EROA and MVEA Are Not the Same Terms
No, EROA (Effective Regurgitant Orifice Area) and MVEA (Mitral Valve Effective Area) are fundamentally different measurements that assess opposite aspects of mitral valve function. EROA quantifies the severity of mitral regurgitation by measuring the area through which blood leaks backward, while MVEA would refer to the forward flow area through the mitral valve (typically used in stenosis assessment) 1.
Key Distinctions
EROA (Effective Regurgitant Orifice Area)
- Measures regurgitant flow - quantifies the cross-sectional area of the regurgitant jet in mitral regurgitation 1
- Calculated using the PISA method - derived from proximal isovelocity surface area measurements divided by regurgitant jet velocity 1
- Severity thresholds for primary MR: EROA ≥0.4 cm² indicates severe regurgitation when holosystolic 1
- Severity thresholds for secondary MR: EROA ≥0.2 cm² defines severe regurgitation (revised from 0.4 cm² in 2014 guidelines) 1
- Represents lesion severity - indicates the magnitude of valve dysfunction that worsens prognosis 1
MVEA (Mitral Valve Effective Area)
- Would measure forward flow area - conceptually similar to effective orifice area used in mitral stenosis assessment 1
- Not a standard term in valvular heart disease literature - the provided evidence does not use "MVEA" as a recognized measurement parameter [@1-15@]
- Distinct from regurgitation assessment - forward flow area and regurgitant orifice area serve completely different clinical purposes 1
Clinical Implications
Why This Distinction Matters
- EROA quantifies backward (regurgitant) flow through an incompetent valve, while effective area in stenosis quantifies restricted forward flow 1, 2
- Different measurement techniques - EROA uses flow convergence methods, while stenotic valve areas use continuity equation or planimetry 1
- Opposite pathophysiology - regurgitation represents volume overload from backward flow; stenosis represents pressure overload from restricted forward flow 1
Measurement Considerations for EROA
- Must integrate multiple parameters - EROA should never be used as the sole arbiter of MR severity 1
- Requires holosystolic regurgitation - single-frame EROA measurements can markedly overestimate severity when MR is limited to early or late systole 1
- Geometric assumptions matter - PISA-derived EROA assumes circular orifice geometry and may underestimate severity in crescentic secondary MR 1
- 3D measurements improve accuracy - anatomic regurgitant orifice area (AROA) from 3D echocardiography provides superior reproducibility compared to 2D PISA methods 3, 4, 5, 6
Common Pitfalls
- Do not confuse EROA with anatomic orifice area - EROA is a functional measurement that may differ from direct anatomic planimetry 3, 4, 5
- Avoid relying on single measurements - comprehensive assessment requires regurgitant volume, regurgitant fraction, and evaluation of chamber dimensions 1
- Account for non-holosystolic regurgitation - late systolic MR in prolapse can yield misleadingly high single-frame EROA values 1
- Consider driving pressure effects - high LV-LA gradients (as in concurrent aortic stenosis) create larger color jets despite smaller EROA 1