Echocardiography is a key tool for diagnosing and evaluating mitral stenosis (MS). It is essential to use an integrative approach when grading MS severity by combining Doppler, 2D imaging, and measurements, rather than relying on one alone. Echocardiography plays a major role in MS by confirming diagnosis, quantifying severity, analyzing consequences, and examining valve anatomy. Mitral valve planimetry directly measures valve area and is considered the reference standard, but additional measurements like pressure gradient and half-time are also useful. Echocardiography aids clinical decision making for patients with MS.

1. By: Dr. Ankur Gupta
Resident, Dept. of Cardiology
Dhiraj Hospital
ECHOCARDIOGRAPHY IN MITRAL STENOSIS

2. • Valve stenosis is a common heart disorder and an important cause of cardiovascular
morbidity and mortality.
• Echocardiography - Key tool for diagnosis and evaluation of valve disease, and primary
non-invasive imaging method for valve stenosis assessment.
• Essential in clinical practice to use an integrative approach when grading the severity of
stenosis.
• Combine all Doppler and 2D data, and not rely on one specific measurement.
• Various conditions influence velocity and pressure gradients.
• Parameters vary depending on intercurrent illness of patients with low vs. high
cardiac output.
• Irregular rhythms or tachycardia can make assessment of stenosis severity
problematic.

3. MITRAL STENOSIS
• Echo - Major role in decision making for MS.
• Confirmation of diagnosis,
• Quantitation of stenosis severity,
• Consequences, and
• Analysis of valve anatomy.

4. CAUSES AND ANATOMIC PRESENTATION
• MS is the most frequent valvular complication of rheumatic fever.
• Rheumatic MS  commissural fusion.
• Other anatomic lesions - chordal shortening and fusion, and leaflet thickening, and later in
the disease course, superimposed calcification.
• This differs markedly from degenerative MS.
• Annular calcification.
• Old age. Associated with hypertension, atherosclerotic disease, and sometimes AS.
• Congenital MS - Abnormalities of the subvalvular apparatus.
• Other rare causes: inflammatory diseases (e.g. systemic lupus), infiltrative diseases, carcinoid
heart disease, and drug-induced valve diseases.
• Leaflet thickening and restriction are common here, while commissures are rarely fused.

6. LA-LV gradient Elevated LA pressure
Elevated pressure in pulmonary capillaries Pulm. cong. / edema
PHT / reactive PHT TR
Right heart failure AF
NOTE: In mitral stenosis there is no ‘burden’ on the left ventricle
(no pressure or volume over load).
Hemodynamics of MS

7. ECHO CHARACTERISTICS OF MS
Doming (diastolic bulging of the AML) Reduced valve opening
Commissural fusion Leaflet tip thickening
Secondary calcification Subvalvular involvement
(thickened and fused tendinae)
Associated problems
Thickened aortic valve Reduced LVF (rheumatic myocarditis)
Enlarged LA Pulmonary hypertension
Other valve involvement Aortic regurgitation
Tricuspid stenosis Thrombus

8. Risk of Thrombus
• Systemic embolism in 20% of all MS patients
• 80% of patients are in Afib
• 45% have spontaneous left atrial contrast
Most thrombi are seen in the left atrial appendage. Thus it can be easily missed on TTE
MV Area — Reference Values
Normal 4-6 cm²
Mild >1.5 cm²
Moderate (cm²) 1-1.5 cm²
Severe (cm²) <1 cm²

9. MITRAL STENOSIS ASSESSMENT
• Based on literature review and expert consensus, these methods were categorized for
clinical practice as:
† Level 1 Recommendation: an appropriate and recommended method for all patients
with stenosis of that valve.
† Level 2 Recommendation: a reasonable method for clinical use when additional
information is needed in selected patients.
† Level 3 Recommendation: a method not recommended for routine clinical practice
although it may be appropriate for research applications and in rare clinical cases.

