EROA - Mitral Regurgitation Calculator
Calculate Effective Regurgitant Orifice Area (EROA) and assess mitral valve regurgitation severity
EROA Calculation Parameters
Radius of Proximal Isovelocity Surface Area
Velocity measured at radial distance from regurgitant orifice
Peak velocity of mitral regurgitation jet
Velocity time integral of mitral regurgitant jet
EROA Calculation Results
Calculation Formulas
VFR: 2 × π × r² × Va = 0.0 ml/s
EROA: VFR / Vmax = 0.000 cm²
Regurgitant Volume: EROA × VTI = 0.0 ml/beat
Clinical Interpretation
Example Calculation
Moderate Mitral Regurgitation Example
PISA Radius (r): 0.6 cm
Aliasing Velocity (Va): 40 cm/s
Maximal Velocity (Vmax): 500 cm/s
Velocity Time Integral (VTI): 15 cm
Calculation Steps
1. VFR = 2 × π × (0.6)² × 40 = 45.2 ml/s
2. EROA = 45.2 / 500 = 0.090 cm²
3. Regurgitant Volume = 0.090 × 15 = 1.4 ml/beat
Result: Mild Mitral Regurgitation
MR Severity Grading (ACC/AHA)
Grade A - At Risk
EROA < 0.2 cm²
RegVol < 30 ml
No symptoms
Grade B - Progressive
EROA 0.2-0.4 cm²
RegVol 30-60 ml
No symptoms
Grade C - Asymptomatic Severe
EROA ≥ 0.4 cm²
RegVol ≥ 60 ml
No symptoms
Grade D - Symptomatic Severe
EROA ≥ 0.4 cm²
RegVol ≥ 60 ml
With symptoms
ECHO Measurement Tips
Use color Doppler to identify PISA
Optimize Nyquist limit (aliasing velocity)
Measure PISA radius at narrowest point
Use continuous wave Doppler for Vmax
Understanding Mitral Regurgitation and EROA
What is Mitral Regurgitation?
Mitral regurgitation occurs when the mitral valve doesn't close properly during left ventricular contraction, allowing blood to flow backward from the left ventricle into the left atrium. This reduces the heart's efficiency in pumping blood to the body.
Common Causes
- •Mitral valve prolapse
- •Rheumatic heart disease
- •Infective endocarditis
- •Ischemic heart disease
- •Connective tissue disorders
EROA Calculation Method
VFR = 2 × π × r² × Va
EROA = VFR / Vmax
RegVol = EROA × VTI
- VFR: Volume Flow Rate (ml/s)
- r: PISA radius (cm)
- Va: Aliasing velocity (cm/s)
- Vmax: Peak regurgitant velocity (cm/s)
- VTI: Velocity time integral (cm)
Medical Disclaimer: This calculator is for educational purposes only. Clinical decisions should always be made by qualified healthcare professionals.
Clinical Significance
Mild MR
Usually asymptomatic and well-tolerated. Regular follow-up recommended.
Moderate MR
May develop symptoms over time. Closer monitoring and possible intervention planning.
Severe MR
Often requires surgical intervention. May cause heart failure if untreated.
Related Cardiovascular Calculators
Important Medical Disclaimer
This EROA calculator is designed for educational purposes and clinical reference only. It should never replace professional medical judgment or clinical assessment.
Healthcare professionals should:
- Correlate results with complete clinical evaluation
- Consider patient symptoms and other diagnostic findings
- Follow current guidelines for mitral regurgitation management
- Verify calculations independently before making clinical decisions
Patients should always consult with qualified healthcare providers for diagnosis, treatment, and medical advice. Never use this calculator for self-diagnosis or treatment decisions.