We sought to analyse the variation in the incidence of patent ductus arteriosus over three recent time points and characterise ductal ligation practices in preterm infants in the United States, adjusting for demographic and morbidity factors.

Using the Kids’ Inpatient Database from 2003, 2006, and 2009, we identified infants born at ⩽32 weeks of gestation with International Classification of Diseases, Ninth Revision diagnosis of patent ductus arteriosus and ligation code. We examined patient and hospital characteristics and identified patient and hospital variables associated with ligation.

Of 182,610 preterm births, 30,714 discharges included a patent ductus arteriosus diagnosis. The rate of patent ductus arteriosus diagnosis increased from 14% in 2003 to 21% in 2009 (p<0.001). A total of 4181 ligations were performed, with an overall ligation rate of 14%. Ligation rate in infants born at ⩽28 weeks of gestation was 20% overall, increasing from 18% in 2003 to 21% in 2009 (p<0.001). The ligation rate varied by state (4–28%), and ligation was associated with earlier gestational age, associated diagnoses, hospital type, teaching hospital status, and region (p<0.001).

The rates of patent ductus arteriosus diagnosis and ligation have increased in the recent years. Variation exists in the practice of patent ductus arteriosus ligation and is influenced by patient and non-patient factors.

Adult patients with CHD often require complex operations, and indications for particular aspects of the operation are sometimes unclear. The aims of our study were as follows: to characterise concomitant procedures performed during adult congenital cardiac surgery, and to better define the risk involved with performing concomitant procedures during a single operation.

We retrospectively studied 458 adult congenital cardiac surgical patients. Major procedures were characterised as aortic, mitral, pulmonary, tricuspid, septal defect, single ventricle, transplant, and others. We constructed logistic regression models to assess the risk for mortality, major adverse event, and prolonged length of stay.

A total of 362 operations involved a single major procedure, whereas 96 involved concomitant procedures. Performing concomitant procedures increased mortality (7.3 versus 2.5%), major adverse events (21.8 versus 14.9%), and prolonged length of stay (29.2 versus 17.1%). The added risks of concomitant procedures on mortality, major adverse event, and prolonged length of stay were 2.9 (95% CI 1.0–8.5, p=0.05), 1.9 (95% CI 1.1–3.3, p=0.02), and 2.4 (95% CI 1.4–4.1, p=0.003), respectively. There were 200 patients with conotruncal anomalies who underwent pulmonary valve surgery. In this subset, the added risks of concomitant procedures in addition to pulmonary valve surgery on mortality, major adverse events, and prolonged length of stay were 6.6 (95% CI 1.2–37.3, p=0.03), 2.8 (95% CI 1.2–6.6, p=0.03), and 3.3 (95% CI 1.5–7.4, p=0.005), respectively.

Concomitant procedures performed during adult congenital heart surgery increase risk. Awareness of this risk may improve surgical decision making and outcomes.

Hypoplastic left heart syndrome is the most expensive birth defect managed in the United States, with a 5-year survival rate below 70%. Increasing evidence suggests that hospital volumes are inversely associated with mortality for infants with single ventricles undergoing stage 1 surgical palliation. Our aim was to examine the relative effects of surgeon and institutional volumes on outcomes and resource utilisation for these children.

A retrospective study was conducted using the Pediatric Health Information System database to examine the effects of the number of procedures performed per surgeon and per centre on mortality, costs, and post-operative length of stay for infants undergoing Risk Adjustment for Congenital Heart Surgery risk category six operations at tertiary-care paediatric hospitals, from 1 January, 2004 to 31 December, 2013. Multivariable modelling was used, adjusting for patient and institutional characteristics. Gaussian kernel densities were constructed to show the relative distributions of the effects of individual institutions and surgeons, before and after adjusting for the number of cases performed.

A total of 2880 infants from 35 institutions met the inclusion criteria. Mortality was 15.0%. Median post-operative length of stay was 24 days (IQR 14–41). Median standardized inpatient hospital costs were $156,000 (IQR $108,000–$248,000) in 2013 dollars. In the multivariable analyses, higher institutional volume was inversely associated with mortality (p=0.001), post-operative length of stay (p=0.004), and costs (p=0.001). Surgeon volume was associated with none of the measured outcomes. Neither institutional nor surgeon volumes explained much of the wide variation in outcomes and resource utilization observed between institutions and between surgeons.

