Young patients with Fontan circulation may have low serum 25-hydroxyvitamin D levels, an affected liver, and unhealthy body compositions. This study aimed to explore the association between vitamin D intake/levels, liver biomarkers, and body composition in young Fontan patients.

We collected prospective data in 2017 to 2018, obtained with food-frequency questionnaires, biochemical analyses of liver biomarkers, and dual-energy X-ray absorptiometry scans in 44 children with Fontan circulation. Body compositions were compared to matched controls (n = 38). Linear regression analyses were used to investigate associations of biomarkers, leg pain, and lean mass on serum levels of 25-hydroxyvitamin D. Biomarkers were converted to z scores and differences were evaluated within the Fontan patients.

Our Fontan patients had a daily mean vitamin D intake of 9.9 µg and a mean serum 25-hydroxyvitamin D of 56 nmol/L. These factors were not associated with fat or lean mass, leg pain, or biomarkers of liver status. The Fontan patients had significantly less lean mass, but higher fat mass than controls. Male adolescents with Fontan circulation had a greater mean abdominal fat mass than male controls and higher cholesterol levels than females with Fontan circulation.

Vitamin D intake and serum levels were not associated with body composition or liver biomarkers in the Fontan group, but the Fontan group had lower lean mass and higher fat mass than controls. The more pronounced abdominal fat mass in male adolescents with Fontan circulation might increase metabolic risks later in life.

Impaired isometric muscle strength was previously reported in adults with Fontan circulation. However, it is unclear if this impairment is present in children and adolescents with Fontan circulation. We investigated isometric muscle strength of the lower limb in patients (6–18 years) with Fontan circulation in comparison with healthy controls.

In this cross-sectional study, 43 patients (6–18 years) with Fontan circulation and 43 age- and sex-matched controls were included. Isometric knee extension and plantar flexion muscle strength were assessed using dynamometry (Newton, N). Lean mass of the legs was assessed with dual-energy X-ray absorptiometry. Analyses were performed on group level (n = 43), and for subgroups that included children aged 6–12 years (n = 18) and adolescents aged 13–18 years (n = 25).

On group level, the patients with Fontan circulation had impaired isometric knee extension strength in comparison with the controls (p = 0.03). In subgroup analyses, impaired isometric knee extension strength was present in the adolescents (p = 0.009) but not in the children groups. For plantar flexion, there was no difference between patients and controls. There was no difference in lean mass between patients and controls (9.6 ± 4.3 kg vs. 10.8 ± 5.6 kg, p = 0.31). However, the lean mass was highly correlated to isometric knee extension strength (patients r = 0.89, controls r = 0.96, p < 0.001) and isometric plantar flexion strength (patients r = 0.7, controls r = 0.81, p < 0.001).

The finding of impaired isometric knee extension muscle strength in adolescents (13–18 years) with Fontan circulation and no corresponding impairment in the children group (6–12 years) could imply that isometric muscle strength gets more impaired with age.

Secundum atrial septal defect is one of the most common congenital heart defects. Previous paediatric studies have mainly addressed echocardiographic and few clinical factors among children associated with adverse events. The aim of this study was to identify neonatal and other clinical risk factors associated with adverse events up to one year after closure of atrial septal defect.

This retrospective case–control study includes children born in Sweden between 2000 and 2014 that were treated surgically or percutaneously for an atrial septal defect. Conditional logistic regression was used to evaluate the association between major and minor adverse events and potential risk factors, adjusting for confounding factors including prematurity, neonatal sepsis, neonatal general ventilatory support, symptomatic atrial septal defects, and pulmonary hypertension.

Overall, 396 children with 400 atrial septal defect closures were included. The median body weight at closure was 14.5 (3.5–110) kg, and the median age was 3.0 (0.1–17.8) years. Overall, 110 minor adverse events and 68 major events were recorded in 87 and 49 children, respectively. Only symptomatic atrial septal defects were associated with both minor (odds ratio (OR) = 2.18, confidence interval (CI) 95% 1.05–8.06) and major (OR = 2.80 CI 95% 1.23–6.37) adverse events.

There was no association between the investigated neonatal comorbidities and major or minor events after atrial septal defect closure. Patients with symptomatic atrial septal defects had a two to four times increased risk of having a major event, suggesting careful management and follow-up of these children prior to and after closure.

To study physical activity and sleep in Fontan patients and healthy controls before and after an endurance training program, and after 1 year.

Fontan patients (n = 30) and healthy controls (n = 25) wore accelerometers for seven consecutive days and nights during a school week before and after a 12-week endurance training program and after 1 year.

