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We report the case of a 5-year-old boy who suffered from an intracardiac air influx with suspected cerebral air embolism during the Fontan procedure. We immediately transformed the cardiopulmonary bypass circuit to perform a retrograde cerebral perfusion, which resulted in successful neuroprotection. He was extubated in the operating room without any neurological defects.

Although enormous effort has focussed on how to build an effective culture in the business community, relatively little effort has addressed how to achieve this in the hospital environment, specifically related to the field of congenital heart disease teams. The examination of culture in pediatric cardiac care is particularly important for several key reasons: first, it represents high-stakes medicine, second, there are multiple stakeholders requiring collaboration between cardiologists, surgeons, anaesthesiologists, perfusionists, nursing staff, and allied health care professionals, and finally, both the patient and the family are intimately involved in the care pathway. This review article investigates some of the critical components to building an effective culture, drawing upon similarities in other disciplines, thereby fostering high performance multidisciplinary teams in congenital cardiology care. Strategies to change culture such as Kotter's model of change are also discussed. High performance teams share one common vital characteristic: psychological safety for team members to speak their minds, thereby fostering an open culture, in which creativity can flourish to facilitate major breakthroughs. Adoption of the "Flight Plan" review promotes patient centric care and champions a psychologically safe culture.

Background: Implantable cardioverter defibrillators (ICDs) are effective in preventing arrhythmic sudden cardiac death in patients with tetralogy of Fallot (TOF). Although ICD therapies for malignant ventricular arrhythmias can be life-saving, shocks could have deleterious consequences. Substrate-based ablation therapy has become the standard of care to prevent recurrent ICD shocks in patients with ischemic cardiomyopathy. However, the efficacy and safety of this invasive therapy in the prevention of recurrent ICD shocks in patients with TOF has not been well evaluated. Methods: Records of a total of 47 consecutive TOF patients (mean age: 43.1 ± 13.2 years, male sex: n = 34 [72.3%]) who underwent ICD implantation for secondary prevention between 2000 and 2018 were reviewed. Results: Twenty (42.6%) patients underwent invasive therapy (radiofrequency catheter ablation, n = 8; surgical ablation with pulmonary valve replacement, n = 12) before ICD implantation. Twenty-seven patients (57.4%) were managed noninvasively. During follow-up (median 80.5 [interquartile range, 28.5-131.0] months), 2 (10.0%) patients in the invasive group and 10 (37.0%) patients in the noninvasive group received appropriate ICD shocks (P = 0.036). Logistic regression analysis showed that invasive therapy was associated with a decreased risk of ICD shocks by 81.1% (odds ratio, 0.189; 95% confidence interval, 0.036-0.990; P = 0.049). Furthermore, invasive therapy was associated with decreased risk of the composite outcomes of ICD shock, death, cardiac transplantation, and hospital admission (odds ratio, 0.090; 95% confidence interval, 0.025-0.365; P = 0.013) compared with noninvasive therapy. Conclusions: Invasive substrate modification therapy was associated with a lower likelihood of ICD shocks and improvement of long-term outcomes in TOF patients. Résumé: Contexte: Les défibrillateurs cardioverteurs implantables (DCI) sont efficaces pour prévenir la mort cardiaque subite provoquée par une arythmie chez les patients présentant une tétralogie de Fallot (TF). Bien que le traitement des arythmies ventriculaires malignes par DCI puisse sauver des vies, les chocs administrés peuvent avoir des conséquences délétères. L’ablation du substrat est devenue le traitement de référence pour prévenir l’administration à répétition de chocs par DCI chez les patients atteints d’une cardiomyopathie ischémique. L’efficacité et l’innocuité de ce traitement invasif pour prévenir l’administration de chocs répétés chez les patients présentant une TF n’ont toutefois pas été bien évaluées. Méthodologie: Nous avons examiné les cas consécutifs de 47 patients présentant une TF (âge moyen : 43,1 ± 13,2 ans; hommes : n = 34 [72,3 %]) ayant reçu un DCI en prévention secondaire entre 2000 et 2018. Résultats: Au total, 20 (42,6 %) patients ont subi un traitement invasif (ablation par cathéter par radiofréquence, n = 8; ablation chirurgicale et remplacement de la valve pulmonaire, n = 12) avant l’implantation d’un DCI. Vingt-sept patients (57,4 %) ont été pris en charge de façon non invasive. Au cours de la période de suivi (durée médiane de 80,5 [intervalle interquartile : 28,5 à 131,0] mois), 2 (10,0 %) patients du groupe ayant subi une intervention invasive et 10 (37,0 %) patients du groupe ayant subi une intervention non invasive ont reçu un choc approprié par DCI (p = 0,036). Les résultats de l’analyse par régression logistique montrent que le traitement invasif est associé à une réduction du risque de choc par DCI de 81,1 % (rapport des cotes : 0,189; intervalle de confiance à 95 % : de 0,036 à 0,990; p = 0,049). En outre, le traitement invasif est associé à une réduction du risque de survenue d’un des événements du paramètre d’évaluation composé, soit un choc administré par DCI, le décès, une transplantation cardiaque ou une hospitalisation (rapport des cotes : 0,090; intervalle de confiance à 95 % : de 0,025 à 0,365; p = 0,013) par rapport au traitement non invasif. Conclusions: La modification invasive du substrat a été associée à une probabilité plus faible de choc administré par DCI et à une amélioration des résultats à long terme chez les patients présentant une TF.

Early surgical tetralogy of Fallot (ToF) repair involved patching across the pulmonic annulus (transannular patch [TAP] repair), which resulted in severe pulmonic regurgitation. Long-term outcome improvements were anticipated with modifications that preserved the pulmonic annulus (annulus-preserving [AP] repair). The objective of the present study was to evaluate the need for late reintervention in adults with AP repair and those with TAP repair.We conducted a retrospective review of adults (born 1981-1996) with childhood intracardiac ToF repairs at a tertiary care center. The primary cardiovascular outcome was need for reintervention after primary intracardiac repair of ToF. Secondary outcomes included a composite of death, heart failure, and ventricular arrhythmias.Two hundred thirty adults were included: 104 with AP repair and 126 with TAP repair. The median age at last follow up was 25 years (interquartile range [IQR] 20-28) and the median follow-up duration was 7.9 years (IQR 3.5-12). Reintervention of any type was significantly more common in the TAP group during both childhood and adulthood (72.2% TAP vs 20.2% AP, HR 5.5, 95% CI 3.4-9.0; P0.001). Pulmonary valve replacement (PVR) was almost 6 times more likely in adults with TAP repair (65.1% TAP vs 16.3% AP, HR 5.7, 95% CI 3.4-9.7; P0.001).Patients who had AP ToF repair had significantly fewer late reinterventions compared with TAP repair, with the majority of reinterventions due to PVR. More long-term follow-up is required.

Although cardiovascular magnetic resonance (CMR) imaging measurements are known to differ between sexes and according to age in the normal heart, little is known about measurement variability in patients with congenital heart disease (CHD). Yet, aggregate CMR data, without adjustment for sex or age

Background Tricuspid regurgitation (TR) is common among adults with corrected tetralogy of Fallot (TOF) or pulmonary stenosis (PS) referred for pulmonary valve replacement (PVR). Yet, combined valve surgery remains controversial. Objectives This study sought to evaluate the impact of concomitant tricuspid valve intervention (TVI) on post-operative TR, length of hospital stay, and on a composite endpoint consisting of 7 early adverse events (death, reintervention, cardiac electronic device implantation, infection, thromboembolic event, hemodialysis, and readmission). Methods The national Canadian cohort enrolled 542 patients with TOF or PS and mild to severe TR who underwent isolated PVR (66.8%) or PVR+TVI (33.2%). Outcomes were abstracted from charts and compared between groups using multivariable logistic and negative binomial regression. Results Median age at reintervention was 35.3 years. Regardless of surgery type, TR decreased by at least 1 echocardiographic grade in 35.4%, 66.9%, and 92.8% of patients with pre-operative mild, moderate, and severe insufficiency. In multivariable analyses, PVR+TVI was associated with an additional 2.3-fold reduction in TR grade (odds ratio [OR]: 0.44; 95% confidence interval [CI]: 0.25 to 0.77) without an increase in early adverse events (OR: 0.85; 95% CI: 0.46 to 1.57) or hospitalization time (incidence rate ratio: 1.17; 95% CI: 0.93 to 1.46). Pre-operative TR severity and presence of transvalvular leads independently predicted post-operative TR. In contrast, early adverse events were strongly associated with atrial tachyarrhythmia, extracardiac arteriopathy, and a high body mass index. Conclusions In patients with TOF or PS and significant TR, concomitant TVI is safe and results in better early tricuspid valve competence than isolated PVR.

