MR Severity

MR Severity Grading
Parameter Mild Moderate Severe
EROA (cm²) <0.2 0.2–0.39 ≥0.4
Regurgitant Volume (mL) <30 30–59 ≥60
Regurgitant Fraction (%) <30% 30–49% ≥50%
Vena Contracta (cm) <0.3 0.3–0.69 ≥0.7

Primary (Organic) MR – leaflet/chordal abnormality

  • Mitral valve prolapse
  • Flail leaflet (chordal rupture)
  • Rheumatic disease
  • Endocarditis
  • MitraClip/iatrogenic

Secondary (Functional) MR – annular or ventricular abnormality

  • Ischemic MR (due to papillary muscle displacement after MI, usually inferior/posterior MI)
  • Dilated cardiomyopathy (annular dilation, papillary displacement)
  • Restrictive LV remodeling

Ischemic / Functional MR

  • Typically central or posteromedial jets.
  • Mechanism: LV dilation → papillary muscle displacement → tethering of leaflets → incomplete coaptation.
  • Ischemic MR after inferior MI often eccentric (posterior pap muscle dysfunction causing anterior jet).

When is MR Eccentric?

  • Eccentric jet (wall-hugging, Coandă effect):
    • Mitral valve prolapse (classic cause)
    • Flail leaflet
    • Chordal rupture
    • Papillary muscle rupture (acute MR)
  • Central jet:
    • Functional/ischemic MR
    • Annular dilation

How to Measure

  • EROA (PISA): Color Doppler → adjust Nyquist (~30–40 cm/s) → measure PISA radius (r) → Flow = 2πr² × aliasing vel → get peak MR Vmax (CW) → EROA = Flow ÷ Vmax
  • RVol: RVol = EROA × MR VTI (trace CW jet)
  • RF: RF = (RVol ÷ LV stroke vol) ×100% (LVSV via LVOT or volumes)
  • VC: Parasternal long-axis, color Doppler, narrowest jet, avg early–mid systole.

Use ≥2–3 concordant findings; integrate with jet area, pulm vein flow, LV size.

Qualitative Assessment (CW Doppler)

  • Mild: Faint, parabolic, often <4m/s
  • Moderate: Denser, parabolic, ~4m/s
  • Severe: Very bright/dense, triangular (late-peaking), often 5-6m/s

Qualitative Assessment (Jet Length)

  • Break the LA into thirds
  • Depending on how far the jet travels backwards to the LA can indicate potential severity
  • A = Mild
  • B = Moderate
  • C = Severe
MR Severity Calculator
Severity EROA RVol
Mild <0.2 <30
Mild–Moderate 0.2–0.29 30–44
Moderate–Severe 0.3–0.39 45–59
Severe ≥0.4 ≥60

References

  1. Zoghbi, W. A., Adams, D., Bonow, R. O., Enriquez-Sarano, M., Foster, E., Grayburn, P. A., Hahn, R. T., Han, Y., Hung, J., Lang, R. M., Little, S. H., Shah, D. J., Shernan, S., Thavendiranathan, P., Thomas, J. D., & Weissman, N. J. (2017). Recommendations for noninvasive evaluation of native valvular regurgitation: A report from the American Society of Echocardiography. Journal of the American Society of Echocardiography, 30(4), 303–371. https://doi.org/10.1016/j.echo.2017.01.007
  2. Lancellotti, P., Tribouilloy, C., Hagendorff, A., Moura, L., Popescu, B. A., Agricola, E., Monin, J. L., Pierard, L. A., Badano, L., & Zamorano, J. L. (2013). Recommendations for the echocardiographic assessment of native valvular regurgitation: An executive summary from the European Association of Cardiovascular Imaging. European Heart Journal Cardiovascular Imaging, 14(7), 611–644. https://doi.org/10.1093/ehjci/jet105
  3. Otto, C. M., Nishimura, R. A., Bonow, R. O., Carabello, B. A., Erwin, J. P., III, Gentile, F., Jneid, H., Krieger, E. V., Mack, M., McLeod, C., O’Gara, P. T., Rigolin, V. H., Sundt, T. M., III, & Thompson, A. (2021). 2020 ACC/AHA guideline for the management of patients with valvular heart disease. Circulation, 143(5), e72–e227. https://doi.org/10.1161/CIR.0000000000000923
  4. Vahanian, A., Beyersdorf, F., Praz, F., Milojevic, M., Baldus, S., Bauersachs, J., Capodanno, D., Conradi, L., De Bonis, M., De Paulis, R., Delgado, V., Freemantle, N., Gilard, M., Haugaa, K. H., Jeppsson, A., Jüni, P., Pierard, L., Prendergast, B. D., Sádaba, J. R., ... Wojakowski, W. (2022). 2021 ESC/EACTS guidelines for the management of valvular heart disease. European Heart Journal, 43(7), 561–632. https://doi.org/10.1093/eurheartj/ehab395
  5. Bonow, R. O., O’Gara, P. T., Adams, D. H., Badhwar, V., Bavaria, J. E., Elmariah, S., Hung, J. W., Lindenfeld, J., Morris, A. A., Satpathy, R., Whisenant, B., & Woo, Y. J. (2020). 2020 focused update of the 2017 ACC expert consensus decision pathway on the management of mitral regurgitation. Journal of the American College of Cardiology, 75(17), 2236–2270. https://doi.org/10.1016/j.jacc.2020.02.005
  6. Grayburn, P. A., Sannino, A., & Packer, M. (2019). Proportionate and disproportionate functional mitral regurgitation: A new conceptual framework that reconciles the results of the MITRA-FR and COAPT trials. JACC: Cardiovascular Imaging, 12(2), 353–362. https://doi.org/10.1016/j.jcmg.2018.11.006