Mitral Steosis Flashcards
What is mitral stenosis?
Incomplete opening of the MV during diastole with thickened mitral leaflets
What is the progression of mitral stenosis?
- Increased LA pressure
- Increased PV pressure
- Increased Lung pressure
- Increased PA pressure
- Increased RV pressure
- Increased RA pressure
- Increased TV annular dilation
- Tricuspid regurgitation
MS reduces the size of what?
The opening between the LV and LA
LA driving pressure must rise in order to do what?
Maintain adequate blood flow
Increase in Right heart pressure leads to what?
Increase venous pressure symptoms
What are some symptoms of Mitral stenosis?
- Dyspnea (SOB)
- Chest pain
- Fatigue
- Exacerbating factors (increasing HR and CO)
What are some complications of Mitral stenosis?
- Left atrial enlargement
- A-fib
- Atypical flow patterns
Why would the Left atrium increases with m/s?
LA will enlarge due to increased pressure
MS accompanied with A fib leads to what?
Combined with A Fib leads to stagnant blood flow in the LA and Blood clots
Atypical flow patterns due to ms lead to what disorders?
- Thromboembolism
- Infective endocarditis
What is important to measure with M/S?
RVSP
Why is it important to measure RVSP with M/S?
Flow pattern
1. MS causes pressure back up
2. Increased pulmonary venous pressure
3. Pulmonary arterial hypertension
With pulmonary arterial hyper tension, is it reversible?
At first
Long standing PAH causes irreversibly increased what?
PVR Pulmonary vascular resistance
This is why surgery timing is also depends on LV/LA/RV
What are signs of MS?
Pressure and heart sounds
1. Depends on the severity of MS
2. LV/LA pressures do not equalize during Diastasis
3. Auscultation
How do we assess MS in echo?
- Assess the MV in 2D
- Determine the etiology of the lesion
- Assess for LAE
- Estimate RVSP or other pulmonary pressures
- Estimate severity of regurgitation
When we assess the MV in 2D what do we do?
- Assess for MS etiology
- Comment on valve anatomy, mobility, and calcification from 2D
- Image: MV area by 2D or 3D
- Measure: thickness of leaflet tips
- SweepL Assess the chordal structures
What specific structures do we look at during a 2D assessment?
- MV leaflets
- LA size
When doing a 2D assessment what can be the most accurate method to quantify MS?
Planimetry
What is planimetry in terms of the 2D assessment?
- Traced from zoom PSAX MV vie w
- Trace around the blood tissue interface
Accuracy of planimetry depends on what?
- Visualization
- Correct position
- Gain settings
- Operator skill
In terms of planimetry, we must transect how/what?
Must transect exactly perpendicular to the MV orifice at the leaflet tips
What does this demonstrate?
How we will complete planimetry, also B and C will overestimate the MVA
When we do a M mode assessment of the MS what do we see?
Reduced MV leaflet excursion
What are some rheumatic MV M-mode characteristics?
- Increased echogenicity of leaflets
- Decreased excursion
- Decreased E-F slope
- Anterior motion PMVL
Where does Rheumatic disease start at?
Leaflet tips
Where does degenerative (MAC) start at?
Basal annulus (usually posterior)
Where does Congenital disease usually start at?
Subvalvular apparatus
What are some MV stenosis etiology?
- Rheumatic
- Degenerative MAC
- Congenital
- Masses
How do we measure the rheumatic MV leaflet thickness?
- Zoom on the MV
- Scroll until the valve is at maximal opening and the leaflets are well seen
- Measure thickness of both leaflets
Note any focal calcification
In terms of rheumatic MV leaflet thickness, the valves will no longer have what?
Classic double bump movement during diastole
If there is Rheumatic MV disease, the MV leaflets will present how?
Reduced leaflet exercising in diastole
Hockey stick” appearance or “doming”
What does this image demonstrate?
Normal and MS in PLAX
What are some Rheumatic MS 2D characteristics?
- Commissural fusion
- Restricted motion
What does commissural fusion look like? In terms of the AMVL and the PMVL
- Doming of the AMVL
- Restricted mobility of PMVL
Why is there a restriction of motion for the rheumatic MS?
- Fusion at the medial and lateral commissures
- Shortening of the chordae tendinae
In terms of rheumatic MS thickening/ Calcification starts where?
At the leaflet tips and moves outward towards annular ring
What does MAC stand for?
Mitral annular calcification
Where does MAC start?
Posteriorly
Where does MAC progress to?
Progresses to include the base of the leaflets and sometimes even the chordae
What kind of artifact does MAC show?
Shadowing artifact
Severe MAC can do what to the leaflet tips?
Render the PML motionless and even restrict the movement of the AML
How can we grade MAC?
We can grade the level of MAC based on the portion of the posterior annulus which is calcified
What is the % of calcified posterior annulus for mild, mod, and severe MAC?
What does the mobile component of MAC lead to?