Congenital heart surgery is a technically demanding specialty resulting in a prolonged training period. With the growing expectation of perfect patient outcomes, there is a need for improved training methods by implementing simulation. We assess the utilization of simulation in the training of congenital heart surgeons and discuss its future implications. A keyword-based PubMed literature search was conducted for hands-on surgical simulation in congenital heart surgery. The abstracts/titles of the search were reviewed and papers using simulation specific to congenital cardiac surgery were selected. Studies that did not include surgeons operating on the simulator, or did not incorporate assessment methods were excluded. Analysis included the problem addressed, simulator-type, methodology, assessment methods, results, benefits/limitations, and reproducibility. Five papers fulfilled our selection criteria of hands-on surgical simulation in congenital heart surgery with an assessment of the simulator or procedural performance. One simulation used animal models and 4 utilized 3D-printed models. Simulators covered either single or multiple complex procedures. All studies highlight usefulness of simulation; however, only 1 study has been replicated with >10 participants. The studies demonstrate how hands-on surgical simulation is possible within congenital heart surgery. Although primarily proof of concept studies, the next step would involve using a greater number of participants and demonstrate how repetition and deliberate practice will improve outcomes. Congenital heart surgery is one of the most technically demanding surgical specialties; therefore, we should lead the way in utilizing simulation to complement the training of our surgeons as we face the challenges ahead.

The Fontan circulation has inherent long-term vulnerabilities such that adult Fontan patients now comprise the largest, most rapidly growing subgroup of adult congenital heart disease referred for transplant assessment. Almost all have Fontan Associated Liver Disease (FALD). There is an absence of mid to late hepatic outcome data after heart transplant alone . Therefore, we analyzed outcomes of survivors of heart only transplant in patients with failing Fontan circulation. Including all ten of our adult Fontan patients surviving >1 year after isolated heart transplant, we report evolution of their clinical features, bloodwork, hemodynamic data and liver ultrasound findings over a median of 4.7 years. Non-progression of FALD, resolution of ascites and freedom from hepatocellular carcinoma in the mid-term highlight the outcomes in this selected group once normal cardiac output and venous pressures are established by heart transplant.

ObjectiveThis study sought to determine the prevalence, predictors, prognostic relevance and evolution of pulmonary hypertension (PH) (mean pulmonary artery pressure ≥25 mm Hg) in adult patients with a subaortic right ventricle (RV) in a biventricular circulation (2V-RV).MethodsWe analysed retrospective data from patients with 2V-RV undergoing cardiac catheterisation in our centre between 2000 and 2018. Echocardiographic assessment of subpulmonary ventricular pressures (left ventricular systolic pressure (LVSP)), age and B-type natriuretic peptide (BNP) were assessed as PH screening tools. Kaplan-Meier curves examined time to a composite outcome of death, transplant or ventricular assist device (VAD). Data from repeat catheterisations were analysed to evaluate PH changes over time, including the effects of therapy.ResultsA total of 141 patients (median age 39 (IQR 33–45) years, 68% men) underwent 191 cardiac catheterisations. At baseline, 55% had PH (isolated postcapillary 24%, combined precapillary and postcapillary 26% and precapillary 5%). BNP (area under the curve 0.80; 95% CI 0.72 to 0.88; pConclusionPH is prevalent in patients with 2V-RV even when asymptomatic. It is difficult to identify by echocardiography and most importantly, is strongly associated with adverse outcomes. PH affects prognosis and transplant options for this patient group and yet is often amenable to treatment. Awareness of these results ought to lower the threshold for invasive haemodynamic assessment and may change the management of failing patients with 2V-RV.

Objective Although heart failure (HF) is the leading cause of premature death in adult congenital heart disease (ACHD), little population-specific data exist. This study reports early experience from a dedicated, sub-specialty adult congenital heart disease-heart failure (ACHD-HF) clinic, aiming to identify risk factors for adverse outcome. Methods Between 2012 and 2015, 126 patients (57% male) attended the ACHD-HF clinic. Baseline and follow-up data were analysed and compared across 4 anatomical/physiological subgroups: cyanotic ACHD, Fontan circulation (1V), biventricular circulation with a subaortic right ventricle (2V-RV) and biventricular circulation with a subaortic left ventricle (2V-LV). Predictors of the composite primary outcome: death, transplant or ventricular assist device (VAD) were identified using multivariable Cox proportional hazard models. Results Mean age at first visit was 38±13years. Patients were grouped as follows: cyanotic ACHD 10%, 1V 24%, 2V-RV 29% and 2V-LV 37%. During a median follow-up of 1.7 (IQR 0.8–2.9) years, 38 patients (30%) reached the primary outcome. Event-free survival was 89%, 78% and 63% at 1, 2 and 3years. Forty (31.7%) patients experienced 69 HF hospitalisations. Between-group differences were noted for systolic function, valvular regurgitation, pacing prevalence and invasive hemodynamics. Multivariable analysis revealed 2V-RV subgroup ( p =0.001), NYHA class ( p =0.002) B-type natriuretic peptide >164pg/ml ( p =0.003) and sodium p =0.036) as independently associated with death, transplant or VAD. Conclusions Our young ACHD-HF patients experienced high adverse event rates during a short period of follow-up. The prognostic markers identified will aid clinicians to stratify short-term risk and thereby guide advanced HF management decisions in ACHD.

Background The effect of the timing of stage-2-palliation (S2P) on survival through single ventricle palliation remains unknown. This study investigated the optimal timing of S2P that minimizes pre-S2P attrition and maximizes post-S2P survival. Methods The Congenital Heart Surgeons' Society's critical left ventricular outflow tract obstruction cohort was used. Survival analysis was performed using multiphase parametric hazard analysis. Separate risk factors for death after the Norwood and after S2P were identified. Based on the multivariable models, infants were stratified as low, intermediate, or high risk. Cumulative 2-year, post-Norwood survival was predicted. Optimal timing was determined using conditional survival analysis and plotted as 2-year, post-Norwood survival versus age at S2P. Results A Norwood operation was performed in 534 neonates from 21 institutions. The S2P was performed in 71%, at a median age of 5.1 months (IQR: 4.3 to 6.0), and 22% died after Norwood. By 5 years after S2P, 10% of infants had died. For low- and intermediate-risk infants, performing S2P after age 3 months was associated with 89% ± 3% and 82% ± 3% 2-year survival, respectively. Undergoing an interval cardiac reoperation or moderate-severe right ventricular dysfunction before S2P were high-risk features. Among high-risk infants, 2-year survival was 63% ± 5%, and even lower when S2P was performed before age 6 months. Conclusions Performing S2P after age 3 months may optimize survival of low- and intermediate-risk infants. High-risk infants are unlikely to complete three-stage palliation, and early S2P may increase their risk of mortality. We infer that early referral for cardiac transplantation may increase their chance of survival.

