Cardiac MRI evaluation of aortic biophysical properties in paediatric Turner syndrome.

BACKGROUND: Aortopathy in Turner syndrome is associated with aortic dilation, and the risk of dissection is increased when the aortic size index is ≥ 2-2.5 cm/m2. We evaluated the aortic biophysical properties in paediatric Turner syndrome using cardiac MRI to determine their relationship to aortic size index. METHODS: Turner syndrome patients underwent cardiac MRI to evaluate ventricular function, aortic dimensions, and biophysical properties (aortic stiffness index, compliance, distensibility, pulse wave velocity, and aortic and left ventricular elastance). Spearman correlation examined correlations between these properties and aortic size index. Data was compared to 10 controls. RESULTS: Of 25 Turner syndrome patients, median age 14.7 years (interquartile range: 11.0-16.8), height z score -2.7 (interquartile range: -2.92 - -1.54), 24% had a bicuspid aortic valve. Turner syndrome had increased diastolic blood pressure (p < 0.001) and decreased left ventricular end-diastolic (p < 0.001) and end-systolic (p = 0.002) volumes compared to controls. Median aortic size index was 1.81 cm/m2 (interquartile range: 1.45-2.1) and 7 had an aortic size index > 2 cm/m2. Aortic and left ventricular elastance were greater in Turner syndrome compared to controls (both p < 0.001). Increased aortic size index correlated with increased aortic elastance (r = 0.5, p = 0.01) and left ventricular elastance (r = 0.59, p = 0.002) but not aortic compliance. Higher ascending aortic areas were associated with increased aortic compliance (r = 0.44, p = 0.03) and left ventricular elastance (r = 0.49, p = 0.01). CONCLUSION: Paediatric Turner syndrome with similar aortic size index to controls showed MRI evidence of abnormal aortic biophysical properties. These findings point to an underlying aortopathy and provide additional parameters that may aid in determining risk factors for aortic dissection.

Paediatric supraventricular tachycardia patients potentially more at risk of developing psychological difficulties compared to healthy peers.

AIM: Assess executive and socio-emotional/behavioural functioning in paediatric supraventricular tachycardia (SVT) patients. METHODS: SVT patients aged 7-17 who had not undergone catheter ablation were included. Parents completed the Child Behaviour Checklist (CBCL/6-18) and the Behavior Rating Inventory of Executive Functioning (BRIEF). Participants age 11-17 years completed the Youth Self-Report (YSR/11-18) and the BRIEF Self-Report (BRIEF-SR). One-sample z test was used to compare questionnaire results to the average t-score range (M = 50, SD = 10). RESULTS: Thirty (18 female) children/adolescents participated (M = 12.6 years old, SD = 3.2 years) with a mean SVT onset age of 7 years (SD = 4.3 years). BRIEF and BRIEF-SR results suggested no difference in executive functioning from average. Mean t-scores of CBCL/6-18 and YSR/11-18 subscales Anxious/Depressed, Withdrawn/Depressed, Somatic Complaints, Thought Problems, Diagnostic and Statistical Manual of Mental Disorders (DSM) Affective Problems, DSM Anxiety Problems and DSM Somatic Problems were significantly elevated compared to average. YSR/11-18 subscales Social Problems, Attention Problems, Internalizing Problems, DSM ADHD Problems and DSM Oppositional Defiant Problems had elevated mean t-scores compared to average. Effect sizes were small to medium (0.2 ≤ d ≤ 0.8). CONCLUSION: Paediatric patients with SVT potentially have a greater risk of developing behaviour, especially internalizing, problems compared to similarly aged children/adolescents without SVT.

Strategies to maintain a family-centered care approach in the era of COVID-19: Experiences of a Canadian pediatric cardiology program.

The COVID-19 pandemic has resulted in strict provincial guidelines to prevent its spread. Physical distancing requirements, the postponement of elective pediatric cardiac surgeries and non-invasive cardiac interventions, and hospital visitor restrictions have significantly impacted services provided by our pediatric cardiac program. Rapid modifications to current inpatient and outpatient practices were required to maintain a family-centered care approach. Strategies our team used to maintain a family-centered care approach focused on six key areas including inpatient care, outpatient pediatric cardiology clinics, family meetings, discharge planning and teaching, the connection of inpatient pediatric patients to the outside world, and social support. The majority of our strategies are adaptable to other pediatric cardiology programs and some may prove useful after the pandemic and as restrictions lift. These strategies each have their own limitations and challenges that must be considered when adapting them to other pediatric cardiology programs and continuing their use after the pandemic has resolved.

