EROA Calculator (PISA Method)
The EROA Calculator estimates the effective regurgitant orifice area using the PISA method from the PISA radius, aliasing velocity, and peak regurgitant velocity. For clinical education only.
Rates and fees change frequently. Always confirm the current figures
with the official authority before relying on this result.
Formula
EROA = (2π·r²·V_aliasing) ÷ V_peak
- PISA models the flow convergence as a hemisphere of radius r.
- An EROA ≥ 0.40 cm² indicates severe mitral regurgitation.
r 0.9 cm, Va 40, Vmax 500
Inputs
- PISA Radius: 0.9 cm
- Aliasing Velocity: 40 cm/s
- Peak Regurgitant Velocity: 500 cm/s
Flow = 2π×0.81×40 = 203.6 mL/s; EROA = 203.6 ÷ 500 = 0.41 cm².
Frequently asked questions
What EROA is severe?
For mitral regurgitation, an EROA of 0.40 cm² or more generally indicates severe disease.