Background: In infants requiring 3-stage single-ventricle palliation for hypoplastic left heart syndrome, attrition after the Norwood procedure remains significant. The effect of the timing of stage 2 palliation (S2P), a physician-modifiable factor, on long-term survival is not well understood. We hypothesized that an optimal interval between the Norwood and S2P that both minimizes pre-S2P attrition and maximizes post-S2P survival exists and is associated with individual patient characteristics. Methods: The National Institutes of Health/National Heart, Lung, and Blood Institute Pediatric Heart Network Single Ventricle Reconstruction Trial public data set was used. Transplant-free survival (TFS) was modeled from (1) Norwood to S2P and (2) S2P to 3 years by using parametric hazard analysis. Factors associated with death or heart transplantation were determined for each interval. To account for staged procedures, risk-adjusted, 3-year, post-Norwood TFS (the probability of TFS at 3 years given survival to S2P) was calculated using parametric conditional survival analysis. TFS from the Norwood to S2P was first predicted. TFS after S2P to 3 years was then predicted and adjusted for attrition before S2P by multiplying by the estimate of TFS to S2P. The optimal timing of S2P was determined by generating nomograms of risk-adjusted, 3-year, post-Norwood, TFS versus the interval from the Norwood to S2P. Results: Of 547 included patients, 399 survived to S2P (73%). Of the survivors to S2P, 349 (87%) survived to 3-year follow-up. The median interval from the Norwood to S2P was 5.1 (interquartile range, 4.1–6.0) months. The risk-adjusted, 3-year, TFS was 68±7%. A Norwood-S2P interval of 3 to 6 months was associated with greatest 3-year TFS overall and in patients with few risk factors. In patients with multiple risk factors, TFS was severely compromised, regardless of the timing of S2P and most severely when S2P was performed early. No difference in the optimal timing of S2P existed when stratified by shunt type. Conclusions: In infants with few risk factors, progressing to S2P at 3 to 6 months after the Norwood procedure was associated with maximal TFS. Early S2P did not rescue patients with greater risk factor burdens. Instead, referral for heart transplantation may offer their best chance at long-term survival. Clinical Trial Registration: URL: https://www.clinicaltrials.gov . Unique identifier: NCT00115934.

Graphical abstract, Highlights • PA-MAIVF is a rare condition that is usually asymptomatic. • Symptoms related to PA-MAIVF generally represent complications. • Early identification of this entity is crucial to guide acute management strategies.

The purpose of this review is to survey the contemporary literature surrounding congenital anomalies of origin of the coronary arteries and to identify remaining gaps in knowledge.In recent years, lineage tracing analyses and mechanistic studies in model organisms have enhanced our understanding of the normal embryologic development of the coronary arteries, and how disruption of this intricate process can lead to congenital coronary anomalies. The true incidence of these anomalies remains unknown. Although a majority of cases are believed to be clinically silent, clinical presentation varies widely, from asymptomatic to sudden cardiac death. Cardiac computed tomography angiography and/or magnetic resonance angiography are the mainstay diagnostic modalities. Management of anomalous coronary arteries depends on the morphology and clinical presentation. Surgery is the gold-standard treatment for anomalous left coronary artery arising from the pulmonary artery and anomalous aortic origin of a coronary artery with intramural or interarterial course.Several large multicenter initiatives are currently underway and should help address some of the numerous knowledge gaps surrounding the evaluation and management of anomalous coronary arteries.

Background: Brain injury, impaired brain growth, and long-term neurodevelopmental problems are common in children with transposition of the great arteries. We sought to identify clinical risk factors for brain injury and poor brain growth in infants with transposition of the great arteries undergoing the arterial switch operation, and to examine their relationship with neurodevelopmental outcome. Methods: The brains of 45 infants with transposition of the great arteries undergoing surgical repair were imaged pre- and postoperatively using magnetic resonance imaging. Brain weight z scores were calculated based on brain volume and autopsy reference data. Brain injury scores were determined as previously described. Neurodevelopment was assessed at 18 months using the Bayley-III scores of infant development. The relationships between clinical variables, brain injury, perioperative brain growth, and 18-month Bayley-III scores were analyzed. Results: On preoperative imaging, moderate or severe white matter injury was present in 10 of 45 patients, whereas stroke was seen in 4 of 45. A similar prevalence of injury was seen on postoperative imaging, and we were unable to identify any clinical risk factors for brain injury. Brain weight z scores decreased perioperatively in 35 of 45 patients. The presence of a ventricular septal defect ( P =0.009) and older age at surgery ( P =0.007) were associated with impaired perioperative brain growth. When patients were divided into those undergoing surgery during the first 2 weeks of life (32/45) versus those being repaired later (13/45), infants repaired later had significantly worse perioperative brain growth (late repair postoperative brain weight z = –1.0±0.90 versus early repair z = –0.33±0.64; P =0.008). Bayley-III testing scores fell within the normal range for all patients, although age at repair ( P =0.03) and days of open chest ( P =0.03) were associated with a lower composite language score, and length of stay was associated with a lower composite cognitive score ( P =0.02). Conclusions: Surgery beyond 2 weeks of age is associated with impaired brain growth and slower language development in infants with transposition of the great arteries cared for at our center. Although the mechanisms underlying this association are still unclear, extended periods of cyanosis and pulmonary overcirculation may adversely impact brain growth and subsequent neurodevelopment.

There is mounting recognition that some of the most urgent problems of adult congenital heart disease (ACHD) are the prevention, diagnosis, and management of heart failure (HF). Recent expert consensus and position statements not only emphasize a specific and pressing need to tackle HF in ACHD (ACHD-HF) but also highlight the difficulty of doing so given a current sparsity of data. Some of the challenges will be addressed by this review. The authors are from 3 different centres; each centre has an established subspeciality ACHD-HF clinic and is able to provide heart transplant, multiorgan transplant, and mechanical support for patients with ACHD. Appropriate care of this complex population requires multidisciplinary ACHD-HF teams evaluate all possible treatment options. The risks and benefits of nontransplant ACHD surgery, percutaneous structural and electrophysiological intervention, and ongoing conservative management must be considered alongside those of transplant strategies. In our approach, advanced care planning and palliative care coexist with the consideration of advanced therapies. An ethos of shared decision making, guided by the patient's values and preferences, strengthens clinical care, but requires investment of time as well as skilled communication. In this review, we aim to offer practical real-world advice for managing these patients, supported by scientific data where it exists. ispartof: CANADIAN JOURNAL OF CARDIOLOGY vol:35 issue:12 pages:1723-1739 ispartof: location:England status: published

Background: The ideal aortic valve substitute in young and middle-aged adults remains unknown. We sought to compare the long-term outcomes of patients undergoing the Ross procedure and those receiving a mechanical aortic valve replacement (AVR). Methods: From 1990 to 2014, 258 patients underwent a Ross procedure and 1444 had a mechanical AVR at a single institution. Patients were matched into 208 pairs through the use of a propensity score. Mean age was 37.2±10.2 years, and 63% were male. Mean follow-up was 14.2±6.5 years. Results: Overall survival was equivalent (Ross versus AVR: hazard ratio, 0.91, 95% confidence interval, 0.38–2.16; P =0.83), although freedom from cardiac- and valve-related mortality was improved in the Ross group (Ross versus AVR: hazard ratio, 0.22; 95% confidence interval, 0.034–0.86; P =0.03). Freedom from reintervention was equivalent after both procedures (Ross versus AVR: hazard ratio, 1.86; 95% confidence interval, 0.76–4.94; P =0.18). Long-term freedom from stroke or major bleeding was superior after the Ross procedure (Ross versus AVR: hazard ratio, 0.09; 95% confidence interval, 0.02–0.31; P Conclusions: Long-term survival and freedom from reintervention were comparable between the Ross procedure and mechanical AVR. However, the Ross procedure was associated with improved freedom from cardiac- and valve-related mortality and a significant reduction in the incidence of stroke and major bleeding. In specialized centers, the Ross procedure represents an excellent option and should be considered for young and middle-aged adults undergoing AVR.