Increased institutional – but not surgeon – volumes are associated with reduced mortality, post-operative length of stay, and costs for infants undergoing stage 1 palliation.

Serum digoxin levels have limited utility for determining digoxin toxicity in adults. Paediatric data assessing the utility of monitoring serum digoxin concentration are scarce. We sought to determine whether serum digoxin concentrations are associated with signs and symptoms of digoxin toxicity in children.

We carried out a retrospective review of patients <19 years of age who received digoxin and had serum digoxin concentrations assessed between January, 2007 and June, 2013. Data collection included patient demographics, digoxin indication, serum digoxin concentrations, signs and symptoms of digoxin toxicity, electrocardiograms, and co-morbidities. Reviewers performing chart review and electrocardiogram analysis were blinded to digoxin levels. Descriptive statistical methods were used and comparisons were made between patients with and without toxic serum digoxin concentrations (>2 ng/ml).

There were 87 patients who met study criteria (male 46%, mean age 8.4 years). CHD was present in 67.8% and electrocardiograms were performed in 72.4% of the patients. The most common indication for digoxin toxicity was heart failure symptoms (61.5%). Toxic serum digoxin concentrations were present in 6.9% of patients (mean 2.6 ng/ml). Symptoms associated with digoxin toxicity occurred in 48.4%, with nausea/vomiting as the most common symptom (36.4%), followed by tachycardia (29.5%). Compared with those without toxic serum digoxin concentrations, significantly more patients with toxic serum digoxin concentrations were female (p=0.02). The presence of electrocardiogram abnormalities and/or signs and symptoms of digoxin toxicity was not significantly different between patients with and without serum digoxin concentrations (p>0.05).

Serum digoxin concentrations in children are not strongly associated with signs and symptoms of digoxin toxicity.

We have taken a novel approach using oral rapamycin – sirolimus – as a medical adjunct to percutaneous therapy in patients with in-stent stenosis and high risk of right ventricular failure.

Peripheral pulmonary artery stenosis can result in right ventricular hypertension, dysfunction, and death. Percutaneous pulmonary artery angioplasty and stent placement acutely relieve obstructions, but patients frequently require re-interventions due to re-stenosis. In patients with tetralogy of Fallot or arteriopathy, the problem of in-stent stenosis contributes to the rapidly recurrent disease.

Rapamycin was administered to 10 patients (1.5–18 years) with peripheral pulmonary stenosis and in-stent stenosis and either right ventricular hypertension, pulmonary blood flow maldistribution, or segmental pulmonary hypertension. Treatment was initiated around the time of catheterisation and continued for 1–3 months. Potential side-effects were monitored by clinical review and blood tests.

Target serum rapamycin level (6–10 ng/ml) was accomplished in all patients; eight of the nine patients who returned for clinically indicated catheterisations demonstrated reduction in in-stent stenosis, and eight of the 10 patients experienced no significant side-effects. Among all, one patient developed diarrhoea requiring drug discontinuation, and one patient experienced gastrointestinal bleeding while on therapy that was likely due to an indwelling feeding tube and this patient tolerated rapamycin well following tube removal.

Our initial clinical experience supports that patients with peripheral pulmonary artery stenosis can be safely treated with rapamycin. Systemic rapamycin may provide a novel medical approach to reduce in-stent stenosis.

The aim of this study was to describe the clinical characteristics, progression, treatment, and outcomes in isolated coronary artery fistula cases diagnosed prenatally.

We carried out a retrospective review of babies diagnosed prenatally with coronary artery fistulas between January, 2000 and December, 2013; five fetuses were included. Echocardiographic features and measurements were noted during pregnancy and after birth. Treatment and outcome were noted.

Gestational age at initial diagnosis was between 19 and 22 weeks; four coronary artery fistulas originated from the right and one from the left circumflex coronary artery. Drainage was into the right atrium in four cases and into the left ventricle in one case. There was cardiomegaly in two cases at the initial scan. The size of the fistulas increased during pregnancy in all except one. All prenatal diagnoses were confirmed postnatally. Among all, two patients developed congestive cardiac failure soon after birth and required transcatheter closure of the coronary artery fistula, 5 and 17 days after birth, respectively; three patients remained asymptomatic, and all of them showed progressive dilation of the feeding artery and had closure of the fistula at 20 months, 4 years, and 7 years of age, respectively. During the follow-up period, which ranged 2–14 years, all the patients were alive and well.

