The Dutch national paediatric heart transplantation programme: outcomes during a 23-year period.

BACKGROUND: Since 1998, there has been a national programme for paediatric heart transplantations (HT) in the Netherlands. In this study, we investigated waiting list mortality, survival post-HT, the incidence of common complications, and the patients' functional status during follow-up. METHODS: All children listed for HT from 1998 until October 2020 were included. Follow-up lasted until 1 January 2021. Data were collected from the patient charts. Survival, post-operative complications as well as the functional status (Karnofsky/Lansky scale) at the end of follow-up were measured. RESULTS: In total, 87 patients were listed for HT, of whom 19 (22%) died while on the waiting list. Four patients were removed from the waiting list and 64 (74%) underwent transplantation. Median recipient age at HT was 12.0 (IQR 7.2-14.4) years old; 55% were female. One-, 5­, and 10-year survival post-HT was 97%, 95%, and 88%, respectively. Common transplant-related complications were rejections (50%), Epstein-Barr virus infections (31%), cytomegalovirus infections (25%), post-transplant lymphoproliferative disease (13%), and cardiac allograft vasculopathy (13%). The median functional score (Karnofsky/Lansky scale) was 100 (IQR 90-100). CONCLUSION: Children who undergo HT have an excellent survival rate up to 10 years post-HT. Even though complications post-HT are common, the functional status of most patients is excellent. Waiting list mortality is high, demonstrating that donor availability for this vulnerable patient group remains a major limitation for further improvement of outcome.

Cardiac allograft vasculopathy and donor age affecting permanent pacemaker implantation after heart transplantation.

AIMS: The need for permanent pacemakers (PMs) after heart transplantation (HT) is increasing. The aim was to determine the influence of cardiac allograft vasculopathy (CAV), donor age, and other risk factors on PM implantations early and late after HT and its effect on survival. METHODS AND RESULTS: A retrospective, single-centre study was performed including HTs from 1984 to July 2018. Early PM was defined as PM implantation ≤90 days and late PM as PM > 90 days. Risk factors for PM and survival after PM were determined with (time-dependent) multivariable Cox regression. Out of 720 HTs performed, 62 were excluded (55 mortalities ≤30 days and 7 retransplantations). Of the remaining 658 patients, 95 (14%) needed a PM: 38 (6%) early and 57 (9%) late during follow-up (median 9.3 years). Early PM risk factors were donor age [hazard ratio (HR) 1.06, P < 0.001], ischaemic time (HR 1.01, P < 0.001), and in adults amiodarone use before HT (HR 2.02, P = 0.045). Late PM risk factors were donor age (HR 1.03, P = 0.024) and CAV (HR 3.59, P < 0.001). Late PM compromised survival (HR 2.05, P < 0.001), while early PM did not (HR 0.77, P = 0.41). CONCLUSIONS: Risk factors for early PM implantation were donor age, ischaemic time, and in adults amiodarone use before HT. Late PM implantation risk factors were donor age and CAV. Late PM diminished survival, which is probably a surrogate marker for underlying progressive cardiac disease.

Cyanosis due to an isolated atrial septal defect: case report and review of the literature.

Isolated atrial defects usually lead to left-to-right shunt and right ventricular volume load. Descriptions of cyanosis with this congenital heart defect are rare.We describe a rare case of inferior caval vein flow directed through an atrial septal defect in the fossa ovalis leading to severe cyanosis, but without any additional intracardiac anatomical abnormalities. The baby with clinical features of Marfan's syndrome had an eventration of the right-sided diaphragm. Surgical closure of the defect resolved the cyanosis, but the child died 10 weeks later of severe valvar dysfunction, related to Marfan's syndrome.Mechanisms of cyanosis in patients with atrial septal defects are discussed. Echocardiographic bubble studies both from the lower and upper half of the body may help to clarify the mechanism of an otherwise unexplained cyanosis.

Expanding the clinical and genetic spectrum of ALPK3 variants: Phenotypes identified in pediatric cardiomyopathy patients and adults with heterozygous variants.

