Mitral Regurgitation Flashcards
(130 cards)
1
Q
What is the “zona coapta”?
A
The several millimetres of tissue that overlap to form mitral coaptation.
2
Q
True or false; coaptation of the mitral valve is isolated to the mitral valve leaflet tips.
A
False.
3
Q
MR is classically subdivided into two broad categories; what are they?
A
Primary and secondary.
4
Q
Secondary mitral regurgitation is also known as what?
A
Functional MR.
5
Q
Primary mitral regurgitation results from what?
A
Intrinsic mitral valve disease in which there is a structural abnormality of the leaflets and/or associated chords.
6
Q
Secondary/functional mitral regurgitation results from what?
A
A dysfunctional/distorted LV due to ischaemic or myopathic remodelling.
7
Q
True of false; in secondary/functional mitral regurgitation, the mitral valve leaflets are essentially normal.
A
True.
8
Q
Carpentier’s functional classification of mitral regurgitation is based on what?
A
The opening and closing motions of the MV leaflets.
9
Q
Describe the leaflet motion in Carpentier’s classification (type I).
A
Normal.
10
Q
Describe the leaflet motion in Carpentier’s classification (type II).
A
Excessive.
11
Q
Describe the leaflet motion in Carpentier’s classification (type IIIa).
A
Restrictive (in diastole and systole).
12
Q
Describe the leaflet motion in Carpentier’s classification (type IIIb).
A
Restrictive (in systole).
13
Q
What is a cleft mitral valve?
A
A congenital abnormality characterised by a slit-like hole/defect in one of the mitral valve leaflets.
14
Q
The most common cause of primary MR is what?
A
MV prolapse or flail.
15
Q
MV prolapse/flail comes under which type of Carpentier’s classification?
A
Type II.
16
Q
True or false; MVP can present without mitral regurgitation.
A
True.
17
Q
How is MVP defined?
A
During systole, if any part of either leaflet billows into the LA (beyond the plane of the mitral annulus) by >2mm.
18
Q
Why can MVP not be accurately assessed in the apical 4-chamber view?
A
Because the mitral annulus is saddle shaped and the lowest portion is not seen in the 4-chamber view.
19
Q
Which view is superior for assessing for MVP?
A
The parasternal long axis view.
20
Q
The most commonly affected scallop in MVP is what?
A
P2.
21
Q
True or false; MVP is not associated with prolapse of other valves.
A
False.
22
Q
Prolapse of the tricuspid/AOV are seen in what percentage of patients with MVP?
A
Approximately 20%.
23
Q
In which direction will the mitral regurgitation be with an anterior MVP?
A
Posteriorly.
24
Q
In which direction will the mitral regurgitation be with a posterior MVP?
A
Anteriorly.
25
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.
26
Flail is caused by disruption/rupture of the papillary muscle and/or what type of chordae?
Primary/first order/marginal chordae.
27
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.
28
True or false; with flail, mitral regurgitation will be severe.
True.
29
MVP/flail typically present as two types; what are they?
Barlow disease and fibroelastic deficiency.
30
What is Barlow disease?
An infiltrative disease characterised by excessive myxomatous tissue associated with mucopolysaccharide accumulation.
31
In fibroelastic deficiency, the loss of valve integrity is due to what?
Abnormal connective tissue structure and function.
32
With Barlow disease, patients with MVP typically present how?
With bileaflet and multisegment prolapse.
33
With fibroelastic deficiency, patients with MVP typically present how?
With localised and unisegmental prolapse.
34
Apart from Barlows disease and fibroelastic deficiency, what other conditions are associated with MVP?
Marfan's syndrome, Ehlers-Danlos syndrome and osteogenesis imperfecta.
35
Marfan's syndrome and Ehlers-Danlos syndrome are considered what types of disorder?
Connect tissue disorders.
36
What is osteogenesis imperfecta and what is it associated with?
Brittle bone disease and MVP.
37
Infective endocarditis comes under which type of Carpentier's classification?
Type I.
38
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.
39
What is Libman-sacks endocarditis?
A form of non-bacterial endocarditis that is seen in association with systemic lupus erythematosus.
40
What is systemic lupus erythematosus?
A chronic auto-immune disease.
41
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.
42
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.
43
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.
44
Depending on the underlying cause of LV geometric alteration, MR can be further classified as what?
Ischaemic or non-ischaemic.
45
Ischaemic MR refers to regurgitation that occurs as a result of what?
LV remodelling and dysfunction due to CAD.
46
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.
47
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.
48
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.
49
What complication of HCM can lead to mitral regurgitation?
SAM - Systolic Anterior Motion.
50
What are the six things used to quantify MR severity?
1. MV Inflow VTI/LVOT VTI, 2. PISA Radius, 3. Regurgitant Fraction, 4. Regurgitant Orifice Area, 5. Regurgitant Volume, and 6. Vena Contracta.
