Background The establishment of the range of reference values and associated variations of two-dimensional speckle-tracking echocardiography (2DSTE) derived left ventricular (LV) strain is a prerequisite for its routine clinical adoption in pediatrics. The aims were to perform a meta-analysis of normal ranges of LV global longitudinal, circumferential, and radial strain (GLS, GCS, and GRS) measurements derived by 2DSTE in children and identify confounding factors that may contribute to variances in reported measures. Methods A systematic review was launched in Medline, Embase, Scopus, CINAHL, and Cochrane. Search hedges were created to cover the concepts of pediatrics, speckle-tracking echocardiography, and left heart ventricle. Two investigators independently identified and included studies if they reported the 2DSTE derived LV GLS, GCS or GRS. The weighted mean was estimated by using random-effects with 95% confidence interval (CI), heterogeneity was assessed by the Cochran's Q statistic and the inconsistency index (I2) and publication was evaluated using the Egger test. Effects of demographic (age), clinical, and vendor variables were assessed in a meta-regression. Results The search identified 2325 children from 43 data sets. The reported normal mean values of GLS among the studies varied from -16.7% to -23.6% (mean -20.2%, 95% CI -19.5% to -20.8%), GCS varied from -12.9% to -31.4% (mean -22.3%, 95% CI -19.9% to -24.6%) and GRS, varied from 33.9% to 54.5 % (mean 45.2 95% CI 38.3 to 51.7). 26 studies reported LS only from the apical 4-chamber view with a mean of -20.4%, (95% CI -19.8% to -21.7%). 23 studies reported CS (mean, -20.3%, 95% CI -19.4% to -21.2%) and RS (mean, 46.7%, 95% CI 42.3% to 51.1%) from the short axis view at the mid-ventricular level. A significant apex-to-base segmental longitudinal strain (SLS) gradient (P < .01) was observed in the LV free wall. There was significant between- study heterogeneity and inconsistency (I2 > 94% and P < .001 for each strain measure), which was not explained by age, gender, body surface area, blood pressure, heart rate, frame rate, FR/HR ratio tissue-tracking methodology, location of reported strain value along the strain curve, ultrasound equipment, or software. These metaregression showed that these effects were not significant determinants of variations among normal ranges of strain values. There was no evidence of publication bias (P = .40). Conclusions This study defined reference values of 2DSTE derived LV strain in children on the basis of a meta-analysis. In healthy children, the mean LV global longitudinal strain value is -20.2%, (95% CI -19.5% to -20.8%), mean global circumferential strain -22.3%, (95% CI -19.9% to -24.6%), and mean global radial strain is 45.2%, (95% CI 38.3% to 51.7%). LV segmental longitudinal strain has a stable apex-to-base gradient that is preserved throughout maturations. Although variations among different reference ranges in this meta-analysis were not dependent on differences in demographic, clinical, or vendor para...

Background We aimed to determine the maturational changes in systolic ventricular strain mechanics by two-dimensional speckle tracking echocardiography in extreme preterm neonates from birth to one year of age, and discern the impact of common cardiopulmonary abnormalities on the deformation measures. Methods In a prospective multi-center study of 239 extreme preterm infants (< 29 weeks gestation at birth), left ventricle (LV) global longitudinal strain and systolic strain rate (GLS, GLSRs), interventricular septal wall (IVS) GLS and GLSRs, right ventricle free wall longitudinal S and SR (RV FWLS, FWLSRs), and segmental LS (SLS) in the RVFW, LVFW and IVS were serially measured at Days 1, 2, 5–7, 32 weeks and 36 weeks post-menstrual age (PMA), and one year corrected age (CA). Premature infants who developed bronchopulmonary dysplasia (BPD) or had echocardiographic findings of pulmonary hypertension (PH) were analyzed separately. Results In uncomplicated preterm infants (n=103, 48%), LV GLS and GLSRs remained unchanged from Day 5–7 to one year CA (p=0.60 and 0.59). RV FWLS, FWLSRs and IVS GLS and GLSR significantly increased over the same time period (p < 0.01 for all measures). A significant base-to-apex (highest to lowest) SLS gradient (p < 0.01) in the RVFW and a reverse apex-to-base gradient (p < 0.01) existed in the LVFW. In infants with BPD and/or PH (n=119, 51%), RV FWLS and IVS GLS were significantly lower (p < 0.01), LV GLS and GLSRs were similar (p=0.56), and IVS SLS persisted as an RV dominant base-to-apex gradient from 32 weeks PMA to one year CA. Conclusions This study tracks the maturational patterns of global and regional deformation by 2DSTE in extreme preterm infants from birth to one year CA. The maturational patterns are ventricular specific. BPD and PH leave a negative impact on RV and IVS strain, while LV strain remains stable.

