echocardiographic assessment of stenotic valvular lesions

ECHOCARDIOGRAPHIC ASSESSMENT OF STENOTIC

VALVULAR LESIONSDEEPAK NANDAN

ANATOMY

Area-2.6-3.5 cm².

Structure 3 cusps,3 commissures supported

by fibrous annulus Arantius nodule 3 sinuses

AORTIC VALVE

Qualitative diagnosis

Thin and delicate

Plax-opening and closing

Basal short axis view-Y-inverted Mercedes Benz sign

2D-IMAGE

Maximum jet velocity

◦ BERNOULLI’s equation

◦ Multiple windows

◦ Parallel alignment

◦ Colour doppler

◦ Angle correction

Doppler assessment

MIPG=4 xV²(maximal jet velocity)m/s

MPG=4x(∑V1²+V2²+…Vn²)/n

MPG=∆P(max)/1.45 +2

MPG=2.4(Vmax)²

Pressure gradients-Instantaneous vMean

Discrepancies

◦ Tech poor doppler recording

◦ Non parallel interrogation angle

◦ Pressure grad depends on flow rate & valve narrowing –AR/LV dysfunction

Bernoulli's VS invasive

Continuity equation:-

SV (lvot)= SV (Ao)

SV=CSAxTVI

CSA (lvot) xTVI (lvot)=CSA (Ao) x TVI (Ao)

AVA=CSA x TVI (lvot) / TVI (Ao)

Aortic valve area

Correlates well with invasive data (GORLINS)

Adv compared to Berrnoulli

co-existing AR

Left ventricular dysfunction

Rarely are all 3 leaflets imaged perpendicular

Triangular shape- measurement error

Deformities n irregularities- further exacerb

AV- superior-inferior rapid moments

0.25 cm2 margin

AVA-Direct planimetry

Ao valve area≈Ao flow rate

Dist- true severe valvular stenosis (vs) mild to mod stenosis with LV dysfn

Stepwise infusion of dobutamine(5—30µg/kg/min)

DOBUTAMINE ECHO

Flexible valves:- AVA ↑ when SV ↑

True stenotis:- AVA↔ when SV ↑

Flexible valves:-Vmax(lvot)/jet ↑

True stenosis:-Vmax(lvot)/jet↔

Safe& clinically useful, limitation- non response to dobutamine

Stress findings of severe stenosis AVA<1cm² jet velocity>40m/s mean gradient>40mm of Hg

Lack of contractile reserve- failure of LVEF to ↑ by 20% is a poor

prognostic sign

Maximal aortic cusp separation (MACS) Vertical distance between right CC and non CC

during systole Stenotic AV → decreased MACS

Limitations Single dimension Asymmetrical AV involvement Calcification / thickness ↓ LV systolic function ↓ CO status

M- mode

AVA MACS

N > 2cm2 N > 15 mm

< 0.75 cm2 < 8 mm

> 1 cm2 > 12 mm

gray area 8 – 12 mm

Ao valve resistance- flow independent measure of

stenosis severity

Resistance=(∆P/∆Q)mean x1333

Resistance=28√gradient( mean)/AVA

OTHER APPROACHES

Left ventricular stroke work loss(SWL)

SWL (%) = (100 ×∆ P mean) / (∆P mean + SBP)

Principle-LV expends work during systole to keep the AV open and to eject blood into the aorta

Depends on the stiffness of AVLess dependent on the flow

>25%--- poor outcome

LVOT overestimated

LVOT TVI recorded too close to valve

Hgh transAo flow rate

mod-sev AR Hgh output state Large body size

LVOT underestimated

LVOT TVI-too far frm val

Small body size Lw transAo flw rate low EF small vent

chamber mod-sev MR mod-sev MS

Discrepencies in AS severity assessmentSevere AS by gradient Severe by area

Valve anatomy, etiology

Exclude other LVOTO

Stenosis severity – jet velocity

mean pressure gradient

AVA – continuity eq

LV – dimensions/hypertrophy/EF/diastolic fn

Aorta- aortic diameter/ assess COA

AR – quantification if more than mild

MR- mechanism & severity

Pulmonary pressure

APPROACH

Av ↑in MPG per yr = 0 to 10mm/yr mean 7mm Hg AVA ↓ by 0.1 to ∓ 0.19cm²

Jet vel < 3m/s – rate of symptom onset needing MVR is 8 % /yr

3-4m/s – 17%/yr

>4m/s – 40% /yr

NATURAL HISTORY

MITRAL STENOSIS

Mitral annulus

The leaflets

Chordae tendinae-papillary muscle

Underlying ventricular wall

Mitral valve-anatomy

Annulus

Leaflets

Anterior- three scallops

Posterior- three scallops

Scallop 1-lateral most

Scallop 3-medial most

LEAFLETS & SCALLOPS

Antero lateral PM- chordae to AL half of both leaflets

Dual blood supply

Postero medial PM- chordae to PM half both leaflets

RCA blood supply

Chordae and papillary muscles

2d echo-features Maximal excursion of leaflet tips Tubular channel

Commissural fusion⇒doming/bowing

Chordal thickening ⇒ abnormal motion

Progressive fibrosis⇒stiffening ⇒calcification

RHEUMATIC MS

Doming of the mitral valve (hockey stick AML)

Funnel shaped opening of mitral valves

Focal thickening and beading of leaflets

calcification

Mitral stenosis 2D

early diastolic doming motion of the AML, restriction of tip motion. Pliable, little fibrosis, calcification, or thickening. Dilated LA

2D-Planimetry

2D short axis imaging of diastolic orifice -planimetry

Smallest orifice at the leaflet tips

Inner edge of the black/white interface traced

Correlates well with hemodynamic assessment

1. Funnel-shaped

Actual limiting orifice at the tip

2. Instrumentation setting

‘’blooming” of the echoes due to increased gain

Technical factors

M-mode assessment

Increased echogenicity of leaflets

Decreased E-F slope >80mm/s⇒MVA =4-6cm² <15mm/s⇒MVA <1.3cm²

Paradoxical anterior motion of PML

Doppler assessment

Trans mitral pressure gradient single most imp factor in determining the

severity & relation to symptoms & functional status

Depends on

Volume statusHeart rate

Early trans mitral flow volume Cardiac output High output states Mitral reguritation

Mean pressure gradient Average MVA Cardiac output

Peak pressure gradient

Pressure half time

Measure of rate of decay of mitral valve gradient

Time in ms at which initial instant pr gradient declines to one half

Time interval from V max to the point where velocity has fallen to Vmax/√2

PHT=½ Peak=V½

V½=Vmax/√2

V½=V max/1.414

V½=Vmax x .707

MVA=220/PHT

Limitation

Post BMV- accuracy ↓

Aortic regurgitation- over estimates MVA

Severe LVH- ↓LV compliance

Prosthetic mitral valve- not validated

Independent of

Cardiac output Mitral regurgitation

PHT

Pressure half time=29% of Deceleration time

MVA=220 ÷ (0.29 × DT)

MVA=759 ÷ DT

Deceleration time

Left atrial dilation

Atrial fibrillation

Spontaneous echo contrast

LA thrombus

Secondary pulm htn-TR

Secondary features of MS

Echo approach to MS Valve morphology Exclude other causes of clinical

presentation MS severity Mean transmitral pr gradient 2D valve area PHT valve area Assos MR LA enlargement Pulmonary art pressure Co-existing TR severity TEE for LA clot

Individuals with score≤8 –excellent for BMV

Those with score≧12-less satisfactory results

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