Background: quantitative assessment and validation of left ventricular (LV) volumes and mass in neonates and infants with complex congenital heart disease (CHD) is important for clinical management but has not been undertaken. We compared matrix-array 3D echocardiography (3D echo) measurements of volumes, mass, and ejection fraction (EF) with those measured by cardiac MRI in young patients with CHD and small LVs because of either young age or LV hypoplasia.
Methods and results: thirty-five patients aged <4 years (median, 0.8 years) undergoing MRI were prospectively enrolled. Three-dimensional echo was acquired immediately after MRI, and volume, mass, and EF measurements, using summation of discs methodology, were compared with MRI. Three-dimensional echo end-diastolic volume (24.4±15.7 versus 24.8±46.4 mL; P=0.01; intraclass correlation coefficient [ICC], 0.96) and end-systolic volume (12.3±8.6 versus 9.6±6.8 mL; P<0.001; ICC, 0.90) correlated with MRI with small mean differences (-0.49 mL [P=0.6] and 2.7 mL [P=0.001], respectively). Three-dimensional echo EF was smaller than MRI by 9.3% (P<0.001), and 3D echo LV mass measurements were comparable to MRI (17.3±10.3 versus 17.6±12 g; P<0.77; ICC, 0.93), with a small mean difference (1.1 g; P=0.28). There was good intra- and interobserver reliability for all measurements.
Conclusions: in neonates and infants with CHD and small LVs (age appropriate or hypoplastic), matrix-array 3D echo measurements of mass and volumes compare well with MRI, providing an important modality for ventricular size and performance analysis in these patients, particularly in those with left-side heart obstructive lesions.