VSD · size & right-heart pressure calculator
Explore vsd · size & right-heart pressure with the method’s inputs, acquisition guidance and source references. Open the calculator to enter measurements or try an illustrative worked example.
Method
RVSP = SBP − 4V²; RVEDP = LVEDP − 4Ved²; relative size = VSD / AoV
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
Clinical question
Enter the measured value in the displayed unit
- RV systolic pressure
- RV end-diastolic pressure
- Anatomical size
- Confirm the variable matches the selected formula.
- Use the unit displayed beside the field.
- Keep measurements from the same representative hemodynamic state.
Systolic blood pressure mmHg
Contemporaneous cuff or invasive value
- Use a pressure obtained in the same hemodynamic state as the echo.
- Confirm the value is entered in mmHg.
- Do not mix values acquired under different loading conditions.
Peak VSD 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.
Independent LVEDP mmHg
Contemporaneous cuff or invasive value
- Use a pressure obtained in the same hemodynamic state as the echo.
- Confirm the value is entered in mmHg.
- Do not mix values acquired under different loading conditions.
End-diastolic VSD 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.
Largest VSD dimension mm
2D echo · inner-edge measurement
- Use the specified view and cardiac phase.
- Align the calipers perpendicular to the structure’s long axis.
- Measure inner edge to inner edge and avoid oblique foreshortening.
Aortic annulus diameter mm
2D echo · inner-edge measurement
- Use the specified view and cardiac phase.
- Align the calipers perpendicular to the structure’s long axis.
- Measure inner edge to inner edge and avoid oblique foreshortening.
Sources and method context
EACVI / ESC / AEPC · primary Doppler studies · 2021 · Imaging the adult with simple shunt lesions · VSD anatomy and imaging · pp. e61–e64 · doi:10.1093/ehjci/jeaa314
- Anatomy, shunt and chamber response · Budts et al. 2021 · VSD sections, Figures 6–7
Multiple windows and colour sweeps define location, borders, number, shunt direction and associated lesions; CMR can quantify Qp/Qs and ventricular volumes.
- Systolic pressure estimate · Noninvasive evaluation of RV and PA systolic pressures · simultaneous Doppler/catheter study · PMID 8465730
Cuff systolic pressure minus the VSD Doppler gradient estimates RV systolic pressure in the appropriate setting. Pressure is not a defect-size grade.
- Sloped CW limitation · Schamberger et al. JASE 2001;14:1197–1202 · doi:10.1067/mje.2001.116351
In sloped spectra, peak instantaneous gradient may exceed the peak-to-peak difference and underestimate right-sided systolic pressures.
- Anatomical reference bands · User-supplied VSD pocket reference, page 13 · retained teaching convention
VSD/AoV <⅓, ⅓–½ and >½. Other references use different boundaries; these bands are labelled and do not produce a universal severity grade.
- Published use of the size convention · Edraki et al. 2022 · pmVSD closure protocol · p. 2 · doi:10.1186/s12872-022-02757-9
A retrospective perimembranous-VSD closure cohort of 146 patients under 18 used the same annular fractions. This documents a population-specific convention, not a universal VSD severity scale or closure criterion.
- End-diastolic method · Existing VSD method · instantaneous simplified Bernoulli pressure balance
Requires independent LVEDP and the same end-diastolic timing. No guideline grading threshold or validation claim is attached to this retained method.
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.