10.  MVA Planimetry (Level 1 Recommendation)
• Theoretically, advantage of being a direct measurement of MVA
• Unlike other methods, does not involve any hypothesis regarding flow conditions, cardiac
chamber compliance, or associated valvular lesions.
• In practice, shows the best correlation with anatomical valve area.
• Therefore, considered as the reference measurement of MVA.
Indices of Stenosis Severity

11. • Planimetry measurement is obtained by direct tracing of the mitral orifice, including
opened commissures, if applicable, on a PSAX view.
• Careful scanning from the apex to the base of the LV  CSA is measured at the leaflet
tips.
• Measurement plane should be perpendicular to the mitral orifice (elliptical shape).
• Gain setting - sufficient to visualize the whole contour of the mitral orifice.
• Excessive gain - underestimation of valve area (esp. when leaflet tips are dense or
calcified).
• Image magnification (zoom mode) - useful to better delineate the contour of the mitral
orifice.
• Optimal timing of the cardiac cycle to measure planimetry  mid-diastole.
• Best performed using the cineloop mode on a frozen image.

12. • Perform several different measurements, esp. in
• Atrial fibrillation,
• Incomplete commissural fusion (moderate MS or after commissurotomy),
• Anatomical valve area may be subject to slight changes according to flow
conditions.
MVA Plani: TTE, PSAX view.
(A) Mitral stenosis. Both commissures fused. MVA 1.17 cm².
(B) Unicommissural opening after BMV. Postero-medial commissure is opened. MVA 1.82 cm².
(C) Bicommissural opening after BMV. MVA 2.13 cm².

13. Limitations of MVA planimetry
• Poor acoustic window
• Severe distortion of valve anatomy (severe valve calcifications of the leaflet tips).
• Technical expertise.
• Degenerative MS - planimetry is difficult and mostly not reliable because of the orifice geometry
and calcification present.
Image quality Alignment
Timing Calcification
Atrial fibrillation Incompl. comm. fusion
Operator experience

14.  Pressure gradient (Level 1 Recommendation)
• Estimation of the diastolic pressure gradient.
• Derived from the transmitral velocity flow curve.
• Simplified Bernoulli equation ∆P = 4v².
• Reliable estimation - good correlation with invasive measurement using transseptal
catheterization.
• CWD is preferred to ensure maximal velocities are recorded.
• When PWD is used, the sample volume should be placed at the level or just after leaflet
tips.

15. • Doppler gradient is assessed using the apical window (parallel alignment of the
ultrasound beam and mitral inflow).
• Ultrasound Doppler beam should be oriented to minimize the intercept angle with mitral
flow to avoid underestimation of velocities.
• Colour Doppler in apical view - useful to identify eccentric diastolic mitral jets -
encountered in cases of severe deformity of valvular and subvalvular apparatus.
• In these cases, the Doppler beam is guided by the highest flow velocity zone identified by
colour Doppler.

16. • Optimization of gain settings, beam orientation, and a good acoustic window are needed
to obtain well-defined contours of the Doppler flow.
• Peak and mean mitral gradients are calculated by integrated software using the trace of
the Doppler diastolic mitral flow waveforms on the display screen.
• Mean gradient is the relevant haemodynamic finding.
• Peak gradient is of little interest as it derives from peak mitral velocity, which is influenced
by LA compliance and LV diastolic function.
• Heart rate at which gradients are measured should always be reported.
• AF - mean gradient - average of five cycles with the least variation of R–R intervals and
as close as possible to normal heart rate.
• In addition, mean mitral gradient has its own prognostic value, in particular following BMV.

17. Mean gradient varies according to the length of diastole: it is 8 mmHg during a short
diastole (A) and 6 mmHg during a longer diastole (B).
Determination of mean mitral gradient from Doppler diastolic mitral flow in a
patient with severe mitral stenosis in atrial fibrillation.

18. Limitations of Pressure gradient
• Although reliable, not the best marker of the severity of MS.
• Dependent on MVA.
• Influenced by other factors: Transmitral flow rate, HR, cardiac output, associated MR.

19.  Pressure half-time (Level 1 Recommendation)
• Time interval in milliseconds between the maximum mitral gradient in early diastole and the
time point where the gradient is half the maximum initial value.
• Decline of the velocity of diastolic transmitral blood flow is inversely proportional to valve area
(cm²).
• .
• PHT is obtained by tracing the deceleration slope of the E-wave on Doppler spectral display of
transmitral flow and valve area is automatically calculated by the integrated software.
• Doppler signal used is the same as for the measurement of mitral gradient.
• As for gradient tracing, attention should be paid to the quality of the contour of the Doppler flow,
in particular the deceleration slope.

