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ECHO

  1. Frequency
    f=cycles/s=Hz
  2. Wavelength(¥)=
    ¥=v/f
  3. Doppler equation
    • V=c x (Fs - Ft) /[2 Ft(cos 0)]
    • V=1.54 x change freq/angle
    • Higher velocity --> higher doppler frequency shift assume cos 0=1(beam parallel to flow)
  4. Bernoulli's equation
    • 4V(2) assumes prox velocity <1.
    • When LVOT/ PS
    • 4[V2(2) - V1(2)]
  5. Stroke volume
    • SV=EDV-ESV
    • SV=CSA X TVI
  6. EF% by volumes
    • SV/EDV X 100%
    • EDV-ESV/EDV X 100%
  7. Wall stress
    • Pressure(P) x Ventricular Radius(R) / [2 x wall thickness]
    • Analogy balloon
    • Bigger balloon with more air pressure has thinner wall & increased wall stress
  8. Cardiac Output
    SV(ml) x HR(beats/min) / 1000mL/L
  9. dP/dT is Rate of pressure rise over time is a load-independent measure of LV function.
    • dP/dT=32mmHg/ (time from 1to 3 m/s MR CW jet in sec)
    • Normal is > 1200
    • Abn < 1000
  10. PAP
    4(Vtr)2 + RAP
  11. PAP with significant PS
    [4(Vtr)2 + RAP] - 4(Vrv-Vpa)
  12. PVR
    10(Vtr)/VTI rvot
  13. AVA continuity
    .785 x D lvot x VTI lvot/ VTI as
  14. Velocity ratio
    • V lvot/ V as
    • >0.5 mild
    • <0.25 severe
  15. MVA(Mitral stenosis) by P1/2t
    220/P1/2t
  16. Aortic Regurgitation volumes
    • RVav=tSVav-fSVmv
    • ROA=RV/VTIav
    • RF=RVav/TSVx100%

    • Severe Mild
    • RV >60 <30
    • RF >50 <30
    • ROA>0.30 <0.10
  17. AR vena contracta
    • Severe >0.6
    • Mild <0.3
  18. AR pressure 1/2 t
    • Severe <200ms
    • Mod Severe 200-350
    • Moderate 350-500
    • Mild >500
  19. Mitral Regurgitation volumes
    • RV=tSVmv-fSVlvot
    • ROA=RVmv/VTImv
    • RF=RVmv/SVmv x100%

    • Severe Mild
    • RV >60 <30
    • RF >50% <30%
    • ROA >0.4. <0.20
  20. MR jet area
    • Severe >40% LA
    • Mild <20% LA
  21. MR Vena Contracta
    • Severe >0.7cm
    • Mild <0.3cm
  22. MR PISA
    • Rflow=6.28 r2 x Va
    • ERO=RFlow/Vmr
    • RV=ERO x VTImr

    • Severe
    • ERO >0.4 cm2
    • RV >60
  23. Aortic dilation with age.
    Predicted sinus diamension.
    • Age 18-40
    • 0.97 + (1.12 BSA)
    • Age >40
    • 1.92 + (0.75 BSA)
  24. Qp:Qs
    D pa2 x VTI pa / D lvot2 x VTI lvot
  25. What is normal fractional shortening?
    24-40%
  26. Index of Myocardial Performance (IMP)
    LIMP or RIMP
    [MR or tr duration - LVOT or rvot duration] / LVOT or rvot duration

    • Norm < 0.40
    • mild 0.4-0.5
    • Mod 0.6-0.9
    • Sev > 0.9
  27. PA acceleration time
    • Estimates mean PA pressure.
    • 79 - (0.45 x Accel t)
    • HR must be between 60-80.
    • Not valid with asd or vsd
  28. Simplified continuity equation.
    • [(3.0 x BSA x 1000) / HR] / AVvti = AVA cm2
    • Assume nl lvot sv
  29. AVA index c/w severe AS
    <= 0.45
  30. Calc AR ERO by vol, what considered severe
    • AV regurg vol / VTIar
    • (SVav - SVmv) / VTIar
    • >0.29 = severe
  31. Calc AR regurg fraction by vol, What is moderate.
    • (SVav - SVmv) / SVav
    • Moderate = 30-50%
    • *invalid with significant MR
    • *not well validated
  32. Expected AV decel rate for moderate AR.
    • 2 - 3.5 m/sec2
    • *least reliable
  33. Calc p1/2t AR
    What are mild, mod, sev parameters.
    • mSec x 0.29
    • Mild >500mSec
    • Severe <200mSec

    *least reliable
  34. AR jet/LVOT diameter ratio for moderate AR.
    • 25-64% mod
    • <25% mild
    • >64% sev
  35. AR jet/LVOT area ratio for moderate AR
    • 5-59% mod
    • <5% mild
    • >59% sev
  36. EF calculation Quinones
    (LVEDd2 - LVEDs2) / LVEDd2 x 100%
  37. PVa velocity >0.35 m/sec indicates
    Increased LA pressure/LVEDP
  38. PISA calc
    Flow rate
    ERO
    RV
    • 2 pi r2 x Va = flow rate
    • 6.28 r2 x Va / peak Vmr = ERO (cm2)
    • ERO cm2 x VTI mr = RV
  39. Simplified MVA by p1/2 t
    759 / decel time
Author
liukuf
ID
94600
Card Set
ECHO
Description
echo review
Updated

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