LAUSR

Background Accurate evaluation of right ventricular (RV) function is always difficult due to its irregular shape and movement. Many indices have been proposed to assess RV function, but none have been universally accepted. This study evaluated RV function in type 2 diabetes mellitus (T2DM) patients using long-axis strain (LAS) and other traditional indices. Methods Fifty-seven patients with T2DM and 39 healthy controls were prospectively enrolled. Four-chamber cardiovascular magnetic resonance (CMR) and RV short-axis cine images were obtained from all participants to measure the tricuspid annular plane systolic excursion (TAPSE), RV ejection fraction (EF), peak longitudinal strain (PLS) and four LAS indices. The inter-and intraobserver variabilities were also calculated. Results Compared with healthy controls, T2DM was associated with a decreased LAS (apex/lateral wall) (-17.4%±4.2% vs. control, -19.7%±3.7%, P=0.008) and LAS (apex/middle point) (-17.5%±4.5% vs. control, -19.5%±3.9%, P=0.026), but both groups had a similar LAS (RV/lateral wall) and LAS (RV/middle point) (all P>0.05). After adjustments for age and body mass index, a significant difference was observed only for LAS (apex/lateral wall) (P=0.028). There were no significant differences in the TAPSE, RVEF and PLS (all P>0.05). LAS (apex/lateral wall) correlated with the TAPSE (r=-0.723, P<0.001), RVEF (r=-0.270, P=0.008) and PLS (r=0.210, P=0.040). The inter- and intraobserver variability of the LAS (apex/lateral wall) were lower than the other three LAS indices. Conclusions Compared with traditional RV function indices, such as the TAPSE, RVEF and PLS, LAS is easy to obtain and shows high repeatability. LAS (apex/lateral wall) may provide a more sensitive T2DM-related RV dysfunction index.