Patients had similar sleep duration and sleep efficiency as healthy controls. Latency to sleep onset in minutes was longer for patients than controls (22.4 (4.3–55.3) minutes versus 14.8 (8.6–29.4) minutes, p < 0.01). More time in moderate-to-vigorous activity daytime was correlated with increased sleep time (p < 0.05; r2 = 0.20), improved sleep efficiency (p < 0.01; r2 = 0.24) and less time as wake after sleep onset (p < 0.05; r2 = 0.21) for patients but not controls. Sleep variables did not change after the exercise intervention for patients or controls. After 1 year, patients had decreased total sleep time, decreased sleep efficiency, increased accelerometer counts during sleep and more time as wake after sleep onset during sleep time, but not controls.

Fontan patients have prolonged latency to sleep onset compared with controls. More time in physical activities was correlated with better sleep quality for the patients. Also, subjects with low sleep efficiency and long latency to sleep onset may benefit most from physical exercise. These patients should be encouraged to engage in individually designed physical exercise as this could improve sleep quality.

Atrial septal defect is the third most common CHD. A hemodynamically significant atrial septal defect causes volume overload of the right side of the heart. Preterm children may suffer from both pulmonary and cardiac comorbidities, including altered myocardial function. The aim of this study was to compare the rate of adverse events following atrial septal defect closure in preterm- and term-born children.

We performed a retrospective cohort study including children born in Sweden, who had a surgical or percutaneous atrial septal defect closure at the children’s hospitals in Lund and Stockholm, between 2000 and 2014, assessing time to the first event within 1 month or 1 year. We analysed differences in the number of and the time to events between the preterm and term cohort using the Kaplan–Meier survival curve, a generalised model applying zero-inflated Poisson distribution and Gary-Anderson’s method.

Overall, 413 children were included in the study. Of these, 93 (22.5%) were born prematurely. The total number of adverse events was 178 (110 minor and 68 major). There was no difference between the cohorts in the number of events, whether within 1 month or within a year, between major (p = 0.69) and minor (p = 0.84) events or frequencies of multiple events (p = 0.92).

Despite earlier procedural age, larger atrial septal defects, and higher comorbidity than term children, preterm children appear to have comparable risk for complications during the first year after surgical or percutaneous closure.

The objective of this research was to study lung function, physical capacity, and effect of endurance training in children and adolescents after Fontan palliation compared with healthy matched controls.

Fontan patients (n=30) and healthy matched control patients (n=25) performed dynamic and static spirometry, and pulmonary diffusing capacity and maximal oxygen uptake tests, before and after a 12-week endurance training programme and at follow-up after 1 year.

Fontan patients had a restrictive lung pattern, reduced pulmonary diffusing capacity (4.27±1.16 versus 6.61±1.88 mmol/kPa/minute, p<0.001), and a reduced maximal oxygen uptake (35.0±5.1 versus 43.7±8.4 ml/minute/kg, p<0.001) compared with controls. Patients had air trapping with a higher portion of residual volume of total lung capacity compared with controls (26±6 versus 22±5%, p<0.05). Vital capacity increased for patients, from 2.80±0.97 to 2.91±0.95 L, p<0.05, but not for controls after endurance training. The difference in diffusing capacity between patients and controls appeared to be greater with increasing age.

Fontan patients have a restrictive lung pattern, reduced pulmonary diffusing capacity, and reduced maximal oxygen uptake compared with healthy controls. Endurance training may improve vital capacity in Fontan patients. The normal increase in pulmonary diffusing capacity with age and growth was reduced in Fontan patients, which is concerning. Apart from general health effects, exercise may improve lung function in young Fontan patients and should be encouraged.

Children after Fontan palliation have reduced exercise capacity and quality of life. Our aim was to study whether endurance training could improve physical capacity and quality of life in Fontan patients.

Fontan patients (n=30) and healthy age- and gender-matched control subjects (n=25) performed a 6-minute walk test at submaximal capacity and a maximal cycle ergometer test. Quality of life was assessed with Pediatric Quality of Life Inventory Version 4.0 questionnaires for children and parents. All tests were repeated after a 12-week endurance training programme and after 1 year.

Patients had decreased submaximal and maximal exercise capacity (maximal oxygen uptake 35.0±5.1 ml/minute per·kg versus 43.7±8.4 ml/minute·per·kg, p<0.001) and reported a lower quality of life score (70.9±9.9 versus 85.7±8.0, p<0.001) than controls. After training, patients improved their submaximal exercise capacity in a 6-minute walk test (from 590.7±65.5 m to 611.8±70.9 m, p<0.05) and reported a higher quality of life (p<0.01), but did not improve maximal exercise capacity. At follow-up, submaximal exercise capacity had increased further and improved quality of life was sustained. The controls improved their maximal exercise capacity (p<0.05), but not submaximal exercise capacity or quality of life after training. At follow-up, improvement of maximal exercise capacity was sustained.

We believe that an individualised endurance training programme for Fontan patients improves submaximal exercise capacity and quality of life in Fontan patients and the effect on quality of life appears to be long-lasting.