In-depth echocardiographic analysis of left atrial function in healthy adults using speckle tracking echocardiography...

Left atrial (LA) dilatation is predictive for complications in a multitude of cardiac diseases; therefore, adequate assessment is essential. Technological advances have made it possible to quantify LA function with Speckle Tracking Echocardiography (STE); however, there are currently no recommendations for normal values with regard to LA function. We aimed to assess LA myocardial and volumetric function in a healthy cohort and investigate correlations with baseline characteristics.

This prospective cohort study included 147 (aged 20-72) healthy individuals and assessed LA volumetric function using maximum, minimum and pre-a-wave volumes and myocardial function using reservoir function using peak strain in LA relaxation (LA-strain), conduit function using peak strain rate in early LA contraction (LA-SRe) and pump function using peak strain rate in late LA contraction (LA-SRa).

Mean LA-strain was 39.7 ± 6.2%, LA-SRe -2.78 ± 0.62 s^-1 and LA-SRa -2.56 ± 0.62 s^-1 . Subjects were divided into 5 age decades (each 50% female). LA-strain and LA-SRe were lower in the oldest groups, whereas LA-SRa was higher. LA-SRa was higher in males(-2.69 ± 0.68 s^-1 vs -2.42 ± 0.52 s^-1 ). Age-specific values are provided. Age proved to be an independent predictor for LA-SRa after correction for blood pressure and heart rate. LA expansion index and passive emptying fraction decreased with age, while active emptying fraction increased with age. LA maximum volume did not increase with age.

This study provides normal values for the three phasic functions of the LA, assessed with STE and volumetric function. Our results suggest the need for age-specific reference ranges, and normal values for this cohort have been calculated.