Prosthetic heart valves
Mechanical or biological, stenotic or regurgitant, patient–prosthesis mismatch or thrombosis — read against the valve's own baseline.
Numbers to remember
- Every prosthesis needs a baseline study after implantation; later gradients are judged against it [21,167]
- Aortic DVI <0.25 suggests significant prosthetic stenosis [21,167]
- Indexed EOA ≤0.65 cm²/m² (aortic) defines severe patient–prosthesis mismatch [93,107]
- Paravalvular regurgitation: grade by the circumferential extent of the jet (≥30% severe) [20,212]
Questions echo must answer
- What valve is it?Type, position and size, and the date of implantation [21,167].
- Is it obstructed?Peak velocity, mean gradient, DVI, acceleration time, effective orifice area — compared with the baseline and the expected values for the model [21,167].
- Is it leaking, and where?Transvalvular (central) or paravalvular; severity [20,212].
- Why?Thrombus, pannus, structural degeneration, endocarditis, dehiscence or patient–prosthesis mismatch [167,212].
Acquisition protocol
- Know the valveRead the operation note; record height, weight and BSA.
- 2DLeaflet or occluder motion, sewing-ring rocking, masses.
- CW Doppler from several windowsVelocity, mean gradient, VTI; heart rate.
- PW in the LVOTDVI = LVOT VTI / prosthetic VTI [21].
- ColourLook all around the sewing ring; acoustic shadowing hides mitral regurgitation on TTE.
- TOE or cine-fluoroscopyWhen obstruction or mitral prosthetic regurgitation is suspected [35,167].
- Valve type, size and date
- Gradients, DVI, AT
- Comparison with baseline
- Central vs paravalvular leak
- Mass or rocking motion
Diagnosis & severity
| Aortic prosthesis | Normal | Possible stenosis | Significant stenosis |
|---|---|---|---|
| Peak velocity | <3 m/s | 3–4 m/s | >4 m/s |
| Mean gradient | <20 mmHg | 20–35 mmHg | >35 mmHg |
| DVI | ≥0.30 | 0.25–0.29 | <0.25 |
| Acceleration time | <80 ms | 80–100 ms | >100 ms |
Values from the ASE prosthetic valve guidance [21,167].
Thresholds that change management
- Obstructed mechanical valve → urgent Heart Team decision between surgery and slow-infusion thrombolysis [6,167].
- Bioprosthetic leaflet thrombosis → anticoagulation and reassessment [6,167].
- Structural degeneration → redo surgery or valve-in-valve [6].
- Severe paravalvular leak with symptoms or haemolysis → surgical or transcatheter closure, after excluding endocarditis [6,136].
Pitfalls & mimics
- Pressure recovery In small bileaflet aortic valves Doppler overestimates the gradient [21].
- High flow Anaemia, fever or regurgitation raise the gradient without obstruction.
- Acoustic shadowing Hides mitral prosthetic regurgitation on TTE — TOE [35].
- Reverberation and side lobes Prosthetic material produces artefacts that mimic masses.