Canonical: https://echosuite.app/guides/aortic-prosthesis-screen/

# Surgical aortic prosthesis · obstruction calculator

Explore surgical aortic prosthesis · obstruction with the method’s inputs, acquisition guidance and source references. Open the calculator to enter measurements or try an illustrative worked example.

Created by [Mohammed Kamareddine, MD](https://echosuite.app/about/) · [Sources & educational scope](https://echosuite.app/about/)

[Open interactive calculator →](https://echosuite.app/calculators/#aortic-prosthesis-screen)

## Method

2024 ASE Table 5 · pair flow-dependent and flow-independent SAVR findings

Use the measurement units shown below. Some fields apply only to a selected method or condition; follow the interactive tool’s method choices. The interactive tool keeps missing measurements incomplete and provides its method-specific results and reference context.

## Measurements and acquisition

### Peak velocity  m/s

Continuous-wave Doppler

- Align the CW cursor as parallel as possible to the jet.
- Acquire a dense, complete envelope without truncation.
- Measure the highest absolute velocity on the selected envelope.

### Mean gradient  mmHg

Complete traced CW envelope

- Align through the valve or shunt and record a complete envelope.
- Trace the modal velocity envelope using the machine tool.
- Use the machine-calculated mean gradient in mmHg.

### DVI · LVOT VTI ÷ prosthesis VTI

Enter the measured value in the displayed unit

- Confirm the variable matches the selected formula.
- Use the unit displayed beside the field.
- Keep measurements from the same representative hemodynamic state.

### EOA vs expected valve reference

Enter the measured value in the displayed unit

- Not available
- Within 1 SD
- 1 to <2 SD below
- ≥2 SD below
- Confirm the variable matches the selected formula.
- Use the unit displayed beside the field.
- Keep measurements from the same representative hemodynamic state.

### Acceleration time  ms

Spectral Doppler timing

- Use a sweep speed that clearly shows the interval boundaries.
- Measure from the specified onset to offset.
- Average representative beats using consistent rhythm handling.

### AT/ET ratio

Spectral Doppler timing

- Use a sweep speed that clearly shows the interval boundaries.
- Measure from the specified onset to offset.
- Average representative beats using consistent rhythm handling.

## Sources and method context

American Society of Echocardiography · 2024 · Guidelines for the Evaluation of Prosthetic Valve Function With Cardiovascular Imaging · Figure 13 and Table 5 · JASE p. 19 · recommendations p. 21

[Primary reference](https://www.asecho.org/wp-content/uploads/2024/01/PIIS0894731723005333.pdf)

- SAVR obstruction ranges · Table 5 · JASE p. 19

Peak velocity, mean gradient, DVI, reference-relative EOA, acceleration time, and AT/ET ranges.

- Required parameter concordance · Table 5 footnote · JASE p. 19

Significant stenosis should include at least one flow-dependent and one flow-independent parameter.

- Acquisition and differential · Key recommendations · PDF p. 21

Multiple Doppler windows and exclusion of high flow, PPM, sub/supravalvular obstruction, and pressure recovery.

Catalogue review status: Exact guideline locator mapped · clinical sign-off pending

These pages describe the educational tool. Interpret measurements with the complete clinical context and the method’s acquisition limitations.

## Keep exploring

- [Aortic prosthetic valve calculator: EOA, DVI and PPM](https://echosuite.app/guides/aortic-prosthesis/)
- [Aortic prosthesis · serial comparison calculator](https://echosuite.app/guides/aortic-prosthesis-serial/)
- [Mitral prosthetic valve calculator: EOA, DVI and PPM](https://echosuite.app/guides/mitral-prosthesis/)
- [Mitral prosthesis · obstruction calculator](https://echosuite.app/guides/mitral-prosthesis-screen/)

[All echo guides](https://echosuite.app/guides/) · [Learning paths](https://echosuite.app/learn/)