Module 2: M mode Flashcards
What is M mode or motion mode?
It displays the motion of a single line of imaging stretched over time
What structures is M mode good at assessing?2
- LV wall
- MV
What is the typical framerate of M-mode?
1800 FPS
Between M mode and 2D which has the higher Temporal (time) Resolution?
M-mode has a much higher temporal resolution
How does M- mode work?
Uses a single scan line to sample at extremely high rates
With FR in the thousands M-mode has the ability to make fast structures appear how?
Continuous
What is M-mode excellent for?3
- Imaging all four valves
- Correlating electrical and mechanical events such as ventricular motion
- Precise measurements of cardiac dimensions
It is standard practice to record M-mode at how many levels? 3
Three levels
1. Aortic valve
2. Mitral valve
3. LV base
What is the general principle of M-mode?
M-mode shows one scan line displayed over time, and that line must be perpendicular to the structure of interest
Should we measure with M-mode if not aligned?
No, if a measurement is made when oblique there will be a overestimation of dimension
What is the purpose of AV/LA M-mode?4
Assess the following
1. Variations in LA size (Related to rhythm)
2. LA size during systole (enlarged?)
3. AV cusp morphology (thickened?)
4. AV cusp excursion (opening?)
What is the process of getting the AV/LA level M mode window? 3
- Set the cursor line
- Transect through the AV leaflet tips
- Parallel to AV valve plane
Label the picture
- LA Filing
- LA Emptying
- Conduit phase
- Rapid phase
- Atrial systolic phase
Label the structures of AV/LA M-mode
- Anterior Ao Root
- RCC AV cusp
- NCC AV cusp
- Posterior Ao root
- LA
- AV Closure line
What are the two measurements we take for AO/LA M mode?
- Aortic root end diastole
- LA end systole
use leading to leading measurement
Label the measurements from left to right
- Aortic root end diastole (it’s at QRS)
- LA (its at end systole @ its largest)
What is the purpose of M-mode of the MV? 4
To assess the following
1. MV morphology (thickening)
2. MV motion (stenosis/ prolapse)
3. Severity of an aortic valve leak which would affect movement of the MV
4. Indirect assessment of LV systolic function
Is there any measures needed for the M- mode of the MV?
Nope!
Label the wave
- Atrial Diastole
- Atrial Systole
- Atrial Diastole
- Ventricular Diastole
- Ventricular Systole
- Ventricular diastole
What is the appearance of the MV in m mode?
Batman symbol
When taking a M- mode MV, it is important to do what?
Have the cursor at the point of coaptation of the MV leaflets
What does the E/A MV values mean? 2
- E wave = early filling (LV sucking in blood)
- A wave = Atrial Kick (Atria Contracting)
Label the structures for a MV waves from left to right
- E wave (Early filling) first peak of the M
- A wave (Atria Contracting) second peak
What is normal EPSS measurement?
7-10mm
How does MV M-mode in dilated cardiomyopathy look like?
Gap between the MV and the IVS when the MV is fulling opening
What is Mitral Stenosis? 2
- Reduced MV leaflet excursion
- Thickened leaflets
What is SAM (systolic anterior motion?)
When the AMVL is dragged anteriorly during mid systole
What is MVP- Mitral valve prolapse?
One or both mitral valve leaflets are dragged backwards into the LA during systole
Where is the M-mode of the LV taken?2
It is taken at:
1. LV base just past the MV leaflet tips
2. Level of Chordae tendonae
What must we remember in terms of getting a M-mode image of the LV?
Must attempt to make the IVS as flat as possible before recording
Why is it useful to have a M-mode of the LV? 3
Very useful to assess
1. Wall motion
2. Ejection fraction/ fractional shortening
3. Subtle wall motion abnormalities of the IVS
Label the M-mode image of the LV
- RV
- LV
- ED
- ES
Label the M-mode image of the LV from top to bottom
- RV Ant. Wall
- Septum
- Post LV wall
- Pericardium
What are the M-mode measurements for LV Diastole? 3
- IVSd
- LVIDd
- LVPWd
What part of the ECG do we take the diastolic measures for LV M-mode?
QRS
What Systole M-mode measurements for LV do we take?
LVIDs
What are some tips to get the measurements for LVIDs?
Measure when the LV is at its smallest
How should we measure the IVSd for LV M-mode?
RV side of the LV septum to LV cavity
How should we measure the LVIDd for LV M-mode?
Posterior IVS to the posterior wall
How should we measure the LVPWd for LV M-mode?
LV cavity to the epicardium
What is the formula for fractional shortening?
What is the formula for ejection fraction?
How do we calculate relative wall thickness?
how often do we get a M-mode of the PV?
Performed infrequently
What may the M-mode of the PV be used to diagnose?
Pulmonary hypertension
What is the Pulmonary PV hypertension M-mode known as?
The flying W
What can Anatomical M-mode correct for? And how?
Poor alignment to any structure by crossing over multiple scan lines.
green line in the image is the AMM, white dotted line is the original M-mode cursor
What is the RV systolic function measurement?
In the Normal RV, the TV annulus moves >17mm toward and away from the apex over the cycle
