Structural parameters
LA size
Mild:Normal(1)
Moderate:Normal or dilated
Severe:Usually dilated(2)
LV size
Mild:Normal(1)
Moderate:Normal or dilated
Severe:Usually dilated(2)
Mitral leaflets or support apparatus
Mild:Normal or abnormal
Moderate:Normal or abnormal
Severe:Abnormal / flail-leaflet / ruptured papillary muscle
Doppler parameters
Color flow jet area(3)
Mild:Small, central jet (usually <4 cm2 or <20% of LA area)
Moderate:Variable
Severe:Large central jet (usually >10cm2 or >40% of LA area) or variable size wall-impinging jet swirling in LA
Mitral inflow –PW
Mild:A wave dominant(5)
Moderate:Variable
Severe:E wave dominant(5) (E usually 1.2 m/s)
Jet density –CW
Mild:Incomplete or faint
Moderate:Dense
Severe:Dense
Jet contour –CW
Mild:Parabolic
Moderate:Usually parabolic
Severe:Early peaking–triangular
Pulmonary vein flow
Mild:Systolic dominance(6)
Moderate:Systolic blunting(6)
Severe:Systolic flow reversal(4)
Quantitative parameters(7)
VC width (cm)
Mild:<0.3
Moderate:0.3-0.69
Severe:≥0.7
R Vol (mL/beat)
Mild:<30
Mild-Moderate:30-44
Moderate-Severe:45-59
Severe:≥60
RF (%)
Mild:<30
Mild-Moderate:30-39
Moderate-Severe:40-49
Severe:≥50
EROA (cm2)
Mild:<0.20
Mild-Moderate:0.20-0.29
Moderate-Severe:0.30-0.39
Severe:≥0.40

CW, Continuous wave; LA, left atrium; EROA, effective regurgitant orifice area; LV, left ventricle; PW, pulsed wave; RF, regurgitant fraction; R Vol, regurgitant volume; VC, vena contracta.

  1. Unless there are other reasons for LA or LV dilation. Normal 2D measurements: LV minor axis ≤2.8 cm/m2, LV end-diastolic volume ≤82 mL/m2, maximal LA antero-posterior diameter ≤2 cm/m2, maximal LA volume ≤36 mL/m2 (2,33,35).
  2. Exception: acute mitral regurgitation.
  3. At a Nyquist limit of 50–60 cm/s.
  4. Pulmonary venous systolic flow reversal is specific but not sensitive for severe MR.
  5. Usually above 50 years of age or in conditions of impaired relaxation, in the absence of mitral stenosis or other causes of elevated LA pressure.
  6. Unless other reasons for systolic blunting (eg. atrial fibrillation, elevated left atrial pressure). pressure.
  7. Quantitative parameters can help sub-classify the moderate regurgitation group into mild-to-moderate and moderate-to-severe.