An allometric model using LAV/BSA^1.48 for children with BSA≤1 m² and LAV/BSA^1.08 for BSA>1 m² accurately normalizes left atrial volume, unlike standard BSA indexing (r=0.52, P<0.0001).
Cross-Sectional (n=300)
Does an allometric model provide a more accurate normalization of left atrial volume compared to standard BSA indexing in children?
Normalization of left atrial volume in children requires allometric scaling (BSA^1.48 for ≤1 m² and BSA^1.08 for >1 m²) rather than standard per-BSA indexing to eliminate residual relationship to body size.
Effect estimate: r=0.52
p-value: p=<0.0001
BACKGROUND: Left atrial volume (LAV) increase is an indicator of diastolic dysfunction and a surrogate marker of significant left to right shunts. Normalization of LAV is currently performed by indexing to body surface area(1) (BSA(1)). The indexed LAV thus derived does not account for the nonlinear relationship of physiologic variables to BSA and has not been tested for independence to body size. Our objective was to identify a valid allometric model for indexing LAV and use it to develop Z-scores in children. METHODS AND RESULTS: LAV was measured in 300 normal subjects by echocardiography using the biplane area length method. LAV/BSA(1) had a residual relationship to BSA (r=0.52, P1 m(2), respectively, and was validated against an independent sample. The mean indexed LAV±SD for BSA≤1 m(2) and >1 m(2) is 31.5±5.5 mL and 26.0±4.2 mL, respectively, and was used to derive Z-scores. CONCLUSIONS: This study demonstrates the fallacy of using "per-BSA(1) standards" for normalization of LAV in pediatrics. LAV/BSA(1.48) for children with BSA≤1 m(2) and LAV/BSA(1.08) for those with BSA>1 m(2) is accurate and can be used to derive Z-scores.
Bhatla et al. (Wed,) conducted a cross-sectional in Normal subjects (pediatric) (n=300). Allometric model for indexing LAV vs. Standard indexing to BSA was evaluated on Residual relationship to BSA (r=0.52, p=<0.0001). An allometric model using LAV/BSA^1.48 for children with BSA≤1 m² and LAV/BSA^1.08 for BSA>1 m² accurately normalizes left atrial volume, unlike standard BSA indexing (r=0.52, P<0.0001).