Three-dimensional Versus Two-Dimensional Echocardiographic Assessment of Left Atrial Volume and Deformation in...

Left atrial (LA) volume and function are important for assessing pediatric diastolic dysfunction (DD). Three-dimensional echocardiographic (3DE) LA assessment may overcome limitations and assumptions inherent in two-dimensional echocardiographic (2DE).

We conducted a cross-sectional study of children under 18 years of age with structurally normal hearts, using transthoracic 3DE apical volume datasets. LA volumetric function and phasic deformation analyses were performed using 3DE (GE, EchoPAC 4DLAQ v206, near fully-automated) and 2DE (TomTec, TTA2.51, CPA, manual) was performed by three operators and processing time was collected. Agreement and reproducibility was assessment for each modality.

Fifty patients (median age 12.8 years) were included. Processing time for 3DE was shorter than for 2DE (0.6 vs. 2.7 min, p < 0.001). 3DE and 2DE showed good agreement for maximum LA volume (LAV_max, ICC = 0.79), with 3DE estimates being lower on average by 5.9 mL than 2DE. Agreement for 3DE LA reservoir strain (LAS_r) was weak (ICC = 0.17), with 3DE values lower by an average of 16.6%. Interobserver agreement for 3DE LAV_max was excellent (ICC = 0.94, 95% CI 0.90-0.96) and comparable to 2DE (ICC = 0.86, 95% CI 0.63-0.94, p = 0.16). Intra-observer reliability for LA volume was similar between 2DE to 3DE (p = 0.11-0.85). No meaningful differences were found in inter-/intra-observer reliability for LA strain between modalities.

3DE provides excellent interobserver reproducibility for LA volume assessment and faster processing times compared to 2DE. 3DE and 2DE show good agreement for LA volume. Agreement for LA strain is weak. Further studies are needed to determine which better predicts clinical outcomes.