Potential surgical strategies for hypoplastic branch pulmonary arteries (BPAs) during tetralogy of Fallot repair include (1) extensive patch augmentation to the hilum (PATCH), (2) limited extension arterioplasty to the proximal pulmonary artery (EXTENSION), or (3) leaving the native vessels unaugmented (NATIVE). We explored the effect of these strategies on reintervention and BPA growth.From 2000 to 2012, 434 children underwent complete tetralogy of Fallot repair. Risk-adjusted parametric models were used to analyze the risk of BPA reintervention for (1) all children, (2) children with BPAs of 4 mm or smaller, and (3) children with BPAs of 3 mm or smaller. Repeated-measures analysis of more than 2,000 echocardiograms was used to characterize postoperative BPA growth and right ventricular pressure by using nonlinear mixed models.Overall survival (99% [3 deaths]) was excellent. The 10-year freedom from BPA reintervention was 84%. In risk-adjusted models (including baseline BPA z-score), PATCH had a decreased freedom from reintervention (73%; p0.01) vs EXTENSION (87%) or NATIVE (91%). For children with BPAs of 4 mm or smaller (28 PATCH, 60 EXTENSION, 75 NATIVE), baseline characteristics were similar. The risk-adjusted 5-year freedom from reintervention was 68% for PATCH, 76% for EXTENSION, and 85% for NATIVE. PATCH trended toward an increased risk of reintervention (p = 0.07). For children with BPAs of 4 mm or smaller left in their NATIVE state, only ∼15% required reintervention. After adjustment for baseline BPA z-score, the time-related BPA growth was decreased (p0.014) and right ventricular pressure was increased (p = 0.03) for the PATCH group.Aggressive PATCH augmentation of hypoplastic BPAs improves the short-term geometry but may lead to late stenosis and higher rates of reintervention. Hypoplastic BPAs in tetralogy of Fallot tend (∼85%) to grow well without instrumentation.

OBJECTIVE We investigated the physiologic impact of acute maternal hyperoxygenation (MH) in human fetuses with and without congenital heart disease (CHD) using fetal cardiac magnetic resonance (CMR) in order to explore the potential therapeutic benefits of chronic MH. METHODS We examined 17 normal and 20 late gestation human fetuses with CHD on a 1.5 T CMR system. Flows were measured in major fetal vessels using phase contrast MRI. The T2 of umbilical venous blood was measured using T2 mapping. The measurements were repeated during acute MH. The results were compared using a Student's t-test, with p-value ≤0.05 considered statistically significant. RESULTS At baseline, the umbilical venous T2 (oxygen saturation) was lower in CHD fetuses than in normals, with significant increase with MH (p = 0.01). Both groups showed significant increase in pulmonary blood flow during MH, which was more dramatic in CHD (p = 0.005). There was a reduction in ductus arteriosus flow in CHD during MH (p = 0.04). There was no significant difference in blood flow in any of the other major vessels. CONCLUSION This study suggests that fetal MR identifies the expected hemodynamic changes associated with acute MH. MRI could be useful as a method for monitoring the impact of chronic MH in fetuses with CHD.

The prevalence of congenital coronary anomalies is between 0.3% and 2%, depending on the definition used and the population studied [1,2,3]. Not all congenital coronary anomalies are correlated with negative outcomes. Only anomalous coronaries with an inter-arterial or intramural course, coronary fistulae, and anomalous left coronary artery from the pulmonary artery (ALCAPA) have been associated with an increased rate of cardiac events [4] . Classical definitions of “high-risk features” do not always correlate with necropsy studies [5]. Despite the uncertainty, stakes are high, as coronary anomalies are the secondmost prevalent cause of sudden cardiac death in young athletes [6]. Surgical series report good outcomes with surgical repair, but observational cohorts also report excellent outcomes [7,8]. Guidelines regarding themanagement of coronary anomalies provide indications for surgical repair, but they are different from the management paradigm practiced by most pediatric cardiologists [9,10] .

Objectives Predicting perioperative morbidity and mortality in cardiac surgery for adult congenital heart disease is challenging because it encompasses a wide spectrum of disease. There is a paucity of published outcome data, and there are no perioperative risk score calculators for this population group. We set out to identify robust determinants of morbidity and mortality in this patient population under going cardiac surgery. Methods We collected data on 20 socioeconomic and pathophysiologic variables in 784 consecutive adults with congenital heart disease who underwent cardiac surgery between 2004 and 2015 at a single center. Using logistic regression, we sought to identify which of these factors were associated with the primary composite adverse outcome of in-hospital mortality, prolonged ventilation exceeding 7 days, and severe acute renal failure requiring dialysis. Secondary outcome analysis identified variables that were significant predictors for 1-year mortality. Results Composite adverse outcome occurred in 54 of 784 patients (6.9%). Significant predictors of the composite adverse outcome by multivariate regression include Mayo End-Stage Liver Disease modified score, cognitive impairment, number of chest wall incisions from previous cardiac surgery, body mass index, and cardiac anatomic category. Two survivors of the composite adverse outcome died within a few weeks postdischarge. Only 657 of 784 patients had 1-year follow-up data; 40 of 657 patients died at 1 year. One-year mortality was predicted by anticoagulation, Mayo End-Stage Liver Disease modified score, and anatomic category. Conclusions Recognition and quantification of noncardiac comorbidities preoperatively predict the risk of adverse events and mortality in addition to cardiac anatomic factors.

Chronic pulmonary regurgitation (PR) leads to RV dilatation and dysfunction, and can also induce LV failure through ventricular-ventricular (VV) interaction. Pulmonary valve replacement (PVR) is advocated to prevent this pathophysiology. A 51-year-old woman with a dysplastic pulmonary valve, severe

ObjectiveThe relationship between right ventricular (RV) fibrosis and right heart reverse remodelling following pulmonary valve replacement (PVR) has not been well studied in adults with repaired tetralogy of Fallot (rTOF). Our aims were to histologically quantify RV fibrosis and to explore the relationship between fibrosis severity and cardiac remodelling post-PVR.MethodsAdults with rTOF and pre-PVR cardiovascular (CMR) imaging were consented to procurement of RV muscle during PVR. Samples were stained with picrosirius red to quantify collagen volume fraction. Clinical data at baseline and at last follow-up were reviewed. Adverse cardiovascular outcomes included death, sustained arrhythmia and heart failure.ResultsFifty-three patients (male 58%, 38±11 years) were studied. Those with severe fibrosis (collagen volume fraction >11.0%, n=13) had longer aortic cross-clamp times at initial repair compared with the remainder of the population (50 vs 33 min, p=0.018) and increased RV mass:volume ratio pre-PVR (0.20 vs 0.18 g/mL, p=0.028). Post-PVR, the severe fibrosis group had increased indexed RV end-systolic volume index (RVESVi) (74 vs 66 mL/m2, p=0.044), decreased RVESVi change (Δ29 vs Δ45 mL/m2, p=0.005), increased RV mass (34 vs 25 g/m2, p=0.023) and larger right atrial (RA) area (21 vs 17 cm2, p=0.021). A trend towards increased heart failure events was observed in the severe fibrosis group (15% vs 0%, p=0.057).ConclusionsSevere RV fibrosis was associated with increased RVESVi, RV mass and RA area post-PVR in rTOF. Further study is required to define the impact of fibrosis and persistent right heart enlargement on clinical outcomes.

Objectives To evaluate the durability of aortic valve (AoV) repair relative to other strategies for children with significant aortic insufficiency (AI). Methods From 2001 to 2012, 90 children with greater than or equal to moderate AI underwent surgery. Resulting procedures were classified according to final operative outcome: AoV repair (repair; n = 46, 51%), Ross procedure (Ross; n = 21, 23%) or replacement with mechanical or tissue prosthesis [aortic valve replacement (AVR); n = 23, 26%]. Repeated measures (n = 1081 echocardiograms) mixed-model analysis and parametric multiphase risk-adjusted hazard analysis were used to evaluate haemodynamic parameters and durability of operations. Results Mean age at operation was similar for repair and Ross groups, but slightly higher for the AVR group (10.6, 11 and 13.2, respectively; P = 0.04). Baseline annular dimensions were similar among groups. Of 46 repairs, 85% involved pericardial leaflet extensions (commonly with leaflet shaving and/or commisuroplasty). The remaining repairs were commissuroplasties. On multivariable analysis, repair was associated with increased early (∼1-2 years) AI and increased outflow tract peak pressure gradients relative to Ross and AVR procedures. On univariate analysis, repairs tended to have a larger annulus size compared with Ross or AVR; however, this was not significant on multivariable analysis. There were 25 reinterventions (surgical reoperation = 16; transcatheter intervention = 9) for 22 children. Freedom from surgical reoperation was 64, 100 and 51% at 6 years for repairs, Ross and AVR, respectively (P = 0.05); however, three of five reoperations after AVR were for failed bioprosthetic devices. The freedom from reintervention was not significantly influenced by the type of AoV operation (P = 0.43). Conclusions Durability of aortic valve repair for children is limited by recurrence of AI and/or stenosis, often within the first few years. After repair, reoperation should be anticipated within ∼7 years.

