis mismatch because the sewing ring
and other valve parts occupy the space normally taken up by blood flow. It does not
cause significant problems unless it is severe.

31.  Prosthetic replacement
 Mortality including sudden, unexplained death.
DIFFERENTIAL DIAGNOSIS:
 Ventricular dysfunction
 Pulmonary hypertension
 The pathology of the remaining native valves
 non cardiac conditions.

32. REFERENCES:
 http://www.echocardiology.org/prosthetic-heart-valves.htm
 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5353566/
 https://www.slideshare.net/ramachandrabarik/evaluation-of-prosthetic-valve-function?qid=adcfbaaf-b825-402f-aeaa-
e09156fb2fb6&v=&b=&from_search=1
 https://clinicalgate.com/echocardiographic-evaluation-of-prosthetic-valves/
 http://www.onlinejase.com/article/S0894-7317(09)00676-2/fulltext
 http://asecho.org/wordpress/wp-content/uploads/2016/04/4.16-Abbas-Aortic-Valve-Prosthesis.pdf
 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC483704/?page=2
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