Coronary artery fistulas can be diagnosed accurately during fetal life. Some babies may develop congestive cardiac failure soon after birth requiring early treatment. Those treated conservatively should be kept under review as intervention may be required later.

Pressure overload increases in patients with moderate aortic valvular stenosis during exercise. In the absence of symptoms, it remains difficult, however, to discriminate patients for surgery based only on pressure overload. Other parameters, such as the dispersion of ventricular re-polarisation (d-QT), which reportedly increases with the transvalvular pressure gradient, have not been fully studied in this condition.

To determine the pattern of QT and d-QT response to exercise testing in children with moderate aortic valve stenosis in order to evaluate the impact of pressure overload from an electrophysiological perspective.

In all, 15 patients were compared with 15 controls paired for age (14.8±2.5 versus 14.2±1.5 years old) and gender (66.7% male). All the patients underwent exercise stress testing with 12-lead electrocardiograph recording. QT was measured from the onset of QRS to the apex (QTa) at rest, at peak exercise, and at 1 and 3 minutes upon recovery. QT was corrected using the Fridericia equation, and d-QT was calculated.

Resting QTc was similar among the study groups, but increased significantly in study patients compared with the control group at maximal effort (p=0.004) and after 1 (p<0.001) and 3 (p<0.001) minutes of recovery. A significant association was identified between groups for d-QT (p=0.034), and post-hoc tests revealed a significant difference only at rest (p=0.001).

Ventricular re-polarisation abnormalities can be unmasked and highlighted by the assessment of electrical re-polarisation during exercise challenge in patients with asymptomatic moderate aortic valve stenosis. Using QT response to exercise could be beneficial for better optimisation of risk stratification in these patients.

Approximately 6000 children are born with CHD in Germany each year. It is increasingly rare that these children die from their chronic illness. In the present study, data recorded in the National Register for Congenital Heart Defects with respect to the prevalence of specific lesions and sex distribution are compared with that recorded in a published German prevalence study (Prevalence Study) and with the meta-analysis by van der Linde et al.

A descriptive data analysis was performed using a minimal data set. The demographic data included sex and birth year; the medical data comprised the cardiovascular diagnosis according to the short list of the International Paediatric and Congenital Cardiac Code.

As the data analysis shows, the National Register is a clinical register including primarily clinical cases/cases relevant to healthcare. The prevalence values and sex ratios recorded in the register are closer to the values given in the literature than those determined by the Prevalence Study. Severe CHD was slightly over-represented in the National Register compared with the van der Linde et al meta-analysis. The deviations with respect to prevalence values are within an acceptable range.

With its 48,000 patients, the National Register plays a unique and important role for research in the field of CHD. Samples from the National Register can be used as a gold standard for future studies, as the patient population registered in it can be considered representative of CHD in Germany and Europe.

Management of individuals with long QT syndrome, catecholaminergic polymorphic ventricular tachycardia, hypertrophic cardiomyopathy, and arrhythmogenic right ventricular cardiomyopathy may involve exercise restriction and/or β-blocker therapy.

This study assessed the practices of a group of paediatric electrophysiologists regarding the management of genotype-positive/phenotype-positive and genotype-positive/phenotype-negative individuals with these conditions.

An online survey was circulated to members of the Pediatric and Congenital Electrophysiology Society in May, 2014. The survey included questions addressing the respondents’ approach regarding exercise recommendations and prescription of β-blocker therapy.

A total of 45 cardiologists completed the survey. The majority of respondents restricted symptomatic patients from competitive sports; however, only approximately half restricted phenotype-negative mutation carriers from this level of activity. Recommendations were less consistent regarding other types of activities. A trend was identified regarding physician physical activity and exercise recommendations for phenotype-negative mutation carriers. Less-active physicians were more likely to restrict exercise. β-blocker therapy was discussed by the majority of respondents for symptomatic patients and a significant number of asymptomatic patients.

Exercise restriction for patients with long QT syndrome, catecholaminergic polymorphic ventricular tachycardia, hypertrophic cardiomyopathy, and arrhythmogenic right ventricular cardiomyopathy varies based on several factors including phenotype, type of exercise, guidelines referred to, and physicians’ own level of activity.

