Assessment of ventricular systolic function Flashcards
What is the sequence and timing of systole? 3
- Depolarization
- Contraction
- Ejection
When does systolic depolarization take place during the ECG?
QRS complex
When does the systolic contraction take place during the ECG?
QT
When does systolic ejection take place during the ECG?
ST segment
What are qualitative echo assessments of LV systolic function?3
- Visual kinetic analysis
- Visual segmental wall motion analysis
- Region wall motion score index
What do we look for during a visual wall motion analysis?5
- Normal
- Hypokinetic
- Akinetc
- Dyskinetic
- Aneurysmal
What are some quantitative echo assessments of LV systolic function? 8
- fractional shortening
- Ejection fraction
- Volumetric assessment
- SImpson’s EF
- Area/ length method
- Dp/DT (change in pressure/ change in time)
- Tissue dopplers
- MPI (myocardial performance index)
Global strain (GS)
How can visual wall motion can use what kind of approaches to analyze the structure?2
- Segmental
- Global
What is a segmental analysis approach?
Abnormalities that are specific to one or more segments
What is a global approach to analysis of a structures?
Function of the heart as a whole
Each of the 16 LV wall segments can be described as what?
- Hyperkinetic
- Normal
- Hypokinetic
- Akinetic
- Dyskinetic
Normal systolic functions implies what?
The heart muscles moves inward and thickens during systole
What is hyperkinesis?
Excessive wall motion
What is hypokinesis?
- Motion/ Wall thickening is reduced
- Not normal but not akinetic
When can we see cases of hyperkinesis?4
Cases with
1. High preload
2. Severe valvular regurgitation
3. Fever
4. Trauma
When may we see hypokinesis in patients?3
Patients that have
1. Coronary arterial disease
2. Cardiomyopathy
3. Long standing valve disease
What is akinesis?
- No thickening
- May have motion if tethered to a moving segment adjacent to it
- Akinetic segment is just being dragged along
When may we see akinesis in patients?2
- Myocardial infarction
- Viral CMO = Viral cardiomyopathy
What is dyskinesis?
Wall segment is moving the opposite direction as normal segments in systole
When might we see dyskinesis? 4
Patients with:
1. Increased right heart pressure
2. Pacemaker
3. BBB (bundle branch block)
4. Long standing scarred segment
What does these images represent?2
Normal vs Abnormal LV base in M-mode
1. Note how the IVS and PW squeeze together in the left image?
2. Compare this to the right image
What is quantitative assessments?5
Measurable assessments like
1. SV/CO/CI
2. FS/EF
3. Strain
4. dp/dt
5. MPI
Where is End diastole on the ECG
Onset of the QRS complex
What is the valve movement frame during End diastole?
Frame after MV closure
Where doe we get LV dimension for End diastole?
Frame where LV diameter/ dimension is largest
Where do we get LV dimension for End diastole?
Frame where LV diameter/ dimension is largest
Where is End systole on the ECG?
Near the end of T wave
What is the valve movement frame during end systole?
The frame preceding MV opening
What is the LV dimension during end systole?
When the LV is the smallest
What is the formula for stroke volume?
SV = EDV - ESV
What is the formula for CO?
CO = SV x HR
What is the CI formula?
CI = CO/BSA
Where should we set the calipers for PLAX measurements like EF and FS?
Just past the leaflet tips
What is the CSA formula?
CSA = ((0.785)(D.LVOT)^2)
What is the expanded Stroke volume formula?
SV = ((0.785)(D.LVOT)^2)(VTI.LVOT)
What is needed for the stroke volume doppler method?
Images are needed for LV stroke volume calc - doppler method
Fractional shortening is the % change in what?
The minor axis of the LV
Fractional shortening is prone to error do to what?
Many assumptions
What is the formula for fractional shortening?
FS = ((LVIDd-LVIDs)/LVIDd)x100
What is the normal values for fractional shortening?
25-47%
What does ejection fraction do?
Takes 2D (or m-mode) measurements and calculates a 3D volume from it
What is the formula for Ejection fraction?
What is Simpsons EF?
When we take our EF mmt
What are normal Simpsons EF values
Male: 52-72%
Female: 54-74%
In terms of LVEF list them in order of least accurate to most accurate
- Teichholz
- Simpsons biplane EF
- 3D trace (only when experienced staff are around)
What does 3D echo real time volume information use to get accomplished? Why is it not commonly used? and what are some challenges?
- Uses multiarray transducer
- When imaging is optimal, this is the ideal way to measure volume, however it is not yet widely used
- Challenges include image resolution and temporal resolutions
What is this an image of?
3D EF
What is the recommended tool for EF? Why?
- Modified Simpsons EF with the biplane apical approach
- It is more universal than 3D
Contrast imaging can play a big role in what? And why?
- The qualitative function of the LV function
- If we can’t see the endocardium clearly, we can’t give a wall motion score, or even measure a simpson
One of the main benefits of contrast imaging is what?
LV wall definition
When would you typically use 3D image with contrast?
when regular 2D imaging is poor but you need EF
What is 2D strain commonly used for?
