Transoesophageal and epicardial echocardiography are indispensible intraoperative imaging modalities to guide paediatric heart disease surgeries and influence surgical decision-making. A less well-described role of intraoperative imaging is its utility in evaluating coronary artery patency and flow. Focused two-dimensional, colour, and spectral Doppler imaging of the coronary arteries should be performed during surgeries involving coronary manipulation or re-implantation, or in cases where there is unexpected ventricular dysfunction or electrographic signs concerning for ischaemia. Intraoperative imaging allows for any anatomical issues to be detected and addressed promptly in the operating room. Imaging of the coronary arteries should identify unobstructed coronary ostia and proximal course without kinking, angulation, narrowing, or significant calibre change to suggest stenosis or extrinsic compression from neighbouring structures. The aim of this review is to highlight the usefulness of transoesophageal and epicardial echocardiography in evaluating coronary artery patency and flow, provide a how-to guide for optimal imaging, and to introduce a practical guideline to achieve best clinical practice.

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.

We report an infant with an abnormal left coronary artery arising from the pulmonary trunk in whom, subsequent to surgical repair, sequential improvements in regional left and right systolic and diastolic myocardial function were quantified by the new ultrasound-based method of regional strain and strain rate imaging. The regional radial and longitudinal myocardial function of the left ventricle was homogeneously reduced prior to repair, while the time course of their recovery differed subsequent to repair. We discuss the concepts and advantages behind this quantitative approach to monitoring regional myocardial function in children.

Background: At present, a considerable number of patients survive who underwent an atrial switch operation for correction of complete transposition. Our study aimed to assess their long-term exercise performance and the serial evolution of cardiac function. Methods: We studied 22 patients 5 to 17 years after an atrial switch operation, and followed them serially for 3.5 ± 2 years after the first evaluation. Cardiorespiratory exercise function was assessed by analysis of gas exhange and by determination of the ventilatory anaerobic threshold. Echocardiography was performed on all evaluations. Results: All patients were in Class I of the classification of the New York Heart Association at all assessments. Ventilatory anaerobic threshold, however, was significantly lower than normal. It averaged 77.9% ± 13.7 of the normal mean value at the initial evaluation, and remained stable when re-evaluated later (76.2 ± 13.7%). At the initial study, the increase in oxygen uptake during graded exercise was below the 95% confidence limit in 6 of the patients, and was below this level in 10 patients at re-assessment. The subnormal values for oxygen uptake during submaximal exercise were associated with moderate to severe haemodynamic dysfunction. At echocardiography, 15 of 17 patients studied twice had mild to moderate right ventricular dilation and tricuspidregurgiation, which remained virtually the same at reasssesment. A stable sinus rhythm was initially present in 17 patients, and persisted in 15 patients during follow-up. Conclusion: At medium term follow-up, cardiorespiratory exercise performance remains stable in patients after atrial switch repair. Serial exercise testing appears useful, because in individual patients in the present study, a decreasing exercise tolerance correlated with development of haemodynamic sequels.

A new technique is presented to create percutaneously an unrestrictive and lasting atrial communication in small children. In 2 infants, a stent was deployed in a restrictive atrial communication and first inflated with an 8 mm balloon. The stent was then further expanded up to 10 or 12 mm. The gradient and turbulent flow between the two atriums disappeared completely. The stent retained a very stable position without embolisation. Other complications, such as formation of thrombus or arrhythmia, were not observed until elective explantation after 2 and 11 months. We conclude that, in infants, dilation of the atrial septum with a stent can provide a safe, lasting, and unrestrictive atrial communication.

The purpose of this study was to assess cardiorespiratory responses to submaximal exercise in patients with univentricular atrioventricular connection after the Fontan operation, and to evaluate whether changes occur during medium-term follow-up. Eighteen patients (age 12.1±5.5 years) underwent graded exercise test on a treadmill 2.3±1.4 year after the Fontan repair. Ventilatory gases were measured using breath-by-breath analysis. Results were compared to gender/age-matched controls. Twelve patients (age 14.2±5.4 years) were reevaluated 2.4±2.1 years after the first test. Aerobic exercise performance was subnormal in all patients during the first test. At the lowest level of exercise, the ventilatory threshold was already surpassed in 6/18 patients, while it was reduced in all other patients (p<0.001). All patients were in stable sinus rhythm throughout the test. Heart rate at all exercise levels was ±10% below normal (p<0.05). The respiratory frequency was increased at all exercise levels (p<0.001). The ventilatory equivalent for oxygen was increased (p<0.001), and the end-tidal tension of carbon dioxide was decreased (p<0.001). The ratio of physiological dead space/tidal volume was increased in all patients (p<0.001), while the normal decrease of this ratio during exercise was not observed. Upon reevaluation heart rate, respiratory rate, oxygen uptake, venti latory equivalent for oxygen, end-tidal carbon dioxide tension and physiological dead space did not change signifi cantly. Only a slight further decrease in ventilatory threshold was observed. Aerobic performance after the Fontan procedure ranges widely from just above resting metabolic rate to the lower limit of normal. Dyspnea during exercise is exacerbated by a decreased ventilatory threshold, increased physiological dead space, and decreased respir-atory efficiency. Cardiorespiratory response to exercise, nonetheless, remains relatively stable during medium-term follow-up.

