Evaluation of Prosthetic Valve Function: EOA, DVI, and Acceleration Time (ASE 2024)
Doppler Indicators of Aortic Prosthesis Function
The same Doppler principles and formulas used for native stenosis assessment are applied to evaluate prosthetic valve stenosis (Nicoara, Skubas et al., 2020). Significant prosthesis obstruction may be indicated by a peak velocity through the aortic prosthesis >3 m/s, along with increased acceleration time (100 ms) and decreased Doppler velocity index (DVI) <0.27 (normal =0.35).
Doppler Velocity Index (DVI)
DVI for an aortic prosthesis is the ratio of the VTI proximal to the valve to the VTI through the valve (Zoghbi et al., 2024). A DVI value ≤0.35 is associated with adverse outcomes in SAVR, but not in TAVI.
For mitral prostheses, the inverse ratio is used (see Figure 5 of the source). In mitral prostheses, DVI is also useful for identifying significant mitral regurgitation (MR), as significant MR increases blood flow velocity through the mitral valve and decreases it in the LVOT.
Effective Orifice Area (EOA)
Since patient-prosthesis mismatch can lead to reduced regression of left ventricular mass and adverse long-term outcomes after aortic valve replacement, the EOA of a newly implanted prosthesis should be calculated using the continuity equation (Nicoara, Skubas et al., 2020).
High pressure gradients on the prosthesis may be due to size mismatch rather than prosthesis dysfunction. In such situations, and when calculating the aortic valve orifice area index, indexing to the ideal body surface area is used (according to the 2025 source).
Summary Table of Aortic Prosthesis Obstruction Indicators
| Indicator | Value Indicating Obstruction | Normal |
|---|---|---|
| Peak Velocity | >3 m/s | [specify] |
| Acceleration Time | increased (100 ms) | [specify] |
| DVI (aortic) | <0.27 | =0.35 |
| DVI (SAVR, adverse outcomes) | ≤0.35 | [specify] |
LVOT Measurement
To calculate the indicators, the diameter of the LVOT must be measured in mid-systole (normal values 18–22 mm) proximal and parallel to the aortic valve plane, from the inner edge of the septal endocardium to the inner edge of the anterior mitral leaflet within 5–10 mm of the aortic valve (Blagodir, 2024).
Frequently asked questions
What DVI value indicates dysfunction of the aortic prosthesis?
A DVI <0.27 indicates significant obstruction (normal =0.35). Additionally, a DVI ≤0.35 is associated with adverse outcomes in SAVR, but not in TAVI.
How is DVI calculated for an aortic prosthesis?
DVI is the ratio of the VTI proximal to the valve (in the LVOT) to the VTI through the valve (Zoghbi et al., 2024). For mitral prostheses, the inverse ratio is used.
Why calculate the EOA of a prosthesis?
Patient-prosthesis mismatch can lead to reduced regression of left ventricular mass and poor long-term prognosis. EOA is calculated using the continuity equation.
What do high gradients on the prosthesis indicate?
High gradients may be caused by size mismatch rather than prosthesis dysfunction. Indexing the EOA to the ideal body surface area is used for differentiation.
Can DVI be used to assess mitral regurgitation?
Yes, in mitral prostheses, DVI is useful for identifying significant MR: with significant MR, velocity through the mitral valve increases and decreases in the LVOT.