From the Guidelines
To assess mitral stenosis with transthoracic echocardiography (TTE) according to ASE guidelines, the key steps include obtaining 2D imaging to evaluate valve morphology, measuring the mitral valve area using planimetry, calculating the mean transmitral gradient, and assessing for pulmonary hypertension and left atrial size. The assessment of mitral stenosis with TTE involves several critical components, as outlined in the 2014 AHA/ACC guideline for the management of patients with valvular heart disease 1.
Key Steps in Assessment
- Obtain 2D imaging from the parasternal long-axis window to identify the characteristic diastolic doming of the mitral valve, and from the short-axis view to demonstrate commissural fusion and allow planimetry of the mitral orifice, as this provides direct visualization of the valve's morphology and function 1.
- Measure the mitral valve area using planimetry in the parasternal short-axis view, ensuring to capture the smallest orifice in space and the largest opening in time, which is crucial for accurately assessing the severity of stenosis 1.
- Calculate the mean transmitral gradient using continuous-wave Doppler, which should be averaged from 3 to 5 beats in sinus rhythm and 5 to 10 beats in atrial fibrillation, taking into account the impact of heart rate on transvalvular gradient 1.
- Assess for pulmonary hypertension by measuring the tricuspid regurgitation velocity and estimating pulmonary artery systolic pressure, as this reflects the hemodynamic consequences of mitral stenosis on the right heart 1.
- Evaluate left atrial size, including dimension, area, and volume index, with careful interrogation for possible left atrial thrombus, which is essential for understanding the chronic effects of mitral stenosis and planning management 1.
Additional Considerations
- The use of 3D echocardiography may offer greater accuracy in certain cases but is not yet routine 1.
- The mitral pressure half-time method can be used as an alternative for calculating the mitral valve area, but it is affected by left atrial and LV compliance, making other methods like the continuity method and proximal isovelocity surface area method valuable alternatives 1.
- Integration of all these measurements is crucial for accurately diagnosing the severity of mitral stenosis and guiding management decisions, with severity classified as mild, moderate, or severe based on the valve area and hemodynamic parameters 1.
From the Research
Assessment of Mitral Stenosis with TTE
According to the American Society of Echocardiography (ASE) guidelines, the following steps can be used to assess mitral stenosis with Transthoracic Echocardiography (TTE):
- Evaluate the mitral valve morphology using 2D echocardiography to assess for signs of rheumatic disease, such as leaflet thickening and calcification 2
- Measure the mitral valve area using the pressure half-time method or planimetry to assess the severity of mitral stenosis
- Assess the presence and severity of mitral regurgitation using color Doppler echocardiography
- Evaluate left atrial size and function to assess the hemodynamic consequences of mitral stenosis
- Assess for the presence of atrial fibrillation, which is a common complication of mitral stenosis 3, 4
Additional Considerations
- The use of 3D echocardiography may provide additional information on mitral valve morphology and function 2
- The assessment of mitral stenosis with TTE should be performed in accordance with ASE guidelines and recommendations
- The management of patients with mitral stenosis should be individualized based on the severity of the disease, the presence of symptoms, and the presence of complications such as atrial fibrillation 3, 4, 5