Based on experience in several centers, the double switch operation has reportedly become the standard surgical therapy for congenitally corrected transposition. We report and discuss here the use of a “ventricle and a half” double switch operation performed due to the concerns raised intraoperatively because of the size of the morphologically right ventricle. Although the long-term course of such a procedure in this setting remains unknown, we submit that the proposed benefits of the double switch operation, even when used in the “ventricle and a half” configuration, may be superior to the alternatives.

The rate of morbidity and mortality related to pulmonary regurgitation and pulmonary stenosis are big concerns after the surgery for CHD. Percutaneous pulmonary valve implantation has been established as a less invasive technique compared to surgery with promising results according to long-term follow-up of the patients. There are only two approved valve options for percutaneous pulmonary valve implantation until now, which are Melody (Medtronic, Minneapolis, Minn, USA) and Sapien (Edwards Lifesciences, Irvine, Ca, USA). Both valves have limitations and do not cover entire patient population. Therefore, the cardiologists need more options to improve outcomes with fewer complications in a such promising area. Herein, we present a case series applying for pulmonary position in conduits and native right ventricular outflow tract of a new transcatheter valve system Myval ® which is designed for transcatheter aortic valve implantation procedures. This is the first patient series in which the use of Myvalv in dysfunctional right ventricular outflow tracts is described, after surgical repair of CHD.

Background: Holt–Oram syndrome is characterised by CHD and limb anomalies. Mutations in TBX5 gene, encoding the T-box transcription factor, are responsible for the development of Holt–Oram syndrome, but such mutations are variably detected in 30–75% of patients. Methods: Clinically diagnosed eight Holt–Oram syndrome patients from six families were evaluated the clinical characteristics, focusing on the cardiac manifestations, in particular, and molecular aetiologies. In addition to the investigation of the mutation of TBX5, SALL4, NKX2.5, and GATA4 genes, which are known to regulate cardiac development by physically and functionally interacting with TBX5, were also analyzed. Multiple ligation-dependent probe amplification analysis was performed to detect exonic deletion and duplication mutations in these genes. Results: All included patients showed cardiac septal defects and upper-limb anomalies. Of the eight patients, seven underwent cardiac surgery, and four suffered from conduction abnormalities such as severe sinus bradycardia and complete atrioventricular block. Although our patients showed typical clinical findings of Holt–Oram syndrome, only three distinct TBX5 mutations were detected in three families: one nonsense, one splicing, and one missense mutation. No new mutations were identified by testing SALL4, NKX2.5, and GATA4 genes. Conclusions: All Holt–Oram syndrome patients in this study showed cardiac septal anomalies. Half of them showed TBX5 gene mutations. To understand the genetic causes for inherited CHD such as Holt–Oram syndrome is helpful to take care of the patients and their families. Further efforts with large-scale genomic research are required to identify genes responsible for cardiac manifestations or genotype–phenotype relation in Holt–Oram syndrome.

As interest increase in the Ross procedure performed as a therapeutic option for children with congenital aortic valvar stenosis, it becomes increasinly important to know the late results of aortic valvotomy in this population. We have therefore examined retrospectively the medical records of 121 consecutives survivors undergoing aortic valvotomy before 10 years of age between 1974 and 1992. The mean age at the first valvotomy was 29 months, with a range from 3 days to 10 years. The mean duration of follow up was 9.4 years, with a range from 1.6 to 22 years. Fifteen patients (12.3%; 70% CL: 10–16) died: 9 following reoperation, and 6 late after surgery. Death was related to the hearts in 86% of cases. The actuarial survival rate was 79% (70% CL: 72/84) at 10 years. Young age at the first valvotomy, and the number of procedures, emerged as risk factors of secondary mortality. Reoperations on the aortic valve, 73 in all, were required in 56 patients. The second procedure was done after a mean interval of 6 years, with a rangefrom 1 day to 18 years. This was for restenosis in three-quarters of the cases. The aortic valve was replaced in 30 patients, at a mean of 9 years, and with a range from 9 months to 18 years, after the first procedure. The survival without replacement at 20 years was 29% (70% CL: 15–49). No factor was identified with a relationship either to reoperation or valvar replacement. Long term results after aortic valvotomy, therefore, show a high late mortality, frequent reinterventions, and an almost inescapable eventual need for valvar replacement. The ongoing use of the Ross operation is justified, even if longterm studies in children are still needed to validate its use.

