MITRAL REGURGITATION

Objectives:Anatomy of Mitral ValveEtiologyAssesment of Severity2DColor DopplerPulse waveContinous wave DopplerSupportive signsFeasibility of RepairRole of Exercise Echo in MR

Role Of Echocardiography in MREchocardiogram report of MR patients should evaluate MechanismEtiologySeverity of regurgitationConsequencesPossibility of repair

Mitral Valve Analysis: RecommendationsTTE is recommended as the first-line imaging modality for mitral valve analysis.

TEE is advocated when TTE is of non-diagnostic value or when further diagnostic refinement is required.

3D-TEE or TTE is reasonable to provide additional information in patients with complex mitral valve lesion.

TEE is not indicated in patients with a good-quality TTE except in the operating room when a mitral valve surgery is performed.

Anatomy Of Mitral valve

Two leaflets (thickness about 1 mm)

Posterior leafletQuadrangular shapeThree individual scallops (P1P2P3) Anterior leaflet Semi-circular shapeArtificially divided into three portions (A1A2A3)

MITRAL VALVE ANATOMY ON TTE

MITRAL VALVE ANATOMY ON TEE

Mitral Annulus

Annular dilatation (PLAX)

Annulus/anterior leaflet ratio > 1.3 or Diameter > 35 mm

The normal contraction of the mitral annulus (decrease in annular area in systole) is 25%.

Mechanism of Mitral RegurgitationCarpentier's Classification

Etiology

Billowing valve: part of the mitral valve body protrudes into the LA; the coaptation is preserved beyond the annular plane. Mild MRFloppy valve is a morphologic abnormality with thickened leaflet (diastolic thickness >5 mm) due to redundant tissueDegenerative mitral regurgitation

EtiologyMitral valve prolapse

Cleft Mitral valve

Etiology

Flail Mitral Leaflet

Etiology

Etiology

Flail Mitral Leaflet

Etiology

Rheumatic MR is characterized byVariable thickening of the leaflets Fibrosis

Rheumatic mitral regurgitation

EtiologyIschaemic heart disease or dilated cardiomyopathy.Imbalance between tethering forces and closing forces

Functional mitral regurgitation

Assessment of severitySettings: Adjust 2D and color gain, NL, ECG, B.P2D visual Assessment Color flow DopplerColor flow imagingVena ContractaThe flow convergence method4. Pulsed DopplerDoppler volumetric methodMitral to aortic time-velocity integral (TVI) ratioPulmonary venous flow5. Continuous wave Doppler of mitral regurgitation jet

Is It Easy?SevereMRMS

Author (A) - Author (A) - Algorithm for distinguishing severe from nonsevere MR in patients with clinically significant mitral regurgitation (MR) jets on color Doppler imaging.

Paul A. Grayburn et al. Circulation. 2012;126:2005-2017

Algorithm for distinguishing severe from nonsevere MR in patients with clinically significant mitral regurgitation (MR) jets on color Doppler imaging. Severe MR corresponds to angiographic grades 3+ and 4+ per American College of Cardiology/American Heart Association guidelines.9 The first step is to determine whether MR severity is obviously mild or severe by American Society of Echocardiography/European Association for Echocardiography criteria (see text).11,12 If not, quantitative parameters are applied in a systemic, integrated fashion to determine whether MR is severe. Unless the MR is unequivocally mild in step 1, no attempt is made to distinguish mild from moderate MR (nonsevere), because studies comparing quantitative echocardiographic measures to an independent reference standard show substantial overlap.49 VCW indicates vena contracta width; MV, mitral valve; VCA, vena contracta area; 3D, 3-dimensional; EROA, effective regurgitant orifice area; PISA, proximal isovelocity surface area; RV, regurgitant volume; RF, regurgitant fraction; VC, vena contracta; CW, continuous-wave Doppler; and LA, left atrium.

Why Severity Assesment?

