Background: Disagreement currently exists regarding the definition of aortic dextroposition. It is suggested that the term be used interchangeably with aortic overriding, along with suggestions that the aortic valve overrides in the normal heart. The dextroposed aorta, however, does not always override the crest of the muscular ventricular septum. It is incorrect to argue that the normal aortic valve overrides. It is the cavity of the right aortic valvar sinus, rather than the valvar orifice, that sits above the muscular septum when the septum itself is intact. Therefore, to circumvent these difficulties, those using the term “dextroposition” find it necessary to distinguish “true” as opposed to “false” categories. The problems arise because “dextroposition” is remarkably ill-suited as an alternative term for aortic valvar overriding. Methods and Results: In this review, combining developmental, morphologic, and clinical data, we show how aortic overriding is best considered on the basis of biventricular connection of the aortic root in the setting of deficient ventricular septation. When analysed in this manner, it becomes an easy matter to distinguish between one-to-one and double outlet ventriculo-arterial connections. Appreciation of these features emphasises the different spatial alignments of interventricular communications as opposed to the plane of deficient ventricular septation. The concept of overriding is applicable not only to biventricular connection of the aortic root, but also the pulmonary and common arterial roots. Conclusions: The diagnostic techniques now available to the paediatric cardiologist illustrate the features of arterial valvar overriding with exquisite accuracy, informing the discussions now required for optimal decision making.

Although usually shown in embryology textbooks, the presence of the fifth pair of pharyngeal arch arteries has long been controversial. To the best of our knowledge, six pairs of bilaterally symmetrical arteries developing within the pharyngeal arches are yet to be found in any mammalian or avian species. Collateral channels between the distal ends of the fourth and sixth arch arteries, in contrast, have been found in up to half of all developing mouse embryos. In only one human embryo, again to the best of our knowledge, has a channel been found that extends from the aortic sac to the dorsal aorta, and hence qualifies as an arch artery. Despite these confounding factors in terms of the developmental heritage of the fifth arch arteries, the purported channels are invoked with increasing frequency to describe various lesions discovered in the setting of the congenitally malformed heart. Persistence of the artery of the fifth arch was initially proposed to explain double-barrelled aorta. It was subsequently proposed to account for various systemic-to-pulmonary channels feeding the pulmonary circulation in the setting of pulmonary atresia. It has also been claimed to persist so as to explain abnormal branching of the brachiocephalic arteries from the aortic arch. In the light of the ongoing doubts concerning the existence of the arteries of the fifth arch themselves, we have reviewed the various descriptions of purported fifth arch arteries within the world literature. We have then sought to validate the descriptions on the basis of our own understanding of development, for this purpose providing images of the remoulding arch arteries in the mouse so as to substantiate our conclusions. While accepting that our own interpretations are speculative, we suggest that more convincing alternative explanations can be advanced to account for the majority of lesions currently interpreted on the basis of persistence of the arteries of the fifth arches. Although the interpretations do not necessarily change the therapeutic approaches to the channels, appropriate description is important in terms of their classification.

Around 15% of children and adolescents experience at least one episode of syncope until adulthood. Excluding cardiac disease, the majority of syncopes are of reflex origin and benign in nature. In this situation, a tilt test is conducted to reproduce symptoms and to evaluate cardiovascular adaptations to orthostatism, but its mechanisms are not yet well defined. Here, we investigated haemodynamics and autonomic activity during tilt in young patients. Patients (n=113) with unexplained syncope were enrolled. Tilt followed a standard protocol without provocative agents. A positive response (fainters) was defined as a sudden development of syncope or presyncope associated with hypotension, bradycardia, or both. Haemodynamic parameters, autonomic activity, and baroreflex sensibility were evaluated. Data were analysed on baseline; immediately after tilting; on tilt adaptation; before fainting or before tilt-down for non-fainters; and on tilt-down. A total of 45 patients experienced syncope after a mean time of 18 minutes. During tilting up, fainters showed lower blood pressure and peripheral resistance values, which decreased progressively with time together with baroreflex sensibility. Sympathetic tone increased massively along time till syncope. No changes in cardiac output and heart rate were observed. Results show a strong effort of the autonomic nervous system to adapt to orthostatic stress through different magnitudes of sympathetic output, which was maximal before syncope without apparent modifications of parasympathetic tone. These changes suggest an imbalance between both branches of the autonomic nervous system, not enabling a time-progressive adaptation and leading the subject to faint.

