From the Guidelines
Right ventricular (RV) strain on echocardiography is best evaluated by assessing RV systolic function using measures like tricuspid annular plane systolic excursion (TAPSE), RV fractional area change (FAC), and RV longitudinal strain, with abnormal values indicating dysfunction, as recommended by the European Association of Cardiovascular Imaging in 2017 1. To evaluate RV strain, several key parameters should be assessed, including:
- RV dilation, where the RV appears enlarged compared to the left ventricle (LV)
- RV systolic function using measures like TAPSE, with values below 17mm suggesting dysfunction, as indicated in the 2017 expert consensus document 1
- RV fractional area change (FAC) less than 35-40%, as recommended in the 2017 European Heart Journal article 1
- RV longitudinal strain of the lateral RV free wall, with values worse than -23% indicating abnormality, as specified in the 2017 European Heart Journal article 1
- Interventricular septal flattening or "D-shaped" left ventricle, especially during systole, indicating pressure overload
- Elevated pulmonary artery systolic pressure (PASP), estimated from tricuspid regurgitation velocity plus right atrial pressure, with values above 35-40 mmHg suggesting pulmonary hypertension
- Right atrial enlargement and inferior vena cava dilation with reduced respiratory variation further support the diagnosis These findings reflect the RV's response to increased afterload, which causes chamber dilation, reduced contractility, and altered geometry as the right heart struggles against elevated pulmonary pressures or increased volume load, as discussed in the 2012 European Heart Journal article on 3D echocardiography 1. In laboratories with proper experience, 3D RV volumes and RV ejection fraction (EF) can be promoted in patients with good acoustic windows, especially when standard indices of longitudinal RV function are globally reduced and no longer representative of overall RV performance, as recommended in the 2017 European Heart Journal article 1.
From the Research
Evaluating Right Ventricular Strain on Echocardiography
To evaluate right ventricular (RV) strain on echocardiography, several methods can be employed, including:
- Measurement of tricuspid annular systolic plane excursion and RV tissue Doppler velocity 2
- Two-dimensional RV free wall longitudinal systolic strain (RVFWS) using speckle-tracking echocardiography, which has emerged as a reproducible, feasible, and highly prognostic technique for quantifying RV function 2, 3, 4
- Assessment of right atrial (RA) function, which complements RV assessment in tricuspid regurgitation (TR) 4, 5
Echocardiographic Findings of Right Ventricular Strain
Echocardiographic findings of right ventricular strain that may suggest pulmonary embolism include:
- Increased right ventricle: left ventricle size ratio
- Abnormal septal motion
- McConnell's sign
- Tricuspid regurgitation
- Elevated pulmonary artery systolic pressure
- Decreased tricuspid annular plane systolic excursion
- Decreased S'
- Pulmonary artery mid-systolic notching
- 60/60 sign
- Speckle tracking demonstrating decreased right ventricular free wall strain 6
Prognostic Value of Right Ventricular Strain
The prognostic value of right ventricular strain depends on the severity of tricuspid regurgitation, with preserved RA and RV strain associated with better clinical outcomes 5. RV strain parameters, such as RV free wall longitudinal strain (RVFWLS), have been shown to be independently associated with mortality and heart failure 3. The combination of RA and RV strain can stratify patients' risk, reflecting a broader effect of TR on right heart chambers 4.