Three-Dimensional Echocardiographic Evaluation of Longitudinal and Non-Longitudinal Components of Right Ventricular Contraction Results from the World Alliance of Societies of Echocardiography Study

Abstract

Background: Right ventricular (RV) functional assessment is mainly limited to its longitudinal component. However, due to the complex orientation of the myofibers, the RV contraction involves coordinated motion along multiple planes. Recently developed 3-dimensional echocardiography (3DE) software has enabled the separate assessment of the non-longitudinal components of RV systolic function and their relative contribution to RV performance. The aims of this study were 1) to establish normal values for 3D-derived longitudinal, radial, and anteroposterior RV ejection fraction (LEF, REF, AEF respectively) and their relative contributions to global RVEF, 2) to calculate 3D RV strain normal values and, 3) to determine sex, age and race related differences in these parameters in a large group of normal subjects (WASE study) Methods: 1043 healthy adult subjects prospectively enrolled at 17 centers in 15 countries were used in this study. 3DE RV wide-angle datasets were analyzed to generate a 3D mesh model of the RV cavity (TomTec). Then, dedicated software (ReVISION) was used to analyze RV motion along the three main anatomical planes and the ejection fraction (EF) values corresponding to each plane were identified as LEF, REF, and AEF. Relative contributions were determined by dividing each EF component by the global RVEF. RV strain analysis included longitudinal, circumferential, and global area strains (GLS, GCS and GAS, respectively). Results were categorized by sex, age (18-40, 41-65 and >65 years), and race. Results: Absolute REF, AEF, LEF and global RVEF were higher in women than in men (p < .001). With aging, both sexes exhibited a decline in all the determinants of longitudinal shortening (p < .001). In elderly women, the lower global RVEF was partially compensated by an increase in radial shortening. Both Black men and women showed lower RVEF, and GAS values compared to White and Asian subjects of the same sex (p < .001). Black men showed significantly higher REF/RVEF and lower LEF/RVEF compared to Asian and White men. These differences in RV contraction patterns across races were not present in women. Conclusion: 3DE evaluation of the non-longitudinal components of RV contraction provides additional information regarding RV physiology, including sex, age and race - related differences in RV contraction patterns that may prove useful in disease states involving the RV.