LV systolic function assessment and can also be used (less commonly) for RV function
How do we get 2D strain?
Machine uses software to find speckles within each wall segment and track them
What does 2D strain calculate?
How much speckles within each segment of the LV move closer together in systole and farther apart in diastole
What is the benefit of 2D strain?
More sensitive than naked eye wall motion detection
What does 2D strain do the data collected?
Puts together the data from all three apical views to create a bulls-eye chart. RED = Normal
What is Dp/Dt?
Changes in pressure/ changes in time
Why would we get dp/dt measurements?
A robust ventricle generates pressure very quickly, abnormal ventricular function is slower for pressure to rise
What does dp/dt measure?
How much time it takes for the LV pressure to rise by 32 mmHg
How do we get measurements for dp/dt? And which points would we use?
- We use the MR jet where 2 arbitrary points are chosen
- Typically 1 m/s and 3m/s
What is the normal values for DP/DT?
What is the formula for dp/dt?
dp/dt = 32/t
For dp/dt, preload significant MR with impaired LV systolic functions how?
- Very commonly occurring together
- Significant MR causes increased preload
Dp/dt is less influenced by what?
Preload and a prefect tool in this setting to assess the true systolic function of the left ventricle
What are some tips to measure dp/dt? 3
- Optimize MR jet in CW
- Increase sweep speed to 100-200 cm/s
- Draw a line from 1m/s on the signal to 3 m/s where it intercepts the signal this is change in time and the normal is <27ms
When would use dp/dt measurements?
For LV function assessments with significant MR
What are some limitations to dp/dt? 2
- Prosthetic MVs may create a click artifact which will obscure the early systolic MR jets
- Eccentric MR jets are difficult to align to the flow with CW doppler
What is MPI or myocardial performance?
MPI is a ratio between isovolumic contraction time + isovolumic relaxation time divided by ejection time
What is the formula for MPI?
MPI = (IVCT+IVRT)/LVET
What is the acronym when MPI is done on the left and right?
LMPI and RMPI
When can MPI be used? 4
In cases with
1. Globally reduced LV systolic function
2. Segmental LV systolic dysfunction
3. Dilated cadiomyopathy
4. Pulmonary HTN
What is the preferred method for MPI?
Doppler
In a diseased heart, ejection time does what?
Shortens as isovolumic times increase
What is the normal LMPI?
<0.44
What is systolic dysfunction? What is the most common cause?
The inability of the LV to contract properly. Usually due to coronary artery disease
What does a decrease in SV/EF mean?
Inadequate contraction to meet the demands of the body
How can LV systolic dysfunction lead to congestive heart failure? 2
- Back up of blood behind the chamber due to its inability to contract and move blood forward
- Chambers start to dilate
What is the most common qualitiative assessment of the RV systolic?
Eyeball
What are quantitative measures for RV systolic assessments? 4
- TAPSE
- S prime
- Fractional area change
- RIMP
RV can be grade how?
- Normal
- Mildly reduced
- Moderately reduced
- Severely reduced
If the RV is hypokinetic how will the RV appear? Why?
Dilated: reduced function means the blood cannot exit the chambers and dilation occurs
What does TAPSE measure?
Tricuspid annular plane systolic excursion
1. When the RV contracts, the TV annulus pulls lengthwise
Lots of movement on TAPSE means what?
Good function
What does TDI measure?
How quickly the tissue expands or contracts using PW doppler
When using TDI to assess systolic function we’ll be looking for what?
s’ or s prime
What are some tips for getting RV annular TDI in A4C? As the RV contracts how does it move?
- Place sample volume slightly apical to the TV lateral annulus
- Moves length wise towards the APEX
What is normal RV s’ ?
> 9.5 cm/s
What is RV fractional area change?
Comparison of area change between systole and diastole.
When getting a RV fractional area change what should we do?
- Trace the endocardial boarder surface in the A4C view.
- start along the IVS from base to apex then along RV free wall to annulus then back to the begging
What is the Fractional area change formula?
FAC = ((EDA-ESA)/EDA)x100
What is the normal measurement for FAC?
FAC>35%
Does the RV and the LV respond the same to high afterload?
Yes,
1. RV will usually dilate and hypertrophy at the same time. The dilation is noticeable
2. LV will hypertrophy, eventually dilating and lead to CHF
RV responds to high preload with what as well?
Dilation as well
RV dilation leads to what?
Lack of coaptation of the TV leaflets, This will either cause or worsen the degree of TR
In the normal heart The RV should measure how?
- RV in the A4C view should be less than 2/3 the size of the LV
- LV should dominate (occupy) the apex
How should the RV be assessed qualitative mildly?
- RV >2/3 of the LV but the RV cavity is still smaller than the LV
- RV apex is still more basal than LV apex
What does a moderate risk RV looks like?
RV and LV are equal size and share the apex
What does a severe risk RV look like?
RV>LV size and RV occupies the apex
What are normal RV dimensions and their values?
What are RV function normal values