Key Echo Equation Flashcards
wavelength
Lambda = c/f= 1.54/f (MHz)
Frequency
f=cycles/sec= Hz
Doppler equation
V= c x delta F/ ( 2Ft(cos theta))
Bernoulli
Delta P= 4V^2
Stroke volume
sV=EDV-ESV
Ejection Fraction
EF%= (SV/EDV) x100%
Wall Stress
PR/2Th
Doppler stroke volume
SV = CSA x VTI
Doppler- rate of pressure rise
dP/dT= 32 mm Hg /time from 1-3m/sec of MR CW jet (sec)
Pulmonary systolic pressure
PAP (systolic) = 4(V tricuspid )^2 + RAP
When pul stenosis present, PAP
PAP = (4(V tricuspid ^2)+ RAP - delta P ( RV -Pa)
Pulmonary vascular resistance
PVR= 10( V tricuspid )/ VTI RVOT
Aortic stenosis continuity equation
Ava cm^2= ( 3.14(LVOT /2)^2 x VTI LVOT )/
VTI aortic stenosis jet
Simplified continuity equation
Ava=
(3.14(lvot/2)^2 x V lvot)/
V aortic stenosis jet
Velocity ratio
V lvot/V as jet
Mitral stenosis
Pressure half time valve area:
MVA = 220/T1/2
Total stroke volume
TSV= SV lvot= CSA lvot x VTI lvot
Forward stroke volume in aortic regurg
FSV= SV mitral ann= CSA ma x VTI ma
Regurg volume in AI
RV= TSV-FSV
Regurg oriface in AI
ROA = RSV/VTI
Total stroke volume in MR
TSV = SV mit ann= CSA ma x VTI ma
Forward stroke volume in MR
FSV= SV lvot = CSA lvot x VTI lvot
Regurgitant volume in MR
RV =TSV -FSV
Regurgitant oriface area MR
ROA= RV/VTI mr
Pisa MR flow rate
R fr= 2(3.14)r^2 x V aliasing
MR oriface area
ROA= Rfr/V mr
MR regurg volume
RV= ROA x VTI mr
Qp:Qs
(CSA pa x VTI pa)/ CSA lvot x VTI lvot
Concentric remodeling vs concentric hypertrophy
Remodel with increased RWT and Nl mass
Concentric hypertrophy increased mass and increased RWT
