Normal reference intervals for left atrial volume and cardiac dimensions according to age and sex assessed by two...

Left atrial volume (LAV) is a recognized prognostic marker of cardiovascular events. However, normal LAV thresholds on cardiac computed tomography angiography (CCTA) remain poorly defined, and the optimal assessment method is unclear. Our aim was to determine normal reference values of maximal systolic LAV (LAVmax) and ventricular dimensions normalized by age, sex, and body surface area (BSA) from CCTA by using dedicated semi-automated analysis software.

This single-centre retrospective study included 250 healthy subjects with no cardiac history or significant CCTA abnormalities, stratified by sex and age. LAVmax was measured using both 3D and area-length methods, and all other cardiac chambers were analysed with dedicated 3D semi-automated software (Vitrea^®). LAVmax increased significantly with age in both sexes but showed no sex difference when indexed to BSA. The 3D volumetric method was more reproducible (r = 0.86, P < 0.001) and yielded larger values compared with area-length method. Reference values for LAVmax and all cardiac chambers were provided for both sexes and each age group. Age, in concert with sex, was associated with significant differences in RV end-diastolic volume and LV ejection fraction (P-values 0.027 and 0.03).

Indexed LAVmax was not significantly different across sexes but increased with age. LAVmax can be reliably reported from CCTA datasets, with 3D volumetric method providing the largest and most reproducible values. Normal values for all cardiac chambers according to age categories and sex were also provided. These normative values enhance the clinical utility of routine CCTA beyond coronary imaging.