Symptomatic pulmonary thromboembolism (PTE) is rare in neonates, and the diagnosis is often made only postmortem. The true incidence is probably underestimated because of its varying presentations, ranging from mild respiratory distress to acute right-heart failure and cardiovascular collapse. We report a sudden cardiorespiratory collapse on day 10 of life in a preterm neonate who was subsequently diagnosed as having a saddle pulmonary embolus. The patient underwent an emergency surgical embolectomy as a salvage procedure. Considering the potentially lethal complications of PTE, neonatologists and pediatricians should maintain a high degree of suspicion in infants with sudden inexplicable deterioration in cardiorespiratory status. Surgical removal of the thrombus is an invasive procedure and potentially carries a high mortality rate. Two term neonatal survivors of surgical intervention have been reported in the medical literature so far. However, we believe that this is the first documented preterm neonatal survivor after surgical intervention for a massive saddle PTE.

Background— Fetal hypoxia has been implicated in the abnormal brain development seen in newborns with congenital heart disease (CHD). New magnetic resonance imaging technology now offers the potential to investigate the relationship between fetal hemodynamics and brain dysmaturation. Methods and Results— We measured fetal brain size, oxygen saturation, and blood flow in the major vessels of the fetal circulation in 30 late-gestation fetuses with CHD and 30 normal controls using phase-contrast magnetic resonance imaging and T2 mapping. Fetal hemodynamic parameters were calculated from a combination of magnetic resonance imaging flow and oximetry data and fetal hemoglobin concentrations estimated from population averages. In fetuses with CHD, reductions in umbilical vein oxygen content ( P P P =0.08) and 32% reduction cerebral V o 2 in CHD fetuses ( P P o 2 ( r =0.37, P =0.004). Conclusions— This study supports a direct link between reduced cerebral oxygenation and impaired brain growth in fetuses with CHD and raises the possibility that in utero brain development could be improved with maternal oxygen therapy.

Background: Recommended thresholds for pulmonary valve replacement (PVR) in asymptomatic patients after tetralogy of Fallot (TOF) repair are continually decreasing. We studied the natural history versus outcomes after PVR in various categories of indexed right ventricular end-diastolic volume (RVEDVi). Hypothesis: We hypothesized that the benefit of PVR would not be outweighed by the risk at lower RVEDVi thresholds. Methods: Acquisition of all repeated measure datapoints and cross-sectional review in 2579 patients (born 1924 - 2011), including 7553 echos, 2579 MRI scans and all interventional data. Analysis was via parametric competing risks techniques and time-related regressions adjusted for repeated measures. Results: Survival was 95%, 81% and 73% at age 20, 40 and 60 years respectively. Freedom from PVR (N=516, mean age 25 years) was 87%, 66% and 45% at 20, 40 and 60 years after repair. Overall, survival after PVR was 98%, 95% and 87% at 1, 10 and 20 years. PVR-free survival in all 345 patients with MRI RVEDVi > 150 was 95% at 15 years. Comparative survival showed no survival advantage with PVR versus natural history for RVEDVi 150-160, 160-170, 170-180 (table); these categories had excellent PVR-free survival approaching 100% at 10 years. Patients with RVEDVi > 200 had late survival decrements with PVR or without. PVR resulted in a large and significant reduction in RVEDVi (mean 40 ml/m 2 , P 150 ml/m 2 . Conclusions: Lowering the RVEDVi threshold for PVR does not appear to offer a clear survival advantage and offers small differences (if any) to RV geometry, risks potential procedure-related morbidity and would mean intervening on many teenagers with repaired TOF who could otherwise anticipate intervention in later life.

Annulus-sparing repair of tetralogy of Fallot (TOF) carries a potential increased risk of reoperation for restenosis and unproven benefits on right ventricular (RV) geometry.Primary TOF repairs (n = 434) between 2000 and 2012 were studied using risk-adjusted parametric techniques. Progression of cardiac dimensions was analyzed using repeated measures regression using reports of all 2,103 echocardiograms undertaken throughout the study period, to a maximum follow-up of 13.7 years.Repair was at a mean age of 180 days: AS approach in 296 (68%) patients; and transannular patch in 138 (32%). Intraoperative revisions (for residual stenosis) were required in 135 patients (29%). There have been 4 deaths (survival 99%). Surgical reoperation for recurrent right ventricular outflow tract stenosis was occasionally required in both groups at comparable rates (transannular patch, 5 of 136 [4%]; annulus-sparing repair, 14 of 296 [5%]; p = 0.83). Larger increases in RV end-diastolic dimensions were evident in transannular patch patients versus annulus-sparing repair patients (p0.0001). Other risks for RV dilation included worse grade of postoperative pulmonary regurgitation, larger right ventricular end-diastolic dimension at the time of diagnosis, and higher operative weight (all p0.0001). Factors associated with successful annulus-sparing repair included (1) pulmonary annulus greater than 7 mm, right ventricular end-diastolic dimension greater than 1.2 cm, and tricuspid annulus greater than 1.4 cm (all preoperatively); and (2) right ventricular outflow tract diameter greater than 10 mm and right ventricular systolic pressure less than 50 mm Hg (both intraoperatively after repair).Pursuit of annulus-sparing repair strategies can lower the use of transannular patch to approximately 30% with low risk of reoperation for the patient. Annulus-sparing repair is associated with significantly reduced long-term RV dilation. Pulmonary valve enlargement to approximately 10 mm and right ventricular systolic pressure less than 50 mm Hg during annulus-sparing repair are associated with low risk of recurrent stenosis.

Few topics in adult congenital heart disease have approached the level of scrutiny bestowed on pulmonary valve replacement (PVR) strategies late after tetralogy of Fallot (TOF) repair. Despite the successes of primary surgery for TOF, there is a growing group of adults with residual right ventricular outflow tract and pulmonary valve dysfunction. Patients with residual chronic pulmonic regurgitation as a consequence of earlier surgery can later develop symptoms of exercise intolerance and complications including heart failure, tachyarrhythmias, and sudden cardiac death. Optimal timing of PVR has sparked debate, which has catalyzed increasing research efforts over the past decade. Although performance of PVR in the absence of symptoms is currently on the basis of the rationale that achievement of complete reverse remodelling is highly desirable, whether this approach results in improvement in patient outcomes in the long-term has yet to be shown. Surgical PVR and percutaneous pulmonary valve intervention are different techniques with specific advantages and disadvantages that require careful consideration for each individual patient, alongside the need for requisite reinterventions over the course of a patient's lifetime. Criteria pertaining to referral strategies are ever being refined as newer technologies for percutaneous therapies continue to evolve. In this article we review the literature surrounding the indications for, the optimal timing of, and the approaches to pulmonary valve procedures in adults with previously repaired TOF.