INTRODUCTION: Biallelic damaging variants in ALPK3, encoding alpha-protein kinase 3, cause pediatric-onset cardiomyopathy with manifestations that are incompletely defined. METHODS AND RESULTS: We analyzed clinical manifestations of damaging biallelic ALPK3 variants in 19 pediatric patients, including nine previously published cases. Among these, 11 loss-of-function (LoF) variants, seven compound LoF and deleterious missense variants, and one homozygous deleterious missense variant were identified. Among 18 live-born patients, 8 exhibited neonatal dilated cardiomyopathy (44.4%; 95% CI: 21.5%-69.2%) that subsequently transitioned into ventricular hypertrophy. The majority of patients had extracardiac phenotypes, including contractures, scoliosis, cleft palate, and facial dysmorphisms. We observed no association between variant type or location, disease severity, and/or extracardiac manifestations. Myocardial histopathology showed focal cardiomyocyte hypertrophy, subendocardial fibroelastosis in patients under 4 years of age, and myofibrillar disarray in adults. Rare heterozygous ALPK3 variants were also assessed in adult-onset cardiomyopathy patients. Among 1548 Dutch patients referred for initial genetic analyses, we identified 39 individuals with rare heterozygous ALPK3 variants (2.5%; 95% CI: 1.8%-3.4%), including 26 missense and 10 LoF variants. Among 149 U.S. patients without pathogenic variants in 83 cardiomyopathy-related genes, we identified six missense and nine LoF ALPK3 variants (10.1%; 95% CI: 5.7%-16.1%). LoF ALPK3 variants were increased in comparison to matched controls (Dutch cohort, P = 1.6×10-5; U.S. cohort, P = 2.2×10-13). CONCLUSION: Biallelic damaging ALPK3 variants cause pediatric cardiomyopathy manifested by DCM transitioning to hypertrophy, often with poor contractile function. Additional extracardiac features occur in most patients, including musculoskeletal abnormalities and cleft palate. Heterozygous LoF ALPK3 variants are enriched in adults with cardiomyopathy and may contribute to their cardiomyopathy. Adults with ALPK3 LoF variants therefore warrant evaluations for cardiomyopathy.

Biallelic Variants in ASNA1, Encoding a Cytosolic Targeting Factor of Tail-Anchored Proteins, Cause Rapidly Progressive Pediatric Cardiomyopathy.

BACKGROUND: Pediatric cardiomyopathies are a clinically and genetically heterogeneous group of heart muscle disorders associated with high morbidity and mortality. Although knowledge of the genetic basis of pediatric cardiomyopathy has improved considerably, the underlying cause remains elusive in a substantial proportion of cases. METHODS: Exome sequencing was used to screen for the causative genetic defect in a pair of siblings with rapidly progressive dilated cardiomyopathy and death in early infancy. Protein expression was assessed in patient samples, followed by an in vitro tail-anchored protein insertion assay and functional analyses in zebrafish. RESULTS: We identified compound heterozygous variants in the highly conserved ASNA1 gene (arsA arsenite transporter, ATP-binding, homolog), which encodes an ATPase required for post-translational membrane insertion of tail-anchored proteins. The c.913C>T variant on the paternal allele is predicted to result in a premature stop codon p.(Gln305*), and likely explains the decreased protein expression observed in myocardial tissue and skin fibroblasts. The c.488T>C variant on the maternal allele results in a valine to alanine substitution at residue 163 (p.Val163Ala). Functional studies showed that this variant leads to protein misfolding as well as less effective tail-anchored protein insertion. Loss of asna1 in zebrafish resulted in reduced cardiac contractility and early lethality. In contrast to wild-type mRNA, injection of either mutant mRNA failed to rescue this phenotype. CONCLUSIONS: Biallelic variants in ASNA1 cause severe pediatric cardiomyopathy and early death. Our findings point toward a critical role of the tail-anchored membrane protein insertion pathway in vertebrate cardiac function and disease.

