Echocardiographic determination of left atrial volumes in children with congenital heart disease.

The feasibility of determining left atrial volumes (LAV) from LA echo dimensions was assessed in 36 children (group I) with normal cineangiographically determined LAV and 16 children (group II) with LAV overload. Conventional LA echo dimensions, obtained within 24 hours of cardiac catheterization, were compared to the angiographic LA anterior-posterior minor axes (LAmA) and LAV. There was excellent correlation betweeh the LA echo dimensions and the LAmA. In all patients, the LA echo less than LAmA, the differences being more pronounced in group II. Good correlations were found between the LAV and the LA echo, and were expressed by the equations LAV = 7.5 LA echo1.8 (r = .85) and LAV = 8.1 LA echo2.1 (r = .86) for groups I and II, respectively. Changes in LA configuration with volume overload were shown to cause a disproportionate increase in LAmA compared to the other LA dimensions and the LA echo dimension, thus necessitating the separate regression equations. Echo LA to aortic ratios were 0.86 +/- 0.11 and 1.21 +/- 0.23 (mean +/- SD) for groups I and II, respectively. This method of estimating LAV can be useful in the management of left-to-right intracardiac shunts and mitral regurgitation in infants and children.