Quantitative Doppler and Hemodynamics Flashcards
What is the best view for measuring the LVOT or transaortic valvular flows in TEE?
Transgastric long axis or the Deep TG long-axis
How to calculate LVOT stroke Volume?
- VTI measured by pulse wave doppler placed subvalvular and proximal to aortic valve in TG long axis.
- CSA LVOT from ME LVOT view where CSA = pie (D/2)^2
- SV = VTI x CSA
How to estimate the CSA of aortic valve?
Estimated planimetry of equalateral triangle shaped orifice observed in midsystole.
How to estimate CO of RV?
CO = SV x HR
SV = CSA x TVI
CSA = pie ( diameter of main pA/2)^2
TVI by CW doppler
How to calculate the regurgitant volume through a valve?
Regurgitant volume = Forward flow through MV - flow through a reference valve like aortic valve (in absence of significant AoV disease)
Formula for regurgitant fraction?
Regurgitant fraction = regurgitant volume/forward flow
What is an important ratio in determing severeity of shunts?
Qp/Qs or the ratio of pulmonic to systemic stroke volume.
What is the simplified Bernoulli equation?
Change in pressure = 4v^2
How to estimate the LVEDP ?
DBP - 4(Vaorticinsufficiency)^2
How to estimate the Left atrial pressure?
SBP - 4(Vmitralvalve)^2
How to estimate Pulmonary artery mean pressure?
Right atrial pressure + 4(Vearlypi)^2
How to estimate Pulmonary artery diastolic pressure?
RAP + 4(Vlatepulmonicinsufficiency)^2
How to convert from Wood units to dynes sec/cm^5?
Multiply by 80
What propagation velocities are associated with normal vs restrictive physiology in the LV?
> 45 cm/s is normal
< 25 cm/s is consistent with restrictive physiology and LVEDP > 15 mm Hg
How is propagation velocity measured?
By the velocity profile across the mitral valve and extending at least 3 cm toward the apex of the left ventricle with color Doppler and M-mode imaging. The slope is measured from the early filling phase from the mitral annular plane to approximately 4 cm toward the LV apex.