Objectives Mortality associated with the modified Blalock–Taussig shunt (MBTS) remains high despite advanced perioperative management. This study was formulated to provide data on (1) current indications, (2) outcomes, and (3) factors affecting mortality and morbidity. Design A retrospective single center chart review identified 95 children (excluding hypoplastic left heart lesions) requiring a MBTS. Mortality and major morbidity were analyzed using the Kaplan Meier method and risk factor analysis using Cox's proportional hazard regression. Results Median age was 8 (0–126) days, weight 3.1(1.7–5.4) kg. Seventy-three percent were neonates, 58% duct dependent and 73% had single ventricle physiology. Ninety-seven percent had a sternotomy approach for shunt placement with 70% receiving a 3.5 mm graft. Mean graft index (shunt cross sectional area [mm2]/BSA [m2]) was 44.39 ± 8.04 and shunt size (mm) to body weight (kg) ratio 1.1 ± 0.2. Hospital mortality was 12%, with an interval mortality of 6%. Shunt thrombosis/stenosis occurred in 23% and pulmonary over circulation in 30%, while shunt reoperation was required in 12% and catheter intervention in 8% of the cohort. At 1-year, survival was 82.0% (95% CI [72.7%, 88.4%]), and survival free of major morbidity 61.4% (95% CI [50.7%, 70.5%]). Duct dependency predisposed to mortality (P = .01, HR 6.74 [1.54, 29.53]) and composite outcome (mortality and major morbidity) (P = .04, HR 2.15, CI [1.036, 4.466]) and higher graft index to mortality (P = .005, HR 1.07 [1.02, 1.12]). Conclusions The commonest indication for a MBTS in the current era was single ventricle palliation. Morbidity and mortality was considerable, partly explained by the higher at risk population. Alternative methods to maintain pulmonary blood flow in place of a MBTS requires further investigation.

Background Chronic hemodynamically relevant pulmonary regurgitation (PR) resulting in important right ventricular dilation and ventricular dysfunction is commonly seen after tetralogy of Fallot (TOF) repair. Late adverse clinical outcomes, including exercise intolerance, arrhythmias, heart failure and/or death accelerate in the third decade of life and are cause for considerable concern. Timing of pulmonary valve replacement (PVR) to address chronic PR is controversial, particularly in asymptomatic individuals, and effect of PVR on clinical measures has not been determined. Methods Canadian Outcomes Registry Late After Tetralogy of Fallot Repair (CORRELATE) is a prospective, multicentre, Canada-wide cohort study. Candidates will be included if they are ≥ 12 years of age, have had surgically repaired TOF resulting in moderate or severe PR, and are able to undergo cardiovascular magnetic resonance imaging. Enrollment of > 1000 individuals from 15 participating centres (Toronto, Montreal, Quebec City, Sherbrooke, Halifax, Calgary, Edmonton, and Vancouver) is anticipated. Clinical data, health-related quality of life metrics, and adverse outcomes will be entered into a web-based database. A central core lab will analyze all cardiovascular magnetic resonance studies (PR severity, right ventricular volumes, and ventricular function). Major adverse outcomes (sustained ventricular tachycardia and cardiovascular cause of death) will be centrally adjudicated. Results To the best of our knowledge, CORRELATE will be the first prospective pan-Canadian cohort study of congenital heart disease in children and adults. Conclusions CORRELATE will uniquely link clinical, imaging, and functional data in those with repaired TOF and important PR, thereby enabling critical evaluation of clinically relevant outcomes in those managed conservatively compared with those referred for PVR.

Objective There is considerable variability in anticoagulation use in neonates with transposition of the great arteries (TGA) and single ventricle physiology (SVP) for secondary stroke prevention and primary cardiovascular indications. Leveraging cross-center differences in anticoagulation use, we compared the risk of new postoperative brain injury in neonates with TGA and SVP treated with anticoagulation relative to untreated neonates. Methods Two-center observational cohort study of 118 term-born neonates with TGA (n = 83) and SVP (n = 35), undergoing cardiopulmonary bypass surgery and pre- and postoperative brain magnetic resonance imaging. Anticoagulation and antiplatelet therapy details were obtained. Magnetic resonance images were scored for stroke, white matter injury, and hemorrhage. New postoperative injury was compared between neonates with and without anticoagulation for the 2-center cohort, and subsequently stratified by cardiac lesion type and anticoagulation indication. Results Thirty-six out of 118 neonates (29%) received anticoagulation: 11 (30%) for preoperative stroke, 20 (56%) for preoperative peripheral/intracardiac thrombus, and 5 (14%) for Blalock-Taussig shunt. Five out of 36 neonates (14%) treated with anticoagulation also received antiplatelet therapy. Although no differences were identified for the 2-center cohort or for neonates with TGA separately, significantly more new postoperative parenchymal brain injury (P = .04), particularly stroke, was found in SVP neonates with compared to without anticoagulation (31% vs 5%). In neonates who experienced preoperative stroke, new subdural hemorrhage (36% vs 0%) was more frequent in neonates treated with anticoagulation therapy compared with those without anticoagulation therapy. Conclusions In our cohort of neonates with TGA and SVP, anticoagulation for preoperative stroke, preoperative thrombus, and/or Blalock-Taussig shunt did not have the anticipated benefit of preventing new perioperative brain injury. These findings indicate the critical need for rigorous randomized trials on the safety and effectiveness of anticoagulation therapy in this population.

Objective To evaluate whether structural and microstructural brain abnormalities in neonates with congenital heart disease (CHD) correlate with neuronal network dysfunction measured by analysis of EEG connectivity. Methods We studied a prospective cohort of 20 neonates with CHD who underwent continuous EEG monitoring before surgery to assess functional brain maturation and network connectivity, structural magnetic resonance imaging (MRI) to determine the presence of brain injury and structural brain development, and diffusion tensor MRI to assess brain microstructural development. Results Neonates with MRI brain injury and delayed structural and microstructural brain development demonstrated significantly stronger high‐frequency (beta and gamma frequency band) connectivity. Furthermore, neonates with delayed microstructural brain development demonstrated significantly weaker low‐frequency (delta, theta, alpha frequency band) connectivity. Neonates with brain injury also displayed delayed functional maturation of EEG background activity, characterized by greater background discontinuity. Interpretation These data provide new evidence that early structural and microstructural developmental brain abnormalities can have immediate functional consequences that manifest as characteristic alterations of neuronal network connectivity. Such early perturbations of developing neuronal networks, if sustained, may be responsible for the persistent neurocognitive impairment prevalent in adolescent survivors of CHD. These foundational insights into the complex interplay between evolving brain structure and function may have relevance for a wide spectrum of neurological disorders manifesting early developmental brain injury.

Infants with severe tetralogy of Fallot may undergo (1) early primary surgical repair (EARLY) or (2) early transcatheter palliation (CATH) before delayed surgical repair. We compared these strategies with (3) elective single-stage tetralogy of Fallot repair (IDEAL).From 2000 to 2012, 453 children underwent tetralogy of Fallot repair (excluding systemic-pulmonary shunts), including 383 in the IDEAL (75%), 42 in the EARLY (9%), and 28 in the CATH (6%) groups. IDEAL repair at The Hospital for Sick Children occurs after 3 months. Risk-adjusted hazard analysis compared freedom from surgical or catheter reintervention. Somatic size, branch pulmonary artery size, and right ventricle systolic pressure were modeled using 2780 echocardiogram reports via mixed-model regression.CATH involved right ventricular outflow tract stent in 18 patients, right ventricular outflow tract balloon in 9 patients, and ductal-stent in 1 patient. Three patients died (1 per group). Risk-adjusted freedom from surgical reoperation was 89% ± 4%, 88% ± 5%, and 85% ± 6% for the IDEAL, EARLY, and CATH groups, respectively, at 10 years. Patients in the EARLY and CATH groups had similar reoperation rates, except for neonates (1 month), for whom EARLY repair conferred an increased risk of reoperation. Risk-adjusted freedom from catheter reintervention was lower in the EARLY group (76%) and especially for the CATH group (53%) at 10 years versus the IDEAL group (83%). Somatic growth and progression of right ventricle systolic pressure were similar among groups at 8 years. Although those undergoing EARLY (P = .02) and CATH (P = .09) tend to have smaller branch pulmonary arteries initially, late pulmonary artery size was not significantly different among groups.Early primary repair for neonates may increase surgical reoperation, whereas transcatheter palliation comes at a cost of increased catheter reintervention. However, overall outcomes between groups, in terms of survival, growth, and hemodynamic parameters, were comparable, suggesting that both strategies are a reasonable option for children with severe tetralogy of Fallot.

