Left Atrial Volume in Children Without Heart Disease and in Those With Ventricular Septal Defect or Patent Ductus Arteriosus or Hypertrophic Cardiomyopathy

Abstract

In adults, the left atrial (LA) volume has been shown to reflect diastolic function and is a powerful predictor of cardiac morbidity and mortality. Normative LA volume values in children and the effect of loading conditions on the LA volume in those with congenital heart disease are lacking. The purposes of the present study were to (1) establish normal LA volume values for children, (2) assess the effect of left ventricular volume loading conditions on LA volume, and (3) describe the effect of abnormal myocardial relaxation on the LA volume. We retrospectively reviewed the echocardiograms from 3 pediatric cohorts: group N (n = 522), children with normal echocardiographic findings; group VSD/PDA (n = 71), children with ventricular septal defect (VSD; n = 50) or patent ductus arteriosus (PDA; n = 21); and group HC (n = 63), children with hypertrophic cardiomyopathy (HC). In group N, we identified the LA volume indexed to the body surface area (LA volume index) as a consistent measure of the LA volume in children 3 to 23 months old (mean 16 ± 3 ml/m(2)) and 2 to 17 years old (mean 22 ± 4 ml/m(2)). LA dilation was more common in group VSD/PDA than in group N (27% vs 2%, p <0.0001) and in children with moderate or large shunts than in those with smaller shunts (61% vs 5%, p <0.0001). In group HC, the LA volume index correlated with the mitral valve E/e' ratio (p <0.0001). In conclusion, this is the first study to establish normal pediatric LA volume values. The LA volume index is a reproducible measure of LA size in children ≥ 3 months old. The LA volume index reflects a chronically increased left ventricular volume load in children with VSD or PDA and chronically elevated left ventricular filling pressures in children with HC.