We carried out a detailed clinical, epidemiological, and echocardiographic study in 41 patients ≤14 years of age who were admitted in a public hospital in Salvador, Brazil, with severe rheumatic heart disease.

Mitral insufficiency was severe in 90%, and moderate in 10%, of the patients. A posteriorly directed jet was seen in 93% of the patients. We identified three mechanisms producing the regurgitation: prolapse of the aortic leaflet of the mitral valve in 13 (32%) patients, rupture of tendinous cords in 14 (34%), and a retracted, non-coapting mural leaflet in 14 (34%). The mean ages, with standard deviations, for these three groups were 7.0 (1.6) years, 7.9 (2.2) years, and 10.5 (2.4) years, respectively (p < 0.001). Rheumatic activity was diagnosed in 58.5% of them. Evidence of previous rheumatic fever was present in 54% of patients with prolapse, in all patients with rupture, and in 93% of those with non-coapting leaflets (p = 0.002).

Prolapse of the aortic leaflet, rupture of tendinous cords, and a retracted, non-coapting mural leaflet are the mechanisms responsible for mitral valvar insufficiency in children and adolescents with severe rheumatic heart disease. Prolapse seems to be an early phenomenon in the natural history of rheumatic heart disease, while rupture and non-coaption of the leaflets were associated with older age and signs of chronic rheumatic disease.

Ventricular septal defects – large, surgically closed or small, untreated – have demonstrated lower peak exercise capacity compared with healthy controls. The mechanisms behind these findings are not yet fully understood. Therefore, we evaluated biventricular morphology in adults with a ventricular septal defect using MRI. Adults with either childhood surgically closed or small, untreated ventricular septal defects and healthy controls underwent cine MRI for the evaluation of biventricular volumes and quantitative flow scans for measurement of stroke index. Scans were analysed post hoc in a blinded manner. In total, 20 operated patients (22±2 years) and 20 healthy controls (23±2 years) were included, along with 32 patients with small, unrepaired ventricular septal defects (26±6 years) and 28 controls (27±5 years). Operated patients demonstrated larger right ventricular end-diastolic volume index (103±20 ml/m2) compared with their controls (88±16 ml/m2), p=0.01. Heart rate and right ventricular stroke index did not differ between operated patients and controls. Patients with unrepaired ventricular septal defects revealed larger right ventricular end-diastolic volume index (105±17 ml/m2) compared with their controls (88±13 ml/m2), p<0.01. Furthermore, right ventricular stroke index was higher in unrepaired ventricular septal defects (53±12 ml/minute/m2) compared with controls (46±8 ml/minute/m2), p=0.02, with similar heart rates. Both patient groups’ right ventricles were visually characterised by abundant coarse trabeculation. Positive correlations were demonstrated between right ventricular end-diastolic volume indices and peak exercise capacity in patients. Left ventricle measurements displayed no differences between groups. In conclusion, altered right ventricular morphology was demonstrated in adults 20 years after surgical ventricular septal defect repair and in adults with small, untreated ventricular septal defects.

