Left Atrial Volumes and Phasic Function in Healthy Children: Reference Values Using Real-Time Three-Dimensional Echocardiography

Evaluation of left atrial (LA) size and function is important in congenital and acquired pediatric cardiac disease. Real-time three-dimensional echocardiography (3DE) offers noninvasive assessment of cardiac volumes and phasic function independent of geometric assumptions. The aim of this prospective multicenter study was to establish pediatric reference values for LA 3DE volumes and phasic function based on a large cohort of healthy children. LA data sets of 432 subjects (0 days-222 months) were analyzed prospectively using a vendor-independent software. LA volumes (maximal [Vmax], minimal [Vmin], and before atrial contraction) as well as phasic function (active and passive emptying fraction [EF]) were assessed. For volumes, sex-specific reference values, percentiles, and z-scores were calculated by the LMS method of Cole and Green. Absolute volumes increased with age and body surface area. Active EF and relative duration of atrial emptying tended to increase with increasing R-R intervals, while passive EF decreased. Reproducibility of volumes was very good (intra- and interobserver variability for Vmax and Vmin (mean bias ± SD, 0.1 ± 0.9 mL and 0.7 ± 2.8 mL). Volumes were well correlated with cardiac magnetic resonance measurements showing known underestimation of volumes by 3DE (mean bias ± SD, Vmax –14.2 ± 14 mL; Vmin –11.5 ± 10 mL). Pediatric LA volumes and phasic function indices were reproducibly measured by 3DE. The provided pediatric reference values can be the basis for evaluation of the LA by 3DE and contribute to detection of LA dysfunction and follow-up of patients with congenital heart diseases. [Display omitted] •3D Echocardiographic pediatric percentiles for left atrial volumes are presented.•The percentiles are sex specific and based on a large cohort of 432 subjects.•3D Echocardiographic reference values for left atrial phasic function are provided.•Data for the calculation of z-scores are provided.