BACKGROUND: Frame rate (FR) of image acquisition is an important determinant of the reliability of 2-dimensional speckle tracking echocardiography (2DSTE)-derived myocardial strain. Premature infants have relatively high heart rates (HR). The aim was to analyze the effects of varying FR on the reproducibility of 2DSTE-derived right ventricle (RV) and left ventricle (LV) longitudinal strain (LS) and strain rate (LSR) in premature infants. METHODS: RV and LV LS and LSR were measured by 2DSTE in the apical 4-chamber view in 20 premature infants (26 ± 1 weeks) with HR 163 ± 13 bpm. For each subject, 4 sets of cine-loops were acquired at FR of <90, 90-110, 110-130, and >130 frames/s. Two observers measured LS and LSR. Inter- and intra-observer reproducibility was assessed using Bland Altman analysis, coefficient of variation, and linear regression. RESULTS: Intra-observer reproducibility for RV and LV LS was higher at FR >110 frames/s, and optimum at FR >130 frames/s. The highest inter-observer reproducibility for RV and LV LS were at FR >130 and > 110 frames/s, respectively. The highest reproducibility for RV and LV systolic and early diastolic LSR was at FR > 110 frames/s. FR/HR ratio >0.7 frames/s/bpm yielded optimum reproducibility for RV and LV deformation imaging. CONCLUSIONS: The reliability of 2DSTE-derived RV and LV deformation imaging in premature infants is affected by the FR of image acquisition. Reproducibility is most robust when cine-loops are obtained with FR/HR ratio between 0.7 – 0.9 frames/s/bpm, which likely results from optimal myocardial speckle tracking and mechanical event timing.

Objectives To test our hypothesis that obese adolescents have left ventricular (LV) dysfunction and remodeling that are associated with markers of cardiovascular risk and insulin resistance (IR). Study design In a cross-sectional study of 44 obese and 14 lean age-, sex-, Tanner stage-, and race-matched adolescents, IR, markers of cardiovascular risks, conventional and 2-dimensional speckle tracking echocardiography (2DSTE) measures of LV function and structure were evaluated and compared. Results The obese adolescents had significantly increased body mass index (BMI) Z-score, systolic blood pressure, fasting insulin, IR, and atherogenic lipids compared with the lean adolescents. A subgroup of obese adolescents had LV remodeling characterized by significantly increased LV mass index (LVMI, g/m2.7) and relative wall thickness (RWT). Almost all obese adolescents had LV dysfunction with peak LV global longitudinal strain (GLS,%), systolic global GLS rate (GLSR, %/s) and early diastolic GLSR significantly lower than in lean adolescents and in the normal pediatric population. BMI Z-score predicted LV remodeling [LVMI (R2= 0.34) and RWT (R2 0.10], and peak LV GLS (R2 0.15), and along with systolic blood pressure, predicted systolic GLSR (R2 0.16); (P ≤ 0.01 for all). Fasting insulin predicted early diastolic GLSR (R2 0.17, P ≤ 0.01). Conclusions Obese adolescents have subclinical ventricular dysfunction associated with the severity of obesity, increased systolic blood pressure, and IR. Ventricular remodeling is present in a subgroup of obese adolescents in association with the severity of obesity. These findings suggest that obesity may have an early impact on the cardiovascular health of obese adolescents.

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