Ventriculo-coronary arterial communications are rare congenital heart defects which have been explained traditionally on the basis of abnormal persistence of such communications found in the normal developing heart. Recent studies, however, have suggested that these embryonic communications might be an incidental finding rather than a normal feature. Thus, it has been suggested that congenital ventriculo-coronary communications do not represent remnants of normal embryonic vessels, but rather represent acquired lesions. In the present study, hearts were constructed in embryonic chicks in which the coronary vasculature was almost completely derived from a quail-donor. After immunohistochemical staining of the quail-derived coronary endothelium, chimeric hearts were analysed with respect to the presence of embryonic ventriculo-coronary communications, and with respect to the origin of these structures from either coronary arteries or endocardium. The results demonstrate the normal presence of ventriculo-coronary communications in avian embryonic hearts. They show, furthermore, that these structures are of coronary endothelial origin. The findings are in accord with the traditional view on the pathogenesis of congenital ventriculo-coronary communications. The roles of elevated ventricular pressure, abnormal remodelling of the developing myocardium, and of abnormal growth of the coronary vasculature are discussed relative to the pathogenesis of congenital ventriculo-coronary communications.

A congenital fistulous connection between the right pulmonary artery and the left atrium is a rare condition, resulting in early cyanosis and cardiac failure. These patients usually required urgent surgery. We present a neonate in whom we successfully closed such a large fistula via catheterization with an Amplatzer Duct Occluder, resulting in rapid clinical improvement, and obviating the need for surgical repair.

Introduction: Pulmonary arterial hypertension, both primary and secondary, continues to pose a therapeutic problem. In this study, we evaluate the efficacy and safety of a low-dose of oral sildenafil in 10 patients with pulmonary arterial hypertension. Methods: We administered a single daily dose of 0.5 milligrams per kilogram of sildenafil for 3 months to 10 patients with pulmonary arterial hypertension. Their average age was 26.8 years. Diagnoses were primary pulmonary arterial hypertension in 3 patients, and secondary pulmonary arterial hypertension due to congenital cardiac disease in the remaining 7 patients. Outcome measures included the clinical state, the mean pulmonary arterial pressure, and the indexed pulmonary vascular resistance; the latter two assessed at the beginning and at the end of the treatment period by cardiac catheterization. We also analysed the cost of the treatment. Results: Oral treatment was well tolerated, and resulted in an improvement of the functional capacity in 9 of the 10 patients. Pulmonary arterial pressure decreased from 70 to 60 millimetres of mercury (p equal to 0.05), and indexed pulmonary vascular resistance decreased from 21.8 to 15.8 Wood units per square metre (p equal to 0.006). The mean cost per patient for 3 months on oral treatment with sildenafil was 120.99 American dollars. Conclusions: A low dose of 0.5 milligrams per kilogram per day of oral sildenafil, instead of 1 to 4 milligrams per kilogram per day, provided early clinical and haemodynamic improvements, and proved less expensive. Additional experience is now required to define more reliably the true long-term benefits of this therapy.

The direct visualization of systemic microcirculation using intravitalmicroscopy permits the classification of proinflammatory and ischemic microvascular alterations during normothermic and hypothermic cardiopulmonary bypass in neonates. We used seven newborn piglets, on average aged 9 days, and weighing 3200 g, as a control group. In addition, we studied nine piglets subjected to 60 minutes of constant non-pulsatile flow using hypothermic extracorporeal circulation at 28°C, and five piglets using normothermic conditions at 37°C. The microvascular network of the greater omentum and the subcutaneous tissue was directly visualized using intravitalmicroscopy. We analysed interactions between leukocytes and endothelial cells, microvascular morphology, and microrheological conditions, focussing on signs of ischemic and proinflammatory alterations. During normothermic cardiopulmonary bypass, the numbers of activated leukocytes were elevated compared to hypothermic cardiopulmonary bypass (p > 0.05). Arteriolar diameter decreased during hypothermia. Capillaries were markedly dilated during normothermia. Patterns of microvascular perfusion, for both types of cardiopulmonary bypass, showed signs of ischemic damage, revealed by a reduced functional capillary density. Perfusion dependent levels of lactate were higher during normothermic cardiopulmonary bypass (p > 0.05). This new experimental approach revealed that non-pulsatile cardiopulmonary bypass, independent of temperature, induces a proinflammatory and ischemic response compared to an unaltered control group. The markedly elevated numbers of activated adherent leukocytes, the reduced capillary density, and the high lactate levels in those undergoing bypass in normothermic conditions indicate a more pronounced inflammatory stimulus and tissue hypoperfusion compared to the possible protective effect of hypothermia for children undergoing cardiopulmonary bypass.

