Echocardiographic Grading of Mitral Regurgitation Severity

Assessment of pulmonary venous flow velocity by pulsed Doppler echocardiography can also be of value in estimating the severity of mitral regurgitation. Normal pulmonary venous flow velocity is biphasic, with a predominant systolic forward velocity and a lesser diastolic forward velocity in older adults. Systolic forward velocity is reduced in patients with mitral regurgitation, and often the diastolic velocity predominates. In severe mitral regurgitation, the systolic flow in the pulmonary vein signal may reverse. Systolic flow reversal is highly specific for severe regurgitation but sensitivity is low. Unfortunately, pulmonary venous flow velocity patterns vary considerably in patients with mitral regurgitation, and the predictive value for regurgitation severity is low. In many laboratories, all these factors are integrated to produce a composite estimate of the severity of regurgitation, usually on a scale of 1 to 4, with 4 being severe mitral regurgitation. Table below exhibits the criteria for grading the severity of mitral regurgitation. 

Echocardiographic Grading of Mitral Regurgitation Severity

Grading System Mild Mild to Moderate Moderate to Severe Severe Angiographic grade 1+ 2+ 3+ 4+ Specific signs Jet area < 4 cm2 Jet area > 40% of LA area Jet area to LA area < 20% Visual orifice width > 0.7 cm Visual orifice width < 0.3 cm Flow reversed in pulmonary veins No or minimal flow convergence Major flail segment of leaflet Papillary muscle rupture Supportive signs Systolic dominant PV flow to A wave dominant mitral inflow Dense continuous wave Doppler signal Low density continuous wave Doppler MR signal E wave dominant mitral inflow, E > 1.2 m/s Normal LV and LA size Enlarged LV and LA Normal LV function Quantitative measurements   Regurgitant volume, mL/beat < 30 30–44 45–59 ≥ 60   Regurgitant fraction, % < 30 30–39 40–49 ≥ 50   Effective orifice area, cm2 < 0.2 0.2–0.29 0.3–0.39 ≥ 40

LA, left atrium; LV, left ventricle; MR, mitral regurgitation; PV, pulmonary vein.

Referensi:
Current Diagnosis & Treatment Cardiology 3rd Edition (McGraw-Hill) 2009

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