Right ventricular (RV) function is a strong predictor of mortality in pulmonary hypertension (PH), but two-dimensional (2D) echocardiography–derived assessments of RV function that could aid in risk assessment and management of patients with PH are of limited utility. RV longitudinal peak systolic strain (RVLS) derived from 2D speckle-tracking echocardiography is a relatively novel method for quantifying RV function but typically is derived from a single apical four-chamber view of the right ventricle and may have inherent limitations. The objective of this study was to determine the utility of regional and global RVLS calculated from multiple views of the right ventricle to comprehensively assess RV function in a cohort of patients with PH.
Regional and global RVLS were obtained from multiple views of the right ventricle (centered on the right ventricle–focused apical position) in 40 patients with PH, defined as a mean pulmonary artery pressure ≥ 25 mm Hg, most of whom also had pulmonary capillary wedge pressures ≤ 15 mm Hg and were thus defined as having pulmonary arterial hypertension. This was compared with other 2D echocardiography–derived parameters of RV function and functional parameters.
Global RVLS calculated from multiple views had a superior correlation with 6-min walk distance compared with other parameters of RV function, including tricuspid annular plane systolic excursion, RV myocardial performance index, and fractional area change. Although global RVLS calculated from multiple views displayed a similar correlation with 6-min walk distance as global RVLS calculated from a single four-chamber view, analysis of regional strains provided by multiple views identified distinct patterns of RV dysfunction, consisting of global, free wall, or septal dysfunction, that were associated with specific clinical characteristics.
Global RVLS derived from multiple right ventricle–focused views yields a comprehensive quantitative assessment of regional and global RV function that correlates moderately with functional parameters and may be useful in the assessment of PH. Distinct patterns of regional RV dysfunction are associated with different clinical characteristics.
Pulmonary arterial hypertension (PAH), a subset of pulmonary hypertension (PH), is a disease of the pulmonary vasculature that leads to right ventricular (RV) dysfunction and failure. RV function is of critical importance in the prognosis of PAH. Hemodynamic parameters, including right atrial pressure and cardiac index, both reflecting RV function, and pro–brain natriuretic peptide, associated with right heart failure, are all important prognostic biomarkers. Patients with PAH are routinely followed using echocardiography, but the conventional two-dimensional (2D) echocardiographic assessment of the right ventricle does not include a clear quantitative assessment of function but rather a quantification of RV dimensions and a qualitative assessment of contractility. This is due both to the complex geometry of the right ventricle and a poor understanding of its mechanical functioning compared with that of the left ventricle. Quantitative assessments of RV function would aid in clinical decision making, as echocardiographic assessments of RV function are routinely used to guide the level of aggressiveness of PAH therapy.
To this end, a number of 2D echocardiography–derived parameters for RV functional assessment, such as tricuspid annular plane systolic excursion (TAPSE), RV fractional area change (FAC), and RV myocardial performance index (MPI), have been proposed, but all have inherent strengths and weaknesses ( Figure 1 ). RV longitudinal peak systolic strain (RVLS) is a relatively novel approach for quantifying RV function and, when calculated using 2D speckle-tracking echocardiography, is angle independent and yields a quantitative assessment of RV systolic function. Moreover, recent studies have demonstrated relationships between RVLS and outcomes and response to therapy in patients with PAH. However, a continued limitation of RVLS from a single RV view is that it does not yield a truly “global” view of RV function. Recently, an approach for a global assessment of RV function has been developed that uses 3 right ventricle–focused views analogous to their apical views of the left ventricle, to allow a full reconstruction of the right ventricle in an 18-segment or a 17-segment model ( Figure 2 ) with a calculation of a true “global RVLS.” In this work, we compared global RVLS between normal controls and patients with PH, correlated global RVLS with other parameters of RV function (including TAPSE, MPI, and FAC) and with functional status as assessed by 6-min walk distance (6MWD), and identified patterns of regional RV dysfunction in patients with PH.