HOW TO ASSESS THE HOW TO ASSESS THE SEVERITYSEVERITY OF OF
MITRAL REGURGITATION ?MITRAL REGURGITATION ?
• Color flow imaging
• PW Doppler
• CW Doppler
• Quantitative Doppler
COLOR FLOW ASSESSMENT OF COLOR FLOW ASSESSMENT OF MITRAL REGURGITATIONMITRAL REGURGITATION
• JET AREA
- central jet <4cm2 or <20% of LA area = mild MR
- >40% of LA area and reaches the posterior wall of LA = severe MR
COLOR FLOW ASSESSMENT OF COLOR FLOW ASSESSMENT OF MITRAL REGURGITATIONMITRAL REGURGITATION
• JET SHAPE AND DIRECTION
- central, eccentric or wall jet
ex. Ab(N) in Posterior leaflet – anteriorly directed jet
Ab(N) in Anterior leaflet – posteriorly directed jet
Dilatation of LV or Mitral Annulus - central,
symmetric regurgitant jet
PW Doppler Assessment of MRPW Doppler Assessment of MR
• Mitral Inflow – velocity increases with severe MR
“E” velocity >1.5 m/sec
• Pulmonary vein flow – systolic flow reversal in severe MR
CW Doppler Assessment of MRCW Doppler Assessment of MR• Shape: symmetrical or asymmetrical
Chronic vs. Acute MR
• Density of signal
Quantitative DopplerQuantitative Doppler
• PISA / Volumetric methodVena Contracta, Effective Regurgitant
Orifice(ERO), Regurgitant Volume (RV)
• Continuity EquationEffective Regurgitant Orifice(ERO),
Regurgitant Volume (RV) and Regurgitant Fraction (RF)
Measurements Required Measurements Required for PISA Methodfor PISA Method
•radius of flow convergence hemisphere (cm)radius of flow convergence hemisphere (cm)
•aliasing velocity on color bar (cm)aliasing velocity on color bar (cm)
•peak regurgitant velocity (cm)peak regurgitant velocity (cm)
•TVI of regurgitant CW jet (cm)TVI of regurgitant CW jet (cm)
PISA MethodPISA Method
• Shift color baseline in direction of flow
MR ↓
• Aliasing velocity will vary (20-40cm) ideal: an aliasing velocity that creates a
hemispheric shape
• Measure the radius (r) in mid-late systole {peak MR velocity} and take note of the aliasing velocity (Va)
PISA MethodPISA Method• Using CW doppler, obtain optimal
regurgitant jet• Measure peak regurgitant velocity (V)• Trace regurgitant VTI
PISA Calculation:
Flow (cc/sec) = 6.28 x [r (cm.)2] x Va (cm/sec)ERO (cm2) = Flow (cc/sec) V (cm/sec)RV (cc) = ERO (cm2) x VTI (cm)
Severity Values for MRSeverity Values for MR
GRADE (MR) ERO (mm2) RV (cc)
Grade I – Mild < 20 < 30
Grade II - Moderate 20 – 29 30 – 44
Grade III – Moderately severe
30 – 39 45 – 59
Grade IV - Severe > 40 > 60
VENA CONTRACTAVENA CONTRACTA• physiologic or effective orifice area of regurgitant jets• have an advantage with PISA for eccentric jets because
it is affected less by the eccentricity of the jetHow to obtain:• Optimize color flow imaging of the regurgitant jet by
demonstrating the PISA, Vena contracta and regurgitant jet.
• Magnify the region of interest with zoom or regional expansion selection.
• Acquire the image using the cine-loop format.• Measure the smallest width immediately distal to the
regurgitant orifice, perpendicular to the direction of the jet.
CONTINUITY EQUATION CONTINUITY EQUATION METHODMETHOD
Measurements Required
Normal Values
Mitral Annulus Diameter (cm)
2.7 – 3.5 cm.
TVI of mitral annulus flow (cm)
7 – 13 cm.
LVOT diameter (cm) 1.8 – 2.4 cm.
TVI of LVOT flow (cm)
18 – 22 cm
CONTINUITY METHODCONTINUITY METHOD• CALCULATION OF MITRAL Regurgitant
Volume (RV)Step 1. Measure the Mitral annulus diameterStep 2. Obtain the TVI Mann.
Step 2. Calculate the MV stroke volumeMV inflow volume(cc)= (MAnn. dia.)2 x 0.785 x TVI MAnn.
Step 3. Measure the LVOT diameter.
Step 4. Obtain the TVILVOT.Step 5. Calculate the AV stroke volume AV outflow volume(cc)= (LVOT dia.)2 x 0.785 x TVI LVOT.
Step 6. Determine the Mitral RV
RV (cc) = MV inflow volume(cc) – AV outflow volume (cc)
Step 7. Calculate the ERO ERO = RV
VTI MR
• Calculation of Mitral Regurgitant Fraction (RF)
Step 8. Calculate the MV RF.
RF(%) = Mitral RV(cc) x 100
MV inflow volume (cc)
REGURGITANT FRACTION REGURGITANT FRACTION VALUESVALUES
Normal or Trivial MR Less than 20%
Moderate MR 30 – 50 %
Severe MR Greater than 50%
PITFALLS in Calculation of PITFALLS in Calculation of Regurgitant Volume / FractionsRegurgitant Volume / Fractions
1. Learning curve of the operator
2. Significant Doppler angle (more than 200) may lead to underestimation of velocity and TVI. Optimal: parallel to bld.flow
3. Incorrect placement of sample volume.
4. Not averaging enough measurements.
5. Incorrect measurement of Annulus diameters.
6. Formula is invalid if multivalvular regurgitant lesions or significant shunts present.
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