Survival prospects for adults with repaired tetralogy of Fallot (TOF) are now excellent. Attention should therefore shift to assessing and improving functional health status and quality of life. We aimed to assess late functional health status of adults surviving TOF repair by matched comparison to their healthy siblings.All 1,693 TOF repairs performed at our institution between 1946 and 1990 were reviewed. A matched comparison was undertaken whereby presumed survivors and their healthy sibling were contacted and asked to complete the Ontario Health Survey 1990 and the 36-Item Short Form Health Survey (SF-36) questionnaire.Both questionnaires were completed by 224 adult survivors and their sibling closest in age. Adults with repaired TOF had lower scores for self-perceived general health status (p0.001), were less likely to rate their health as good or excellent (p0.001), and had lower SF-36 scores for physical functioning and general health (p = 0.001) than their siblings. However, patients reported similar satisfaction with their lives, similar levels of social participation and support, and were as likely to be in long-term partnerships. Worse physical and mental health scores were associated with older age at surgery and at time of questionnaire completion and recent requirement for noncardiac medication.Although reporting lower functional health status then their siblings, quality of life and life satisfaction for adults who underwent surgery for TOF during childhood is comparable to that of their siblings without heart defects. Follow-up of younger adults is required to understand current health outcomes attributable to improvements in the management of TOF.

BackgroundWe sought to prospectively determine foetal echocardiographic factors associated with neonatal interventions in borderline hypoplastic left ventricles.MethodsFoetuses were included who had a left ventricle that was 2–4 standard deviations below normal for length or diameter and had forward flow across the mitral and aortic valves. Factors associated with an intervention in the first month of life or no need for intervention were sought using univariate and multivariate logistic regression models.ResultsFrom 2005 to 2008, 47 foetuses meeting the criteria had an additional diagnosis (+foetal coarctation/+transverse arch hypoplasia): atrioventricular septal defect 7 (+2/+0), double outlet right ventricle 2 (+0/+0), Shone's complex 19 (+9/+4), and ventricular disproportion 19 (+13/+11; 4 both). There were seven pregnancies terminated, three foetal demises, and five had compassionate care. There were 32 livebirths that either had a biventricular repair (n = 20, n = 2 dead), univentricular palliation (n = 2, both alive), or no intervention (n = 9). Overall survival of livebirths to 6 months of age was 79%. Factors associated with early intervention on first foetal echocardiogram were: obstructed or retrograde arch flow (p = 0.08, odds ratio 3.3), coarctation (p = 0.05, odds ratio 11.4), and left ventricle outflow obstruction (p = 0.05, odds ratio 12.5). Neonatal factors included: Shone's diagnosis (p = 0.02, odds ratio 4.9), bicuspid aortic valve (p = 0.005, odds ratio 11.7), and larger tricuspid valve z-score (p = 0.05, odds ratio 3.6). A neonatal factor associated with no intervention was a larger mitral valve z-score (mean −3.8 versus −4.2 intervention group, p = 0.04, odds ratio 2.8).DiscussionThe need for early intervention in foetuses with borderline hypoplastic left ventricle can be predicted by foetal echocardiography.

“Hypoplastic left heart syndrome” is an unsatisfactory term describing lethal underdevelopment of the left ventricle (LV). It represents the more severe end of a spectrum of LV hypoplasia, mandating single-ventricle palliation or cardiac transplantation. Less severe “borderline” ventricular hypoplasia may instead allow various biventricular therapeutic strategies and better long-term outcomes. In this review, we consider factors causing and modifying the abnormal development of the LV. LV hypoplasia is typically seen in association with left ventricular outflow tract obstruction, itself part of a spectrum of related defects with common etiologies. Secondary responses to outflow obstruction are complex but involve abnormal flow dynamics and shear stresses that result in compromised and poorly orchestrated ventricular growth and development. Subsequent remodeling is likely influenced by genetic modifiers, including intrinsic myocardial growth signaling pathways, possibly including those of HAND transcription factors. In addition, during the latter stages of gestation, cardiomyocytes undergo a switch in myogenic potential and lose the ability to undergo mitosis. Ventricular hyperplasia can therefore no longer occur; remodeling is instead limited to muscular hypertrophy. Subtle differences in this switch in myogenic potential—and modulators thereof—are likely to be of clinical and therapeutic importance, especially in children with “borderline LVs” being considered for fetal interventions or post-natal biventricular repair strategies. Finally, by more clearly understanding the initiators and propagators of abnormal ventricular development, we can hope to lean away from grouping a heterogeneous group of infants together under the unsatisfactory term “hypoplastic left heart syndrome.”

Lipopolysaccharide (LPS) preconditioning reduces ischemic injury in adult brain by activating Toll-like receptor 4 (TLR-4). We sought to investigate the effect of brain maturity on the efficacy of LPS preconditioning against hypoxic-ischemic (HI) injury in the developing rat brain. Rat pups at the specified age were randomly assigned to LPS-treated (0.1 mg/kg) or saline-treated groups. HI injury was induced 48 h later by occluding the right common carotid artery followed by transient hypoxia. Brains were removed 1 wk after HI injury, and infarct volumes were compared between the two groups. TLR-4 expression was also compared among different ages. We found that LPS treated P7, P9, and P14 rat pups had significantly smaller infarct volume compared with saline-treated pups (p = 0.006, 0.03, and 0.01, respectively). This significant reduction in infarct volume was not observed in P3 and P5 rats. TLR-4 expression was significantly higher in older rats compared with P3 and P5 rats (p < 0.01). These findings indicate that LPS-induced preconditioning is a robust neuroprotective phenomenon in the ischemic developing brain that is age dependent. Pattern of TLR-4 expression is also affected by brain maturity and likely to be responsible for differences in the efficacy of LPS preconditioning.

Objectives. To understand relationships and survival implications between structural heart disease and hypertrophic cardiomyopathy in Noonan syndrome (Noonan syndrome-HCM), we reviewed the clinical course of 138 children with Noonan syndrome diagnosed with cardiovascular abnormalities and compared survival with the 30 children with Noonan syndrome-HCM with 120 contemporaneous children with nonsyndromic HCM. Methods. Study cohorts represent consecutive cases diagnosed at our institution 1966 through 2006. Outcomes were modeled using multiphase parametric techniques followed by multivariable regression with bagging. Results. Cardiac abnormalities in Noonan syndrome: Cardiac abnormalities in the 138 Noonan syndrome children included pulmonary valve dysplasia (52%), hypertrophic cardiomyopathy (22%), atrial septal defect (20%), ventricular septal defect (10%), mitral valve dysplasia (6%), coarctation (3%), and Fallot's tetralogy (2%). Need for surgery was high but not different from children with structural defects coexisting with HCM. Overall, late survival in children with Noonan syndrome and cardiac defects was good (91 ± 3% at 15 years), although significantly worse for those with Noonan syndrome-HCM (P < .01). Noonan syndrome-HCM vs. nonsyndromic HCM: In the 30 children with Noonan syndrome-HCM, structural cardiac malformations coexisted in 18 (57%). The incidence of structural cardiac malformations in nonsyndromic HCM was instead 3/120 (2.5%, P < .001). Risk-adjusted late survival was significantly worse for Noonan syndrome-HCM than for nonsyndromic HCM (P= .02). Conclusions. Noonan syndrome-HCM frequently coexists with structural cardiac malformations, whereas nonsyndromic HCM does not; their natural histories may therefore be different. Late survival is significantly worse for Noonan syndrome-HCM than nonsyndromic HCM.