Patients with bidirectional cavopulmonary anastomosis have unphysiologically high superior caval vein pressure as it equals pulmonary artery pressure. Elevated superior caval vein pressure may cause communicating hydrocephalus and macrocephaly. This study analysed whether there exists an association between head circumference and superior caval vein pressure in patients with single ventricle physiology.

We carried out a retrospective analysis of infants undergoing Fontan completion at our institution from 2007 to 2013. Superior caval vein pressures were measured during routine catheterisation before bidirectional cavopulmonary anastomosis and Fontan completion as well as head circumference, adjusted to longitudinal age-dependent percentiles.

We included 74 infants in our study. Median ages at bidirectional cavopulmonary anastomosis and Fontan were 4.8 (1.6–12) and 27.9 (7–40.6) months, respectively. Head circumference showed significant growth from bidirectional cavopulmonary anastomosis until Fontan completion (7th (0–100th) versus 20th (0–100th) percentile). There was no correlation between superior caval vein pressure and head circumference before Fontan (R2=0.001). Children with lower differences in superior caval vein pressures between pre-bidirectional cavopulmonary anastomosis and pre-Fontan catheterisations showed increased growth of head circumference (R2=0.19).

Patients with moderately elevated superior caval vein pressure associated with single ventricle physiology did not have a tendency to develop macrocephaly. There is no correlation between superior caval vein pressure before Fontan and head circumference, but between bidirectional cavopulmonary anastomosis and Fontan head circumference increases significantly. This may be explained by catch-up growth of head circumference in patients with more favourable haemodynamics and concomitant venous pressures in the lower range. Further studies with focus on high superior caval vein pressures are needed to exclude or prove a correlation.

The physiological importance of the lateral tunnel stenosis in the Fontan pathway for children with single ventricle physiology can be difficult to determine. The impact of the stenosis and stent implantation on total cavopulmonary connection resistance has not been characteriszed, and there are no clear guidelines for intervention.

A computational framework for haemodynamic assessment of stent implantation in patients with lateral tunnel stenosis was developed. Cardiac magnetic resonances images were reconstructed to obtain total cavopulmonary connection anatomies before stent implantation. Stents with 2-mm diameter increments were virtually implanted in each patient to understand the impact of stent diameter. Numerical simulations were performed in all geometries with patient-specific flow rates. Exercise conditions were simulated by doubling and tripling the lateral tunnel flow rate. The resulting total cavopulmonary connection vascular resistances were computed. A total of six patients (age: 14.4±3.1 years) with lateral tunnel stenosis were included for preliminary analysis. The mean baseline resistance was 1.54±1.08 WU·m2 and dependent on the stenosis diameter. It was further exacerbated during exercise. It was observed that utilising a stent with a larger diameter lowered the resistance, but the resistance reduction diminished at larger diameters.

Using a computational framework to assess the severity of lateral tunnel stenosis and the haemodynamic impact of stent implantation, it was observed that stenosis in the lateral tunnel pathway was associated with higher total cavopulmonary connection resistance than unobstructed pathways, which was exacerbated during exercise. Stent implantation could reduce the resistance, but the improvement was specific to the minimum diameter.

In patients with CHD, cardiac MRI is often indicated for functional and anatomical assessment. With the recent introduction of MRI-conditional pacemaker systems, cardiac MRI has become accessible for patients with pacemakers. The present clinical study aims to evaluate safety, susceptibility artefacts, and image reading of cardiac MRI in patients with CHD and MRI-conditional pacemaker systems.

CHD patients with MRI-conditional pacemaker systems and a clinical need for cardiac MRI were examined with a 1.5-T MRI system. Lead function was tested before and after MRI. Artefacts and image readings were evaluated using a four-point grading scale.

A total of nine patients with CHD (mean age 34.0 years, range 19.5–53.6 years) received a total of 11 cardiac MRI examinations. Owing to clinical indications, seven patients had previously been converted from conventional to MRI-conditional pacemaker systems. All MRI examinations were completed without adverse effects. Device testing immediately after MRI and at follow-up showed no alteration of pacemaker device and lead function. Clinical questions could be addressed and answered in all patients.

Cardiac MRI can be performed safely with high certainty of diagnosis in CHD patients with MRI-conditional pacemaker systems. In case of clinically indicated lead and box changing, CHD patients with non-MRI-conditional pacemaker systems should be considered for complete conversion to MRI-conditional systems.

We sought to benchmark the utilisation of echocardiography in the outpatient evaluation of heart murmurs by evaluating two large paediatric cardiology centres.