Background: It is important to identify early predictors of functional limitations in children after congenital heart surgery to optimise their independence as they prepare for school. The purpose of this study is to determine potentially modifiable predictor variables of functional abilities in pre-school children who underwent complex cardiac surgery at 6 weeks of age or earlier. Methods: This prospective inception cohort study comprised a sample of 165 survivors (63% boys) who had complex cardiac surgery (75% biventricular repairs) at Stollery Children’s Hospital, Edmonton, Alberta. We excluded children with chromosomal abnormalities. When children were 4–5 years of age, the parents completed the Adaptive Behavioral Assessment System II. Regression analysis was used to assess the association between multiple risk factors and each of the four continuous composite scores. Results: The mean scores for the practical domain and general adaptive composite score of the Adaptive Behavioural Assessment System were lower than the conceptual and social domains, with 13.3% of the children having a delay in the practical domain. There was a significant association between the general adaptive (p=0.003; 0.012), conceptual (p=0.0004; 0.042), social (p=0.0007; 0.028), and the practical (p=0.046; 0.003) domain composite scores with the mother’s education and preoperative plasma lactate, respectively. Conclusion: Maternal education may be a marker for the social context of children, and warrants societal attention to improve functional outcomes. Preoperative lactate as a potentially modifiable variable may warrant increased attention to early diagnosis and aggressive resuscitation of young infants with congenital heart disease.

Objective: We sought to determine the prevalence of attention-deficit/hyperactivity disorder in a population of children who underwent neonatal heart surgery involving repair of the aortic arch for Norwood Stage I, interrupted aortic arch, and combined repair of aortic coarctation with ventricular septal defect. Methods: Children between the ages of 5 and 16 were surveyed using the ADHD-IV and the Child Heath Questionnaire-50. Classification as attention-deficit/hyperactivity disorder was defined for this study as either a parent-reported diagnosis of attention-deficit/hyperactivity disorder or ADHD-IV inattention score of ⩾93 percentile. Results: Of the 134 surveys, 57 (43%) were returned completed. A total of 25 (44%) children either had a diagnosis of attention-deficit/hyperactivity disorder and/or ADHD-IV inattention score ⩾93 percentile. Eleven of the 13 (85%) children with interrupted aortic arch, 3 of the 7 (42.9%) children with combined coarctation/ventricular septal defect repair, and 9 of the 33 (27.3%) children with hypoplastic left-heart syndrome were classified as having attention-deficit/hyperactivity disorder. Only 7 of the 25 (28%) children received medical treatment for this condition. Quality of life indicators in the Child Heath Questionnaire-50 Questionnaire were highly correlated with the ADHD-IV scores. Conclusion: The risks for the development of attention-deficit/hyperactivity disorder are multifactorial but are significantly increased in this post-surgical population. This study revealed a low treatment rate for attention-deficit/hyperactivity disorder, and a significant impact on the quality of life in these children.

Background: Transcatheter closure of coronary artery fistula has emerged as a safe and effective alternative to surgery. However, follow-up angiographic data after closure of the coronary artery fistula is extremely limited. We report our clinical and angiographic follow-up of children who underwent either transcatheter or surgical closure. Method: Clinical profile, echocardiography parameters, and closure technique were retrospectively reviewed from the hospital charts. Since 2007, 15 children have been intervened and followed up with electrocardiography, echocardiography, and angiography. Results: A total of 15 children (six girls), with mean age of 6.7±5.4 years and weighing 16.3±9.8 kg, underwent successful closure (transcatheter=13, surgical=2) without periprocedural complication. Coronary artery fistula arose from the right (n=7) and left coronary artery (n=8) and drained into the right atrium or the right ventricle. Transcatheter closure was carried out using a duct occluder. Of the patients, two underwent surgical closure of the fistula on a beating heart. At 31.8±18.7 months follow-up, all the children were asymptomatic and had no evidence of myocardial ischaemia or infarction. However, follow-up angiography revealed thrombotic occlusion of fistula with the patent parent coronary artery in those having branch coronary artery fistula, and five of seven patients with parent coronary artery fistula had near-complete occlusion of fistula extending into the native coronary artery. Conclusion: Follow-up angiography revealed a high incidence of parent artery occlusion when the fistula was arising from the native artery and not from one of its branches. Coronary artery fistula intervention of the parent coronary artery fistula always carries the potential risk of ischaemia, unless the distal-most exiting segment is the primary site of occlusion.

Kawasaki disease is an acute, febrile syndrome in infancy, characterised by vasculitis of medium-sized arteries, and affects predominantly young children. Family-based studies on Kawasaki disease supports the contribution of genetic factors in disorder manifestation. In a recent genome-wide association study, the polymorphism rs1801274 of FCGR2A [Fc fragment of immunoglobulin G, low-affinity IIa, receptor] gene has been implicated in disease pathogenesis. The aim of the present study was to explore the association of this variant, for the first time, in a group of Kawasaki-diseased patients of Greek origin. A total of 47 Kawasaki-diseased children and 50 control subjects were enrolled in the study. Polymerase chain reaction–restriction fragment length polymorphism assay was performed in rs1801274 genotyping. No association was observed between this polymorphism genotypes’ or alleles’ distribution between Kawasaki-diseased patients and controls. Furthermore, no association was revealed between this polymorphism and cardiovascular complications in Kawasaki-diseased patients. In the literature, the reported data over this polymorphism association with Kawasaki disease in Caucasian patients are contradictory. In addition, the disease shows low prevalence in the Caucasian populations. Therefore, the independent genetic association studies on rs1801274 with Kawasaki disease in various Caucasian groups increase the amount of genetic data, which could be used in a future meta-analysis, increasing the statistical power of the resultant conclusions.

