Age- and sex-based normal values of layer-specific longitudinal and circumferential strain by speckle tracking echocardiography: the Copenhagen City Heart Study

AIMS: Technical advancements in 2D-speckle tracking echocardiography (2DSTE) have allowed for quantification of layer-specific global longitudinal strain (GLS) and circumferential strain (GCS) of the left ventricle (LV). The aim of this study was to establish age- and sex-based reference ranges of peak systolic layer-specific GLS and GCS and to assess normal values of regional strain. METHODS AND RESULTS: We performed 2DSTE analysis of 1997 members of the general population from the fifth round of the Copenhagen City Heart Study, who were free of cardiovascular disease and risk factors. The mean age was 46 ± 16 years (range 21-97) and 62% were female. Mean values for peak systolic whole wall GLS (GLSWW.Sys), endomycardial (GLSEndo.Sys), and epimyocardial (GLSEpi.Sys) were 19.9 ± 2.1% (prediction interval [PI]: 15.8-24.0%), 23.5 ± 2.5% (PI: 18.6-28.4%), and 17.3 ± 1.9% (PI: 13.6-21.1%), respectively. Mean peak systolic whole wall GCS (GCSWW.Sys), was 21.6 ± 3.7% (PI: 14.3-28.9%), endomyocardial (GCSEndo.Sys) was 31.9 ± 4.7% (PI: 22.7-41.1%), and epimyocardial (GCSEpi.Sys) was 14.3 ± 3.8% (PI: 6.8-21.8%). A significant discrepancy in normal strain values between males and females was observed. Men had lower mean values and lower reference limits for all strain parameters. Furthermore, GLS and GCS changed differently with age in males and females. Finally, regional LS decreased from the apical to the basal LV region in both sexes, and regional CS varied significantly by LV segment. CONCLUSION: In this study, we reported age- and sex-based reference ranges of layer-specific GLS and GCS. These reference ranges varied significantly with sex and age.