Riata lead failure in pediatric and congenital heart disease patients.

BACKGROUND: Implantable cardioverter defibrillator (ICD) lead failures occur at higher rates in pediatric and congenital heart disease (CHD) patients. OBJECTIVE: To determine the rate and timing of Riata lead failure in pediatric and CHD patients. METHODS: This was a retrospective, multicenter cohort study of pediatric patients and adults with CHD with implantation of a Riata or Riata ST lead between 2002 and 2009. The prevalence and timing of electrical failure and conductor coil externalization (CCE) were determined. RESULTS: Fifty-eight patients and 63 leads from seven centers were included. Median (interquartile range [IQR]) age at implant was 14.4 (11.5-18.7) years and median follow-up was 8.7 (7.3-11.1) years. The underlying diagnosis was a primary arrhythmia disorder in 45%, cardiomyopathy in 31%, and CHD in 28% of patients. Electrical failure occurred in 43% and CCE in 16% of leads at median lead ages of 4.7 (3.4-7.5) and 4.3 (3.9-7.0) years, respectively. Median lead survival free from electrical failure or CCE was 7.9 (95% confidence interval, 5.8-10.0) years. Forty-one percent of leads were functional at the end of the follow-up period, and 33% were extracted with a complication rate of 5%. CONCLUSIONS: The rate of Riata lead electrical failure was high in children and patients with CHD, while the rate of CCE was comparable with published data. Counseling on lead management should factor in the high rate of electrical failure with considerations for elective replacement.

Characterization of Myocardial Repolarization Reserve in Adolescent Females With Anorexia Nervosa.

BACKGROUND: Patients with anorexia nervosa exhibit abnormal myocardial repolarization and are susceptible to sudden cardiac death. Exercise testing is useful in unmasking QT prolongation in disorders associated with abnormal repolarization. We characterized QT adaptation during exercise in anorexia. METHODS AND RESULTS: Sixty-one adolescent female patients with anorexia nervosa and 45 age- and sex-matched healthy volunteers performed symptom-limited cycle ergometry during 12-lead ECG monitoring. Changes in the QT interval during exercise were measured, and QT/RR-interval slopes were determined by using mixed-effects regression modeling. Patients had significantly lower body mass index than controls; however, resting heart rates and QT/QTc intervals were similar at baseline. Patients had shorter exercise times (13.7±4.5 versus 20.6±4.5 minutes; P<0.001) and lower peak heart rates (159±20 versus 184±9 beats/min; P<0.001). The mean QTc intervals were longer at peak exercise in patients (442±29 versus 422±19 ms; P<0.001). During submaximal exertion at comparable heart rates (114±6 versus 115±11 beats/min; P=0.54), the QTc interval had prolonged significantly more in patients than controls (37±28 versus 24±25 ms; P<0.016). The RR/QT slope, best described by a curvilinear relationship, was more gradual in patients than in controls (13.4; 95% confidence interval, 12.8-13.9 versus 15.8; 95% confidence interval, 15.3-16.4 ms QT change per 10% change in RR interval; P<0.001) and steepest in patients within the highest body mass index tertile versus the lowest (13.9; 95% confidence interval, 12.9-14.9 versus 12.3; 95% confidence interval, 11.3-13.3; P=0.026). CONCLUSIONS: Despite the absence of manifest QT prolongation, adolescent anorexic females have impaired repolarization reserve in comparison with healthy controls. Further study may identify impaired QT dynamics as a risk factor for arrhythmias in anorexia nervosa.

An Echocardiographic Study of Left Ventricular Size and Cardiac Function in Adolescent Females with Anorexia Nervosa.