Tracking of structural and functional cardiac measures from infancy into school-age.

Objective Cardiac structure and function are important predictors for cardiovascular disease in adults. Not much is known about tracking of cardiac measures, other than left ventricular mass, from early life onwards. We examined whether and to what extent cardiac measures track from infancy into school-age. Methods We performed a population-based prospective cohort study among 1072 children. Aortic root diameter, left atrial diameter, left ventricular mass, relative wall thickness and fractional shortening were measured repeatedly by echocardiography. We explored tracking between infancy (1.5, six and 24 months) and school-age (six and 10 years). Results Of all cardiac measures, aortic root diameter, left atrial diameter and left ventricular mass were significantly correlated between infancy and school-age ( r = 0.10-0.42, all p-values < 0.01), with the strongest correlations between 24 months and 10 years. Of the different structures, aortic root diameter showed the strongest correlations. Approximately 30% of children who were in the lowest or highest quartile of a measure at the age of 1.5 months remained in that quartile at the age of 10 years. When analysing the effects of the infant cardiac measures on the same outcomes at 10 years in conditional regression models, we observed effect estimates of the same size for the different age windows. Conclusion Our results suggest moderate tracking of structural cardiac measures from early infancy until school-age, which become stronger at older ages, but not of relative wall thickness or fractional shortening. Moderate tracking of cardiac structures suggests that cardiac structures are at least partly determined in early life.

Early Infant Growth Velocity Patterns and Cardiovascular and Metabolic Outcomes in Childhood.

OBJECTIVE: To evaluate the impact of infant growth on childhood health by examining the associations of detailed longitudinal infant weight velocity patterns with childhood cardiovascular and metabolic outcomes. STUDY DESIGN: In a population-based prospective cohort study of 4649 children, we used repeated growth measurements at age 0-3 years to derive peak weight velocity (PWV), age at adiposity peak (AGEAP), and body mass index at adiposity peak (BMIAP). At age 6 years, we measured blood pressure, left ventricular mass, and cholesterol, triglyceride, and insulin concentrations and defined children with clusters of risk factors. We assessed associations using 2 multivariable linear regression models. RESULTS: A 1-SDS-higher infant PWV was associated with higher diastolic blood pressure (0.05 SDS; 95% CI, 0.02-0.09) and lower left ventricular mass (-0.05 SDS; 95% CI, -0.09 to -0.01), independent of body size. A 1-SDS-higher BMIAP was associated with higher systolic (0.12; 95% CI, 0.09-0.16) and diastolic (0.05; 95% CI, 0.01-0.08) blood pressure, but these associations were explained by childhood BMI. We did not observe any associations of PWV, BMIAP, and AGEAP with cholesterol and insulin concentrations. Higher PWV and AGEAP were associated with elevated risk of clustering of cardiovascular risk factors in childhood (P < .05). CONCLUSION: Infant weight velocity patterns are associated with cardiovascular outcomes. Further studies are needed to explore the associations with metabolic outcomes and long-term consequences.

Longitudinal growth during fetal life and infancy and cardiovascular outcomes at school-age.

OBJECTIVE: Low birth weight is associated with cardiovascular disease. We examined the effects of fetal and infant growth patterns on cardiovascular outcomes in children. METHODS: In a population-based prospective cohort study among 6239 children, we estimated fetal-femur length and weight by 20 and 30 weeks ultrasound, and child length and weight at birth, 0.5, 1, 2 and 6 years. We measured blood pressure (BP), carotid-femoral pulse wave velocity, aortic root diameter, left ventricular mass and fractional shortening at 6 years. We used regression analyses to identify longitudinal growth patterns associated with height-standardized vascular outcomes and body-surface-area-standardized cardiac outcomes. RESULTS: Younger gestational age and lower birth weight were associated with higher BP, smaller aortic root diameter and lower left ventricular mass in childhood (all P values <0.05). Children with decelerated or normal fetal growth followed by accelerated infant growth had higher BP, whereas those with decelerated growth during both fetal life and infancy had a relatively larger left ventricular mass. Longitudinal growth analyses showed that children with increased BP tended to be smaller during third trimester of fetal life, but of normal size during infancy, than children with normal BP. Children with increased aortic root diameter or left ventricular mass tended to be larger during fetal life, but of similar size during infancy. CONCLUSION: Specific fetal and infant growth patterns are associated with different cardiovascular outcomes in children. Further studies are needed to identify the underlying mechanisms and the long-term cardiovascular consequences.

