From the Guidelines
The assessment of right heart disease with transthoracic echocardiography (TTE) according to ASE guidelines involves a systematic approach beginning with evaluation of right ventricular (RV) size and systolic function, as well as estimation of pulmonary artery systolic pressure using the tricuspid regurgitation velocity plus estimated right atrial pressure, as outlined in the 2017 ACR appropriateness criteria for suspected pulmonary hypertension 1.
Key Components of TTE Assessment
- Evaluation of RV size using multiple views, including apical 4-chamber, RV-focused views, and parasternal views, with chamber dimensions measured at end-diastole 1.
- Assessment of RV systolic function using parameters such as tricuspid annular plane systolic excursion (TAPSE), RV fractional area change, S' velocity by tissue Doppler, and RV free wall strain, as these are critical for determining RV function 1.
- Estimation of pulmonary artery systolic pressure using the tricuspid regurgitation velocity plus estimated right atrial pressure, with normal values <35-40 mmHg, as this is a key indicator of pulmonary hypertension 1.
- Evaluation of right atrial size by volume measurement, with normal values <30 mL/m², as well as assessment of RV wall thickness and interventricular septal motion for signs of RV pressure or volume overload 1.
- Additional parameters such as inferior vena cava size and collapsibility, tricuspid valve morphology and function, and pulmonary valve assessment should also be evaluated to provide a comprehensive understanding of right heart function 1.
Importance of TTE in Right Heart Disease Assessment
TTE is a crucial diagnostic tool for assessing right heart disease, including pulmonary hypertension, RV dysfunction, and congenital abnormalities, as it provides a non-invasive and relatively low-cost means of evaluating cardiac anatomy and function 1. The use of TTE in conjunction with other diagnostic modalities, such as right heart catheterization (RHC), can help to confirm the diagnosis and guide treatment decisions 1. The 2017 ACR appropriateness criteria for suspected pulmonary hypertension recommend the use of TTE as the initial diagnostic test for patients with suspected pulmonary hypertension, due to its high sensitivity and specificity for detecting moderate to severe pulmonary hypertension 1.
From the Research
Steps to Assess Right Heart Disease with TTE
According to the ASE guidelines, the following steps are recommended to assess right heart disease with TTE:
- Evaluate right ventricular size and function using 2D and 3D echocardiography 2
- Assess right atrial size and function, as well as tricuspid valve function 3
- Measure right ventricular longitudinal strain, RV end-systolic dimensions, and right atrial size and function to evaluate right heart function 4
- Use a multi-parametric approach, including venous excess imaging (VExUS), to evaluate the systemic consequences of right heart failure 4
- Consider the use of artificial intelligence (AI) and point-of-care ultrasound to improve the accuracy and efficiency of right heart evaluation 4
Key Parameters to Evaluate
The following parameters should be evaluated when assessing right heart disease with TTE:
- Right ventricular dimensions and function, including longitudinal strain and end-systolic dimensions 2, 4
- Right atrial size and function, including pressure and volume 3, 4
- Tricuspid valve function, including regurgitation and stenosis 3
- Pulmonary artery pressure and flow, including mean pulmonary arterial pressure and pulmonary vascular resistance 2
Imaging Techniques
The following imaging techniques can be used to assess right heart disease with TTE:
- 2D echocardiography, including parasternal and apical views 2, 3
- 3D echocardiography, including full-volume and zoom modes 2, 3
- Speckle tracking imaging, including longitudinal and radial strain analysis 3, 4
- Artificial intelligence (AI) algorithms, including segmentation- and non-segmentation-based quantification 4