Embolus
What area does congenital mitral stenosis usually involve?
Subvalvular apparatus
What does Cor triatriatum stand for?
LA membrane with 3 atria
What is a parachute MV?
MV stenosis due to 1 pap muscle instead of 2
Where is the pap muscle often placed for parachute MV?
To far superior in the LV
What condition is parachute MV usually associated with?
Shone’s syndrome
What is associated with shone’s syndrome?
- Supravalvular ring
- Parachute MV
- Subarctic stenosis
- Bicuspid AV
- Aortic coarctation
What kind of masses are caused my mitral stenosis?
- Large MV vegetation from bacterial endocarditis
- Large LA myxoma
What is a Myxoma?
Large benign LA tumor
What are two ways we assess for LA enlargement?
- LA dimension - PLAX
- LAVI (A4C ad A2C)
What are four ways we estimate RVSP or other pulmonary pressures?
- RAE
- TR peak velocity/ PG
- PAT (Pulmonary acceleration time)
- mPAP, PAEDP
How do we estimate MS severity Qualitatively?
Colour
How do we estimate MS severity Quantitatively?
- Mean PG
- P1/2t (MVA)
- Continuity equation (MVA)
What do we look for during a colour doppler assessment of MS?
Aliasing during diastole
What do we look for during a doppler assessment of MS?
- Mean trans-mitral pressure gradient
- Calculate MVA by measuring Pressure half time
- Continuity equation
What are things we look for during the continuity equation?
- Pulmonary artery pressure
- Coexisting mitral regurgitation
What do we use to trace MV inflow peak velocity throughout diastole?
CW
What does the CW trace of the MV inflow through diastole give us?
Mean (average) PG
Why do we get a mean/ average PG from the CW trace?
PG varies throughout the diastolic cycle
What is something we need to keep in mind when we do a MV inflow of mean pressure gradient?
The ECG: A-fib = 3-5 cycles
When we look at MV inflow mean pressure gradient, Mean PG is altered by what?
Preload: Higher flow volume will increase pressure through MV
What is the pitfall of tracing MV inflow?
Care must be taken to properly adjust gain settings
In terms of pressure half time what is it normally in the MV?
quick
With MS, the rate of atrial emptying is “slowed” due to what?
The narrow orifice and the LA pressure drops more slowly
In terms of MS what is the MVA and the Pressure have time?
Increased MS = Decreased MVA = Increased P1/2T
How should we not measure the P1/2T slope?
The slope should not be traced from the early inflow signal
What is the formula for MVA?
220/ Pressure half time
What is considered Mild, Mod, and severe in terms of MVA by P1/2T?
When assessing the spectral waveform for MVA what do we look for?
- Peak Velocity
- Is there an A wave
- Slope grade
What is the continuity equation for MS?
If LVOT is used to calculate the MVA but there is significant AI, what happens
The SV through the 2 valves is no longer equal. You may use RVOT instead of LVOT
Continuity for MVA is less accurate if what happens?
- Significant MR»_space;»> MVA underestimated
- Significant AR»_space;»» MVA overestimated
- ASD or other intracardiac shunt
What are some Pros and cons for 2D planimetry in terms of MVA?
Pro: Direct visualization
Con: Easy to over/underestimate
What are some pros and cons for P1/2T in terms of MVA?
Pro: Quick, use CW, PW(if AR present)
Con: Arrhythmias, noisy signal, must acquire peak velocity
What are some pros and cons of using mean gradients for MVA calculation?
Pro: Quick
Con: Over/under estimate if preload altered
What are some pros and cons of continuity equation for MVA calcuation?
Pro: Not as preload dependent
Con: Time consuming, all 3 measurements must be precise
What are two ways to treat MS?
- Pharmacological
- Surgical
What are some pharmacological ways to treat MS?
- Beta blockers
- Diuretics
- Anticoagulants
- Anti-arrhythmis
What are two ways to treat MS surgically?
- Valve repair
- Valve replacement
What can we do in terms of valve repair?
- Balloon valvuloplasty
- Commissurotomy
What are some ways we can replace valves?
- Bioprosthetic
- Mechanical
- Percutaneous (emerging)
Which of the following pathologies is MAC associated with?
- Hypertension
- COPD
- Cardiomyopathy
- All of the above
Hypertension
Choose the answer which is FALSE regarding parachute MV
- Congenital abnormality
- Only involving one papillary muscle
- Associated with Shone’s syndrome
- Not a true stenosis, but a membrane within the LA
Not a true stenosis, but a membrane within the LA
MVA is proportional to P1/2T
T/F?
False
Which of the following is not a possible consequence of MS?
- LT atrial enlargement
- Left ventricular hypertrophy
- Thrombus/ infective endocarditis/ emboli
- Increased RVSP
LVH
Because the LA increased it will increase the amount of thrombus/infective endocarditis/ emboli in the LV.
This also leads to an increase in RVSP