20. MVA by PHT: MS in atrial fibrillation. Valve area is 1.02 cm².

21. • Deceleration slope is sometimes bimodal, the decline of mitral flow velocity being more rapid in
early diastole than during the following part of the E-wave.
Non-linear decreasing slope of the E-wave. The deceleration slope should not be traced from
the early part (left), but using the extrapolation of the linear mid-portion of the mitral velocity
profile (right).

22. • In rare patients - concave shape of the tracing - PHT measurement may not be feasible.
• AF - tracing should avoid mitral flow from short diastoles and average different cardiac
cycles.
PITFALLS OF MVA PHT
• Gradient and compliance are subject to important and abrupt changes (Immediately after
BMV)
• Discrepancies between the decrease in mitral gradient and the increase in net
compliance.
• Rapid decrease of mitral velocity flow, i.e. short PHT can be observed despite severe MS.
• In patients with low LA compliance.
• Severe AR  Shortens PHT.
• Early diastolic deceleration time is prolonged with impaired LV relaxation, while shortened
in case of decreased LV compliance.

23. • Impaired LV diastolic function is a likely explanation of the lower reliability of PHT to
assess MVA in the elderly.
• Elderly rheumatic MS, degenerative calcific MS often associated with AS and
hypertension and, thus, impaired diastolic function.
• Hence, the use of PHT in degenerative calcific MS may be unreliable and should be
avoided.
Diastolic dysfunction Aortic regurgitation
Following BMV Concave shape of tracing
Degenerative calcified MS Additional AR where the AR signal
interferes with MV inflow signal

24.  Continuity equation (Level 2 Recommendation)
• Based on the conservation of mass, stating in this case that the filling volume of diastolic
mitral flow is equal to aortic SV.
where D is the diameter of the LVOT (in cm)
VTI (cm).
• Accuracy and reproducibility of the continuity equation for assessing MVA are hampered
by the number of measurements increasing the impact of errors of measurements.
• Cannot be used in AF or associated significant MR or AR.

25.  Proximal isovelocity surface area (PISA) method (Level 2 Recommendation)
• Based on the hemispherical shape of the convergence of diastolic mitral flow on the atrial side
of the mitral valve, as shown by colour Doppler.
• Enables mitral volume flow to be assessed and, thus, to determine MVA by dividing mitral
volume flow by the maximum velocity of diastolic mitral flow as assessed by CWD.
where r is the radius of the convergence hemisphere
(in cm), Valiasing is the aliasing velocity (in cm/s),
peak VMitral the peak CWD velocity of mitral inflow (in cm/s), and α is the opening angle of mitral
leaflets relative to flow direction
• Can be used in the presence of significant MR.

26. • Technically demanding and requires multiple measurements.
• Accuracy is impacted upon by uncertainties in the measurement of the radius of the
convergence hemisphere, and the opening angle.
• Use of colour M-mode improves its accuracy, enabling simultaneous measurement of
flow and velocity.

27.  Other indices of severity: Mitral valve resistance (Level 3 Recommendation)
• Ratio of mean mitral gradient to transmitral diastolic flow rate, which is calculated by dividing
SV by diastolic filling period.
• Alternative measurement of the severity of MS
• Correlates well with pulmonary artery pressure.
• Not shown to have an additional value for assessing the severity of MS as compared with valve
area.
• Estimation of pulmonary artery pressure, using Doppler estimation of the systolic gradient
between RV and RA, reflects the consequences of MS rather than its severity itself.

28. • Advised to check its consistency with mean gradient and valve area, as there may be
a wide range of pulmonary artery pressure for a given valve area.
• Pulmonary artery pressure is critical for clinical decision-making and it is therefore
very important to provide this measurement.

29. OTHER ECHOCARDIOGRAPHIC FACTORS IN THE EVALUATION OF
MITRAL STENOSIS
 Valve anatomy
• Major component of echo assessment of MS because of its implications on the choice of
adequate intervention.
• Commissural fusion is assessed from the PSAX view.
• Degree of commissural fusion is estimated by echo scanning of the valve.
• Commissural anatomy may be difficult to assess, in particular in patients with severe valve
deformity.
• Commissural fusion is an important feature to distinguish rheumatic from degenerative MS.
• Complete fusion of both commissures generally indicates severe MS.
• Lack of commissural fusion does not exclude significant MS.
• In degenerative aetiologies or even rheumatic MS, restenosis after previous
commissurotomy may be related to valve rigidity with persistent commissural opening.

