RIGHT ATRIAL STRAIN IN A NORMAL ADULT AFRICAN POPULATION AND ITS CORRELATION WITH AGE

Background The right atrial longitudinal strain (RALS) has been shown to be a useful parameter to define right atrial (RA) subclinical dysfunction in several cardiovascular disorders prior to changes in traditional RA two dimensional and volumetric parameters. There is a scarcity of data regarding normal values for RALS in a normal African population. Objectives We sought to establish normal values for RALS and its correlation with age, in a Sub-Saharan black African population. Methods This was a retrospective cross-sectional study of 100 normal individuals (recruited as controls for another study) performed at Chris Hani Baragwanath Hospital (2017-2019). All echocardiographic measurements were done as per standard guidelines. RALS was measured using Philips QLAB 9 (Amsterdam, The Netherlands) speckle-tracking software. Results Median age was 37.5 years (IQR 26- 46, 60% females). The mean right atrial volume indexed to body surface area (RAVI) was 19.5 ± 5.7 mL/m 2 and the mean RALS was 32.7 ± 10.5%. There was a trend towards decreasing RALS with age (r=-0.15, P=0.129) with no change in RAVI with age ( P=0.27). Males had a tendency towards higher RAVI and RALS measurements compared to females (20.8 ± 6.3 mL/m 2 and 18.7 ± 5.2 mL/m 2 , P=0.07: 34.6 ± 9.6% and 31.4 ± 10.9 %, P=0.141, respectively) . BMI was an independent predictor of RALS on multivariate analysis ( r= -0.43, P =0.003) Conclusion We have defined the normal reference values for RALS in a black population. RALS tended to decrease with age prior to change in RAVI and can serve as a marker of subclinical RA dysfunction . BMI was an important determinant of RALS.