Changes in left atrial phasic strain and mechanical dispersion: Effects of age and gender.

Abstract

Left atrial (LA) function by two-dimensional (2D) strain is an emerging tool with increasing clinical utility. Age and gender are key modulators of strain parameters; however, the specific time course for LA structural and functional changes is not clearly defined. A total of 147 healthy individuals (20-69years) underwent transthoracic echocardiography; subjects were evaluated by age (decade) and gender. LA and left ventricular (LV) volumetric and strain measurements were performed. Left atrial reservoir (ƐR) and conduit strain (ƐCD) with negatively correlated with age (r=-.36; r=-.56; P<.001, respectively) being significantly lower by the 6th and 5th decades, respectively. Contractile strain (ƐCT) positively correlated with age (r=.36; P<.001), being significantly higher by the 6th decade. ƐR and ƐCD were higher in young females (20-34years) compared to young males (P=.033 and P<.001, respectively). ƐCT was significantly higher in middle-aged adult males (35-50yrs; P=.010), though seen later in females (≥51years; P=.005). Standard deviation of time to positive strain (SD-TPS) significantly higher by the 5th decade and correlated with age in both males (r=.44; P<.001) and females (r=.40; P=.001). We demonstrate that ƐR and ƐCD are lower with age, with differing rates between males and females. As a compensatory mechanism for decline in ƐCD, ƐCT is higher, more notably in males; comparatively, females display a more prominent decline in ƐR and ƐCD with age. Alteration in electromechanical properties occurred in both genders with SD-TPS becoming higher with age.