Various physiologic mechanisms have been proposed to account for the development of hypoplasia of the left heart. The mechanism thus far most widely accepted suggests that the entity starts as severe or critical aortic stenosis during fetal gestation. Obstruction at the level of the abnormal aortic valve is then held to increase left ventricular afterload, resulting in decreased systolic and diastolic function. Shunting across the patent oval foramen is then reversed, so that blood flows from left to right. This reversal of flow during fetal gestation decreases the volume of blood crossing the mitral valve, thus decreasing the further potential for growth of the left ventricle.1 Additional support for this postulated physiologic mechanism was provided with the advent of fetal echocardiography during the 1980s.2–4 It was the group of Allan, working at Guy's Hospital in London, which first documented the fetal development of hypoplasia of the left heart by serial echocardiographic observation.4 In their retrospective study of 7000 pregnancies, 462 fetuses were diagnosed to have a structural cardiac defect at the time of the initial echocardiogram. Among those, 28 patients had dilated and dysfunctional left ventricles and aortic valves. The majority of these patients were also found to have concomitant endocardial fibroelastosis. Out of 15 patients in the series who were followed with serial echocardiograms, five progressed to develop hypoplasia of the left heart. With echocardiographic technology undergoing refinement over the same period, it was during this era that the first fetal cardiac intervention was performed using echocardiographic guidance.2,5,6 With still further technologic advances, fetal diagnosis of hypoplasia of the left heart can now be made as early as 13 weeks gestational age.7 One entity which is frequently associated with the hypoplastic left ventricle and aortic stenosis is endocardial fibroelastosis. There is an overlap of pathology between these three entities.8–10 In this report, we describe our own experience in intervention in a fetus suspected of developing hypoplasia of the left heart.

We report the case of a novel mitochondrial DNA mutation in the MT-ATP8 gene in an infant with tetralogy of Fallot. Next-generation sequencing was applied to sequence whole mitochondrial DNA of the patient. A known Leber's hereditary optic neuropathy-associated mutation (G9804A), a heteroplasmic T7501C mutation (17%), and a novel C8481 T Pro > Leu missense mutation in the MT-ATP8 gene was identified.

Introduction: Persistent foetal tachyarrythmias complicated by hydrops fetalis carry a poor prognosis, with foetal death reported in excess of a quarter despite treatment. We present our experience with direct intraperitoneal amiodarone administration in eight hydropic foetuses with resistant supraventricular tachycardia. Methods: Amiodarone was injected slowly into foetal peritoneal cavity under ultrasound guidance. All mothers were loaded with oral amiodarone before the procedure and maintained on it. The procedure was repeated guided by foetal rhythm. Result: All eight cases had severe hydrops with a median foetal heart rate of 255 bpm (range 240–300 bpm), and the median gestational age was 27+1 weeks (range 21–33+3 weeks) at presentation. In six cases, the average time for supraventricular tachycardia to revert to sinus rhythm from the first procedure was 11.5 days. In one case, intravascular injection of amiodarone into the umbilical vein was performed before intraperitoneal injection, which resulted in conversion to sinus rhythm sustained until delivery. In the last case, supraventricular tachycardia and severe hydrops persisted and the baby was delivered 5 days later at 34 weeks’ gestation. Hydrops resolved in five foetuses with a mean resolution time of 28.4 days. The mean gestational age at delivery was 34+5 days and seven of eight cases survived beyond the neonatal period with good postnatal outcomes. Conclusion: Intraperitoneal administration of amiodarone is a relatively simple and effective strategy in refractory supraventricular tachycardia complicated by severe hydrops. The intraperitoneal route assures delivery of the drug to the severely hydropic foetus and enables a bolus dose to be delivered for sustained absorption.

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.