Abstract 11129: Three-Dimensional Rotation, Twist and Torsion Analyses by Real-Time 3-D Speckle Tracking Imaging: Feasibility, Reproducibility, Maturational Changes, and Normal Ranges in Pediatric Population
Background: Although 2-D analysis of left ventricular (LV) rotation, twist and torsion has been validated in adults and children; these measures are highly dependent on 2-D planes with limited robustness and reproducibility.
Objectives: We sought: 1) to evaluate feasibility and reproducibility of LV rotation, twist and torsion by real-time 3D speckle tracking imaging (RT 3D-STI); and 2) to establish the maturational growth pattern and normal values of these measures in pediatric population.
Methods: A prospective study was conducted in 252 consecutive healthy subjects (131 male/121 female, mean age 6.23 ± 4.5 years, and range from birth to 18 years) using RT 3-D echocardiography (3DE). The LV rotation, twist and torsion measurements were made off-line using new TomTec software (4D LV-Analysis 3.0, TomTec Imaging Systems, Munich, Germany). Manual landmark selection and endocardial border editing were performed in 3 planes (apical 2-, 4-, and “3-“ chamber views) and semi-automated border identification and tracking yielded LV rotation, twist and torsion measurements.
Results: LV rotation, twist and torsion analysis by RT 3D-STI was feasible in 224 of 252 subjects (88.9%), excluding 28 subjects secondary to the low frame rates or incomplete 3-D images. There is no correlation between rotational or twist and age, height, weight, BSA or HR, respectively, using canonical correlation analysis. However, there is a negative correlation between age and LV torsion (Rs=- 0.18, P= 0.007). The normal ranges were defined in this cohort for rotation and twist, and for each age group for torsion (data not shown). The intra-observer and inter-observer variabilities for apical and basal rotation, twist and torsion ranged from 3.0% ± 63.3% to 17.2% ± 46.1% and from 3.2% ± 93.2% to 7.4% ± 58.3%, respectively.
Conclusions: Analyses of LV rotation, twist and torsion by this new RT3D STI methodology are feasible in pediatric population; but their reproducibilities are variable. There are no maturational changes in rotation and twist but torsion decreases with age in this cohort. Further refinement is warranted to improve the reproducibility and to validate the utility of this new methodology in congenital and acquired heart diseases.
- © 2011 by American Heart Association, Inc.