OBJECTIVE: This retrospective case-control study investigated cardiac dimensions and ventricular function in female adolescents with anorexia nervosa (AN) compared with controls. METHODS: Echocardiographic measurements of left ventricular (LV) dimensions, LV mass index, left atrial size and cardiac index were made. Detailed measures of systolic and diastolic ventricular function were made including tissue Doppler imaging. Patients were stratified by body mass index ≤10th percentile (AN ≤ 10th) and >10th percentile (AN > 10th). RESULTS: Ninety-five AN patients and 58 controls were included. AN and AN ≤ 10th groups had reduced LV dimensions, LV mass index, left atrial size and cardiac index compared with controls. There were no differences between groups in measures of systolic function. Measures of diastolic tissue Doppler imaging were decreased in AN and AN ≤ 10th. No differences in echocardiographic measurements existed between controls and AN > 10th. DISCUSSION: Female adolescents with AN have preserved systolic function and abnormalities of diastolic ventricular function. AN ≤ 10th may be a higher risk group.

Electrocardiogram interpretation by Canadian general paediatricians: Examining practice, accuracy and confidence.

BACKGROUND: Paediatric electrocardiograms (ECGs) are ordered and interpreted by general paediatricians; however, no previous studies have evaluated the accuracy of their ECG interpretations. OBJECTIVE: To determine general paediatricians' practice and opinions regarding ECG use, accuracy of their interpretation of paediatric ECGs, and the relationship between accuracy and self-perceived confidence. METHODS: In the present cross-sectional study, Canadian general paediatricians were asked to complete a questionnaire and interpret 18 paediatric ECGs. The questionnaire assessed characteristics of ECG use, self-perceived confidence and opinions regarding ECG use in general paediatric practice. For the ECGs provided, respondents were asked whether the ECG was normal or abnormal, what abnormality the ECG demonstrated and how confident they were in this interpretation. RESULTS: ECG interpretation was performed by 124 general paediatricians. General paediatricians frequently use ECGs in their practice and regard this investigation as useful in patient assessment. The mean (± SD) accuracy of identifying ECGs as normal or abnormal, and identifying the specific abnormality was 80±12% and 56±20%, respectively. The sensitivity and specificity of identifying abnormal ECGs were 80% (95% CI 78% to 82%) and 79% (95% CI 75% to 83%), respectively. Correct ECG interpretation for isolated rhythm disturbances (73%) was significantly better than for abnormalities in axis (25%), chamber hypertrophy (41%) and ECG intervals (49%) (P<0.001). Overall confidence in ECG interpretation correlated with and was the only significant predictor of interpretation accuracy (r=0.396, P<0.001). CONCLUSION: General paediatricians were adept at detecting abnormal ECGs, but were less able to identify the abnormalities. Further education in ECG interpretation may be important for this population.

HISTORIQUE: Ce sont des pédiatres généralistes qui demandent et interprètent les électrocardiogrammes (ECG) en pédiatrie, mais aucune étude n'a porté sur l'exactitude de leur interprétation. OBJECTIF: Déterminer la pratique et les avis des pédiatres généralistes en matière d'utilisation des ECG et de l'exactitude des ECG en pédiatrie et établir le lien entre la précision et l'autoperception de la confiance. MÉTHODOLOGIE: Dans la présente étude transversale, les pédiatres généralistes canadiens ont été invités à remplir un questionnaire et à interpréter 18 ECG en pédiatrie. Le questionnaire visait à évaluer les caractéristiques liées à l'utilisation des ECG, l'autoperception de la confiance et les avis relatifs à l'utilisation des ECG en pédiatrie générale. Les répondants étaient invités à préciser si les ECG four-nis étaient normaux ou anormaux, les anomalies démontrées et leur confiance quant à leur interprétation. RÉSULTATS: Cent vingt-quatre pédiatres généralistes ont interprété les ECG. Les pédiatres généralistes utilisent souvent les ECG dans leur pratique et les considèrent comme utiles dans l'évaluation des patients. L'exactitude moyenne dans l'identification des ECG comme normaux ou anormaux et dans la détermination de l'anomalie précise correspondait à 80±12 % et à 56±20 %, respectivement. La sensibilité et la spécificité de l'identification des ECG anormaux s'établissaient à 80 % (95 % IC 78 % à 82 %) et à 79 % (95 % IC 75 % à 83 %), respectivement. La bonne interprétation des ECG révélant des troubles isolés du rythme cardiaque (73 %) était considérablement plus élevée que celle des anomalies de l'axe (25 %), de l'hypertrophie ventriculaire (41 %) et des intervalles d'ECG (49 %) (P<0,001). Dans l'ensemble, la confiance à l'égard de l'interprétation des ECG était corrélée avec l'exactitude des interprétations et en était le seul prédicteur important (r=0,396, P<0,001). CONCLUSION: Les pédiatres généralistes décelaient bien les ECG anormaux, mais réussissaient moins bien à déterminer les anomalies exactes. Il serait peut-être important de leur fournir un perfectionnement dans l'interprétation des ECG.

