Abstract 12606: Meta-analysis of the Normal Ranges of Right Ventricular Strains by Echocardiography in Healthy Adults

Background: Right ventricular (RV) systolic strain has been increasingly shown to be prognostic in some cardiovascular diseases. Despite this, the reference range including the lower limit of normal (LLN) and factors associated with RV strain measurements are not well-established. This meta-analysis aimed to determine the means and LLNs of two- (2D) and three-dimensional (3D) right ventricular global (RVGLS), free wall (RVFWLS) and septal wall (RVSWLS) longitudinal strains in healthy individuals and factors affecting strain measurements. Methods: Pubmed, Embase and Cochrane databases were searched until 31 December 2019 for eligible studies reporting RVGLS, RVFWLS and/or RVSWLS in at least 30 healthy subjects. We pooled the means and LLNs of RV strains by two- (2D) and three- (3D) dimensional echocardiography, and performed meta-regression analyses. Results: From 591 articles screened, 37 eligible studies totaling 2970 subjects were analyzed. Pooled means and LLNs (95% confidence intervals) for 2D- strains were RVGLS -23.3% (-24.3%, -22.3%) and -16.2% (-17.2%, -15.1%) in 22 studies; RVFWLS -27.2% (-28.5%, -25.9%) and 18.5% (-20.0%, -17.1%) in 23 studies; RVSWLS -20.4% (-22.0%, -18.9%) and -11.5% (-13.6%, -9.6%) in 10 studies; and similar results for 3D- RV strains (Table). Right ventricular fractional area change and vendor software were associated with 2D-RVGLS and RVFWLS means and LLNs. Conclusion: We reported the pooled means and LLNs of RV systolic strains in healthy subjects, to define thresholds for abnormal, borderline and normal strains. Important factors associated with RV systolic strains include right ventricular fractional area change and vendor software.