Mitral Regurgitation Flashcards
What is the “zona coapta”?
The several millimetres of tissue that overlap to form mitral coaptation.
True or false; coaptation of the mitral valve is isolated to the mitral valve leaflet tips.
False.
MR is classically subdivided into two broad categories; what are they?
Primary and secondary.
Secondary mitral regurgitation is also known as what?
Functional MR.
Primary mitral regurgitation results from what?
Intrinsic mitral valve disease in which there is a structural abnormality of the leaflets and/or associated chords.
Secondary/functional mitral regurgitation results from what?
A dysfunctional/distorted LV due to ischaemic or myopathic remodelling.
True of false; in secondary/functional mitral regurgitation, the mitral valve leaflets are essentially normal.
True.
Carpentier’s functional classification of mitral regurgitation is based on what?
The opening and closing motions of the MV leaflets.
Describe the leaflet motion in Carpentier’s classification (type I).
Normal.
Describe the leaflet motion in Carpentier’s classification (type II).
Excessive.
Describe the leaflet motion in Carpentier’s classification (type IIIa).
Restrictive (in diastole and systole).
Describe the leaflet motion in Carpentier’s classification (type IIIb).
Restrictive (in systole).
What is a cleft mitral valve?
A congenital abnormality characterised by a slit-like hole/defect in one of the mitral valve leaflets.
The most common cause of primary MR is what?
MV prolapse or flail.
MV prolapse/flail comes under which type of Carpentier’s classification?
Type II.
True or false; MVP can present without mitral regurgitation.
True.
How is MVP defined?
During systole, if any part of either leaflet billows into the LA (beyond the plane of the mitral annulus) by >2mm.
Why can MVP not be accurately assessed in the apical 4-chamber view?
Because the mitral annulus is saddle shaped and the lowest portion is not seen in the 4-chamber view.
Which view is superior for assessing for MVP?
The parasternal long axis view.
The most commonly affected scallop in MVP is what?
P2.
True or false; MVP is not associated with prolapse of other valves.
False.
Prolapse of the tricuspid/AOV are seen in what percentage of patients with MVP?
Approximately 20%.
In which direction will the mitral regurgitation be with an anterior MVP?
Posteriorly.
In which direction will the mitral regurgitation be with a posterior MVP?
Anteriorly.
Define a flail leaflet.
Flail leaflet is defined as occurring when the leaflet becomes everted and loses its normal convex shape with the leaflet tip seen within the LA.
Flail is caused by disruption/rupture of the papillary muscle and/or what type of chordae?
Primary/first order/marginal chordae.
How do flail and MVP differ?
In flail, the tip of the leaflet will point towards the LA whereas with MVP the leaflet tip will continue to point towards the ventricle.
True or false; with flail, mitral regurgitation will be severe.
True.
MVP/flail typically present as two types; what are they?
Barlow disease and fibroelastic deficiency.
What is Barlow disease?
An infiltrative disease characterised by excessive myxomatous tissue associated with mucopolysaccharide accumulation.
In fibroelastic deficiency, the loss of valve integrity is due to what?
Abnormal connective tissue structure and function.
With Barlow disease, patients with MVP typically present how?
With bileaflet and multisegment prolapse.
With fibroelastic deficiency, patients with MVP typically present how?
With localised and unisegmental prolapse.
Apart from Barlows disease and fibroelastic deficiency, what other conditions are associated with MVP?
Marfan’s syndrome, Ehlers-Danlos syndrome and osteogenesis imperfecta.
Marfan’s syndrome and Ehlers-Danlos syndrome are considered what types of disorder?
Connect tissue disorders.
What is osteogenesis imperfecta and what is it associated with?
Brittle bone disease and MVP.
Infective endocarditis comes under which type of Carpentier’s classification?
Type I.
Apart from MV prolapse or flail, what are four other known primary MR aetiologies?
Rheumatic valve disease, congenital causes (such as a cleft mitral valve), systemic lupus erythematosus/Libman-Sacks endocarditis or mitral stenosis/calcification.
What is Libman-sacks endocarditis?
A form of non-bacterial endocarditis that is seen in association with systemic lupus erythematosus.
What is systemic lupus erythematosus?
A chronic auto-immune disease.
The mechanism for secondary MR is mainly a consequence of what?
Abnormal leaflet tethering forces (because of PM displacement) due to LV or annular distortion and dysfunction.
When is mitral annular dilatation considered to be present (male and female).
When the annular diameter measures >3.1 (female) or >3.4 (male) in end diastole.
In secondary MR, leaflet coaptation is not only affected by abnormal leaflet tethering forces (due to PM displacement/LV distortion) and annular dilatation, but what else?
Reduced closing forces as a result of impaired systolic function.
Depending on the underlying cause of LV geometric alteration, MR can be further classified as what?
Ischaemic or non-ischaemic.
Ischaemic MR refers to regurgitation that occurs as a result of what?
LV remodelling and dysfunction due to CAD.
True or false; with ischaemic MR, LV remodelling can be symmetric or asymmetric. If remodelling is symmetric, the MR jet will be eccentric, whereas if remodelling is asymmetric, the MR jet will be central.
False; symmetric remodelling will result in a central jet of MR and asymmetric remodelling will results in an eccentric jet of MR.
In the case of non-ischaemic MR, the pathophysiology is similar to ischaemic MR; remodelling of the LV causes displacement of the PMs which increases tethering and malcoaption of the leaflets. What therefore is the difference?
The root cause of the LV abnormalities is not CAD.
Less commonly, annular dilatation alone (without LV dilatation/dysfunction) can be the cause of secondary MR. In what setting does this typically occur?
In the setting of Atrial Fibrillation.
What complication of HCM can lead to mitral regurgitation?
SAM - Systolic Anterior Motion.
What are the six things used to quantify MR severity?
- MV Inflow VTI/LVOT VTI, 2. PISA Radius, 3. Regurgitant Fraction, 4. Regurgitant Orifice Area, 5. Regurgitant Volume, and 6. Vena Contracta.
What value is considered severe for MV Inflow VTI/LVOT VTI?
> 1.4.
What values are considered mild and severe for MV PISA radius?
Mild <0.4cm and Severe >1.0cm.