PISA: EROA, regurgitant volume & fraction
EROA, RVol, RF · Zoomed colour Doppler of the flow convergence with the baseline shifted towards the jet; CW of the regurgitant jet
Normal range & thresholds
EROA = 2πr² × Va / Vmax; RVol = EROA × VTI(jet); RF = RVol / total SV [4].
| Mild | Moderate | Severe | |
|---|---|---|---|
| Primary MR EROA / RVol / RF | <0.20 cm² · <30 mL · <30% | 0.20–0.39 · 30–59 · 30–49% | ≥0.40 cm² · ≥60 mL · ≥50% |
| Secondary MR (ESC/EACTS 2025) | EROA ≥0.30 cm² · RVol ≥45 mL | ||
| AR EROA / RVol / RF | <0.10 · <30 · <30% | 0.10–0.29 · 30–59 · 30–49% | ≥0.30 · ≥60 · ≥50% |
In asymptomatic organic MR, EROA ≥0.40 cm² predicted mortality and cardiac events [59].
Pathophysiology
Flow accelerating towards an orifice forms hemispheric shells of equal velocity; where the colour aliases, velocity equals the Nyquist limit, so flow rate = shell area × aliasing velocity. Dividing by the peak orifice velocity gives the effective orifice area — the size of the leak independent of driving pressure [4].
Raised by
- Organic MR (prolapse, flail), secondary MR, AR, TR
Lowered by
- Lower BP and diuresis reduce secondary MR EROA (dynamic)
Technique & pitfalls
- Zoom, narrow sector, Nyquist shifted to 30–40 cm/s; measure r at mid-systole for MR; angle-correct non-planar convergence.
- Grade secondary MR only when euvolaemic and on optimal GDMT [6].
- Proportionality: interpret secondary MR EROA against LVEDV (proportionate vs disproportionate MR) [186].
Pseudo-change & artefact
- Hemisphere assumption fails with crescentic orifices (secondary MR underestimated) and constrained convergence; late-systolic MR overestimated by peak EROA; multiple jets.
Treatment thresholds
- Primary MR severe + triggers → repair (card 41) [6,7].
- Secondary MR severe with COAPT-like anatomy → TEER class I (ESC/EACTS 2025) [6,64]; the contrast with MITRA-FR is explained partly by disproportionate MR [185,186].
- AR severe + LV triggers → surgery (card 40) [6].
Next step
- Volumetric cross-check; 3D vena contracta area; CMR regurgitant fraction when discordant.
Drugs
GDMT, CRT and BP control reduce secondary MR EROA; nothing reduces primary MR.
Reversibility
Secondary MR partly reversible with reverse remodelling.