51
What value is considered severe for MV Inflow VTI/LVOT VTI?
>1.4.
52
What values are considered mild and severe for MV PISA radius?
Mild <0.4cm and Severe >1.0cm.
53
What values are considered mild, moderate and severe for regurgitant fraction?
Mild ≤ 30%, Moderate 31-49% and Severe ≥ 50%.
54
What values are considered mild, moderate and severe for regurgitant orifice area (EROA)?
Mild ≤0.20cm*2, Moderate 0.21-0.39cm*2 and Severe ≥0.40cm*2.
55
What values are considered mild, moderate and severe for regurgitant volume?
Mild ≤30 mL/beat, Moderate 31-59mL/beat and Severe ≥ 60mL/beat.
56
What values are considered mild, moderate and severe for vena contracta?
Mild <0.3cm, Moderate 0.3-0.6cm, Severe ≥ 0.7cm.
57
What indirect indicators are suggestive of more severe mitral regurgitation?
LA dilatation, LV dilatation/dysfunction, pulmonary vein systolic flow reversal and pulmonary HTN.
58
The velocity of the regurgitant MR jet is usually high. How does it differ between acute and chronic MR?
In chronic MR, velocity remains high throughout systole. In acute MR, the velocity starts to fall towards the end of systole.
59
In acute MR, why does the velocity of the MR jet start to fall towards the end of systole (in contrast to in chronic MR, where velocities remain high)?
Because the pressure gradient between the LV and LA equalises more rapidly than it does in chronic MR.
60
True of False; Usually the LA (and LV) are not dilated in acute MR.
True.
61
In severe MR, CW Doppler may show a slow rise to peak velocity, why is this?
Because of LV impairment (a known consequence of severe MR).
62
The density of the CW Doppler tracing is directly related to what?
The number of red blood cells in the regurgitant jet.
63
True of False; faint Doppler signals are associated with severe MR, and very dense/bright signals are associated with more mild MR.
False; The denser the signal, the more RBCs, the more severe the mitral regurgitation.
64
Late systolic MR jets are suggestive of what?
MV Prolapse.
65
Velocity jets are influenced by loading conditions. What does this mean?
High systemic BP with increase MR velocity and volume (such as in aortic stenosis/hypertension) whilst high LAP will reduce MR velocity and volume.
66
What does the peak E velocity reflect?
The initial diastolic gradient between the LA and LV.
67
Why does peak E velocity increase with MR?
Due to elevated LA pressures (and early transmitral diastolic flow).
68
An E velocity of what is indicative of severe MR?
>1.5m/s.
69
True or False; in the majority of cases, if E/A reversal is present, mitral regurgitation severity is not severe.
True; E/A ratio is usually >1 with severe MR.
70
What is considered "normal" for pulmonary vein flow patterns.
Normally, the systolic (S) wave is larger than the diastolic (D) wave.
71
When is pulmonary vein flow blunting present?
When the diastolic (D) wave is greater than the systolic (S) wave.
72
When is pulmonary vein flow reversal present?
When the S wave is inverted.
73
In regards to pulmonary vein flow patterns, what is indicative of severe MR?
Pulmonary vein flow reversal.
74
In what setting can non-severe MR cause pulmonary vein flow reversal?
In the setting of non-severe eccentric jets.
75
True or False; with severe MR, pulmonary vein flow reversal is always present?
False (especially in the setting of a very dilated LA).
76
What other factors, apart from MR, will cause blunted pulmonary vein flow?
Other causes of elevated LA pressures such as diastolic dysfunction and Atrial Fibrillation.
77
What are the three components to a colour Doppler MR jet that can be used to quantify the severity of MR?
1. The flow convergence zone, 2. The vena contracta, and 3. The jet body.
78
What is the flow convergence zone?
The zone of increased flow velocity before the regurgitant orifice on the left ventricular side of the mitral valve.
79
The size of the flow convergence zone corresponds to what?
The magnitude of regurgitant blood flow and the size of the regurgitant orifice.
80
How is the size of the flow convergence zone affected by the magnitude of regurgitant volume?
It grows larger with greater regurgitant volume.
81
PISA is usually measured in what view?
The apical 4-chamber view.
82
To measure PISA, the Nyquist limit should be reduced to what?
Around 40cm/s.
83
The PLAX view can be used to measure PISA when?
For posteriorly directed eccentric jets.
84
When can PISA be overestimated?
In the presence of a flail leaflet or marked prolapse.
85
PISA is commonly underestimated, this is because it assumes what?
A circular ROA and that PISA height = 1/2 the width.
86
True or False; with functional/secondary MR the ROA is elliptical resulting in a semi-elliptic PISA meaning PISA is often underestimated.
