# Equations-1.txt

Home > Preview

The flashcards below were created by user liukuf on FreezingBlue Flashcards.

1. Frequency
f=cycles/s=Hz
2. Wavelength(¥)=
¥=v/f=1.43mm/mHz
3. Doppler equation
• V=v x change freq/doppler shift
• Higher velocity --> higher doppler frequency shift
4. Bernoulli's equation
• 4V(2) assumes prox velocity <1.
• When LVOT/ PS
• 4[V2(2) - V1(2)]
5. Stroke volume
SV=EDV-ESV
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. Stroke Volume
SV=CSA x VTI
9. Cardiac Output
SV(ml) x HR(beats/min) / 1000mL/L
10. 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 (sec)
• Normal is > 1200
11. PAP
4(Vtr)2 + RAP
12. PAP with significant PS
[4(Vtr)2 + RAP] - 4[(Vrv)2 - (Vpa)2]
13. PVR
10(Vtr)/VTI rvot
14. AVA continuity
.785 x D lvot x VTI lvot/ VTI as
15. Velocity ratio
• V lvot/ V as
• >0.5 mild
• <0.25 severe
16. MVA(Mitral stenosis) by P1/2t
220/P1/2t
17. 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
18. Aortic Regurgitation jet width/LVOT%
• Severe >65%
• Mild <25%
19. AR vena contracta
• Severe >0.6
• Mild <0.3
20. AR pressure 1/2 t
• Severe <200ms
• Mod Severe 200-350
• Moderate 350-500
• Mild >500
21. 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
22. MR jet area
• Severe >40% LA
• Mild <20% LA
23. MR Vena Contracta
• Severe >0.7cm
• Mild <0.3cm
24. MR PISA
• Rflow=2(pi)r(2) x Va
• =6.28 r(2) x Va
• ROA=RFlow/Vmr
• RV=ROA x VTImr

• Severe
• ROA >0.4 cm2
• RV >60
25. Aortic dilation with age.
Predicted sinus diamension.
• Age 18-40
• 0.97 + (1.12 BSA)
• Age >40
• 1.92 + (0.75 BSA)
26. Qp:Qs
Dpa(2) x VTI pa / Dlvot(2) x VTI lvot
27. What is normal fractional shortening?
24-40%
28. Index of Myocardial Performance (IMP)
[MR/tr duration - LVOT/rvot duration] / LVOT/rvot duration

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

*least reliable
36. AR jet/LVOT diameter ratio for moderate AR.
• 25-64% mod
• <25% mild
• >64% sev
37. AR jet/LVOT area ratio for moderate AR
• 5-59% mod
• <5% mild
• >59% sev
38. EF calculation Quinones
(LVEDd2 - LVEDs2) / LVEDd2 x 100%
39. PVa velocity >0.35 m/sec indicates
Increased LA pressure/LVEDP
40. 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
41. Simplified MVA by p1/2 t
759 / decel time

### Card Set Information

 Author: liukuf ID: 87212 Filename: Equations-1.txt Updated: 2011-05-22 21:44:32 Tags: ECHO Equations Folders: Description: ECHO Equations Show Answers:

What would you like to do?

Home > Flashcards > Print Preview