Right Ventricular Volumes, Ejection Fraction, and Systolic Function Indices in Normal Neonates by Three-Dimensional Speckle-Tracking Echocardiography.

The aim of this study was to test the feasibility of measuring right ventricular (RV) volumes, ejection fraction (EF), and systolic function indices in neonates using three-dimensional speckle-tracking echocardiography (3D-STE). Thirty-eight neonates underwent complete echocardiographic evaluation, including the acquisition of three full-volume 3D datasets or more from each of the apical, parasternal, and subcostal windows while naturally sleeping. Datasets were analyzed using a commercially available software (Tomtec). Global RV 3D volumes and EF were measured. In addition, 2D free wall longitudinal strain (LS), tricuspid valve annulus (TVA), tricuspid annular plane systolic excursion (TAPSE) and its index to RV length (TAPSEi), and fractional area change (FAC) were obtained from a non-shortened apical 4-chamber view of the RV, derived from the 3D dataset. Three or more datasets obtained from the apical window were available for analysis for each subject. At least one dataset was adequate for analysis in all subjects. Mean indexed 3D diastolic, systolic, stroke volumes, and EF were measured at 28.5 ± 3.4 ml/m2, 13 ± 2.0 ml/m2, 15.6 ± 1.9 ml/m2, and 54.6 ± 3.2%, respectively. Free wall 2D LS was calculated at (- 27.9 ± 2.5%). In addition, mean TVA measured 11.1 ± 0.8 mm, TAPSE measured 6.8 ± 0.9 mm, and TAPSEi and FAC were calculated at 24.2 ± 2.1 and 46 ± 3.4%, respectively. 3D-STE is feasible in normal neonates without the need for sedation. Reference values of RV 3D volumes and 2D indices of systolic function were obtained. These data could be helpful in patients where the size or systolic function of the RV is in question. Larger studies are required to establish nomograms for the above indices in this age group.