Left Ventricular Systolic Myocardial Deformation: A Comparison of Two- and Three-Dimensional Echocardiography in Children

Background: The clinical applicability and reliability of three-dimensional (3D) speckle-tracking echocardiography has not been well studied in pediatric patients. The aim of this study was to compare two-dimensional (2D) echocardiography and 3DE real-time full-volume-derived strain and rotation indices in healthy children and patients with dilated cardiomyopathy (DCM). Methods: Children with either normal function or DCM were prospectively recruited in an outpatient setting, and deformation indices, including circumferential, radial, and longitudinal strain and torsion, were measured by 2D and 3D echocardiography. Control subjects were compared with patients using the Mann-Whitney U test, correlations between 2D and 3D measurements were analyzed using Spearman correlation analysis, and reproducibility analyses are reported using intraclass correlation coefficients and coefficient of variations. Results: The study cohort consisted of 15 patients (47%) with DCM and 17 control subjects (53%). The median age of the cohort was 13.4 years (range, 5.7-19.3 years). By both 2D and 3D analysis, magnitudes of global longitudinal (P = .01), circumferential (P = .007), and radial (P = .004) strain were significantly lower in patients with DCM in comparison with control subjects. Using receiver operating characteristic curves, lower values of absolute circumferential (area under the curve = 0.95, P < .0001) and longitudinal (area under the curve = 0.93, P < .0001) strain were associated with left ventricular dysfunction. No difference was noted in torsion between control subjects and patients. Three-dimensional analysis was superior to 2D analysis in terms of intraobserver, interobserver, and test-retest reliability. Conclusions: Left ventricular deformation shows significant changes while torsion is preserved in outpatients with DCM compared with control subjects. Three-dimensional global strain can discriminate subtle left ventricular dysfunction and has better reproducibility in comparison with 2D echocardiography. High-resolution 3D imaging is a useful clinical assessment tool for cardiac performance and may overcome some of the limitations of 2D analysis.