The importance of the right ventricle in cardiovascular physiology has been underestimated for decades. Previously considered a mere conduit, the right ventricle is currently known to play a major role in maintaining global cardiac function intact. In parallel, right ventricular (RV) systolic function has been shown to be an essential determinant of clinical outcomes in several scenarios, and should thus be considered in the individualized management of patients. The need to diagnose RV dysfunction is evident. Because of its wide availability, echocardiography is the most frequently used imaging test in clinical practice to assess RV size and function. That assessment can be hindered by the complex RV anatomy; thus, important international societies of cardiovascular imaging have recommended the routine and systematic addition of several echocardiographic measurements and techniques., That approach includes conventional parameters, such as RV basal diameter (normal ≤ 41 mm) and tricuspid annular plane systolic excursion (TAPSE – normal ≥ 17 mm), as well as advanced parameters, such as the s wave of the RV free wall on tissue Doppler (normal ≥ 9.5 cm/s), ejection fraction on 3D echocardiography (normal ≥ 45%) and longitudinal strain of the RV free wall (normal ≥ -20%).
In this scenario, strain (systolic shortening percentage) and strain rate (shortening rate), calculated by speckle tracking on two-dimensional echocardiography (2D speckle tracking or 2D-STE), emerge as alternatives in the RV systolic function analysis. The longitudinal strain of the RV free wall, excluding the ventricular septum, showed prognostic value in patients with signs and symptoms of cardiopulmonary disease, such as heart failure, myocardial infarction, pulmonary hypertension, congenital heart diseases, RV arrhythmogenic cardiomyopathy and amyloidosis. Right ventricular longitudinal strain is a parameter less dependent on the angle, with less intra- and interobserver variability, that can apparently detect early RV dysfunction. Its drawbacks include the high dependence on image quality and the variability of the software of the equipment available in the market. Recently an international consensus has been reached to standardize the use of 2D-STE to obtain RV strain. The specific use of right-ventricle-focused apical 4-chamber view is recommended for correct strain measurement. Extreme care should be taken to define the region of interest (ROI) of the endocardial border (suggested ROI: 5 mm), because of the RV shape and thin walls. The pericardium should be excluded from the analysis, because of the risk of strain underestimation.
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