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Background: The study objective was to assess the severity, progression rate, and risk factors for aortic root dilatation (ARD) in pediatric tetralogy of Fallot (TOF) and to study its relationship to complications including aortic regurgitation., Methods and Results: Seven hundred sixty-eight TOF patients were studied with echocardiography (median age at repair 6.1 months; interquartile range, 4.5-11.3 months) and compared with 304 controls. Five hundred ninety-two (77%) had usual TOF, 41 (5.3%) TOF-type double outlet right ventricle, and 135 (17.6%) TOF with pulmonary atresia. Median follow-up was 3.7 years (interquartile range, 0.5-6.9 years, total follow-up 3002 patients-years). Aortic root dimensions were enlarged at TOF diagnosis and during follow-up. Mean aortic valve annulus Z score at first postoperative echo was 3.3±2.7, associated with TOF type (TOF1 Z score unit per year) was observed in <1% of patients. Of the 768 patients, only 3 (0.39%) developed moderate/severe aortic regurgitation and 2 required aortic surgery for subvalvar aortic stenosis and aortic dissection, respectively., Conclusions: ARD is common before and after TOF repair, but our data suggest that aortic root dimensions remain stable in the majority of pediatric TOF patients. Progressive ARD and aortic-related complications are distinctly uncommon during childhood.

Background: In pediatric echocardiography, myocardial strain measurements are likely influenced by cardiac size and growth in healthy children. The application of this technique in clinical practice has been hampered by the lack of good normal reference values for the pediatric population. The aim of this study was to determine reference values and Z score equations for left ventricular systolic circumferential and longitudinal strain in a healthy pediatric population., Methods: Two hundred thirty-three healthy subjects 1 to 18 years of age were prospectively recruited. Left ventricular systolic longitudinal and circumferential strain measurements were recorded using two-dimensional speckle-tracking. Normalization for body size was performed using parametric nonlinear regression modeling. Several analyses were performed to detect potential residual associations with body size, residual heteroscedasticity, or departure from an adequate Z score distribution., Results: There were weak but statistically significant nonlinear associations between body size and most strain values. Body surface area was superior to adjust for body size compared with age, height, and weight. Most strain values displayed a second-order polynomial relationship with body surface area. Z score equations were computed with adequate normal distributions and without residual associations in relation to BSA for most strain parameters., Conclusions: There was a weak but significant influence of body size on most left ventricular circumferential and longitudinal systolic strain parameters used in pediatric echocardiography. Z scores are presented for strain measurements normalized to body surface area and adjusted for heteroscedasticity. The use of these normalized values may reduce the risk for misclassification caused by normal variation in myocardial strain values during growth., (Copyright © 2016 American Society of Echocardiography. Published by Elsevier Inc. All rights reserved.)

In pediatric echocardiography, cardiac dimensions are often normalized for weight, height, or body surface area (BSA). The combined influence of height and weight on cardiac size is complex and likely varies with age. We hypothesized that increasing weight for height, as represented by body mass index (BMI) adjusted for age, is poorly accounted for in Z scores normalized for weight, height, or BSA. We aimed to evaluate whether a bias related to BMI was introduced when proximal aorta diameter Z scores are derived from bivariate models (only one normalizing variable), and whether such a bias was reduced when multivariable models are used. We analyzed 1,422 echocardiograms read as normal in children ≤18 years. We computed Z scores of the proximal aorta using allometric, polynomial, and multivariable models with four body size variables. We then assessed the level of residual association of Z scores and BMI adjusted for age and sex. In children ≥6 years, we found a significant residual linear association with BMI-for-age and Z scores for most regression models. Only a multivariable model including weight and height as independent predictors produced a Z score free of linear association with BMI. We concluded that a bias related to BMI was present in Z scores of proximal aorta diameter when normalization was done using bivariate models, regardless of the regression model or the normalizing variable. The use of multivariable models with weight and height as independent predictors should be explored to reduce this potential pitfall when pediatric echocardiography reference values are evaluated.

