Mitral Valve disease questions Flashcards
What is natural history of mitral stenosis
Symptomatic on exertion when MVA becomes <2.5cm
Symptomatic at rest when <1.5
Natural progression of MS causes valve area reduction at 0.1 to 0.3 per year
Progression from onset of RF to onset of signs of MS takes 10 to 20 years
Pulmonary hypertension >50mmHg the mean survival is 3 years
What is natural history of Mitral stenosis
exertional symptoms at MVA < 2.5cm2
rest symptoms at MVA < 1.5 cm2
natural progression of MS is about 0.1 to 0.3 cm2
The progression from onset of RF to signs of MS takes about 10 to 20 years
the progression from signs of MS to mild symptoms of MS takes 10 to years
the 10 year survival is 80% in pts with NHYA I or II
10 year survival in NHYA III or NHYA IV is 10 to 15%
Pulmonary hypertension the mean survival is 3 years
List poor prognostic features of MR include
1) symptoms for > 1 year
2) atrial fibrillation
3) age > 60 years
4) EF < 50%
What are symptoms of MR
Fatigue, weakness–related to low cardiac output
Dyspnea, orthoponea and PND
Pulmonary hypertension and right heart failure
What are the signs of MR
Displaced volume-loaded apex beat
Apical thrill
3rd heart sound
Apical pansystolic murmur–radiating to the axilla
Apical diastolic flow murmur
Right ventricular heave and an increased pulmonary compliance of the 2nd heart sound
What are the causes of mitral stenosis
1) Rheumatic fever (Lancefield group A beta-haemolytic streptococcus
2) Congential parachute mitral valve
3) Endocardial fibroelasosis
4) Carcinoid syndrome
5) Cor triatriatum
6) left atrial myxoma
7) pulmonary vein stenosis
Symptoms of Mitral stenosis
Long latent period
Fatigue
Dyspnea, orthopnea, PND
Left atrial distention resulting in
a) atrial fibrillation and subsequent thrombo-embolic events
b) left recurrent laryngeal nerve compression presenting with hoarseness (Ortner’s syndrome)
c) esophageal compression producing dysphagia
d) rarely, left main bronchus compression causing left lung collapse
Pulmonary hypertension
a) peripheral edema and ascities
b) hemoptysis due to distention and rupture of bronchial veins
What are the signs of mitral stenosis
Low volume pulse
irregular pulse
opening snap
loud S1
Mid-diastolic rumbling murmur loudest at the apex
Pulmonary hypertension
a) mitral facies
b) central cyanosis
c) loud P2
d) tricuspid regurgitation-pan-systolic murmur at the right sternal edge
f) pulmonary regurgitation–Graham steel early diastolic murmur on inspiration
What is etiology of ischemic MR
infarcted, ruptured or non-ruptured papillary muscles (type II)
Chronic —restricted movement of P2 and P3 scallops of the posterior MV due to left ventricular dilation displacing the papillary muscles (Type IIIb)—functional dilation of the annulus (Type I).
Carpentiers’ classification of MR
Type I: Normal leaflet motion
Type II: excess leaflet motion
Type III: restricted leaflet motion
a) during diastole
b) during systole
Classification of different degrees of MR
Factor Mile Moderate Severe
Jet area (% of LA area) <20 20-40% > 40%
Vena contracta < 0.3 0.3 to 0.7 > 0.7
Regurgitant volume (ml) <30 30 to 60 > 60
Regurgitant fraction(%) < 30 30 to 50 >50
Effective regurgitant <0.2 0.2 to 0.4 > 0.4
orifice aea
Describe Barlows diseasae
Prolapse is defined as >2mm billowing of the anterior or posterior leaflet beyond the annular plane into the left atrium with or without MR
familial, non-familial, associated with Marfan Syndrome
Histological analysis–myxomatous proliferation of acid mucopolysaccharides withing the zona spongiosa of the mitral valve leafletsthinning and elongation of the chordae tendinae.
What are methods to measure Mitral valve Area
1) Planimetry: short axis view on 2D echocardiography
2) pressure half-time: MVA = 220/PHT
3) continuity equation:
4) Gorlin equation MVA = CO/ 38 x HR x DFO x square root of mean gradient
What are determinants of the Wilkins mitral stenosis score
Leaflet mobility
Leaflet thiickening
Leaflet calcification
subvalvular thickening
Each scores between 0 and 4 with max score at 16
A Wilkins score of > 9 suggests the lesion unlikley to be amenable to PMBV
List different surgical repair techniques for mitral valve disease
Posterior MVL prolapse
1) quadrangular or triangular resection
2) sliding annuloplasty
3) artificial chord implantation
Anteior MVL prolapse
1) triangular resection 2) artificial chord implantation/ chordal transfer
Bileaflet MV prolapse
1) leaflet resection
2) artificial chord implantation
3) Alfieri stitch
4) MV replacement
Partial papillary muscle rupture
1) reimplantation of the papillary muscle
Complete papillary muscle rupture
1) MVRWhat are the surgical approaches to the mitral valve
1) Standard left atriotomy
Mobilise the pericardial reflections around the inferior and superior pulmonary veins
Sondergards groove is developed by reflecting the right atrium back over the left atrium
incision is made in the left atrium anterior and medial the right superior pulmonary vein and
and continued inferiorly
2) Bi-atrial trans-septal incision
3) Superior roof incision
4) Bi-atrial Dubost incision
vertical incision is made between the RSPV and Inferior pulmonary vein, which extends across the left atrium, right atrium, and interatrial septum
What is systolic anterior motion
SAM occurs when the tips of the mitral leaflets are displaced anteriorly into the left ventricular outflow tract
results in a venturi effect pulling on the mitral leaflets causing MR and left ventricular outflow tract obstruction.
