Normal reference values of left ventricular strain using three-dimensional speckle tracking echocardiography: results from a multicentre study

AIMS: Three-dimensional (3D) speckle tracking echocardiography (3DSTE) has been shown to be an accurate and reliable clinical tool for the evaluation of global and regional left ventricular (LV) function through strain analysis, but the absence of normal values has precluded its widespread use in clinical practice. The aim of this prospective multicentre study was to establish normal reference values of LV strain parameters using 3DSTE in a large healthy population. METHODS AND RESULTS: A total of 303 healthy subjects (156 males 51%, between 18 and 82 years of age, ejection fraction EF 61 ± 3%), stratified to provide approximately equal proportions of healthy subjects of 18-30, 31-40, 41-50, 51-60, and >60 years of age, underwent 3DSTE. Data were analysed for LV volumes, EF, mass, and global and regional circumferential, longitudinal, radial, and area strain. Significant but small differences between men and women were found for longitudinal and area strains, as well as between different age groups for all LV strain parameters. However, large differences in normal values were observed between different segments, walls, and levels of the LV for radial and longitudinal strains, whereas circumferential and area strains demonstrated generally consistent normal ranges across the LV. CONCLUSIONS: Normal ranges of global and regional LV strain using 3DSTE have been established for clinical use. Differences in the magnitude of LV strain are present between men and women as well as different age groups. Moreover, there are differences between different segments, walls, and levels as part of the functional non-uniformity of the normal LV that necessitates the use of segment-specific normal ranges for radial and longitudinal strains. Circumferential and area strains demonstrate the most consistent normal ranges overall.