Table 4.

Grading MR severity.

Method	Mild	Moderate	Severe
2D assessment of MV anatomy	Mild anatomical abnormality of the MV	Moderate leaflet tenting, thickening or calcification	Flail leaflet segment, clear coaptation defect on 2D or 3D echo, papillary muscle rupture/avulsion, large leaflet perforation, marked leaflet retraction
LA size	Normal (may dilate secondary to MS or moderate+ diastolic dysfunction)	Normal or mildly dilated	Always dilated
LV size	Not dilated secondary to MR	Normal or mildly dilated	Eventually becomes dilated
Jet area	Small jet with low area. Typically narrow, frequently brief and end-systolic		Large central jet that encompasses >50% LA area. Wall adhering jet (Coanda effect) that reaches the upper LA or is seen to wrap around the roof of the LA
Flow convergence	Not seen, brief or small	Intermediate size or non-holosystolic	Large and holo-systolic
CW Doppler	Faint/partial/parabolic	Dense but partial/parabolic	Density similar to forward flow signal/triangular (when acute severe or torrential)
Vena contracta (cm)	<0.3	Single plane <0.3–≥0.69 Biplane 0.31–≥0.79	Single plane ≥0.7 Biplane ≥0.8 cm
Pulmonary vein flow	S dominant (may be blunted in AF or diastolic dysfunction)	S dominant but may be blunted if eccentric MR (may be blunted in AF or diastolic dysfunction)	S flow reversal
Mitral forward flow	A dominance (E may be dominant in the young or moderate+ diastolic dysfunction)	Variable	E wave dominant (E velocity >1.5 m/s)
EROA (cm2)	<0.2	0.2–0.39	≥0.4 (may be lower in secondary MR or when EROA is elliptic)
Regurgitant volume (mL)	<30	31–59	≥60 (may be lower in secondary MR or when EROA is elliptic)
Regurgitant fraction (%)	<30%	30–49%	>50%

Data from the ASE table for grading the severity of chronic MR by echocardiography (15).