MITRAL VALVE PROLAPSE

Echocardiographic Evaluation

Introduction

• Degenerative MR, leading cause of organic MR in western

countries.

• Type II according to Carpentier classification.

John Brerton Barlow John Michael Criley

Introduction

• Once called as Barlow’s syndrome

• Most commonly assosciated with myxomatous degeneration

(degenerative valve disease).

Two subtypes

• Flail MV - chordal rupture or papillary rupture

• Billowing MV – excess tissue with free edge prolapse, late

systolic click, holosystolic.

Barlow’s syndrome

• Degenerative valve disease

• Myxoid infiltration - leaflet thickening, chordal elongation.

• Diffuse thickening of the valve - billowing of one or more segments,

scallops of the valve.

• Typically young (< 40 yrs), asymptomatic.

• Valve is typically large and thickened( >5mm on M mode echo).

• Accumulation of proteoglycans within the spongiosa layer

of the valve.

Fibroelastic deficiency

• Deficient connective tissue

• Thinning of the mitral leaflets and chordae

• Rupture of chordae

• Flail Mitral leaflet

• Older

• New onset murmur – due to chordal rupture

• Middle scallop – P2 – most commonly involved.

ASSESSMENT

M mode

• First echocardiographic technique to diagnose MVP.

Criteria for MVP

• > 3mm late systolic buckling

• Pan systolic hammocking 5mm or more.

• Very specific, not sensitive.

• 10-20% of patients with auscultatory findings of MVP had a

false negative result on M mode.

• M mode useful when 2D echo is equivocal.

• Color M mode - whether MR is pansystolic or late systole.

2D Echo

PLax view

• Systolic displacement of an apparently normal or myxomatously

thickened MV or a portion of it beyond the plane of mitral annulus.

• Mitral annulus plane – line joining the junction of the posterior aortic

wall with the AML and the junction of the posterior left atrial and left

ventricular walls.

• Specific. less sensitive

Short axis view of LV

• Scallop or segmental prolapse by showing localised redundancies in

the anterior and posterior leaflet viewed in semi open or semi closed

position.

Coanda effect

• The tendency of a jet stream to adhere to a wall.

APICAL 4C VIEW

• Should not be used to assess MVP.

• A false diagnosis of MVP is possible.

• Normal MV leaflet breaking the plane of annulus which has

a saddle shaped contour.

2D TEE

• Poor acoustic window pts.

• Higher frequencies – superior quality.

• Chordal rupture are better visualised.

• Segment/scallop prolapsing.

Mid esophageal 4C view – P2 and A2

5C view – P1 and A1

Anteflexion of the probe – P3 and A3.

• Inability to view the mitral valve in entirety.

3D TEE

• Enface view from the LA aspect.

• Individual scallops can be visualised.

• Vena contracta of MR can be visualised,planimetered.

• 2D TEE predicted segment/scallop prolapse in 9 out of 18 patients

compared to surgery,whereas 3DTEE it was 16 out of 18 pts.

Manda and Nanda et al.,

• There is now a general consensus as reflected in the recent guidelines

by both the American Society of Echocardiography and the European

Assosciation of Echocardiography, that color flow jet assessment

should only be used for diagnosing MR and not for MR

quantification.

• Precise quantification is by using vena contracta width and the flow

convergence method.

Vena Contracta width.

• Narrowest neck of the regurgitant flow through or immediately below

the regurgitant orifice.

• VC width is thus the diameter of the effective regurgitant orifice

(ERO).

• USG beam to be perpendicular to the MR flow (PLax)

• Very eccentric jets – Apical views to benefit from axial resolution.

• VC > 7mm is assosciated with severe MR with high sensitivity and

specificity.

• Less than 3 mm severe MR is excluded.

• 3-7 mm gray zone –further confirmation using quantitative

method.

PISA

• Simple, fast and reproducible

• Proved to be reliable by multiple investigators.

• Parallel to the regurgitant flow.

• Apical views usually (parasternal in case of eccentric jets)

• Alaising velocity should be shifted down in the direction the mitral

regurgitant jet ,adjusted to obtain an appropriate hemispheric proximal

flow convergence.

• Higher velocities >40 cm/sec in case of severe MR .

• Focused zoom mode for measurement of radius .

• Measurement of the flow convergence at the level of T wave and use

of the peak velocity of the regurgitant jet –allow accurate estimation

of the ERO and of the Rvol.

Specific situations in degenerative MR

Mid late systolic MR :

• Bileaflet prolapse

• Regurgitant volume of patients with mid-late systolic MR was

smaller.

• Mid term outcomes are better.

• ERO was not linked to outcome

• Rvol provides information of MR severity.

Topilsky Y et al , MVP with mid late systolic MR

pitfalls of evaluation and clinical outcome compared with holosystolic regurgitation.

Circulation 2012;125(13):1643-51

Multiple jets

• Very redundant valve with diffuse myxomatous changes.

• PISA method can be used.

• ERO , Rvol to be calculated for each jet and the sum of the

effective regurgitant orifice and Rvol to be obtained.

• Continuity equation in absence of AR.

EDV- ESV = SV + RV

RV = SV – (AORTIC FLOW * AREA)

RV = SV- (TVI * LVOT)

3D echo

• VC width

• 3D PISA

• Anatomic regurgitant orifice area

Consequences of MR

• LV size

• LV EF

• LA

• PSAP

Surgical indications and methods in MVP

• Asymptomatic patients are followed with no restrictions to activity.

• Surveillance TTE or TEE not recommended in patients with mild

mitral regurgitation.

• Symptomatic with severe MR

• Asymptomatic with enlarged LV (ESD> 45 mm)

• Reduced LV ejection fraction < 60% need further consideration.

• ACC/AHA guidelines – Class IIa – surgery in patients with severe

MR with AF or pulmonary hypertension.

• Repair is better than surgical replacement.

• Repair – longer durability,increased success rate, better long term

survival rate(better LVEF).

• Most common repair of the posterior leaflet is a triangular resection

and suture repair, supplemented by a flexible posterior annuloplasty

band.

• Surgical replacement – more than one fourth of AML is involved.

• Repair of AML – triangular resection, chordae shortening, chordae

transfer, commisssural annuplasty.

• Neochordae.

• MV replacement – both leaflets prolapse (40%),calcified

MV, infected cusps with severe destruction.