Normal Range of Left Ventricular Strain, Dimensions and Ejection Fraction Using Three-dimensional Speckle-Tracking Echocardiography in Neonates

Aims: Three-dimensional speckle-tracking echocardiography (3D-STE) is a promising new technique to evaluate left ventricular (LV) mechanics. The feasibility and normal values of LV strain using 3D-STE have recently been established in adults and children. Unfortunately, no data are available in neonates. The aims of this study were to evaluate the feasibility and establish normal values of 3D LV volumes, ejection fraction (EF), and the 4 normal strains in healthy neonates. Materials and Methods: Of 50 consecutive newborns who were delivered at our hospital or returned to their first newborn follow-up within the first 3 weeks of life, 38 babies underwent full echocardiographic evaluation, including the acquisition of at least 3 full volume data sets from the apical window, while naturally sleeping. Data sets were analyzed offline. Global LV longitudinal, circumferential, and radial strain, as well as 3D LV volumes and EF, were measured using 3D-STE. Results: Of the 50 newborns, 2 patients were excluded because of significant intra-cardiac shunts, and in another 10 subjects, parents did not give consent. At least one data set was adequate for analysis in all the remaining subjects. Mean indexed LV diastolic, systolic volumes, and EF were 24.7 3.6 ml/m(2) , 9.2 1.3 ml/m(2) , and 63% 3.7%, respectively. Normal global longitudinal, circumferential, radial, and tangential 4D strain were -20.9% +/- 2.8%, -32.4% +/- 3.1%, 44.3% +/- 3.4%, and -39.7% +/- 3.4%, respectively. Conclusions: 3D-STE is feasible in newborns without the needed for sedation. Reference values of normal, regional, and global LV 4D strain and volumes were obtained.