Aetiology, LA and Suitability for Balloon Valvuloplasty Flashcards
What are the congenital causes of MS?
- Annular hypoplasia
- Anomalous mitral arcade
- Parachute MV
What are the echo characteristics of a Parachute MV?
- Single papillary muscle (A4C) placed more superiorly than normal
- Leaflets have reduced mobility as both leaflets are tethered to the same papillary muscle
Characteristic Features of Shone’s Syndrome?
- Supravalvular mitral ring/membrane
- Valvular mitral stenosis (parachute MV)
- Aortic coarctation
- Subaortic stenosis or BAV
What are the causes of acquired MS?
- Rheumatic MV Disease
2. Excessive MAC
Characteristics of Rheumatic MVD?
- Fusion of commissures
- Thickening and fibrosis of leaflets
- Leaflet calcification
- Thick, short and matted chords
- A ‘fish mouth’ orifice (reduced orifice)
- Calcification of commissures often occurs
What is the echo appearance of rheumatic MS?
- Diastolic doming of MV leaflets: occurs due to commissure fusion
- Pmvl shorter than amvl
- Pmvl often fixed with restricted motion
- Amvl looks like ‘hockey stick’ due to leaflet tethering
- Commissure fusion with significant reduction in MV orifice (PSAX)
- Subvalvular involvement may be seen; appears as short and thick chords (A4C with posterior tilting)
- CFI shows ‘tunneling’ effect caused by subvalvular involvement
When is leaflet doming absent in MS?
If leaflets are excessively fibrosed or calcified
Examples of when is leaflet doming present in the absence of MS?
- MV prolapse
- Mass lesions or vegetations involving free edge of amvl
When is there reduced MV opening in the absence of MS?
Reduced MV opening due to low cardiac output
Characteristics of Mitral Annular Calcification (MAC)?
- Commences at posterior aspect; progresses laterally
- Heavy MAC extends to body of leaflet and subvalvular apparatus => reduced mobility => functional MS
- Leaflet tips are spared
What is the echo appearance of MAC?
- Areas of increased echogenicity at mitral annulus
- Excessive MAC extends into mitral leaflets
- Mitral leaflet tips are usually spared
- Absence of commissural fusion
What differentiates MAC from rheumatic MS?
- Absence of commissural fusion differentiates MAC from rheumatic MS
- Rheumatic MS = commissural fusion
- MAC = no commissural fusion
Other causes of LV inflow obstruction that can clinically mimic MS?
- Cor triatriatum (membrane transecting LA cavity)
- Large MV vegetations
- LA myxoma (tumour prolapses through MV during diastole and can mimic MS)
Affect of MS on LA size?
- MS decreases MVA which obstructs LA emptying during diastole
- Increased LAP leads to LA dilatation
- LA dilatation increases risk of AF and LA thrombus formation
How does LA thrombus form as a result of MS?
- Patients with MS prone to development of AF
- AF + dilated LA = stasis of blood flow which can lead to thrombus formation
- Thrombus formation most common in LAA
- SEC (‘smoke’) precursor for thrombus formation
What is Percutaneous Balloon Mitral Valvuloplasty?
- PBMV procedure involves passing a balloon catheter from the RA into the LA via the IAS
- Catheter then manipulated through MV into the LV
- Preferred method of treatment for MS patients
- Success rate dependent on anatomical MV appearance
What is Wilkin’s Score?
Wilkin’s score predicts patient outcome for balloon valvuloplasty - if patient will have a good result from the procedure or not
What categories are taken into account for Wilkin’s Score?
- Mobility
- Subvalvular thickening
- Thickening (leaflet)
- Calcification
Each category graded 1 - 4 with a total score between 4 and 16
What is considered a good/bad result for Wilkin’s Score?
- A score ≤ 8 recognises patients most likely to have a good result
- A score > 8 recognises patients less likely to have a good result
What is the Padial Score?
Padial score is used to determine the degree of MR likely to occur following a balloon valvuloplasty
What categories are taken into account for Padial Score?
- Leaflet thickening (amvl)
- Leaflet thickening (pmvl)
- Commissural calcification
- Subvalvular thickening
Each category graded 1 - 4 with a total score between 4 and 16
Significance of Padial Score for predicting severe MR?
A score ≥ 10 identifies patients likely to develop severe MR following balloon valvuloplasty
Suitability of PBMV for patients with greater than mild MR?
PBMV requires splitting of MV commissures so patients with greater than mild MR are not suitable as further splitting could lead to severe MR
Suitability of PBMV for patients with LA thrombus?
- Presence of LA thrombus means manipulation of catheter in LA can lead to systemic embolisation
- Therefore, these patients are not suitable for PBMV
- TOE recommended for all patients being considered for PBMV to exclude LA thrombus