30. • Evaluates leaflet thickening and mobility in long-axis parasternal view.
• Chordal shortening and thickening - PLAX and apical views.
• Increased echo brightness - calcification.
• Impairment of mitral anatomy is expressed in scores combining different components of mitral
apparatus or using an overall assessment of valve anatomy.

31.  Associated lesions
1) LA thrombus
• Quantitation of LA enlargement - Evaluating LA area or volume.
• M-mode lacks accuracy because enlargement does not follow a spherical pattern in most
cases.
• LA spontaneous contrast on TEE - better predictor of the thrombo-embolic risk than LA size.
• TEE has much higher sensitivity than TTE to diagnose LA/LA appendage clot.

32. 2) Associated MR
• Rheumatic MR - Restriction of leaflet motion.
• Post BMV MR - leaflet tearing is frequent.
• Choice of intervention.
• Quantitation should combine semi-quantitative and quantitative measurements.
• Careful for intermediate MR - more than mild MR is a relative contraindication for BMV.
• Analysis of the mechanism of MR is important in patients presenting with moderate-to-severe
MR after BMV.
• Presence of MR does not alter the validity of the quantitation of MS, except for the continuity-
equation valve area.

33. 3) Other valve diseases
• MS  SV  aortic gradient  underestimating AS severity.
• Severe AR  PHT method for assessment of MS is not valid.
• To look for rheumatic involvement of TV.
• More frequently, associated tricuspid disease is functional TR.
• Diameter of the tricuspid annulus >40 mm seems to be more reliable than quantitation of
regurgitation to predict the risk of severe late TR after mitral surgery.

34. GRADING OF MITRAL STENOSIS
• Routine evaluation of MS severity – A combination of measurements of mean gradient
and valve area using planimetry and PHT.
• In case of discrepancy - Planimetry.
• Associated MR should be accurately quantitated, esp. when moderate or severe.
• Intervention - considered when moderate MS ± moderate MR + symptoms.
• Consequences of MS include - quantitation of LA size and estimation of PASP.
• The description of valve anatomy is summarized by an echocardiographic score.

37. • Severity assessment of rheumatic MS should rely mostly on valve area.
• Multiple factors influence other measurements, in particular mean gradient and
systolic pulmonary artery pressure.
• Mean gradient and systolic pulmonary artery pressure  supportive signs.
• Cannot be considered as surrogate markers of MS severity.
• Normal resting values of pulmonary artery pressure may be observed even in severe MS.
• In degenerative MS, mean gradient can be used as a marker of severity given the
limitations of planimetry and PHT.

39. • Multivariate analyses performed in studies reporting a follow-up of at least 10 years
identified valve anatomy as a strong predictive factor of event-free survival.
• Indices of the severity of MS or its haemodynamic consequences immediately after BMV
• Predictors of event-free survival,
• MVA, mean gradient, and left atrial or pulmonary artery pressure.
• Strong predictors of long-term results of BMV
• Degree of MR following BMV,
• Baseline patient characteristics - age, functional class, and cardiac rhythm.

40. IN NUTSHELL
Color Doppler , PISA and Continuity Equation
Candle flame
PISA for quantification
MVA = Mitral volume flow/ Peak velocity of diastolic mitral
flow
Continuity Equation (does not work if AR and MR are both
present)

41. Quantifification of Mitral Stenosis in Atrial Fibrillation
Planimetry Several different measurements
Mean gradients Average 5 cycles with small variation of R-R
intervals close to normal HR
PHT Avoid mitral flow from short diastoles/ average
different cardiac cycles

42. Valvuloplasty
• Indication
• Clinically significant MS (valve area <1.5 cm² or <1.8 cm² in
unusually large patients)
• Results
• Good immediate results (valve area >1.5 cm² with no
regurgitation).
NOTE: PHT method is not reliable immediately after valvuloplasty!

43. Prevalvuloplastic Echo-evaluation
Mobility Subvalvular thickening
Valve thickening Calcification
Calcification of commissures Thrombus
Mitral regurgitation Tricuspid regurgitation

44. Finally, echocardiographic
measurements of valve stenosis
must be interpreted in the
clinical context of the individual
patient.
Thank you