Abstract 16855: Left Ventricular Volumes, Stress, and Strain in Normal Children and Young Adults Measured by 3-Dimensional Echocardiography
Background: 3D echocardiography (3DE) is increasingly being used clinically to calculate ventricular volumes and function. Normal pediatric values of 3D LV volumes and strain are not well established; moreover, there are no reports of the stress-strain relationship (an index of contractility) based upon 3D technology in this cohort.
Methods: 3D LV datasets were obtained as part of routine echocardiographic examinations in eligible pediatric patients (≤ 21 years of age) between January 2014 and March 2015. Included patients had structurally normal hearts. Exclusion criteria included non-cardiac disorders with a potential impact on ventricular function and family history of cardiomyopathy. Image acquisition was performed using the Philips IE33 with X3/5/7 probes. Strain (3D; circumferential, GCS; and longitudinal, GLS) was analyzed according to a commercial 3D speckle-tracking analysis package (4D LV Analysis 3.1; Tomtec). LV mid-wall global average stress was calculated from the 3D LV volumes and 2D cross-sectional area/long-axis dimensions.
Results: 237 patients were included (age= 0.2 mo-21 y). The correlation between 3D and 2D LV mass and volumes was excellent (mass, R=0.94; end-diastolic volume, R=0.94; end-systolic volume, R=0.90; p<0.001 for all). Mean+-SD strain values (%) were: 3D=-33.9±2.8; GCS=-28.0 ± 3.1; GLS=-20.7 ± 3.0; only GLS varied significantly with age (R=0.26; p<0.001). Overall, 3D strain was inversely linearly related to wall stress (R=0.26; p<0.001); the strongest relationship was present in patients from age 0-5 years (R=0.48; p<0.01). When normalized to stress, absolute LV strain decreased with age (Figure 1: R=0.33; p<0.001).
Conclusions: 3DE may be used to calculate LV stress, strain, and volume parameters. Among strain parameters, age-related changes were seen only in GLS. Examination of the stress-strain relationship using these techniques may yield new insights into maturational changes in myocardial contractility.
Author Disclosures: J.D. Kuebler: None. M. Nathan: None. G. Marx: None. S. Colan: None. D.M. Harrild: None.
- © 2015 by American Heart Association, Inc.