Deep Learning-Augmented ECG Analysis for Screening and Genotype Prediction of Congenital Long QT Syndrome.

Importance: Congenital long QT syndrome (LQTS) is associated with syncope, ventricular arrhythmias, and sudden death. Half of patients with LQTS have a normal or borderline-normal QT interval despite LQTS often being detected by QT prolongation on resting electrocardiography (ECG). Objective: To develop a deep learning-based neural network for identification of LQTS and differentiation of genotypes (LQTS1 and LQTS2) using 12-lead ECG. Design, Setting, and Participants: This diagnostic accuracy study used ECGs from patients with suspected inherited arrhythmia enrolled in the Hearts in Rhythm Organization Registry (HiRO) from August 2012 to December 2021. The internal dataset was derived at 2 sites and an external validation dataset at 4 sites within the HiRO Registry; an additional cross-sectional validation dataset was from the Montreal Heart Institute. The cohort with LQTS included probands and relatives with pathogenic or likely pathogenic variants in KCNQ1 or KCNH2 genes with normal or prolonged corrected QT (QTc) intervals. Exposures: Convolutional neural network (CNN) discrimination between LQTS1, LQTS2, and negative genetic test results. Main Outcomes and Measures: The main outcomes were area under the curve (AUC), F1 scores, and sensitivity for detecting LQTS and differentiating genotypes using a CNN method compared with QTc-based detection. Results: A total of 4521 ECGs from 990 patients (mean [SD] age, 42 [18] years; 589 [59.5%] female) were analyzed. External validation within the national registry (101 patients) demonstrated the CNN's high diagnostic capacity for LQTS detection (AUC, 0.93; 95% CI, 0.89-0.96) and genotype differentiation (AUC, 0.91; 95% CI, 0.86-0.96). This surpassed expert-measured QTc intervals in detecting LQTS (F1 score, 0.84 [95% CI, 0.78-0.90] vs 0.22 [95% CI, 0.13-0.31]; sensitivity, 0.90 [95% CI, 0.86-0.94] vs 0.36 [95% CI, 0.23-0.47]), including in patients with normal or borderline QTc intervals (F1 score, 0.70 [95% CI, 0.40-1.00]; sensitivity, 0.78 [95% CI, 0.53-0.95]). In further validation in a cross-sectional cohort (406 patients) of high-risk patients and genotype-negative controls, the CNN detected LQTS with an AUC of 0.81 (95% CI, 0.80-0.85), which was better than QTc interval-based detection (AUC, 0.74; 95% CI, 0.69-0.78). Conclusions and Relevance: The deep learning model improved detection of congenital LQTS from resting ECGs and allowed for differentiation between the 2 most common genetic subtypes. Broader validation over an unselected general population may support application of this model to patients with suspected LQTS.

Pacing in Pediatric Patients with Postoperative Atrioventricular Block.

Surgery for congenital heart disease may compromise atrioventricular (AV) nodal conduction, potentially resulting in postoperative AV block. In the majority of cases, AV nodal function recovers during the early postoperative period and may only require short-term pacing support, typically provided via temporary epicardial wires. Permanent pacing is indicated when the postoperative AV block persists for more than 7 to 10 days due to the risk of mortality if a pacemaker is not implanted. Although there is a subset of patients who may have late recovery of AV nodal function, those with continued postoperative AV block will need lifelong pacing therapy.

Regional Elevation of Liver T1 in Fontan Patients.