Background: There is a paucity of echocardiographic data describing right ventricular (RV) dimensions and function in the early transitional newborn period., Methods: Fifty healthy term newborns underwent serial echocardiography at a mean of 15 ± 2 and 35 ± 2 hours of age. RV dimensions and functional indices were measured as recommended in the American Society of Echocardiography's recent guidelines. Additional novel parameters included RV anteroinferior basal diameter, fractional area change (FAC) from the apical three-chamber view, and speckle-tracking echocardiography-derived peak longitudinal strain in the RV lateral (apical four-chamber view) and inferior (apical three-chamber view) walls. Results obtained at both time points were compared., Results: Linear dimensions and tissue Doppler velocities were highly reproducible, while time intervals and FAC measurements were more variable. Three-chamber FAC was higher than four-chamber FAC (36 ± 5% vs. 24 ± 7%, P < .001). Lateral wall peak longitudinal strain was similar to the value for the inferior wall (22 ± 4% vs 18 ± 5%, P > .05). A small increase in RV dimensions was noted on day 2 of life (midcavity diameter, 1.71 ± 0.19 vs 1.55 ± 0.19 cm, P < .01; RV anteroinferior basal diameter, 2.24 ± 0.29 vs 2.06 ± 0.24 cm, P < .01; end-diastolic-area in the apical four-chamber view, 4.32 ± 0.64 vs 4.10 ± 0.69 cm(2), P = .04), while no changes occurred in functional indices. RV dimensions and FAC showed moderate linear correlations with birth weight. Z scores could be computed for the majority of measured indices., Conclusions: Using conventional and novel indices, the investigators describe a comprehensive echocardiographic protocol for neonatal RV imaging, establish reference ranges, and describe the effect of physiologic postnatal transition on RV dimensions and function. This will facilitate future investigations of RV dysfunction in neonatal cardiopulmonary disorders., (Copyright © 2014 American Society of Echocardiography. Published by Elsevier Inc. All rights reserved.)

Several articles have proposed echocardiographic reference values in normal pediatric subjects, but adequate validation is often lacking and has not been reviewed. The aim of this study was to review published reference values in pediatric two-dimensional and M-mode echocardiography with a specific focus on the adequacy of the statistical and mathematical methods used to normalize echocardiographic measurements. All articles proposing reference values for transthoracic pediatric echocardiography were reviewed. The types of measurements, the methods of normalization, the regression models used, and the methods used to detect potential bias in proposed reference values were abstracted. The detection of residual associations, residual heteroscedasticity, and departures from the normal distribution theory predictions were specifically analyzed. Fifty-two studies met the inclusion criteria. Most authors (87%) used parametric normalization to account for body size, but their approaches were very heterogeneous. Linear regression and indexing were the most common models. Heteroscedasticity was often present but was mentioned in only 27% of studies. The absence of residual heteroscedasticity and residual associations between the normalized measurements and the independent variables were mentioned in only 9% and 22% of the studies, respectively. Only 14% of studies documented that the distribution of the residual values was appropriate for Z score calculation or that the proportion of subjects falling outside the reference range was appropriate. Statistical suitability of the proposed reference ranges was often incompletely documented. This review underlines the great need for better standardization in echocardiographic measurement normalization., (Copyright © 2013 American Society of Echocardiography. Published by Mosby, Inc. All rights reserved.)

Purpose: Scientific evidence on the long-term impact of gestational diabetes mellitus (GDM) on offspring’s myocardial relaxation is scarce. Studies have linked GDM with transient ventricular hypertrophy in newborns resulting in diastolic dysfunction, but long-term assessment is lacking. The main objective of this study was to evaluate myocardial relaxation in 3-year-old children in relation to the degree of insulin resistance of their mother during pregnancy. Methods: We prospectively assessed myocardial relaxation by echocardiography imaging on 106 children at 3 years of age. Subjects were divided into 3 groups [GDM, insulin resistance (IR) and normoglycemic (CTRL)], based on their mother’s 75g-OGTT and HOMA-IR results at second trimester screening. We collected information on children adiposity and body size, maternal characteristics and maternal and cord blood measurement of C-peptide and insulin. Results: The study population comprised 29 children from GDM mothers, 36 children from IR mothers and 41 CTRL children. Compared to the CTRL group, we found that a higher proportion of children in the IR group and the GDM group met the criteria for impaired myocardial relaxation, but this did not reach statistical significance (odds ratio adjusted for heart rate and body surface area of 1.4 [0.2–9.5] and 3.5 [0.6–20.6], respectively). Conclusion: We did not detect an increased risk of impaired myocardial relaxation at three years of age in children exposed in-utero to IR and GDM, compared to children from normoglycemic mothers. [ABSTRACT FROM AUTHOR]

