Ch 14 Normal Doppler Patterns Flashcards
How do we take a Vmax measurement?
Place a caliper at the highest velocity (peak) of a spectral waveform to measure the max velocity
What other measurement may also be generated after a Vmax is done?
A maximum instantaneous pressure gradient
What does VTI stand for?
Velocity time integral
How can we take measurements of changing velocities over a period of flow?
By tracing the outline of the specific spectral doppler waveform of interest (called a VTI)
What do VTI measurements represent?
-Velocity (cm/s or m/s) vs time
-Meaning the tracing represents the distance measured flow has traveled (cm)
(think of VTI as stroke distance)
A VTI can be thought of as “stroke distance”, what does this mean?
Is the distance a column of blood travels with each heartbeat
The result of a VTI is the appearance of what 3 things?
-Vmax velocity
-Max instantaneous pressure gradient
-Mean instantaneous pressure gradient (obtained at regular intervals throughout the period of flow)
How do we obtain a PW of the LV inflow (MV)?
-Done in AP4 (b/c of parallel alignment)
-PW sample volume box placed centrally at tips of MV leaflets, on the LV side of valve
How will flow appear on the PW tracing of MV inflow?
Flow is antegrade, appearing above the baseline in diastole
What are we able to visualize + quantify from doing a PW of the MV inflow?
Allows visualization + quantification of the movement of blood from LA to LV in diastole
What does the Vmax caliper of the E wave velocity represent? What part of the ECG does it correlate with?
-Early diastolic filling (80%)
-After T wave on ECG
What does the Vmax caliper of the A wave velocity represent? What part of the ECG does it correlate with?
-Late diastolic filling after atrial contraction (20%)
-After P wave on ECG
What is the E/A slope (aka deceleration time)?
Time b/w peak E velocity + point of deceleration to the baseline in ms
What is the E/A ratio?
Generated after completion of measurements + allows evaluation of diastolic dysfunction
What is the normal range for Peak E (m/s)?
0.46-1.12
What is the normal range for Peak A (m/s)?
0.35-0.98
What is the normal range for deceleration time (m/s)?
112.8-296.4
What is the normal range for E/A ratio?
0.64-2.74
What are the E/A ratio + E wave basic expectations for normal young healthy adults?
-E/A ratio >1
-E wave of approx 1 m/s or greater
(E wave normally bigger than A wave)
MV inflow changes with aging due to what?
The LV becoming less compliant + more stiff
What happens to the E/A ratio as people age?
The A wave increases in size compared to the E wave - b/c LV is harder to fill, a stronger atrial kick is required
List 4 changes to MV inflow due to aging?
-Reduction in E velocity
-Prolongation of early diastolic deceleration
-Increase in A velocity
-E/A ratio of <1
What is grade 1 impaired relaxation of MV inflow?
Normal age related change causing A wave to be bigger than E wave
List 4 pitfalls when using PW over the LV infow (MV)?
-Not being truly parallel to flow (watch where flow is going)
-Sample volume size (3mm is ideal, larger will lead to spectral broadening)
-Sample volume placement (placing SVB too high/low leads to different appearances of waveforms)
-High HRs can lead to E/A wave fusion (increase sweep speed to see waveforms)
What is the typical SVB size we use?
3mm (avoid making larger + causing spectral broadening)
If a pt has a high HR of 120 during an exam, should we continue using doppler in the exam?
-Dopplers are considered undiagnostic now
-Some labs recommend not measuring in these cases
How do we use tissue doppler + PW on the medial/lateral MV annulus?
-Done in AP4 (ensure beam remains parallel as possible to myocardial motion throughout heartbeat)
-Activate TDI imaging
-PV SVB placed at fibrous MV annulus (medial/septal + lateral)
How will myocardial motion be displayed above + below the baseline with tissue doppler?
-Above the baseline as systolic motion
-Below the baseline as diastolic motion
Explain what S’, E’ and A’ are in tissue doppler?
S’: Apically directed systolic myocardial velocity
E’: Early diastolic atrially directed myocardial velocity (after T wave)
A’: Late diastolic atrially directed myocardial velocity
What 3 measurements are routinely done with tissue doppler of medial/lateral MV annulus?
-Vmax caliper of E’ medial/septal
-Vmax caliper of E’ lateral (should be higher than medial/septal in normal pt)
-E/E’ (ratio comparing E wave from MV inflow to E’ from TDI annular motion)
(allows for evaluation of diastolic dysfunction)
Why does E’ lateral have a higher Vmax than E’ medial/septal in TDI?
B/c lateral side is a free wall, it has much more room to move. The medial/septal side is tethered into the IVS, preventing it from moving as much.
What is the normal range for septal E’ (cm/s)?
5.0-17.0
What is the normal range for lateral E’ (cm/s)?
6.0-22.0
(remember is higher than septal b/c is a free wall)
How to obtain PW over the pulmonary veins?
-Done in AP4
-Place PW SVB 0.5-1.0cm into the RUPV/RLPV (NOT at the back of the LA)
(RUPV = RSPV, RLPV = RIPV)
PW on the pulmonary veins demonstrate biphasic flow, what does this mean?
-Systolic + diastolic forward flow is antegrade
-Atrial flow reversal is retrograde
Systolic forward flow of the pulmonary veins occurs due to what? What part of the ECG does this correlate with?
-Due to LA relaxation + movement of MV annulus towards LV apex in systole
-Is closely related to LA pressures
-Aligns with T wave on ECG
Diastolic forward flow of the pulmonary veins occurs due to what? What part of the ECG does this correlate with?
-Due to the open conduit b/w the PVs, LA, open MV + LV
-Parallels MV E wave + DT (deceleration time)
-Occurs after T wave on ECG
Atrial flow reversal of the pulmonary veins occurs due to what? What part of the ECG does this correlate with?
-Due to retrograde flow into the PVs following atrial contraction/kick
-Small volume of blood gets pushed backwards
-Occurs after P wave on ECG
Explain what S, D and AR is on PW tracing of the PVs?
S: systolic forward flow
D: diastolic forward flow
AR: atrial reversal
What 4 measurements are done on a PW tracing of the PVs?
-Vmax S
-Vmax D
-Vmax AR
-S/D ratio (compares flow velocities from systolic + diastolic components)
(allows for evaluation of diastolic dysfunction + LV end-diastolic pressures)
How is PW obtained of the LVOT?
-Done in AP5 (possible to angle view so LVOT/AO is more parallel than standard view)
-Place PW SVB centrally within LVOT b/w 0.5-1.0cm from AoV
How does flow appear on the PW tracing of the LVOT?
Monophasic + retrograde = flow results below the baseline
What can we visualize + quantify on a PW tracing of the LVOT?
Allows visualization + quantification of movement of blood through LVOT on the way to the AoV in systole