echocardiography in mitral stenosis

DR RAJESH K F

ECHOCARDIOGRAPHY IN MITRAL STENOSIS

CAUSES AND ANATOMIC PRESENTATION

Rheumatic Commissural fusionLeaflet thickening Chordal shortening and fusion Superimposed calcificationDegenerative MS Annular calcificationRarely leaflet thickening and calcification at

base

Congenital MS Subvalvular apparatus abnormalitiesInflammatory-SLEInfiltrative Carcinoid heart disease Drug induced valve diseaseLeaflet thickening and restriction Rarely commissural fusion

2D ECHO

Commissural fusion PSAX echo scanning of valve Important in distinguishing degenerative from rheumatic valve Complete fusion indicate severe MS Narrow diastolic opening of valve leaflets

Restricted mobility -PLAX

Early diastolic doming motion of the AML- restriction of tip motion

Leaflet thickening -PLAX

Chordal thickening, shortening and fusion –PLAX and A4C

Superimposed calcification

Dilated LALA and LA appendage

thrombusParadoxical septal

motionDilated RV and RA

Wilkins score -Mitral valve score <8 are excellent candidates for BMV

Limitations of wilkin score

Assessment of commissural involvement is not included

Limited in ability to differentiate nodular fibrosis from calcification.

Doesn’t account for uneven distribution of pathologic abnormalities.

Frequent underestimation of subvalvular disease.

Doesn’t use results from TEE or 3D echo

Cormier’s method

3D ECHO

TEE and TTEHigher accuracy than 2D echoDetailed information of commissural fusion

and subvalvular involvementMVA measurement in calcified and irregular

valveMVA measurement after BMVRestenosis after commissurotomy commissural refusion valve rigidity with persistent commissural opening

From LA From LV

RT3DE score of MS severity

Total RT3DE score ranging from 0 to 31 points

Total score of mild MV involvement was defined as <8 points

Moderate MV involvement 8–13Severe MV involvement >14

M MODE ECHO

Decreased E-F Slope>80 mm/s MVA=4-6cm² <15mm/s⇒ MVA <1.3cm²Thickened Mitral LeafletsAnterior Motion or

Immobility of Posterior Mitral Leaflet-tethering at tips

Diastolic Posterior Motion of Ventricular Septum (severity of stenosis)

TEE

For diagnosis and quantification little yield

Spontaneous echo contrast

LA and LA appendage thrombus

Use of transgastric plane 90 -1200 for evaluation of chordal structures

Assessment of commissural calcification and fusion to predict procedural outcome after BMV

Commissure score

NON CALCIFIED FUSION

ANTEROLATERAL COMMISSURE

POSTEROMEDIAL COMMISSURE

ABSENT 0 0

PARTIAL 1 1

EXTENSIVE 2 2

TOTAL SCORE O TO 4

Scores for anterolateral and posteromedial commissures were combined such that each valve had an overall commissure score ranging from 0–4

A high score indicated extensively fused, non‐calcified commissures that were therefore more likely to split

A low score indicated either minimal fusion or the presence of resistant commissural calcification

ASSESSMENT OF MS SEVERITY

2D OR 3D ECHOMVA BY PLANIMETRYDOPPLERPRESSURE GRADIENTSMVA BY PHTCONTINUITY EQATIONPISAMITRAL VALVE RESISTANCEPASP

MVA BY PLANIMETRY

2D EchoBest correlation with anatomical areaScanning method to avoid overestimationmeasured at leaflet tips in a plane

perpendicular to mitral orifice Elliptical in shapeDirect measure of mitral orifice including

opened commissures in PSAX

Excessive gain setting may underestimate valve area

Zoom mode is better for delineationHarmonic imaging can improve planimetry

measurementOptimal time is mid diastole obtained by cine

loop mode on a frozen imageMultiple measurements in AF or incomplete

commissural fusiondifficult in calcified valve,chest deformity and

previous commissurotomy

Real time 3D echocardiography

identify true smallest orifice independent of its orientation

most accurate ultrasound technique for measuring MVA, with a superior pre- and postprocedural agreement with the Gorlin’s derived MVA

