Normal reference values and determinants of right heart strain derived from speckle tracking echocardiography: a...

Normal ranges for speckle tracking echocardiography (STE)-derived right atrial (RA) and right ventricular (RV) strain indices have not yet been fully standardized. This study aimed to quantitatively summarize available evidence regarding normal RV and RA deformation parameters in healthy adults and to investigate factors contributing to measurement variability.

PubMed, Embase, and Web of Science were systematically searched for studies published until July 1, 2025 that reported STE-derived right-heart strain and strain-rate measurements in healthy adults. A random-effects model was applied to generate pooled estimates for RV global longitudinal strain (RV-GLS), RV peak systolic and diastolic longitudinal strain rates (RV-PSSRL and RV-PDSRL), RA reservoir, conduit, and booster strain (RA-εs, RA-εe, and RA-εa), as well as RA peak positive, early negative, and late negative strain rates (RA-SRs, RA-SRe, and RA-SRa). Subgroup and meta-regression analyses assessed the effects of race, sex, age, feature tracking (FT) software, STE vendor and STE imaging mode [two-dimensional (2D)-and three-dimensional (3D)-STE]. Heterogeneity was assessed using the I² statistic, and publication bias was examined by Egger regression analysis.

The pooled means for RV-GLS, RV-PSSRL, and RV-PDSRL were -25.62%, -1.50 s^-1, and 1.69 s^-1, respectively. RA-εs, RA-εe, and RA-εa were 42.95%, 20.86%, and 19.30%, respectively; while RA-SRs, RA-SRe, and RA-SRa were 2.03 s^-1, -2.14 s^-1, and -1.80 s^-1, respectively. Variability in right-heart deformation measurements was significantly associated with race, sex, age, FT software, and STE imaging mode (all P<0.05), whereas the influence of STE vendor was generally limited (most P>0.05).

This study established pooled reference values for STE-derived RV and RA strain and strain-rate parameters in healthy adult populations. STE demonstrates strong potential as a practical and reliable technique for the quantitative assessment of right heart function in routine clinical practice.