Calculate effective regurgitant orifice area and regurgitant volume from the PISA method for mitral regurgitation.
Result
How to use this tool
Measure the radius of the proximal flow convergence hemisphere at mid-systole, in centimetres.
Use the Nyquist limit at which the PISA shell was measured.
Use the continuous-wave Doppler peak velocity of the regurgitant jet.
Volume needs the velocity–time integral of the same jet.
Formula & worked example
PISA radius 0.8 cm, aliasing velocity 40 cm/s and peak velocity 500 cm/s give EROA about 0.32 cm², moderate. With a VTI of 150 cm, regurgitant volume is about 48 mL.
Limitations — read this before you rely on it
Educational echocardiography calculation using the PISA method. This tool is for education only and is not medical advice, a diagnosis, or a substitute for professional assessment. It does not grade regurgitation alone, assumes a hemispheric convergence zone, and cannot diagnose or guide treatment.
Frequently asked questions
The effective area of the leaking valve orifice, estimated from flow convergence. Larger EROA means more severe regurgitation.
In secondary (functional) MR, severe thresholds are lower (EROA 0.20 cm² or more) because the mechanism and prognosis differ.
No. Guidelines integrate vena contracta, jet area, volume, chamber size and pulmonary pressures.
Flattened or constrained convergence, eccentric jets and multiple jets all reduce accuracy; the echo laboratory accounts for these.
Centimetres and cm/s throughout, so EROA comes out in cm² and volume in mL.