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MITRAL REGURGITATION. 2D ASSESSMENT. LOOK CAREFULLY AT THE MITRAL VALVE APPARATUS. Tenting. HOW TO ASSESS THE SEVERITY OF MITRAL REGURGITATION ?. Color flow imaging PW Doppler CW Doppler Quantitative Doppler. COLOR FLOW ASSESSMENT. COLOR FLOW ASSESSMENT OF MITRAL REGURGITATION.
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HOW TO ASSESS THE SEVERITY OF MITRAL REGURGITATION ? • Color flow imaging • PW Doppler • CW Doppler • Quantitative Doppler
COLOR FLOW ASSESSMENT OF MITRAL 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 MITRAL 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 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 MR • Shape: symmetrical or asymmetrical • Chronic vs. Acute MR • Density of signal
Quantitative Doppler • PISA / Volumetric method • Vena Contracta, Effective Regurgitant Orifice(ERO), Regurgitant Volume (RV) • Continuity Equation • Effective Regurgitant Orifice(ERO), Regurgitant Volume (RV) and Regurgitant Fraction (RF)
Measurements Required for PISA Method radius of flow convergence hemisphere (cm) aliasing velocity on color bar (cm) peak regurgitant velocity (cm) TVI of regurgitant CW jet (cm)
PISA 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 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)
VENA 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 jet How 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 METHOD • CALCULATION OF MITRAL Regurgitant Volume (RV) Step 1. Measure the Mitral annulus diameter Step 2. Obtain the TVI Mann. Step 2. Calculate the MV stroke volume MV 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)
PITFALLS in Calculation of Regurgitant Volume / Fractions • Learning curve of the operator • Significant Doppler angle (more than 200) may lead to underestimation of velocity and TVI. Optimal: parallel to bld.flow • Incorrect placement of sample volume. • Not averaging enough measurements. • Incorrect measurement of Annulus diameters. • Formula is invalid if multivalvular regurgitant lesions or significant shunts present.