Third trimester fetal hemodynamics and cardiovascular outcomes in childhood: the Generation R study.

OBJECTIVE: Low birth weight is associated with cardiovascular disease in adulthood. Hemodynamic adaptations related to fetal growth restriction may underlie these associations, through persistent influences on cardiovascular development. We examined the associations of third trimester fetal hemodynamics with cardiovascular outcomes in childhood. METHODS: In a prospective cohort study among 917 pregnant women and their children, we measured fetal growth, and fetal arterial and cardiac hemodynamic variables with ultrasound and Doppler examinations at a gestational age of 30.3 (95% range 28.8-32.3) weeks. At the age of 6 years, we measured blood pressure, carotid-femoral pulse wave velocity, and left cardiac structures and function. RESULTS: We observed that fetal hemodynamics were not associated with childhood blood pressure and carotid-femoral pulse wave velocity. The fetal aorta ascendens diameter and left cardiac output were positively associated with childhood aortic root diameter [0.14 standard deviation score (SDS), 95% confidence interval (CI) 0.07-0.22 and 0.08 SDS, 95% CI 0.01-0.15 per SDS change in diameter and output, respectively]. Fetal left ventricular diastolic filling pattern was inversely associated with aortic root diameter (-0.07 SDS, 95% CI -0.13 to 0.00 per SDS change in E/A ratio) at 6 years. Analyses adjusted and stratified for estimated fetal weight showed no differences in results. CONCLUSION: Our results suggest that third trimester fetal vascular resistance parameters do not affect blood pressure or arterial stiffness in childhood. Fetal cardiac functional and structural measures are associated with cardiac outcomes in childhood. Whether these early adaptations lead to greater risks of cardiovascular disease should be further studied.

Maternal educational level and blood pressure, aortic stiffness, cardiovascular structure and functioning in childhood: the generation R study.

BACKGROUND: In adults, low level of education was shown to be associated with higher blood pressure levels and alterations in cardiac structures and function. It is currently unknown whether socioeconomic inequalities in arterial and cardiac alterations originate in childhood. Therefore, we investigated the association of maternal education with blood pressure levels, arterial stiffness, and cardiac structures and function at the age of 6 years and potential underlying factors. METHODS: The study included 5,843 children participating in a prospective cohort study in the Netherlands. Maternal education was assessed at enrollment. Blood pressure, carotid-femoral pulse wave velocity, left atrial diameter, aortic root diameter, left ventricular mass, and fractional shortening were measured at the age of 6 years. RESULTS: Children with low educated (category 1) mothers had higher systolic (2.80mm Hg; 95% confidence interval (CI) = 1.62-2.94) and diastolic (1.80mm Hg; 95% CI = 1.25-2.35) blood pressure levels compared with children with high educated (category 4) mothers. The main explanatory factors were the child's body mass index (BMI), maternal BMI, and physical activity. Maternal education was negatively associated with fractional shortening (P trend = 0.008), to which blood pressure and child's BMI contributed the most. No socioeconomic gradient was observed in other arterial and cardiac measurements. CONCLUSIONS: Socioeconomic inequalities in blood pressure are already present in childhood. Higher fractional shortening among children from low socioeconomic families might be a first cardiac adaptation to higher blood pressure and higher BMI. Interventions should be aimed at lowering child BMI and increasing physical activity among children from low socioeconomic families.

Parental smoking during pregnancy and cardiovascular structures and function in childhood: the Generation R Study.