Less experience dependent and more reproducible

Mitral leaflet separation (MLS) index

Distance between the tips of the mitral leaflets in parasternal long-axis and four-chamber views

it can be used as a semiquantitative method for the assessment of MS severity

A value of 1.2 cm or more provided a good specificity and PPV for the diagnosis of non severe MS

less than 0.8 cm -severe MS.It is not accurate in patients with heavy mitral

valvular calcification and post BMV

PRESSURE GRADIENT

Apical windowCWD /PWD at or after tip of mitral valveMaximal and mean gradient Bernoulli equation( P =4V2)Derived from transmitral velocity flow curve Heart rate to be mentionedCD to identify eccentric mitral jet

Maximal gradient influenced by LA compliance and LV diastolic function

In AF average of 5 cycles with least variation of R-R interval and as close possible to normal HR

MVG dependent on HR,COP and associated MR

Tachycardia, increased COP and associated MR overestimates gradient

Maximal gradient is markedly affected

PRESSURE HALF TIME

T1/2 is time interval in msecs between max mitral gradient in early diastole and time point where gradient is half max gradient

Or it is the time when velocity falls to 1/1.414 peak

PHT related to decceleration timePHT =.29x DT

MVA=220/PHT

The empirically determined constant of 220 is proportional to the product of net compliance of left atrium and LV, and the square root of maximum transmitral gradient in a model that does not take into account active relaxation of LV

Obtained by tracing deceleration slope of E wave on Doppler spectral display

Concave not feasibleIf slope is bimodal deceleration slope in mid

diastole rather than early diastole is traced

AF avoid short cycles and average different cardiac cycles

Less dependent on COP or coexistent MRUseful when mean transmitral gradient is

misleading MR -transmitral gradient overesimatedLow COP –mean transmitral gradient -

underestimated

MS MS+MR MR

Factors that may affect PHT by influencing LA pressure decline

More rapid LA pressure decline shorten PHTLA draining to second chamber –ASDLA pressure drop rapidlyPHT shortenedStiff LA –low LA complianceLA pressure drop rapidlyPHT shortened

Factors affect PHT by influencing LV pressure rise

More rapid LV pressure rise shorten PHTIf LV fills from a second source PHT –ARLV pressure rise more rapidlyPHT will be shortenedIf LV is stiff-low ventricular complianceLV pressure may rise more rapidlyPHT will be shortened

All factors affect PHT (ASD, AR, low LA or LV compliance )

shorten PHT Leads to overestimation of MVATherefore PHT never under estimate MVATherefore if PHT >220 MS is severeIf PHT is < 220 consider other methods to

assess severity

Prosthetic MVANot been validatedAffected mainly by DDMore accurate method is continuity equation

Not reliable

After BMVNormally LA and LV compliance counteract

each other when gradient and compliance are subject to

important and abrupt changes alter relation between PHT and MVA

Upto 48 hrs post BMV

CONTINUITY EQATION

LVOT AREA

MVA X VTI mitral= LVOT area X VTI aortic

MVA = LVOT area X VTI aortic VTI mitral

MVA= p D2 X VTI aortic 4 VTI mitralD is diameter of LVOT in CM and VTI in CMSV can be estimated from PAMethod not useful in AF,AR or MRUseful in degenerative calcific MS

PISA

Based on hemispherical shape of convergence of diastolic mitral flow on atrial side of mitral valve and flow acceleration blood towards mitral valve

MVA x MV = PISA x AV

MVA = PISA x AV

MV

PISA = 2pr2 x a 180MVA = 2pr2 x AV x a MV

180

Zoom on the flow convergenceUpshift the baseline velocity and use an

aliasing velocity of 20–30 cm/sMeasure the radius of the flow convergence

region and the transmitral velocity at the same time in early diastole

Measure the α angle formed by the mitral leaflets

Use of a fixed angle value of 100° can provide an accurate MVA estimation in patients with MS.

Can be used in presence of significant MR, AR, differing heart rhythms

Not affected by LA,LV complianceMultiple measurements requiredM mode improves accuracy

Colour M-mode PISA

Instantaneous measurement of MVA throughout diastole

Under guidance of magnified 2D colour imaging, colour M-mode tracings were recorded by placing the M-mode cursor line through the centre of the flow convergence.

Diastole was divided into four phases of equal duration: early, mid, mid-late, and late diastole.

Peak radius of flow convergence was measured during each phase to calculate mitral flow rate

Each radius was measured from the red–blue aliasing level to the tip of the leaflet at the orifice

Colour M-mode analysis was then paired with continuous wave Doppler

Three to five measurements of each variable (on matched cycle for colour M-mode and Doppler methods) were averaged, depending on the patient's rhythm.