During diastole the left ventricular outflow diameter is normal
What is physiology of SAM
Due to forward displacement of elongated mitral valve relative to the septum during systole
Venturi effect of the high-velocity blood stream carries the protruding edge of the anterior mitral leaflet toward the aortic annulus in early systole
What are consequences of SAM
Variable degree of mitral regurgitation
intraventricular gradient due to obstruction of the LVOT
What are risk factors for SAM
Excess height of posterior mitral valve leaflet (>1.5cm) undersized annuloplasty ring Narrow -aortic angle (130degree) Excessively high PL/AL Small LV cavity inappropriate filling rhytm disturbances prominent septal bulge (HOCM)
What is intra-operative management of SAM
Increase preload
Increase afterload (partial aortic cross clamp) (increase MA 80-90 mmHg)
Stop inotropes
treat rhythm disturbances (avoid tachcardiac)
Check the LVOT peak gradient (it’s critical…if < 40 its ok to go back to ICU if > 50 then go back on
also check for degree of MR (no more then mild)
CPB and do one of the following
add neochordae to displace posterior leaflet into ventricle
confirm appropriate annuloplasty ring size
check coptation depth < 12
What are advantages of repairing the mitral valve over replacing it
Greater freedom from mortality (operative and long term)
less Structural valve deterioration compared to bio
Less rates of re-operation
lower rates of infective endocarditis
decreased post op thrombo-embolism
lower rates of post operative hemorrhage complications related to anticoagulation
improved LV ejection fraction
What is Freedom from re-intervention for patients older then 70 for different mitral valve surgery
Repair of anterior mitral valve leaflet 78% at 10 years
Repair of posterior mitral valve leaflet 98% at 10 years
open mitral valve commissurtomty 80% at 10 years
close mitral valve comussurotomy 70% at 10 years
Porcine bioprosthesis 75% at 10 years
Bovine pericardial bioprosthesis 80% at 10 years
Mechanical prosthesis 98% at 10 years
List 5 echocardiographic findings of ischemic MR
Annular dilation
leaflet tenting
Leaflet coaptation below the plane of the annulus
papillary muscle displacement
regional wall motion abnormality (LV dilation
Failure of leaflet coptation during systole (loitering)
Papillary muscle rupture (acute)
list ecocardiographc findings of chronic MR
LV posterolateral wall motion abnormality LV dilation Normal leaflet morphology restricted leaflet motion plan of coaptation below the annulus annular dilation central jet of MR
What echo features should be assessed with ischemic MR
Valve tenting–valve being pulling towards in the ventricle
Tenting area
position/displacement of papillary muscle
left ventricular function/wall motion abnormalities
direction of jet (eccentric)
assess closure near medial commissure
MR severity
What would you accept as minimally acceptable indexed EOA for mitral valve?
> 1.2 cm2/m2
page 869 of Cohn states
EOAI of 1.3 to 1.5 as measured by continuuity equation may increase the risk of PPM
List 5 methods for repairing anterior mitral valve leaflet prolapse
transfer of secondary chord to the unsupported free edge
limited resection of a triangular wedge of anterior leaflet
alfieri stitch
chordal shortening: the papillary muscle is split and the chord is shortened by embedding it in the muscle
chordal replacement withe PTFE (size 5-0)
quandrangular resection of the posterior leaflet and transferring that portion of the posterior leaflet with its supporting chord–to the anterior leaflet.
What are techniques to repair anterior mitral leaflet
triangular resection chordal shortening chordal transfer new chordae alfieri stich
What is classification of AV groove disruption
Type 1: Dissociation at annulus
Type 2: Dissociation at the base of the papillary musclee
Type 3 dissociation between annulus and PM
What are risk factors for AV groove disruption
1% decreased by preservation of PML
age, female, annular calcification, annular abscess, complete resection of mitral valve leaflets, deep sutures, manipualtion after insertion, small LV, large valve size
How is atrioventricular disruption following mitral valve replacement treated
Patient back on CPB
remove the prosthetic valve
Implant a bovine pericardial patch across the atrioventricular groove
implant a smaller prosthetic valve with a low profile
avoid lifting the heart with the prosthesis in situ
What are intra-operative risk factors for AV groove separation in Mitral valve replacement
Oversizing of valve Aggressive debridement of posterior annulus/posterior leaflet Vigourous retraction De-airing maneuvers Bioprosthetic valve Papillary muscle resection
