Patient with a prosthetic valve (by type)
Know the valve, have a baseline, then separate stenosis, patient–prosthesis mismatch, high flow, thrombus and pannus.
Echo approach, step by step
Prosthetic valve assessment starts before the probe: know the type, size and implant date, and have the baseline study [21,167]. A baseline TTE should be recorded after implantation (within weeks to 3 months); every later study is compared with it [7,21,167].
- IdentifyMechanical (bileaflet, tilting disc, caged ball) or biological (stented, stentless, homograft, transcatheter); size; position [21,167].
- Record BSA, BP and HRGradients depend on flow and rate [21].
- 2DSewing ring stability (rocking), leaflet or occluder motion, thickening, calcification, masses [167].
- Aortic prosthesis DopplerVmax, mean gradient, EOA (continuity), DVI, acceleration time and AT/ET [21,167].
- Mitral prosthesis DopplerE, mean gradient at the recorded HR, PHT, EOA, VTI-PrMV / VTI-LVOT [21,167].
- RegurgitationTransvalvular versus paravalvular. For TAVI, the circumferential extent of paravalvular jets in short axis [20,167].
- PPMIndexed EOA against the published normal value for that model and size [93,107].
- EscalateTOE for mitral prostheses (acoustic shadowing), endocarditis and thrombosis; fluoroscopy for mechanical leaflet motion; CT for pannus or leaflet thrombosis (HALT) [167,212].
- Type, model, size, date
- Baseline study available
- BSA, BP, HR recorded
- Leaflet / occluder motion
- Gradients, EOA, DVI (or VTI ratio)
- AT, AT/ET (aortic) or PHT (mitral)
- Transvalvular / paravalvular regurgitation
- EOAi (PPM)
- TOE / fluoroscopy / CT needed?
Causes & echo clues
Types of prosthesis and what normal looks like [21,167]
| Type | Normal appearance and Doppler |
|---|---|
| Bileaflet mechanical | Two leaflets, three orifices; small normal "washing" jets at the hinges; localised high velocity in the central orifice (pressure recovery) |
| Tilting disc | Single disc, major and minor orifice; a small central or peripheral washing jet |
| Caged ball | High gradients are normal; ball motion within the cage |
| Stented bioprosthesis | Thin, mobile cusps; gradients similar to a mild native AS |
| Stentless / homograft | Low gradients; resembles the native root |
| Transcatheter (TAVI) | Frame visible; lower gradients with supra-annular self-expanding valves; mild paravalvular leaks are common |
High gradient: why? [21,167]
| Mechanism | EOA | DVI (aortic) | AT (aortic) | Clue |
|---|---|---|---|---|
| Obstruction (thrombus, pannus, degeneration) | Low | <0.25 | >100 ms | Restricted leaflets; rising versus baseline |
| Patient–prosthesis mismatch | Low EOAi but normal for this model and size | Normal | Normal | Unchanged from the baseline study |
| High flow (anaemia, fever, AR) | Normal | Normal | Normal | High LVOT VTI |
| Pressure recovery (small bileaflet valves) | Normal | Normal | Normal | Doppler exceeds catheter gradient |
| Mitral: significant MR through the prosthesis | Apparently low | — | — | High VTI ratio with normal PHT |
Clinical pathway to the diagnosis
- Symptoms, INR history and haemolysis tests(LDH, haptoglobin, reticulocytes).
- TTE compared with the baseline[21,167].
- Stenosis patternDifferentiate thrombus from pannus. Thrombus favours a short history, subtherapeutic INR and a soft, larger mass. Pannus favours a long history and a dense, small subvalvular mass. Use TOE, fluoroscopy and CT [167,212].
- Mechanical valve thrombosisManagement depends on whether the valve is obstructed, the patient's condition, thrombus size and surgical risk: optimise anticoagulation, give slow-infusion thrombolysis, or operate [6,167].
- Bioprosthetic thrombosisAnticoagulation often reverses it [6,167].
- SurveillanceACC/AHA 2020: TTE for surgical bioprostheses at 5 and 10 years and then annually; annually after TAVI; earlier with symptoms [7].
Clinical pearls & pitfalls
PitfallMitral prosthesis regurgitation is often hidden by acoustic shadowing on TTE. Indirect signs (high E, VTI ratio >2.5 with normal PHT, unexplained raised PASP) should prompt TOE [21,167].
- Compare with the baseline, not with population normals. A gradient that has always been high is PPM; a gradient that is rising is pathology [21,167].
- Severe PPM (aortic EOAi ≤0.65 cm²/m², or ≤0.55 if BMI ≥30) is associated with worse outcomes [93,107,167].
- The small, low-velocity washing jets of mechanical valves are normal. Do not report them as regurgitation [21].
- Pressure recovery in small bileaflet aortic valves makes Doppler overestimate the gradient [21].
Red flags
- New dyspnoea, embolism or muffled clicks with a mechanical valve → valve thrombosis [167,212]
- Fever → prosthetic valve endocarditis (TOE) [136]
- Haemolysis → paravalvular regurgitation [167]
- Rising gradient in a bioprosthesis → thrombosis or degeneration [167]