Doppler Principles Flashcards
Mitral Flow
0.6-1.3/1.5 m/s
Tricuspid Flow
0.3-0.7 m/s
Pulmonary Artery Flow
0.6-0.9 m/s
LVOT Flow
0.7-1.1 m/s
Aortic Flow
1.0-1.7/1.9 m/s
Normal Flow Patterns: MV
-Mitral valve flow obtained from A4C
-Positive deflection
-Biphasic flow
Normal Flow Patterns: TV
-Tricuspid valve flow obtained from A4C, RV Inflow, PSAX;AOV
-Positive deflection
-Biphasic flow
Normal Flow Patterns: AOV
-Aortic Flow (Ascending Aorta) is obtained from the A5C view and Subcostal
-Negative deflection
-Early peak (acceleration time)
-Right Parasternal & Suprasternal view (ascending AO) is a POSITIVE deflection
-DESCENDING AO is Negative!
Normal Flow Patterns: PV
-Pulmonic valve flow obtained Inflow, PSAX @ AoV views & pulmonary artery outflow tract view & subcostal SAX view @ PA Level
-Negative deflection
-Early peak flow in systole
Normal Flow Patterns: LVOT
-Left ventricular outflow tract (V1)
-Pre-aortic Valve
-A5C view
Systolic Ejection Time
Systolic flow velocity duration ejected from LV
Time to Peak
Start of flow to the maximum peak of flow
Peak Acceleration Time
Time to the upstroke & maximum acceleration of flow expressed in cm/sec
Flow Velocity Integral
Velocity of flow over the distance of time
Normal AOV
Peaks early, laminar flow profile, reaches about 2 m/s, early acceleration time. Audio signal is not harsh but crisp.
AS
Turbulent flow is seen through out with spectral broadening, peaks 50% after start of flow, measures 4m/s.
Audio signal strong harsh.
To accurately assess AS…
-Obtain at least 3 different projections:
Apical, Right Parasternal, Suprasternal, Subcostal
-Choose the highest with the most reproducible profile, consistent, and with smooth borders.
Mitral Regurgitation
-Apical projection, open up A5C view & use CFM to guide CW probe
-Occurs 40-80 ms after the QRS
-Occurs as the MV opens & as soon as the MV closes
-Reaches as high as 6 m/s due to pressure difference between LV & LA
-Occurs during the isovolumic phases
Aortic Stenosis…
-Apical projection, open up A5C view & use CFM to guide CW probe
-AS occurs 80 to 100 msec after the QRS
-Only occurs when the AOV opens
-Rarely approaches 5.5-6 m/s
In Aortic Stenosis,never measure post…
…PVC,PJC,PAC; measure the jet due to overestimating (an increased)
A-fib in Aortic Stenosis measure
the longest diastolic which will give you the longest systole ejection time (5-10)
ECHO vs CATH (4)
-Cath measures peak to peak gradients between LV & AO
-Echo measures peak instantaneous gradient
-CATH & ECHO will not match; Echo will be higher
-ECHO MEAN gradient will match Cath Peak to Peak
Which form of Conventional Doppler is used to detect AS & LVOT velocity?
Continuous Wave Doppler
Bernoulli Equation
4 (V2² - V1²) = Change in pressure (mmHg)
∆P= 4(V2)²
Continuity Equation
Area1 X Velocity 1 = Area 2 X Velocity 2
Area 2 = Area 1 X Velocity 1
Velocity 2
What is the Continuity Equation?
Determines valve area
•Based on conservation of mass
•“What goes in must go out”
•Flow area 1 = Flow area 2
How do we measure the continuity equation?
-2D – LVOT measured in systole at the level of the AOV cusps insertion
-PW Doppler- TVI of LVOT in A5C
-CW Doppler- TVI of AOV from highest wave
profile
Normal Mitral Wave Profile…(3)
…Has a rapid Pressure half-time, peak flow (even though it is biphasic) does not exceed 1.3-1.5 m/s, & during diastasis the flow returns to the baseline.
Mitral Stenosis velocities…(4)
…Exceed 1.5 m/s, spectral broadening is noted, during diastasis – a persistent gradient exist & a slow Pressure half-time is present.
What does the Bernoulli Equation do?
Changes Velocity to Pressure Gradient
Spectral Broadening
-
