From the Guidelines
To assess mitral stenosis with transthoracic echocardiography (TTE), follow these steps, prioritizing the most recent and highest quality evidence from the 2022 European Heart Journal study 1.
Steps to Assess Mitral Stenosis with TTE
- Obtain standard views including parasternal long-axis, short-axis, apical four-chamber, and apical two-chamber views to visualize the mitral valve anatomy, as recommended by the American College of Cardiology/American Heart Association (ACC/AHA) 1.
- Evaluate valve morphology by assessing leaflet thickening, calcification, mobility, and commissural fusion, which is crucial for determining the severity of mitral stenosis and guiding management decisions 1.
- Measure the mitral valve area using planimetry in the parasternal short-axis view at the tips of the leaflets, considered the reference standard, and calculate the mitral valve area using the pressure half-time method by measuring the deceleration time of the mitral inflow E-wave on continuous-wave Doppler, as suggested by the European Society of Cardiology (ESC) 1.
- Assess the mean transmitral gradient using continuous-wave Doppler across the mitral valve from the apical four-chamber view, and estimate pulmonary artery systolic pressure by measuring the tricuspid regurgitation velocity and adding the estimated right atrial pressure, which is essential for evaluating the severity of mitral stenosis and its impact on pulmonary circulation 1.
- Evaluate for left atrial enlargement and any associated valvular lesions, and assess for complications such as atrial fibrillation, left atrial thrombus, or pulmonary hypertension, as recommended by the Australian Guideline (RHD Australia) 1.
Additional Considerations
- Consider using 3D TTE/TOE for greater accuracy of measurement of mitral valve area, especially when there is discrepancy between clinical symptoms and severity of MS by echocardiography, as suggested by the Japanese guidelines (JCS/JSCS/JATS/JSVS) 1.
- Use exercise stress echocardiography to obtain detailed information on mitral anatomy before intervention and to determine appropriateness for valve repair over replacement, as recommended by the ACC/AHA 1.
- Perform cardiac catheterization or exercise testing with Doppler measurements to assess changes in mitral gradient and PASP, and to support decision on timing of intervention, as suggested by the ESC 1.
From the Research
Assessment of Mitral Stenosis with TTE
To assess mitral stenosis using Transthoracic Echocardiography (TTE), several steps can be followed:
- 2D Echocardiography: This method is used to visualize the mitral valve and assess its morphology 2.
- Planimetry of the Mitral Valve Area: This technique allows for a reliable assessment of the degree of stenosis in 75% of all patients 3.
- Doppler Echocardiography: This method measures the transmitral pressure gradient and determines pressure half-time, from which the mitral valve area can be calculated 3, 4.
- Assessment of Associated Regurgitations and Pulmonary Hypertension: Doppler echocardiography can detect accompanying disorders such as mitral and aortic regurgitation or aortic stenosis, as well as subsequent disorders like pulmonary hypertension or relative tricuspid incompetence 3, 4.
- 3D Echocardiography: This technique can provide a more accurate assessment of the mitral valve area, especially in patients with poor echocardiographic windows or for teams less accustomed to evaluating mitral stenosis patients 5, 6.
Key Parameters to Assess
Some key parameters to assess when evaluating mitral stenosis with TTE include:
- Mitral valve area (MVA)
- Transmitral pressure gradient
- Pressure half-time
- Presence of associated regurgitations or pulmonary hypertension
- Left atrial volume
Limitations and Considerations
It is essential to note that the transmitral pressure gradient can undergo considerable day-to-day variations, limiting its value for quantification 3. Additionally, echocardiography may underestimate left atrial volume compared to cardiac magnetic resonance (CMR) imaging 5.