We report the successful use of a cutting-balloon catheter in dilating stenoses in major systemic-to-pulmonary collateral arteries which had been resistant to high pressure balloons. After dilation using the cutting balloon, we implanted stents to produce a marked improvement in both pulmonary blood flow and arterial saturation. The technique provides useful palliation for patients having such stenotic collateral arteries.

Velocardiofacial syndrome is identified by a submicroscopic deletion of chromosome 22q.11 (del22q.11). This study presents data on the early motor development and behaviour of 11 children (8 males, 3 females) with del22q.11 (mean age 41mo, SD 9.7mo) with a congenital heart defect. To control for the impact of the congenital heart defect, a control group of 19 children (15 males, 4 females; mean age 46mo, SD 9mo) with the same types of congenital heart defects but without del22q.11 was selected. Motor development in both groups was measured with the Peabody Developmental Motor Scales-2. Behaviour was assessed with the Child Behaviour Checklist. Children with del22q.11 scored significantly lower (p<0.05) on motor performance than the children of the control group. Most deficient motor skills were found for the subtests Locomotion and Stationary. On the behaviour questionnaire, a statistically significant (p<0.05) difference between the two groups was found only for the subscale Withdrawn. These data reveal a significant motor delay in many young children with del22q.11, which is not caused by the presence of a congenital heart defect or by behavioural features.

In patients who have undergone a superior cavopulmonary anastomosis, the superior caval venous flow provides the only, or the most important, pulmonary blood supply, while the inferior caval venous blood is not oxygenated, being mixed with the pulmonary venous blood before entering the systemic circulation. In healthy children, the contribution of superior caval venous flow to total cardiac output has been shown to decrease during growth. Patients who have undergone a superior cavopulmonary anastomosis, however, often have a higher oxygen saturation than predicted by the age-matched ratio of superior to inferior caval venous flows. This study was designed, therefore, to assess the ratio of flows in the superior and inferior caval veins subsequent to a superior cavopulmonary anastomosis. We carried out 18 magnetic resonance imaging studies with velocity-mapping and heart catheterisations so as to assess the contribution of superior caval venous flow to total cardiac output. Patients were divided into 3 groups according to their age. There were five aged from 8 to 24 months, eight aged from 24 to 48 months, and five older than 48 months. No significant difference could be found in the ratios of superior-to-inferior caval venous flow, nor of superior caval venous-to-systemic flow, between the 3 groups. The ratio of venous flows was 0.89 ± 0.34 in those aged from 8 to 24 months, 1.09 ± 0.42 in those from 24 to 48 months, and 1.25 ± 0.27 in the older patients (F analysis of variance 1.06, p 0.37). The ratio of superior caval venous-to-systemic flow was 0.46 ± 0.08 in the youngest patients, 0.50 ± 0.09 in those aged from 24 to 48 months, and 0.55 ± 0.05 in the older patients (F analysis of variance 0.76, p 0.49). These findings suggest that the hemodynamics of a cavopulmonary anastomosis may affect the normal decrease of superior caval venous flow with age. This could be related to a redistribution of flow, with a proportionally higher flow to the head and upper body after construction of a superior cavopulmonary anastomosis. Since increasing cyanosis and progressive exercise intolerance are the main indications for creation of a total cavopulmonary connection, these findings should be taken into account when determining the timing for completion of the Fontan circulation.

Background: Systemic right ventricular dysfunction is a major concern in the follow-up of patients who underwent an atrial redirection procedure for transposition (concordant atrio-ventricular and discordant ventriculo-arterial connections). No good non-invasive method is currently available for quantifying right ventricular function. Aims: We have used ultrasonically based imaging of strain rate and strain to quantify regional deformation in the right ventricle after the Senning operation, comparing properties of regional deformation of the right ventricle with right ventricular ejection fraction as measured using magnetic resonance imaging. Methods: In 20 asymptomatic patients who had undergone the Senning procedure, we measured peak systolic strain rate and systolic strain values in the right ventricular free wall, the septum and the left ventricular lateral wall using colour Doppler myocardial imaging, comparing the data with findings obtained in 30 healthy subjects. Global right ventricular ejection fraction was assessed using magnetic resonance imaging. Results: Properties of deformation of the right ventricular free wall were reduced and homogeneous after the Senning procedure compared to normals, with significantly lower values for peak systolic strain rate and systolic strain (−1.1 ± 0.4 vs. −2.5 ± 0.9 s−1; p < 0.05 and −16 ± 7% vs. −38 ± 13%; p < 0.05, respectively). There was a significant correlation between regional longitudinal right ventricular systolic strain values and right ventricular ejection fraction (r = −0.87, p < 0.001). In the septum, peak systolic strain rate was again reduced and homogeneous (−1.2 ± 0.4 vs. −1.8 ± 0.5 s−1; p < 0.05 vs. normals). Also in the left ventricle, the lateral wall peak systolic strain rate and systolic strain values were reduced (−1.5 ± 0.5 vs. −2.1 ± 0.9 s−1; p < 0.05 and −20 ± 6% vs.−25 ± 9%; p < 0.05, vs. normals, respectively). Conclusions: Properties of regional longitudinal deformation of the systemic right ventricle are reduced after the Senning procedure compared to normal controls, and correlate well with global right ventricular performance. These findings suggest that ultrasonic strain rate and strain imaging could be used in the non-invasive follow-up of ventricular function in these patients.