How to Diagnose and Assess Severity of Mitral Regurgitation by Echo

1. How to Diagnose and Assess Severity of Mitral Regurgitation by Echo Noel Black Chief Cardiac Physiologist South Eastern Trust

2. Calculating (PISA) • Apical 4Ch view • Narrow sector width • Minimise depth • Zoom • Adjust Colour Doppler alaising velocity (20-40 cm/s)

3. PISA • Measure the radius of the hemisphere. (red/blue interface) • PISA radius =2πr2 (cm2) • Mild MR: <0.4 • Severe MR:>1.0

4. Consideration Non-circular orifice

5. Colour Doppler Indicators of Mitral Regurgitation Severity

6. Continuous wave and Pulse wave Doppler • Continuous wave spectral Strength • Apical 4Ch view CW of regurgitant jet • Faint in mild mitral regurgitation • Denser in moderate and severe regurgitation.

7. Peak Mitral Valve E velocity • Increased mitral valve E velocity (>1.2m/s) may indicate significant regurgitation. • Assumes ejection fraction is>40%) • Decreased mitral valve DT (<150msec) may indicate significant regurgitation. • Assumes normal diastolic LV function.

8. Pulmonary Vein Systolic Flow Reversal • PW doppler 1cm into the pulmonary veins • Systolic S (systolic) wave is normally larger than the D (diastolic) wave. • If D wave is larger there is blunting of forward flow. • S wave inversion demonstrates systolic flow reversal (indicative of severe MR).

9. Limitation • Eccentric jets may affect pulmonary vein flow

10. Determination of Pulmonary Artery Pressures at Rest and Exercise

11. Multimodality Indicators of Mitral Regurgitation Severity

12. Regurgitant Volume, Regurgitant Fraction and ERO • Regurgitant volume • Step 1 • A4ch view measure diameter of the mitral annulus. • CSAMV =0.785 X (mitral annulus diameter)2

13. Regurgitant volume • Step 2 • Apical 4Ch view measure the VTI of the mitral inflow (using PWD) • Commonly at valve tip level. • VTIMV in cm • Step 3. Stroke Volume • SVMV (mL/beat) =CSAMV X VTIMV

14. Regurgitant volume • Step 4 • In PLAx measure the diameter of the LVOT (cm). • Calculate CSA of the LVOT (cm2) • CSALVOT = 0.785 x (LVOT diameter)2

15. Regurgitant volume • Step 5 • In the Ap5 Ch view measure the VTI of the LVOT outflow (using PWD) • VTILVOT (cm) • Step 6. Stroke volume • SVLVOT = CSALVOT x VTILVOT

16. Regurgitant Volume/Fraction • Step 6 • Mitral regurgitant volume (RV)(mL) • RV =SVMV – SVLVOT • Mild MR:<30 Mod MR:31-59 • Severe MR:>60 • Step 7 • Mitral regurgitant Fraction (MF)(cm2) • RF = RV / SVMV (x100) • Mild MR:<30 Mod MR:31-49 • Severe MR:>50

17. Regurgitant orifice area • Step 8 • Measure the VTI of the mitral regurgitation VTIMR (cm) (using CWD) • Calculate Regurgitant Orifice Area (ROA) in cm2 • ROA = RV / VTIMR • Mild MR:<0.20 • Mod MR:0.21-0.39 • Severe MR:>0.40

18. Regurgitant Orifice Area PISA method • Step 1. Measure the radius of the hemisphere. (red/blue interface) • PISA =2πr2 (cm2) • Calculate regurgitant flow rate • RFR mL/s =PISA X aliasing velocity

19. Regurgitant orifice area • Step 2. CWD of the mitral regurgitation. Measure peak velocity (VMR) in cm/s. • Calculate Regurgitant Orifice Area in cm2. • ROA =Regurgitant flow rate / VMR

20. Common pitfalls • Measuring regurgitant jet area or VC width on colour doppler with inappropriate colour gain settings • Underestimating severity of eccentric jets on CFD. • Failure to align the doppler beam with regurgitant flow during CW doppler interrogation. • Inaccurate measurement of mitral valve orifice area or LVOT diameter when calculating RV. • Trying to calculate RV when there is coexistant aortic regurgitation. • Failure to average several readings when the patient is in AF.

21. TOE • Superior 2D images of anatomic structures • Chordal rupture/ruptured papillary muscle • Assessment of the jet area • eccentric jets • Prosthetic heart valves • reduced masking effect • Pulmonary vein assessment

22. Factors affecting operative decision on the patient with MR Symptoms Severity of MR Feasibility of surgical repair Decision to operate Haemodynamic effects of MR on LV, LA and RV Operative risk to the patient