Although criteria exist for appropriate use of echocardiography, there are no benchmarking data demonstrating its utilisation.

We performed a retrospective cohort study of outpatients aged between 0 and 18 years at the Sibley Heart Center Cardiology and the Children’s Hospital of Philadelphia Division of Cardiology, given a sole diagnosis of “innocent murmur” from 1 July, 2007 to 31 October, 2010. Using internal claims data, we compared the utilisation of echocardiography according to centre, patient age, and physician years of service.

Of 23,114 eligible patients (Sibley Heart Center Cardiology: 12,815, Children’s Hospital of Philadelphia Division of Cardiology: 10,299), 43.1% (Sibley Heart Center Cardiology: 45.2%, Children’s Hospital of Philadelphia Division of Cardiology: 40.4%; p<0.001) underwent echocardiography. There was wide variability in the utilisation of echocardiography by individual physicians at both centres (Sibley Heart Center Cardiology 18.3–85.5%, median 45.4%; Children’s Hospital of Philadelphia Division of Cardiology 13.9–81.8%, median 34.7%, p=0.45). Children in their first month of life represented the group with highest utilisation of echocardiography (62.3%), whereas children aged >1–5 years had the lowest utilisation (32.7%).

In two large paediatric cardiology practices, the overall utilisation of echocardiography by physicians with a sole diagnosis of innocent murmur was similar. There was significant and similar variability in utilisation by provider at both centres. Although these data serve as initial benchmarking, the variability in utilisation highlights the importance of appropriate use criteria.

The present study aims to evaluate the epidemiological characteristics of paediatric pulmonary hypertension within the entire Turkish population over a period of 5 years using the registry of the National Health Insurance System.

All individuals aged <18 years who were admitted to a Turkish hospital for the first time between 2009 and 2013 with a discharge diagnosis of idiopathic pulmonary hypertension and secondary pulmonary hypertension were identified.

The overall annual incidence of idiopathic pulmonary hypertension during childhood was 11.7 cases/million, whereas the overall annual incidence of secondary pulmonary hypertension during childhood was 9.5 cases/million. There was a gradual and significant increase in the annual incidence of idiopathic pulmonary hypertension and that of secondary pulmonary hypertension during the 5-year study period (p=0.001 for both). In the years 2012 and 2013, idiopathic pulmonary hypertension was significantly more frequent in children aged <2 years when compared with children aged above 2 years (p=0.002 for both). The male to female ratio was 1.2:1 for idiopathic pulmonary hypertension, whereas the female to male ratio was 1.1:1 for secondary pulmonary hypertension during childhood.

The incidence of paediatric pulmonary hypertension in Turkey is higher than those reported for the Western populations. Moreover, no female dominance could be observed. These discrepancies may be attributed to the differences in the study design, study cohort, timing of the study, and the definitions adopted for pulmonary hypertension classification.

New paediatric cardiology trainees are required to rapidly assimilate knowledge and gain clinical skills to which they have limited or no exposure during residency. The Pediatric Cardiology Fellowship Boot Camp (PCBC) at Boston Children’s Hospital was designed to provide incoming fellows with an intensive exposure to congenital cardiac pathology and a broad overview of major areas of paediatric cardiology practice.

The PCBC curriculum was designed by core faculty in cardiac pathology, echocardiography, electrophysiology, interventional cardiology, exercise physiology, and cardiac intensive care. Individual faculty contributed learning objectives, which were refined by fellowship directors and used to build a programme of didactics, hands-on/simulation-based activities, and self-guided learning opportunities.

A total of 16 incoming fellows participated in the 4-week boot camp, with no concurrent clinical responsibilities, over 2 years. On the basis of pre- and post-PCBC surveys, 80% of trainees strongly agreed that they felt more prepared for clinical responsibilities, and a similar percentage felt that PCBC should be offered to future incoming fellows. Fellows showed significant increase in their confidence in all specific knowledge and skills related to the learning objectives. Fellows rated hands-on learning experiences and simulation-based exercises most highly.

We describe a novel 4-week-long boot camp designed to expose incoming paediatric cardiology fellows to the broad spectrum of knowledge and skills required for the practice of paediatric cardiology. The experience increased trainee confidence and sense of preparedness to begin fellowship-related responsibilities. Given that highly interactive activities were rated most highly, boot camps in paediatric cardiology should strongly emphasise these elements.