BACKGROUND: Foetal smoke exposure might lead to foetal developmental adaptations that permanently affect the cardiovascular system. We assessed the associations of both maternal and paternal smoking during pregnancy with childhood cardiovascular structures and function. METHOD: In a prospective cohort study among 5565 children, we examined whether maternal and paternal smoking during pregnancy are associated with blood pressure, carotid-femoral pulse wave velocity and left cardiac structures and function in 6-year-old children. RESULTS: As compared with children from non-smoking mothers, children from mothers who smoked more than 10 cigarettes per day had a higher diastolic blood pressure [difference 1.43 mmHg (95% confidence interval: 0.22, 2.63)]. Maternal smoking during pregnancy was not associated with systolic blood pressure, childhood carotid-femoral pulse wave velocity or left cardiac structures. Maternal smoking of 10 or more cigarettes per day was associated with a higher fractional shortening in childhood [difference 1.01% (95% confidence interval: 0.18, 1.84)]. Among mothers who did not smoke during pregnancy, paternal smoking was associated with aortic root diameter but not with other cardiovascular outcomes. CONCLUSIONS: Maternal smoking during pregnancy is associated with higher diastolic blood pressure and fractional shortening, although the effect estimates are small. The stronger effect estimates for maternal smoking compared with paternal smoking might suggest that direct intrauterine adaptive responses are involved as underlying mechanisms.

Infant feeding patterns are associated with cardiovascular structures and function in childhood.

Nutrition in infancy seems to be associated with cardiovascular disease and its risk factors in adulthood. These associations may be explained by cardiovascular developmental adaptations in childhood in response to specific infant feeding patterns. The aim of this study was to assess whether duration and exclusivity of breastfeeding and timing of introduction of solid foods affect cardiovascular development in childhood. In a population-based prospective cohort study from fetal life onward, information about duration and exclusivity of breastfeeding and timing of introduction of solid foods was obtained from delivery reports and questionnaires. Blood pressure, carotid-femoral pulse wave velocity (PWV), left atrial diameter (LAD), aortic root diameter (AOD), left ventricular (LV) mass, and fractional shortening (FS) were measured at a median age of 6.0 y (95% range: 5.6-7.4 y). Analyses were based on 5003 children. Age at introduction of solid foods was negatively associated with systolic and diastolic blood pressure at the age of 6 y. Compared with children who had ever been breast-fed, never-breast-fed children had a higher carotid-femoral PWV (ß: 0.13 m/s; 95% CI: 0.03, 0.24 m/s), a smaller LAD (ß: -0.29 mm; 95% CI: -0.55, -0.03 mm), and less LV mass (ß:-1.46 g; 95% CI: -2.41, -0.52 g) at the age of 6 y. Among breast-fed children, duration and exclusivity were not associated with cardiovascular structures or function. Breastfeeding pattern and age at introduction of solid foods were not associated with AOD or FS. Feeding patterns in infancy may influence cardiovascular development in childhood. Further research is required to replicate these findings and to investigate whether these changes contribute to an increased risk of cardiovascular disease in later life.

Parental psychological distress during pregnancy and childhood cardiovascular development. The Generation R Study.

BACKGROUND: Maternal psychological distress during pregnancy might lead to higher fetal cortisol exposure, which subsequently leads to fetal cardiovascular developmental adaptations and cardiovascular dysfunction in later life. AIMS: We examined whether maternal and paternal psychological distress was associated with the cardiovascular outcome measurements in school age children. STUDY DESIGN AND SUBJECTS: In a population-based prospective cohort study among 4831 children, we assessed maternal and paternal psychological distress during pregnancy by questionnaire, using the Brief Symptom Inventory (see Fig. 1). OUTCOME MEASURES: At the child age of six years, we performed blood pressure and carotid-femoral pulse wave velocity measurements, and M-mode measurements of left cardiac structures and fractional shortening. RESULTS: We did not observe associations of high maternal and paternal psychological symptom scores with childhood blood pressure and carotid-femoral pulse wave velocity after adjustment for potential confounders. Maternal overall psychological symptoms were associated with a lower childhood left ventricular mass (difference -1.10 g (95% confidence interval -2.13 to -0.07) between mothers with high scores and normal scores), but not with other cardiac structures and fractional shortening. Paternal overall psychological symptoms showed a similar association with childhood left ventricular mass (difference -1.34 grams (95% confidence interval -3.69 to 1.02) between fathers with high scores and normal scores). CONCLUSIONS: Our results do not support the hypothesis that maternal psychological distress affects cardiovascular development in early life. Similar associations of maternal and paternal psychological distress with left ventricular mass suggest that these associations could be due to unmeasured social and environmental factors, rather than direct intra-uterine effects.