Hypoplastic left heart syndrome may coexist with noncardiac congenital defects or genetic syndromes. We explored the impact of such lesions on outcomes after staged univentricular palliation.Society of Thoracic Surgeons database 2002 to 2006: Children diagnosed with hypoplastic left heart syndrome who underwent stage 1 Norwood (n = 1,236), stage 2 superior cavopulmonary anastamosis (n = 702) or stage 3 Fontan (n = 553) procedures were studied. In-hospital mortality, postoperative complications, and length of stay were compared at each stage between those with and without noncardiac-genetic defects. Congenital Heart Surgeons' Society database 1994 to 2001: All 703 infants enrolled in the Congenital Heart Surgeons' Society critical left ventricular outflow tract obstruction study who underwent primary stage 1 palliation were reviewed. The impact of noncardiac defects-syndromes on survival was explored using multivariable parametric models with bootstrap bagging.Society of Thoracic Surgeons database: Stage 1 in-hospital mortality (26% vs 20%, p = 0.04) and mean postoperative length of stay (42 versus 31 days, p0.0001) were greater, and postoperative complications significantly more prevalent in infants with noncardiac-genetic defects. Congenital Heart Surgeons' Society database: Noncardiac-genetic defects were present in 55 (8%). Early hazard for death after Norwood was significantly worse in infants with noncardiac defects-syndromes (p = 0.008). Chromosomal defects (n = 14) were highly unfavorable: the early risk of death was doubled (10-year survival 25 +/- 9% vs 54 +/- 2%, p = 0.005). Turner syndrome accounted for the majority of chromosomal defects in this population (11 of 14, 79%). Mode of death was rarely attributable to the noncardiac-genetic defect.Survival in hypoplastic left heart syndrome is strongly influenced by the presence of noncardiac abnormalities. Strategies to improve mortality in infants with noncardiac abnormalities should be explored. Presence of chromosomal defects, especially Turner syndrome, should enter decision-management options for parents and physicians.

Aims Replacement of bioprosthetic valves in the right ventricular (RV) outflow tract (RVOT) is inevitable due to acquired valvar dysfunction. Percutaneous pulmonary valve implantation (PPVI) may result in acceptable clinical improvement avoiding surgical reintervention. To report outcomes of PPVI in dysfunctional surgically implanted bioprosthetic valves. Methods and results All children undergoing PPVI into a bioprosthetic pulmonary valve between October 2005 and February 2008 were reviewed. Acute haemodynamic changes were compared and an analysis of variance applied to assess changes in ventricular geometry and pressure over time. Fourteen children (seven males), median weight 57.8 kg and 14.7 years of age were identified, with an echocardiographic RVOT gradient of 59.6 ± 26.8 mmHg and a pulmonary regurgitation (PR) grade of 3.6 ± 0.8 (out of 4). Implantation was successful in all. Twenty-four hours after implantation, there was a significant improvement in RV pressure (RVP) (from 82.2 ± 15.6 to 59.4 ± 9.9 mmHg, P < 0.001) and degree of PR to 0.6 ± 0.9 ( P < 0.001). Mean hospital stay was 2.0 ± 0.4 days. Freedom from reintervention was 92 and 89% at 1 and 2 years, respectively. Follow-up echocardiography (mean 12.9 ± 9.8 months) revealed a further reduction in RVP ( P < 0.001) and RVOT gradients ( P < 0.001) and an increase in left ventricular end-diastolic volume ( P = 0.01) and aortic valve annulus diameters ( P < 0.001). Conclusions Percutaneous pulmonary valve implantation for RVOT dysfunction in a previously implanted prosthetic valve is feasible and safe. Short-term follow-up data are encouraging, yet longer-term information is required to determine if this form of palliation has a significant impact on management strategies.

Background: Although there is agreement of the importance of cardiac catheterization, especially interventional procedures, cardiac catheterization in postoperative critical care unit (CCU) period is often debated. The focus of this study was to explore the indications for and determinants of outcome after cardiac catheterization in this setting. Methods: Between March 2004 and October 2006, 49 children (2.8% of cardiac surgeries) underwent 62 catheterizations before discharge from the CCU. Morphological, surgical, and catheterization data were accrued and analyzed using parametric competing risks models and multivariable risk-hazard analysis. Results: Median age at surgery was 167 days (0–13.5 years) and time to catheterization was 8.5 (0–84) days following surgery. Catheterization procedures were either interventional (n = 35) or noninterventional (n = 27). Children who required a more urgent investigation following initial surgery more often had deployment of a stent at catheterization (P = 0.01) or subsequent surgical pulmonary artery augmentation (P < 0.01). Surgical reoperation was required following 23 (37%) catheterizations and was more common following index surgery involving a cavopulmonary shunt. Overall mortality was high (43%). Delayed invasive investigation beyond 2–3 weeks (P = 0.04) or a splinted sternum (P < 0.001) were risk factors for death. In addition, reoperation after a noninterventional catheterization predicted worse survival (P < 0.001). Conclusions: The need for invasive investigation in the immediate CCU period is associated with a poor outcome, especially when the investigation is delayed or an intervention is not possible. Identification of at-risk patients may improve outcomes. Best outcomes follow expedient catheterization with definitive management (often stent deployment or pulmonary artery augmentation). © 2009 Wiley-Liss, Inc.

ObjectiveDelayed preconditioning genetically reprograms the response to ischemic injury. Subclinical bacterial lipopolysaccharide acts through preconditioning, powerfully protecting against experimental stroke. We investigated the potential for lipopolysaccharide to protect against brain injury related to cardiopulmonary bypass.MethodsNeonatal piglets were blindly and randomly preconditioned with lipopolysaccharide (n = 6) or saline (n = 6). Three days later, they experienced 2 hours of deep hypothermic circulatory arrest before being weaned and supported anesthetized for 20 hours in an intensive care setting. Controls included cardiopulmonary bypass without deep hypothermic circulatory arrest (n = 3) and no cardiopulmonary bypass (n = 3). Brain injury was quantified by light and fluorescent microscopy (Fluoro-Jade; Histo-Chem, Inc, Jefferson, Ark).ResultsAll animals were clinically indistinguishable before surgery. Perioperative and postoperative parameters between experimental groups were similar. No control animal scored falsely positive. Histologic scores were 0.33 ± 0.21, 0.66 ± 0.42, and 0.5 ± 0.24 in the cortex, basal ganglia, and hippocampus, respectively, in the lipopolysaccharide-treated animals but significantly worse in all saline control animals (1.33 ± 0.21, P < .01; 1.66 ± 0.33, P = .09; and 6.0 ± 1.5, P < .01). One lipopolysaccharide-treated brain was histologically indistinguishable from controls.ConclusionThis is the first evidence that lipopolysaccharide can precondition against cardiopulmonary bypass–related injury. Because lipopolysaccharide preconditioning is a systemic phenomenon offering proven protection against myocardial, hepatic, and pulmonary injury, this technique offers enormous potential for protecting against systemic neonatal injury related to cardiopulmonary bypass.

Background Torsion is an essential component of left ventricular (LV) function. Systolic rotation, as a component of torsion, winds the heart muscle up like a spring, setting up recoil for early diastole. We used a new 2-dimensional speckle tracking strain method to study differences in twisting in subendocardial and subepicardial layers of the LV in open-chest pigs. Our aim was to identify the relative contributions of the inner or outer layers of the LV wall to rotation and, hence, systole. Methods A total of 23 juvenile pigs were imaged in the short axis, epicardially, to obtain images at a level just below the papillary muscles with high-frequency (14 MHz) ultrasound. Speckle tracking software using scanline files was used to measure the torsional contribution of septum, anterior, posterior, and inferior LV wall segments. Two zones on the septum were evaluated separately: one with apparent circumferential fiber orientation in the inner layer and one with a speckle pattern suggesting longitudinal fiber orientation on the right ventricular aspect of the septum. Pressure rate changes (dP/dt) during the cardiac cycle were measured as an index of LV function and correlated with the regional torsion. Results Mean peak rotations measured by speckle tracking echocardiography at the apex showed counterclockwise rotation of LV septal wall (10.68 ± 2.67 degrees for the inner layer and 8.27 ± 1.73 degrees for the outer layer). The time difference for time to peak rotation was 213.22 ± 77.95 and 241.17 ± 54.67 milliseconds for inner and outer layers, respectively. Significant differences were shown between the inner and outer layer of the LV for both rotation ( P = .000) and timing of rotation ( P = .02). The dP/dt measurements correlated well with the inner rotation magnitude of the LV and with the difference of short-axis rotation between inner and outer layers of the LV wall. Conclusions Inner and outer layers of the LV wall, especially at the septum, have different rotational behaviors. When used with very high-resolution imaging, this method could contribute to the understanding of functional contributions of the LV wall and their relative contribution to cardiac segmental twisting.