CONCLUSION
Creating reliable reference values for LA S/SR is challenging, and the present results confirm good intrastudy reproducibility, with mean values in the upper range of previous meta-analyses. In the near future, automated border detection algorithms may be required to generate highly reproducible normal values. Furthermore, our study showed atrial S/SR as an additional indicator of elevated NT-proBNP levels in the general population, demonstrating the incremental value of both ATS and PACS in addition to conventional and ventricular strain echocardiography. Thus, the LA S/SR may be regarded as an important addition to the multiparametric approach used for evaluating LV filling.