True.
87
The flow convergence zone can be used to measure what (with the help of PISA method)?
Regurgitant volume and EROA.
88
What is the vena contracta?
The narrowest region of a colour jet in which blood passes through the valve.
89
Out of the three components to a colour Doppler MR jet, where is velocity at its highest?
The vena contracta.
90
The width of the vena contracta is a good indicator of MR severity as it corresponds to what?
The diameter of the regurgitant orifice area.
91
The vena contracta is best measured where?
In zoom mode in the PLAX or apical views.
92
What view should the vena contracta not be measured in and why?
The apical 2-chamber view as it will appear wider than it actually is.
93
True or False; Vena contracta can be used to help gauge severity even with an eccentric jet of MR.
True.
94
When can vena contracta not be used?
In the presence of multiple MR jets.
95
When measuring vena contracta, colour flow gains should be adjusted to what?
Between 40-50cm/s.
96
True or false; vena contracta sizes are dependent on LV function/flow rate.
False.
97
Vena contracta assumes what that can lead to an underestimation of MR severity?
A circular effective regurgitant orifice area.
98
The portion of the MR jet that is seen in the LA is known as what?
The jet body.
99
Jet area and jet length are two methods that have been proposed to help quantify the severity of MR however these parameters are not reliable, why?
They are highly dependant on colour gain and aliasing settings.
100
Jet area and jet length methods can underestimate the severity of MR, how?
Because of the coanda effect (with an eccentric jet).
101
What is the coanda effect?
It is where an eccentric MR jet impinges the LA wall.
102
Eccentric MR jets can be underestimated because of the coanda effect. Central jets can be overestimated how?
Because of "entrainment" whereby blood cells along the sides of the jet are drawn along with the regurgitant blood.
103
Elevated LA pressures will affect MR velocity and volume how?
They will be reduced.
104
The PISA method is based on what?
1. The properties of flow dynamics and 2. The continuity principle.
105
How is flow rate calculated?
Flow Rate = Area X Velocity.
106
With regards to flow rate, what must happen to the velocity if the area is decreased?
It must be increased.
107
With regards to flow rate, what must happen to the velocity if the area is increased?
It must be decreased.
108
The difference between mitral valve inflow and LVOT outflow gives what?
The regurgitant volume.
109
When is it not appropriate to calculate regurgitant volume?
If there is coexistent aortic regurgitation.
110
What is the equation to calculate regurgitant volume?
RV = SV(mv) - SV(lvot)
111
How is stroke volume calculated?
SV = CSA X VTI
112
How is CSA calculated (two ways)?
CSA = 0.785 X d*2 or CSA = π X r*2
113
What is the equation to calculate regurgitant fraction?
RF = (RV/SV(mv)) X 100
114
True of False; EROA is not affected by loading conditions/raised left atrial pressures.
True.
115
The continuity principle not only states that flow is constant throughout the heart, but what else?
Flow is constant along the MR jet.
116
At what point is the velocity known with certainty?
When the blood cells reach the aliasing velocity/Nyquist limit, the colour will switch from blue to red.
117
How is the radius of the hemisphere measured in PISA?
From the edge of the red hemisphere and the centre of the regurgitant orifice.
118
How is PISA calculated?
PISA = 2πr*2
119
How is EROA calculated?
EROA = (2πr*2 X Nyquist Limit)/Vmax
120
What is the continuity equation for EROA?
EROA X Vmax = 2πr*2 X Nyquist Limit
121
Apart from the PISA method, how can EROA be calculated?
EROA = RV/VTI(MR)
122
What are the three consequences of MR?
Pulmonary HTN, Atrial Fibrillation and impaired LV function.
123
What are the advantages of mitral valve repair over replacement?
Avoidance of long-term anticoagulation and preservation of the continuity between the mitral annulus and PMs which helps to maintain normal LV geometry/systolic function.
124
When annular-papillary continuity is preserved, what typically happens after mitral surgery.
Ejection fraction typically remains stable or improves.
125
True or false; mitral valve repair operations have a low rate of re-operation for recurrent MR.
True.
126
For patients with severe symptomatic primary MR, surgery should be considered when?
If the LVEF >35% and LV end diastolic diameter is <5.0(male) or <4.6(female).
127
Patients with severe LV dysfunction, and/or a dilated LV should first undergo what, prior to surgery?
Optimisation of medical therapy.
128
In asymptomatic patients with severe MR, when should surgery be considered?
In the presence of Atrial Fibrillation, LV dysfunction/dilation and pulmonary HTN.
129
The ESC recommend surgery with an LV end systolic diameter of what (in asymptomatic patients)?
>4.5cm.
130
The ESC recommend surgery with an LV end systolic diameter of what (in asymptomatic patients)?
>4cm.