Effect Of Blood Pressure

Settings & 2D visual Assessment

NameAgeBlood PressureECGGain: 2D and ColorAliasing velocity

2D visual Assesment:

30

Color Flow ImagingLess accurate & Most commonDepends on many technical and haemodynamic factors.Not recommended to quantify the severity of MR. should only be used for diagnosing MR.Better in Mild and Severe Mitral regurgitation.

Colour-flow imaging in MR Optimize colour gain/scale Evaluate in two views Need blood pressure evaluationUsefulness/Advantages Ease of use Evaluates the spatial orientation of MR jet Good screening test for mild vs severe MRLimitationsThe colour flow area of the regurgitant jet is not recommendedto quantify the severity of MR. The colourflow imaging should only be used for diagnosing MR. Can be inaccurate for estimation of MR severity Influenced by technical and haemodynamic factors Underestimates eccentric jet adhering the LA wall (Coandaeffect)33

Vena Contracta Width

PLAX and AP-4CV

Identify the three components of the regurgitant jet (VC, PISA, jet into LA)

Smallest vena contracta

Mean vena contracta width (four- and twochamber views) better correlated with the 3D vena contracta.The VC is the area of the jet as it leaves the regurgitant orifice; it reflects thus the regurgitant orifice areaMild MR VC < 3 mmSevere MR VC > 7 mm

Flow converges toward a restrictive orifice remaining laminar and forming isovelocity surfaces that approximate hemispheres

Proximal isovelocity surface area (PISA)

Apical 4CV Zoom the image of the regurgitant mitral valve Decrease the Nyquist limit Measure the PISA radius at mid-systole using the first aliasing and along the direction of the ultrasound beamMeasure MR peak velocity and TVI (CW)Calculate flow rate, EROA, R Vol

Proximal isovelocity surface area (PISA)

Proximal isovelocity surface area (PISA)Flow = Area x Velocity

EROA = Flow/Peak velocity

EROA = (2r2 Va)/Peak velocity

Reg Vol = EROA TVI

Proximal isovelocity surface area (PISA)

Doppler volumetric methodCalculate LVOT stroke volume (SV)SVLVOT = LVOT diameter2 0.785 TVILVOT

Calculate mitral inflow (MI) stroke volumeSVMI = mitral annulus diameter2 0.785 TVIMI

Subtract LVOT SV from MI SV = Regurgitant Volume

Mitral To Aortic TVI Ratio

TVI ratio >1.4 Severe MR TVI ratio1.5 m/s Severe MR

CW Doppler of MR jet

Velocity itself does not provide useful information about the severity of MR.

A dense MR signal with a full envelope indicates more severe MR than a faint signal.

CW Doppler of MR jet

Pulmonary venous flow

Both the pulsed Doppler mitral to aortic TVI ratio and the systolic pulmonary flow reversal are specific for severe MR.

They represent the strongest additional parameters for evaluating MR severity.

Consequences of mitral regurgitationLeft ventricle size and functionLA size and VolumesPulmonary Artery Pressure

Lets Summarize

Probability of successful mitral valve repair in MR

36 Years old Asymptomatic female with severe MR and LVEDs 38mm and EF 65% presents for routine clinic visit Admit for surgery

Followup after 6 months with Echocardiogram

Followup after 1 year and echo after 2 years

Followup after 1 year and echo after 1 year

Recommended Follow-upSeverityCinical ExamEchocardiogram

Moderate organic MR 1 Year2 Year

Severe organic MR 6 Months 1 Year

EF borderline or6 months6 monthsLVEDs close to 40 mm

Thanks for your patience listening

AetiologyPrimary MR (organic/structural): Primary pathology of the valve Non-ischaemic: degenerative disease (Barlow, fibroelastic degeneration, Marfan,EhlerDanlos, annular calcification), rheumatic disease, toxic valvulopathy, infective endocarditis Ischaemic: ruptured (complete/partial) papillary, scarred/retracted papillary muscle.Secondary MR (functional/non-structural): malcoaptation related to LV (LA) remodelling with no structural abnormalities of the valve non-ischaemic and ischaemic Secondary MR (functional/non-structural): malcoaptation related to LV (LA) remodelling with no structural abnormalities of the valve non-ischaemic and ischaemic