Enlarged right ventricular size at 11 years' follow-up after closure of secundum-type atrial septal defect in children.

BACKGROUND: The fate of right ventricular dimensions after surgical closure of secundum-type atrial septal defects remains unclear. The objectives of this study were to assess ventricular dimensions, exercise capability, and arrhythmias of patients operated for secundum-type atrial septal defect and compare the results with those in healthy references. METHODS: A total of 78 consecutive patients underwent surgical closure for a secundum-type atrial septal defect between 1990 and 1995. In all, 42 patients were included and underwent a cross-sectional evaluation including echocardiography, magnetic resonance imaging, exercise testing, and 24-hour ambulatory electrocardiography. Patients were matched with healthy controls for gender, body surface area, and age. RESULTS: The mean age at surgery was 4.6 plus or minus 2.8 years, and the mean age at follow-up was 16 plus or minus 3 years. There were no residual intracardiac lesions. The mean right ventricular endsystolic volume was significantly larger in patients (142 ± 26 millilitres) than in references (137 ± 28 millilitres; p = 0.04). In 25% of the patients, right ventricular end-systolic volume was larger than the 95th percentile for references. No relevant arrhythmias were detected. Exercise testing did not reveal differences with healthy references: maximal power (169 ± 43 Watt patients versus 172 ± 53 controls; p = 0.8), maximal oxygen uptake (38 ± 8 versus 41 ± 13 millilitres per minute per kilogram; p = 0.1). COMMENT: After surgical closure of secundum-type atrial septal defect, right ventricular end-systolic volume is increased. These findings have no impact on rhythm status or exercise capacity at this stage of follow-up, but may have implications for the timing of surgery or the technique of closure if confirmed in longer follow-up.

Growth, obesity, and cardiac structures in early childhood: the Generation R Study.

Cardiac structural adaptations in response to physical growth and obesity in older children have been identified and might have long-term consequences. We examined the associations of growth and obesity with cardiac structures during the first 2 years of life. In a population-based prospective cohort study among 974 children, left atrial diameter, left ventricular diastolic diameter, left ventricular mass, aortic root diameter, and fractional shortening were repeatedly measured by ultrasound at the ages of 1.5, 6, and 24 months. Height, weight, and subcutaneous fat mass were measured at the same visits, and blood pressure was measured at the age of 24 months. Height, weight, body mass index, and body surface area were positively associated with all of the cardiac structures during the first 2 years of life. At the age of 24 months, as compared with normal weight children, obese children had a greater left ventricular mass (1.04 SD score [95% CI: 0.20 to 1.89]) and a higher fractional shortening (0.91 SD score [95% CI: 0.02 to 1.80]). Nonsignificant tendencies were found for left atrial diameter, left ventricular diastolic diameter, and aortic root diameter. Our results suggest that normal variation in growth affects cardiac structures in early life. Overweight and obese children show cardiac adaptations already at the age of 2 years. Further studies are needed to assess whether these structural adaptations influence the risk of cardiovascular disease in later life.

Glucocorticoid receptor-9beta polymorphism is associated with systolic blood pressure and heart growth during early childhood. The Generation R Study.