Background: Foetuses with simple tetralogy of Fallot almost universally have a patent ductus arteriosus. Two recently identified cases had an absent patent ductus arteriosus, requiring emergent intervention at birth. The objective of this study was to determine whether foetuses diagnosed with tetralogy of Fallot and no patent ductus arteriosus have poorer outcomes compared with those with tetralogy of Fallot+patent ductus arteriosus. Methods: All foetal cases of tetralogy of Fallot between January, 2000 and 2012 were retrospectively identified from The Hospital for Sick Children (Toronto, Canada) database. Cases – tetralogy of Fallot+no patent ductus arteriosus confirmed on postnatal echo – and controls – tetralogy of Fallot+patent ductus arteriosus, matched for gestational age – were identified from prenatal records, and both clinical and echocardiographic data were reviewed. Optimal outcome was defined as valve-sparing repair with no residual lesions. Student’s t-tests and Fisher’s exact χ2 were used to compare groups. Results: n=115 foetuses were diagnosed with tetralogy of Fallot: 11 (9%) had no patent ductus arteriosus, and were matched to 22 controls – mean gestational age at diagnosis 23.2±4.2 weeks, 23.4±6.6 weeks, respectively. Cases had a higher proportion of right aortic arches (64% versus 14%, p<0.001). Foetal and postnatal echocardiographic data did not reveal significant differences in branch pulmonary artery sizes, pulmonary valve sizes, or ventricular function. No differences were identified for cyanosis at birth (2/10 versus 7/20, p=0.67), or catheter intervention (5/10 versus 4/22, p=0.12). Optimal outcome rates were similar between cases and controls (4/11 (36%) versus 5/21 (24%), p=0.68). Conclusions: The patent ductus arteriosus does not appear to have an impact on clinical outcome in foetuses with tetralogy of Fallot.

Antibiotic prophylaxis in congenital cardiac disease has long been a topic of debate. Although there is little dispute around antibiotic cover for surgical procedures and catheter interventions where foreign material is being inserted, there are little data specific to non-device-placement procedures such as atrial septostomy or balloon valvotomy. We sought to assess the effect of routine prophylaxis on post-interventional infections via a retrospective pseudo-randomised analysis, and an online survey on paediatric interventional cardiologists in the United Kingdom and United States.

Purpose: To explore the use of three-dimensional patient-specific cardiovascular models using rapid prototyping techniques (fused deposition modelling) to improve surgical planning in patients with complex congenital heart disease. Description: Rapid prototyping techniques are used to print accurate three-dimensional replicas of patients' cardiovascular anatomy based on magnetic resonance images using computer-aided design systems. Models are printed using a translucent polylactic acid polymer. Evaluation: As a proof of concept, a model of the heart of a 1.5-year-old boy with transposition of the great arteries, ventricular septal defect and pulmonary stenosis was constructed to help planning the surgical correction. The cardiac model allowed the surgeon to evaluate the location and dimensions of the ventricular septal defect as well as its relationship with the aorta and pulmonary artery. Conclusions: Cardiovascular models constructed by rapid prototyping techniques are extremely helpful for planning corrective surgery in patients with complex congenital malformations. Therefore they may potentially reduce operative time and morbi-mortality.

It has been shown that mitochondrial deoxyribo nucleic acid mutations may play an important role in the development of cardiomyopathy, and various types of cardiomyopathy can be attributed to disturbed mitochondrial oxidative energy metabolism. Several studies have described many mutations in mitochondrial genes encoding for subunits of respiratory chain complexes. Thus, recent studies confirm that pathologic mitochondrial deoxyribo nucleic acid mutations are a major reason of diseases and determining them by next-generation sequencing will improve our understanding of dysregulation of heart development. To analyse mitochondrial deoxyribo nucleic acid mutations, the entire mitochondrial deoxyribo nucleic acid was amplified in two overlapping polymerase chain reaction fragments from the cardiac tissue of the 22 patients with congenital heart disease, undergoing cardiac surgery. Mitochondrial deoxyribo nucleic acid was deep sequenced by next-generation sequencing. A total of 13 novel mitochondrial deoxyribo nucleic acid mutations were identified in nine patients. Of the patients, three have novel mutations together with reported cardiomyopathy mutations. In all, 65 mutations were found, and 13 of them were unreported. This study represents the most comprehensive mitochondrial deoxyribo nucleic acid mutational analysis in patients with congenital heart disease.