Background: The benefit of fetal echocardiograms (FE) to detect severe congenital heart diseases (SCHD) in the setting of a normal second-trimester ultrasound is unclear. We aimed to assess whether the increase in SCHD detection rates when FE are performed for risk factors in the setting of a normal ultrasound was clinically significant to justify the resources needed. Methods: This is a multicenter, population-based, retrospective cohort study, including all singleton pregnancies and offspring in Quebec (Canada) between 2007 and 2015. Administrative health care data were linked with FE clinical data to gather information on prenatal diagnosis of CHD, indications for FE, outcomes of pregnancy and offspring, postnatal diagnosis of CHD, cardiac interventions, and causes of death. The difference between the sensitivity to detect SCHD with and without FE for risk factors was calculated using generalized estimating equations with a noninferiority margin of 5 percentage points. Results: A total of 688 247 singleton pregnancies were included, of which 30 263 had at least one FE. There were 1564 SCHD, including 1071 that were detected prenatally (68.5%). There were 12 210 FE performed for risk factors in the setting of a normal second-trimester ultrasound, which led to the detection of 49 additional cases of SCHD over 8 years. FE referrals for risk factors increased sensitivity by 3.1 percentage points (95% CI, 2.3-4.0; P <0.0001> Conclusions: In the setting of a normal second-trimester ultrasound, adding a FE for risk factors offered low incremental value to the detection rate of SCHD in singleton pregnancies. The current ratio of clinical gains versus the FE resources needed to screen for SCHD in singleton pregnancies with isolated risk factors does not seem favorable. Further studies should evaluate whether these resources could be better allocated to increase SCHD sensitivity at the ultrasound level, and to help decrease heterogeneity between regions, institutions and operators. [ABSTRACT FROM AUTHOR]

Supplemental Digital Content is available in the text. Background: Patients with bicuspid aortic valve (BAV) have a higher risk of developing aortic valve dysfunction and progressive proximal aorta dilatation, which can lead to aortic dissection. To this day, identification of children at risk of developing severe aortic dilatation during their pediatric follow-up is still challenging because most studies were restricted to adult subjects. The overarching goal of this study was to identify risk factors of aortic dilatation in children with BAV. Methods: We extracted clinical and echocardiographic data of all BAV subjects aged 0 to 20 years followed at Centre Hospitalier Universitaire Sainte-Justine between 1999 and 2016. We excluded subjects with concomitant heart defects and conditions affecting proximal aorta dimensions. Proximal aorta diameters (expressed as Z scores) were modeled in relation to age and potential predictive variables in a linear mixed model. The primary outcome was the rate of dilatation. Results: We included 761 subjects (3134 echocardiograms) in final analyses. The mean ascending aorta Z score progression rate for BAV patient with a normally functioning aortic valve was estimated at 0.05 Z score unit per year. The strongest predictors of an increased dilatation rate were severe aortic stenosis, moderate and severe aortic regurgitation, and uncorrected coarctation of the aorta. Aortic valve leaflet fusion pattern and sex were not associated with progression rate. Conclusions: Children with a normally functioning BAV exhibited a very slow proximal aorta dilatation rate. Ascending aorta dilatation rate was significantly increased in patients with more than mild aortic valve dysfunction but was independent from BAV leaflet fusion type. [ABSTRACT FROM AUTHOR]

A correction to the article "Bias Related to Body Mass Index in Pediatric Echocardiographic Z Scores" that was published in the 2015 issue is presented.