# Equations-1.txt

 The flashcards below were created by user liukuf on FreezingBlue Flashcards. Frequency f=cycles/s=Hz Wavelength(¥)= ¥=v/f=1.43mm/mHz Doppler equation V=v x change freq/doppler shiftHigher velocity --> higher doppler frequency shift Bernoulli's equation 4V(2) assumes prox velocity <1. When LVOT/ PS4[V2(2) - V1(2)] Stroke volume SV=EDV-ESV EF% by volumes SV/EDV X 100%EDV-ESV/EDV X 100% Wall stress Pressure(P) x Ventricular Radius(R) /2 x wall thicknessAnalogy balloon Bigger balloon with more air pressure has thinner wall & increased wall stress Stroke Volume SV=CSA x VTI Cardiac Output SV(ml) x HR(beats/min) / 1000mL/L 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 PAP 4(Vtr)2 + RAP PAP with significant PS [4(Vtr)2 + RAP] - 4[(Vrv)2 - (Vpa)2] PVR 10(Vtr)/VTI rvot AVA continuity .785 x D lvot x VTI lvot/ VTI as Velocity ratio V lvot/ V as>0.5 mild<0.25 severe MVA(Mitral stenosis) by P1/2t 220/P1/2t Aortic Regurgitation volumes RVav=tSVav-fSVmvROA=RV/VTIavRF=RVav/TSVx100% Severe Mild RV >60 <30 RF >50 <30 ROA>0.30 <0.10 Aortic Regurgitation jet width/LVOT% Severe >65%Mild <25% AR vena contracta Severe >0.6Mild <0.3 AR pressure 1/2 t Severe <200msMod Severe 200-350Moderate 350-500Mild >500 Mitral Regurgitation volumes RV=tSVmv-fSVlvotROA=RVmv/VTImvRF=RVmv/SVmv x100% Severe MildRV >60 <30RF >50% <30%ROA >0.4. <0.20 MR jet area Severe >40% LAMild <20% LA MR Vena Contracta Severe >0.7cmMild <0.3cm MR PISA Rflow=2(pi)r(2) x Va =6.28 r(2) x VaROA=RFlow/Vmr RV=ROA x VTImr SevereROA >0.4 cm2RV >60 Aortic dilation with age. Predicted sinus diamension. Age 18-40 0.97 + (1.12 BSA)Age >40 1.92 + (0.75 BSA) Qp:Qs Dpa(2) x VTI pa / Dlvot(2) x VTI lvot What is normal fractional shortening? 24-40% Index of Myocardial Performance (IMP) [MR/tr duration - LVOT/rvot duration] / LVOT/rvot duration Norm < 0.40mild 0.4-0.5Mod 0.6-0.9Sev > 0.9 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 Simplified continuity equation. [(3.0 x BSA x 1000) / HR] / AVvti = AVA cm2Assume nl lvot sv AVA index c/w severe AS <= 0.45 Calc AR ERO by vol, what considered severe AV regurg vol / VTIar(SVav - SVmv) / VTIar>29 = severe Calc AR regurg fraction by vol, What is moderate. (SVav - SVmv) / SVavModerate = 30-50%*invalid with significant MR*not well validated Expected AV decel rate for moderate AR. 2 - 3.5 m/sec2*least reliable Calc p1/2t AR What are mild, mod, sev parameters. mSec x 0.29Mild >500mSecSevere <200mSec *least reliable AR jet/LVOT diameter ratio for moderate AR. 25-64% mod<25% mild>64% sev AR jet/LVOT area ratio for moderate AR 5-59% mod<5% mild>59% sev EF calculation Quinones (LVEDd2 - LVEDs2) / LVEDd2 x 100% PVa velocity >0.35 m/sec indicates Increased LA pressure/LVEDP PISA calc Flow rate ERO RV 2 pi r2 x Va = flow rate6.28 r2 x Va / peak Vmr = ERO cm2 ERO cm2 x VTI mr = RV Simplified MVA by p1/2 t 759 / decel time Authorliukuf ID87212 Card SetEquations-1.txt DescriptionECHO Equations Updated2011-05-22T21:44:32Z Show Answers