EROA (PISA Method)

EROA (PISA Method): Effective Regurgitant Orifice Area. The gold-standard quantitative method for grading Mitral Regurgitation severity.

PISA Radius (cm)

Aliasing Vel (cm/s)

Peak MR Vel (cm/s)

Guidelines & Evidence

Verified

Last Review: 2026-07-17

When to Use

Quantification of mitral regurgitation severity

Assessment of degenerative vs functional MR

MV repair vs replacement decision-making

Serial follow-up of known MR

Complementary to visual assessment and regurgitant volume

How it Works

PISA Method Concept

Proximal isovelocity surface area (PISA) maps velocity contours in regurgitant flow

PISA is hemisphere of flow approaching regurgitant orifice

Velocity at PISA = regurgitant velocity (peak spectral CW velocity)

Regurgitant flow = area of PISA × velocity

Formula

EROA = (2π × r2) × (aliasing velocity / peak MR velocity) r = PISA radius (cm) Aliasing velocity = Nyquist limit (typically 50–70 cm/sec) Peak MR velocity from continuous-wave Doppler EROA in cm2

MR Severity by EROA

EROA (cm2)	EROA Classification	MR Severity
<0.20	Minimal	Trivial–Mild
0.20–0.39	Small	Mild–Moderate
0.40–0.59	Moderate	Moderate–Moderately Severe
>0.60	Large	Severe

Last Comprehensive Review: 2026-07-17

Recent Journal Updates

British J Clinical PharmacologyJul 21, 2026

Impact of parameter settings on the estimation of drug exposure with the individualized dispensing patterns method

Clinical Context

We think this might be relevant to the clinical guidance for EROAPISA Method.

Alzheimers & DementiaJul 19, 2026

The design of embedded pragmatic clinical trials: methodological developments and statistical lessons learned from the first cycle of the NIA IMPACT collaboratory

Clinical Context

We think this might be relevant to the clinical guidance for EROAPISA Method.

Tropical Med & Intl HealthJul 17, 2026

Addressing Behavioural Determinants of Cutaneous Leishmaniasis Through Community Dialogue in Kalu District, Ethiopia: A Mixed‐Methods Study

Clinical Context

We think this might be relevant to the clinical guidance for EROAPISA Method.

EROA (PISA Method)

When to Use

When to Use

How it Works

PISA Method Concept

Formula

MR Severity by EROA

Clinical Pearls

Technical Considerations

Complementary Calculators

Recent Journal Updates

EROA (PISA Method)

When to Use

When to Use

How it Works

PISA Method Concept

Formula

MR Severity by EROA

Clinical Pearls

Technical Considerations

Complementary Calculators

Recent Journal Updates