MVA was then calculated separately for each phase of diastole

MITRAL VALVE RESISTANCE

MVR=Mean mitral gradient/ transmitral diastolic flow rate

Transmitral diastolic flow rate= SV/DFP

It correlate well with pulmonary artery pressure

PASP

CWDEstimation of the systolic gradient between

RV and RAMultiple acoustic windows to optimize

intercept angleEstimation of RAP according to IVC diameter

STRESS ECHOCARDIOGRAPHY

Useful to unmask symptoms in patients with MVA<1.5cm2 and no or doubtful complaints

Discrepancy between resting doppler and clinical findings

Semi-supine echocardiography exercise (30 to 60 secs of leg lifts) is now preferred to post exercise echocardiography

Allows monitoring gradient and pulmonary pressure in each step of increasing workload

Mean mitral gradient and PASP to be assessed during exercise

Mean gradient >15 mmhg with exercise is considered severe MS

A PASP > 60 mmHg on exercise has been proposed as an indication for BMV

Dobutamine stress echo mean gradient >18 mmhg with exercise is considered severe MS

Associated lesions

Quantitation of LAEAssociated MR and its mechanismSeverity AS (underestimated)AR- t1/2 method to assess MS is not validTR ,tricuspid annulusSecondary pulmonary HTN-TR

GRADING OF SEVERITY OF MS

MILD MODERATE SEVERE

SPECIFIC

VALVE AREA(cm2)

>1.5 1-1.5 <1

NONSPECIFIC

MEAN GRADIENT (mmHg)

<5 5-10 >10

PASP (mmHg)

<30 30-50 >50

THANK U

1 Pressure half time in MS affected by all exceptA ASDB MR C ARD HOCM

2 In case of a pure MS transmitral mean gradient is 14 mmhg and mitral area by planimetry is 1.1cm2 it is graded asA severeB moderateC mild D indeterminate

3 Commissural fusion is not a feature of MS inA RHDB Calcific MSC SLED Carcinoid disease

4 Not included in Wilkins score is A commissural fusionB restricted mobility C leafllet thickeningD subvalvular fusion

5 harmonic imaging useful inA 2D MVAB PHTC PISAD M mode

6 mitral leaflet separation index less than ----cms indicate severe MSA 0.4B 0.6C 0.8D 0.2

7 continuity equation useful in MVA calculation in A AFB ARC MRD Calcific MS

8 Mean gradient greater than ---- mmhg with exercise echocardiography is considered severe MSA 10B 12 C 15D 18

9 In a case of severe AR with MS mitralPHT obtained is 280 severity of MS isA mild B moderate C severe D none of the above

10 Method to assess severity of MS in diastolic dysfunction isA PHTB PISAC continuity equationD mitral valve resistance

1 Pressure half time in MS affected by all exceptA ASDB MR C ARD HOCM

2 In case of a pure MS transmitral mean gradient is 14 mmhg and mitral area by planimetry is 1.1cm2 it is graded asA severeB moderateC mild D indeterminate

3 Commissural fusion is not a feature of MS inA RHDB Calcific MSC SLED Carcinoid disease

4 Not included in Wilkins score is A commissural fusionB restricted mobility C leafllet thickeningD subvalvular fusion

5 harmonic imaging useful inA 2D MVAB PHTC PISAD M mode

6 mitral leaflet separation index less than ----cms indicate severe MSA 0.4B 0.6C 0.8D 0.2

7 continuity equation useful in MVA calculation in A AFB ARC MRD Calcific MS

8 Mean gradient greater than ---- mmhg with exercise echocardiography is considered severe MSA 10B 12 C 15D 18

9 In a case of severe AR with MS mitralPHT obtained is 280 severity of MS isA mild B moderate C severe D none of the above

10 Method to assess severity of MS in diastolic dysfunction isA PHTB PISAC continuity equationD mitral valve resistance

3D echo planimetry

Mitral valve area measurement using anyplane echocardiography.

allows on-line assessment of the mitral valve area.

Images are displayed as two simultaneous intersecting orthogonal long-axis scans (B-mode scans) and two perpendicular short-axis scans (C-mode scans)

These C-mode scans allow the display of short-axis views of the mitral valve from an apical transducer position

9 Usual mitral valve angle in PISA method to assess severity of MS is ----degreeA 80B 100 C 150D 180