BACKGROUND: glucocorticoid receptor-9ß polymorphism (rs6198) is associated with the susceptibility for cardiovascular disease. AIM: to examine whether the GR-9 ß variant is also associated with blood pressure and heart growth in early childhood. STUDY DESIGN: this study was embedded in a population-based prospective cohort study from fetal life onwards. Analyses were based on 857 children. OUTCOME MEASURES: Left cardiac structures (aortic root diameter, left atrial diameter and left ventricular mass), shortening fraction and heart beat were measured postnatally at the ages of 1.5, 6 and 24 months. Blood pressure was measured at 24 months of age. RESULTS: the distribution of the GR-9ß genotype showed 75.1% homozygous reference, 23.5% heterozygous and 1.4% homozygous variant subjects. No differences in cardiovascular outcomes were observed at the ages of 1.5 and 6 months. At the age of 24 months, homozygous variants showed an increased systolic blood pressure of 2.65 mmHg (95% CI: 0.16, 5.14), an increased heart rate of 9.10 beats per minute (95% CI: 1.28, 16.7) and an increased left ventricular mass of 4.99 g (95% CI: 1.33, 8.65) compared to homozygous references. This means an increase of 2.6%, 8.6% and 16%, respectively. GR-9 ß polymorphism was significantly associated with left ventricular mass growth during the first 2 years. CONCLUSION: our findings suggest that genetically determined differences in cortisol exposure affect cardiovascular development in early life.

Breastfeeding is not associated with left cardiac structures and blood pressure during the first two years of life. The Generation R Study.

BACKGROUND: Shorter duration of breastfeeding in infancy has been suggested to be associated with an increased risk of cardiovascular disease in adulthood. Early cardiovascular adaptations due to breastfeeding may explain these associations. AIM: To investigate whether breastfeeding affects left cardiac structures and blood pressure development in early childhood. STUDY DESIGN: Prospective cohort study from fetal life until the age of two years. SUBJECTS: Information about the duration and exclusivity of breastfeeding was collected by questionnaires at the ages of 2, 6 and 12 months in 933 children. OUTCOME MEASURES: Left cardiac structures (left atrial diameter, aortic root diameter and left ventricular mass), fractional shortening and blood pressure at the ages of 1.5, 6 and 24 months. RESULTS: No differences in cardiac structures, fractional shortening and blood pressure were observed between breastfed and non-breastfed children. Duration and exclusivity of breastfeeding were not consistently associated with any cardiac structure, fractional shortening, or blood pressure until the age of 24 months. Also, there was no association of breastfeeding with cardiac growth between 6 months and 24 months. All analyses were adjusted for child age and sex. Additional adjustment for child anthropometrics, maternal age, anthropometrics, family history, maternal cardiovascular risk factors, pregnancy or delivery complications, parity, socio-economic status, smoking status and alcohol consumption during pregnancy did not materially change the effect estimates. CONCLUSIONS: Our results do not support the hypothesis that early postnatal cardiovascular adaptations underlie the previously shown associations between breastfeeding and cardiovascular disease in adulthood. Further studies are needed to investigate whether and at what age the associations appear.

Reliability of echocardiographic measurements of left cardiac structures in healthy children.

BACKGROUND: Echocardiographic measurements are widely used as outcomes of different studies. The aim of this study was to assess intraobserver and interobserver reliability of echocardiographic measurements in healthy children. MATERIALS AND METHODS: We studied 28 children, with a median age of 7.5 years, and inter-quartile range from 3 to 11 years. Intraobserver and interobserver reliability were assessed by repeated measurements of the diameters of the aortic root, the left atrium, and left ventricular end-diastolic structure. We also measured the ventricular end-diastolic septal thickness and the end-diastolic thickness of the left ventricular posterior wall. We calculated intraclass correlation coefficients, with corresponding 95% confidence intervals, and computed Bland and Altman plots, permitting us to derive limits of agreement plus or minus 2 standard deviations for the mean differences in cardiac measurements. RESULTS: We found high intraobserver and interobserver intraclass correlation coefficient, ranging from 0.91 for ventricular septal thickness, with 95% confidence intervals from 0.78 to 0.96, to 0.99 for the diameter of the aortic root, 95% confidence interval from 0.97 to 1.00. Limits of agreement in the Bland and Altman plots ranged from zero millimetres for left ventricular end-diastolic posterior wall thickness to 1.60 millimeters (6.3%) for left atrial diameter. CONCLUSIONS: Our study demonstrated good repeatability and reproducibility for ultrasonic measurements of left cardiac structures in children, showing that values obtained for measurement of these structures in both clinical and epidemiological research projects can be confidently accepted.