Supravalvular aortic aneurysms are less frequent than abdominal ones. Among Supravalvular aortic aneurysm aetiologies, we focused on dystrophic lesions as they can be secondary to genetic causes such as elastin anomaly. We report on a familial 7q11.23 triplication – including the ELN gene – segregating with a supravalvular aortic aneurysm. During her first pregnancy, our index patient was diagnosed with tuberous sclerosis and with a Supravalvular aortic aneurysm. The foetus was affected equally. For the second pregnancy, parents applied for preimplantation diagnosis, and a subsequent prenatal diagnosis was offered to the couple, comprising TSC1 molecular analysis, karyotype, and multiplex ligation probe amplification. TSC1 mutation was not found on foetal deoxyribo nucleic acid. Foetal karyotype was normal, but multiplex ligation probe amplification detected a 7q11.23 duplication. Quantitative-polymerase chain reaction and array-comparative genomic hybridisation carried out to further assess this chromosome imbalance subsequently identified a 7q11.23 triplication involving ELN and LIMK1. Foetal heart ultrasound identified a Supravalvular aortic aneurysm. A familial screening was offered for the 7q11.23 triplication and, when found, heart ultrasound was performed. The triplication was diagnosed in our index case as well as in her first child. Of the 17 individuals from this family, 11 have the triplication. Of the 11 individuals with the triplication, 10 were identified to have a supravalvular aortic aneurysm. Of them, two individuals received a medical treatment and one individual needed surgery. We provide evidence of supravalvular aortic aneurysm segregating with 7q11.23 triplication in this family. We would therefore recommend cardiac surveillance for individuals with 7q11.23 triplication. It would also be interesting to offer a quantitative-polymerase chain reaction or an array-comparative genomic hybridisation to a larger cohort of patients presenting with isolated supravalvular aortic aneurysm, as it may provide further information.

Fibrates are peroxisome proliferator-activated receptor-α agonists and are clinically used for treatment of dyslipidemia and hypertriglyceridemia. Fenofibrate is reported as a cardioprotective agent in various models of cardiac dysfunction; however, limited literature is available regarding the role of gemfibrozil as a possible cardioprotective agent, especially in a non-obese model of cardiac remodelling. The present study investigated the role of gemfibrozil against partial abdominal aortic constriction-induced cardiac hypertrophy in rats. Cardiac hypertrophy was induced by partial abdominal aortic constriction in rats and they survived for 4 weeks. The cardiac hypertrophy was assessed by measuring left ventricular weight to body weight ratio, left ventricular wall thickness, and protein and collagen content. The oxidative stress in the cardiac tissues was assessed by measuring thiobarbituric acid-reactive substances, superoxide anion generation, and reduced glutathione level. The haematoxylin–eosin and picrosirius red staining was used to observe cardiomyocyte diameter and collagen deposition, respectively. Moreover, serum levels of cholesterol, high-density lipoproteins, triglycerides, and glucose were also measured. Gemfibrozil (30 mg/kg, p.o.) was administered since the first day of partial abdominal aortic constriction and continued for 4 weeks. The partial abdominal aortic constriction-induced cardiac oxidative stress and hypertrophy are indicated by significant change in various parameters used in the present study that were ameliorated with gemfibrozil treatment in rats. No significant change in serum parameters was observed between various groups used in the present study. It is concluded that gemfibrozil ameliorates partial abdominal aortic constriction-induced cardiac oxidative stress and hypertrophy and in rats.

To date, no transcatheter valve has been approved for placement in the pulmonary position in Japan. Consequently, percutaneous balloon dilatation may be advised for stenotic right ventricular outflow lesions; however, technical difficulties persist, particularly in adults. We describe the acute haemodynamic changes and outcome of balloon dilatation of right ventricular outflow obstruction using triple ultra-high pressure balloons. This is the first report of such a technical development, which seems to be safe and effective. A total of three adult patients, aged 25, 29, and 37 years, with severe conduit obstruction were referred for balloon dilatation. A triple ultra-high-pressure balloon technique was used in the three patients after unsuccessful double-balloon dilatation, or for highly calcified lesions, which were expected to require ultra-high pressure for effective relief. Following balloon dilatation, the pressure gradient decreased from 24, 30, 65 to 3, 25, 30 mmHg, respectively. There were no procedural complications except slightly increased pulmonary regurgitation. Balloon dilatation using a triple ultra-high pressure balloon technique can be a safe and effective palliative procedure for conduit obstruction in adult patients.