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Echocardiographic Evaluation of Prosthetic Heart Valves Patricia Tung, M.D. February 10, 2010.

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Presentation on theme: "Echocardiographic Evaluation of Prosthetic Heart Valves Patricia Tung, M.D. February 10, 2010."— Presentation transcript:

1 Echocardiographic Evaluation of Prosthetic Heart Valves Patricia Tung, M.D. February 10, 2010

2 Objectives  Types of prostheses  Prosthetic dysfunction  Echocardiographic surveillance of prostheses

3 Types of Prostheses  Mechanical valves  Tissue valves  Homograft valves

4 Mechanical Valves

5 Tissue Valves

6 Homograft Valves

7 Objectives  Types of prostheses  Prosthetic dysfunction  Echocardiographic surveillance of prostheses

8 Mechanisms of Prosthetic Valve Dysfunction  Structural failure Stenosis Stenosis Regurgitation Regurgitation  Thromboembolic complications  Endocarditis  Patient Prosthesis Mismatch

9 Structural Failure Bioprosthetics

10 Cohn et al. Ann Thorac Surg, 1998.

11 Homograft Dysfunction  Subject to severe tissue calcification  Usually reserved for complex aortic root abscesses  Hyperlipidemia accelerates prosthesis calcification  Secondary prevention may slow this process

12 Physical Exam Findings

13 TTE  valve area and regurgitation  exclude significant obstruction  Flow velocity is crucial measurement  Often inadequate for infection or small structural changes (strut fracture, small vegetation, paravalvular leak) TEE  inspection of valve apparatus and seating  may not accurately quantify valve flow velocities Echocardiographic Evaluation

14 Normal Appearance PV

15 Normal Doppler Clicks

16 Normal Doppler Flow Patterns

17 Fluid Dynamics and Velocities

18 Normal Finding: Regurgitation

19 Pathologic Regurgitation Characterized by: An eccentric or large jet An eccentric or large jet Marked variance on the color flow display Marked variance on the color flow display A jet that originates around the valve sewing ring A jet that originates around the valve sewing ring Visualization of a proximal flow acceleration region on the LV side of the mitral valve Visualization of a proximal flow acceleration region on the LV side of the mitral valve

20 Prosthetic Valve Regurgitation

21 Prosthetic Valve Stenosis Pressure gradients - Calculated using the Bernoulli equation (4v 2 ) - Good correlation when validated against invasive pressure measurements - mechanical valves, especially bileaflet, result in overestimation of the gradient due to differing fluid dynamics

22

23 Prosthetic Aortic Valve Area

24 Prosthetic AVA: Velocity Ratio  Measure velocity increase across valve  Ratio of outflow tract velocity/aortic jet velocity reflects degree of stenosis  Ratio = 1 if no obstruction present  Given inherent stenosis, normal range is 0.35 to 0.5 for aortic prosthesis

25 Prosthetic Mitral Valve Area  Can be estimated using the pressure half- time approach as for native mitral valve stenosis.  The expected half-time for a PV is longer than with a native valve.

26 Incidence of Thromboembolic Complications Fatal Complication Non-Fatal Complication Valve Thrombosis Aortic 0.2 per 100 patient years 1.0 to 2.0 per 100 patient years 0.1 percent per year Mitral- 2.0 to 3.0 per 100 patient years 0.35 percent per year

27 Prosthetic Valve Thrombosis  TEE is often negative if the thrombi are small or if new thrombus has not formed since the initial embolic event.  Thus an embolic event in a patient with a prosthetic valve (esp mechanical) must be presumed to be related to the PV even if the TEE is negative.

28 Prosthetic Valve Endocarditis  Difficult to detect with TTE  Often involves sewing ring and annulus, resulting in paravalvular abscess rather than a discrete vegetation

29 Prosthetic Valve Endocarditis

30 Patient Prosthesis Mismatch  Size of prosthesis results in inadequate blood flow given metabolic demands  Prosthesis itself functions well  Indexed effective orifice area < or = 0.85cm2/m2  Predicts high transvalvular gradients, persistent LVH and increased rate of cardiac events following AVR

31 Objectives  Types of prostheses  Prosthetic dysfunction  Echocardiographic surveillance of prostheses

32 Recommended Surveillance  Baseline echocardiogram 6-8 weeks postoperatively  Routine echocardiographic surveillance annually thereafter  Evaluate for Regression of hypertrophy or dilation Regression of hypertrophy or dilation Recovery of LV systolic function Recovery of LV systolic function Changes in PA pressures Changes in PA pressures

33

34 Summary  Prosthetic valve dysfunction is well detected by echocardiography  Dysfunction includes Structural failure Structural failure Thromboembolic complications Thromboembolic complications Endocarditis Endocarditis PPM PPM  Distinguishing normal from pathologic function can be challenging; most useful is comparison to baseline post-prosthesis

35 References  Otto, C. Textbook of Clinical Echocardiography, Fourth Edition  Libby et al. Braunwald’s Heart Disease. Eighth Edition  Pibarot, P and Dumesnil JG. Prosthesis-patient mismatch: definition, clinical impact, and prevention. Heart 2006;92:  Bonow RO, Carabello BA, Chatterjee K, et al: ACC/AHA 2006 guidelines for the management of patients with valvular heart disease: A report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (writing committee to revise the 1998 Guidelines for the Management of Patients with Valvular Heart Disease): Developed in collaboration with the Society of Cardiovascular Anesthesiologists: endorsed by the Society for Cardiovascular Angiography and Interventions and the Society of Thoracic Surgeons. Circulation 2006; 114:e84.


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