Clinical outcome 5 to 18 years after the Fontan operation performed on children younger than 5 years.

OBJECTIVE: This study assessed clinical condition at midterm follow-up after total cavopulmonary connection for a functionally univentricular heart performed on children younger than 5 years. METHODS: Thirty-four Fontan patients (median age 10.4 years, range 6.8-20.7 years, 22 boys, median follow-up 7.8 years, 5.0-17.8 years) underwent electrocardiography, Holter monitoring, bicycle exercise testing, cardiac magnetic resonance imaging, and N-terminal prohormone brain natriuretic peptide (NT-pro-BNP) analysis. RESULTS: Twenty-three patients (68%) were in sinus rhythm. Holter monitoring demonstrated normal mean heart rate, low maximal heart rate, and no clinically significant arrhythmias or sinus node dysfunction. With maximal bicycle ergometry (n = 19), maximum workload (60% of normal), maximum heart rate (90% of normal), and maximal oxygen uptake (69% of normal) were all significantly lower in the Fontan group than in a control group (P < .001). Variables of submaximal exercise indicated less efficient oxygen uptake during exercise in all Fontan patients. Ejection fraction was lower than in control subjects (59% +/- 13% vs 69% +/- 5%, P < .001). Mean end-diastolic and end-systolic volumes and ventricular mass were higher than in control subjects (P < .001). Mean NT-pro-BNP levels were increased relative to reference values, but only 8 patients had levels above the upper reference limit. CONCLUSION: At midterm follow-up, Fontan patients were in acceptable clinical condition, with preserved global ventricular function, moderately decreased exercise capacity, and NT-pro-BNP levels within reference range. Systemic ventricular mass was elevated, however, suggesting contractility-afterload mismatch. Long-term consequences for ventricular function merit further investigation.

Cardiac structures track during the first 2 years of life and are associated with fetal growth and hemodynamics: the Generation R Study.

BACKGROUND: The aim of this study is to examine whether cardiac size and function track in early childhood and are associated with fetal and early postnatal growth and blood flow characteristics. METHODS: This study was embedded in a population-based prospective cohort study from fetal life onward. Fetal growth and fetal and placental blood flow parameters in second and third trimester of pregnancy were measured by ultrasound and Doppler. Left cardiac structures and shortening fraction were measured postnatally at the ages of 1.5, 6, and 24 months. Analyses were based on 1,001 children. RESULTS: Left ventricular mass tended to remain in the lowest and highest quartiles from the age of 1.5 to 24 months (odds ratio 1.70, 95% confidence interval [CI] 1.10-2.63) and 2.15 (95% CI 1.41-3.30), respectively. Similar results were found for aortic root diameter and left atrial diameter. Birth weight was positively associated with aortic root diameter (0.08 mm, 95% CI 0.01-0.17; per SD increase) and left ventricular mass (0.65 g, 95% CI 0.09-1.21; per SD increase). Resistance indices of the umbilical and uterine arteries showed weak tendencies toward inverse associations with left cardiac structures. Fetal cardiac output was positively associated with both left atrial diameter (increase of 1.96 mm, 95% CI 1.28-2.64; per mL/min increase) and left ventricular mass (increase of 1.79 g, 95% CI 0.35-3.22; per mL/min increase). CONCLUSIONS: This study suggest moderate tracking of left cardiac structures during the first 2 years and that small size and hemodynamic variations in fetal life have consequences for postnatal cardiac size and function.