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DOPPLER IN REGURGITANT LESIONS. Regurg Lesions…..Doppler Indirect Semiquantitative ….jet area ratios Quantitative… RVol,RF,EROA. INDIRECT INDICATORS. Shape of regurg signal : “V” cut-off sign (AV valves) Shortened PHT or DS ( semilunar valves )
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Regurg Lesions…..Doppler Indirect Semiquantitative….jet area ratios Quantitative…RVol,RF,EROA
Shape of regurg signal : “V” cut-off sign (AV valves) Shortened PHT or DS (semilunar valves) Mild AV valve reg…Pr gradient is high & remains relatively constant through out the entire systole…symmetrical U shaped doppler velocity curve….. In Severe …Gradient initaiallyhigh,but decreases towards the latter half of systole….rapid & asymmetric V shaped doppler V” cut-off sign : d/t rapid equalisation (cross over) of LA & LV pressures
Shortened PHT in semilvalves… Larger the regorifice,the greater the rate of decline of diastpr gradient b/w aorta & LV . So PHT decreases in severe DS (V peak/DT) increases in severe
Flow reversal velocities : TR….hepatic veins MR…Pulmonary veins AR…DA & Abd aorta Syst to diast PV flow velocity ratio [VTIs/VTID] in MR
Flow reversal in semil valve regurg: velocity & duration during diastole…index of severity Pandiast flow reversal in DA…at least moderAR Pandiast flow reversal in Abd A…extremely sensitive (100%) & specific (97%) for severe AR End diastolic flow velocity>18cm/s..predict moderate to severe AR sensitivity (88%) & specificity (92%)
Limitations of flow reversal: CoexL-R shunt or aortic anomalies Arrythmias Poor setting of wall filters Resp Variation LA compliance & pressures Eccentric jets
COLOUR FLOW DOPPLER (1)Vena Contracta: narrowest portion of a jet that occurs at or just downstream from the orifice. high velocity, laminar flow and is slightly smaller than the anatomic regurgitant orifice due to boundary effects transducer needs to be angulated It is preferable to use a zoom mode The color flow sector should also be as narrow as possible,
2)AR jet ht & JH/LVOT diameter ratio 3)Regurgitantjet area & Regurgitant jet area to receiving chamber area ratio 4)PISA method JH : significant overlap >8 mm .. To discriminate b/w grades 1-2 vs 3-4 JH/LVOH >40% .. To discriminate b/w grades 1-2 vs 3-4 ; <25% ..mild AR JH/LVOH…. Best indicator for predicting the severity of AR
JH : max AP diameter of the regurg jet just below AV in PLAX LVOT : measured @ end diastole at the same location
IN AR RJA : PSAX @ LVOT level LVOA :@ end diastole @ same location RJA : >8 cm2 i/o severe MR (sens/specif…82/94)/ TR(71/91) InAR, RJA/LVOA of 25% …mild-moderate vs moderately severe to severe AR
RJA & LAA … from multiple orthogonal planes including A4C , PLAX, PSA
Limitations of CFDI in Regurgassessmnt Wall jets .. Underestimates jet size Coexistent Jets…MS/Prosthetic MV Instrument factors … Gain settings ; PRF ; Incident angle ; Driving pressure, Receiving chamber size & compliance, regurgvolume,size & shape of regurg orifice.
Regurgitant Volume : Rvol = SV RV – SV CV Regurg Fraction : Rvol ÷ SV forward x 100
Calculation of RV & RF Method 1 SV LVOT = CSA (cm2) x VTI (cm) LVOT….diameter …PLAX…@ aortic annulus…from inner edge to inner edge of aortic cuspal insertion. CSA LVOT= 0.785xD2 VTI of LVOT … from A5C .. PWD sample volume in centre of LVOT proximal to aortic valve
SVMV = CSAMV x VTIMV MV annulus diameter ….from A4C … mid diastole…from inner edge to inner edge VTI…from A4C…PwD sample vol at MV annulus So for MR RV = SVMV - SV LVOT RF = SVMV - SV LVOT / SVMV =RV/SVMV AR : RV =SV LVOT– SV MV RF = SV LVOT– SV MV/ SV LVOT= RV/SV LVOT Considered as the the most accurate method for calculating RV & RF
(2)SV LV by 2d echo … Simpsons biplane method LV EDV-LVESV In MR … RV = SV(2D) – SV LVOT RF = SV(2D) – SV LVOT / SV2D =RV/SV2D In AR .. RV = SV(2D) – SV MV RF= SV(2D) – SV MV/SV(2D) = RV/SV2D Less accurate Used when it is difficult to measure mitral annulus diameter or LVOT diameter
(3)RF in AR Measure syst , diastdiameter of aorta (@ top of aort arch) From suprasternal long axis view Systolic VTI … PwD sample vol is positioned proximal to head & neck vessels Diastolic VTI … PwD sample vol is placed just distal to left subclavian artery with in Desc.aorta Calculate Syst SV & Diast reversed SV RF= SV diast/SV syst Rarely used..as imaging of aorta in suprasternal notch is challenging
Limitations of RV & RF calculations Assumptions of SV calculation Errors in diameter measurements Errors in VTI Presence of multivalv lesions/intracardiac shunts
The flow rate proximal to a narrowed orifice is the product of the hemisheric flow convergent area & the velocity of that isovelocity shell Q=2 π r2Vr Bld flow thru hemishere must pass thru the orifice ;So 2 π r2Vr = Ao x Vo Ao = 2 π r2 Vr / Vo EROA= 2 π r2 VN / VR Rvol=EROA x VTIRJ
EROA (1)Spectral dopplertechniq .. Principle of conservation of mass Calculated from the premise that RV thru an incomp valve is equal to flow @ the regurg orifice Rvol=EROAxVTI RJ EROA=Rvol/VTI RJ
(2)PISA method : variation in the application of the cont equation.
Simplified method for MR Rvol…when appropriate CW D MR jet cannot be obtained…the ratio b/w the max mitral reg velocity & VTIRJ is a constant of 3.25 (Rossi et al.) Rvol= 2 π r2 VN /3.25 (ie 2 π r2 VN/VR x VTIRJ) Tricuspid EROA = (2 π r2 VN /VR-VN) (α/180) After 2 corrections for (1)flattening of PISA close to the reg orifice (corrected by multiplying flow rate by (VR/VR-VN) (2)Distorted regorificesmallisovelocity contours…corrected by multiplying 2 π by α/180
Simplified method for evaluating MR/TR using the flow convergence region prox to the regurg orifice…measures the radius of PISA dome…
Trace MR…40% healthy indiv….elderly 3 methods…color flow Doppler mapping: regurgitantjet area,venacontracta, and flow convergence (PISA).