Background: Fontan-associated liver disease (FALD) is characterized by hepatic congestion and progressive hepatic fibrosis in patients with the Fontan operation. This condition is generally clinically silent until late, necessitating techniques for early detection. Liver T1 mapping has been used to screen for FALD, but without consideration of regional variations in T1 values. Methods: Liver T1 measured with a liver-specific T1 mapping sequence (PROFIT1) in Fontan patients was compared with cohorts of patients with biventricular congenital heart disease (BiV-CHD) and controls with normal cardiac function and anatomy. Results: Liver T1 was significantly elevated in the Fontan cohort (n = 20) compared with patients with BiV-CHD (n = 12) and controls (n = 9) (781, 678, and 675 milliseconds, respectively; P < 0.001), with a consistent pattern of significantly elevated T1 values in the peripheral compared with central liver regions (ΔT1 = 54, 2, and 11 milliseconds; P < 0.001). PROFIT1 also yielded simultaneous T2∗ maps and fat fraction values that were similar in all groups. Fontan liver T1 values were also significantly elevated as compared with BiV-CHD and controls as measured with the cardiac (modified Look-Locker inversion) acquisitions (728, 583, and 583 milliseconds, respectively; P < 0.001) and values correlated with PROFIT1 liver T1 (R = 0.87, P < 0.001). Conclusions: Fontan patients have globally increased liver T1 values and consistent spatial variations, with higher values in the peripheral liver regions as compared with spatially uniform values in BiV-CHD and controls. The spatial patterns may provide insight into the progression of FALD. Liver T1 mapping studies should include uniform spatial coverage to avoid bias based on slice locations in this population.

Contexte: L'hépatopathie associée à une intervention de Fontan (FALD, pour Fontan-associated liver disease) se caractérise par une congestion hépatique et une fibrose hépatique évolutive chez les patients qui ont subi une intervention de Fontan. Il s'agit d'un état pathologique silencieux en début de progression, pour lequel des techniques de détection précoce sont requises. La cartographie T1 du foie est utilisée pour le dépistage de la FALD, mais sans que les variations locales des valeurs obtenues soient prises en compte. Méthodologie: Des valeurs T1 hépatiques ont été mesurées avec une séquence cartographique conçue pour le foie (PROFIT1) chez des patients qui ont subi une intervention de Fontan. Ces valeurs ont été comparées à celles d'une cohorte de patients atteints de cardiopathie congénitale biventriculaire (CC-BiV) et à celles de témoins dont l'anatomie et la fonction cardiaques étaient normales. Résultats: Les valeurs T1 hépatiques étaient significativement plus élevées chez les patients ayant subi une intervention de Fontan (n = 20) que chez les patients atteints de CC-BiV (n = 12) et chez les témoins (n = 9) (781 ms, 678 ms, 675 ms, p < 0,001), et ces valeurs tendaient à être plus élevées dans les régions périphériques que dans les régions centrales du foie (ΔT1 = 54 ms, 2 ms, 11 ms, p < 0,001). La séquence PROFIT1 a aussi permis l'obtention des valeurs de cartographie T2∗ et de teneur en matières grasses dans le foie, et ces valeurs étaient comparables pour tous les groupes. L'utilisation d'une séquence cardiaque (MOLLI, pour modified Lock-Locker inversion) a également engendré des valeurs T1 hépatiques significativement plus élevées chez les patients ayant subi l'intervention de Fontan que chez les patients atteints de CC-BiV et les témoins (728 ms, 583 ms, 583 ms, p < 0,001). Ces valeurs étaient par ailleurs corrélées avec les valeurs T1 hépatiques obtenues par la séquence PROFIT1 (R = 0,87, p < 0,001). Conclusions: Dans l'ensemble, les patients ayant subi l'intervention de Fontan présentaient des valeurs T1 hépatiques élevées accompagnées de variations spatiales. Les valeurs périphériques étaient systématiquement plus élevées, tandis que celles obtenues chez les patients atteints de CC-BiV et chez les témoins étaient uniformes. Les tendances qui sous-tendent ces variations spatiales pourraient fournir des pistes pour mieux comprendre la progression de la FALD. Enfin, les études de cartographie T1 hépatiques dans cette population devraient couvrir uniformément le foie pour éviter les biais liés à la coupe.

Implementation of Virtual Fontan Heart Camps During a Pandemic.

BACKGROUND: Children with a Fontan operation represent a unique form of congenital heart disease (CHD) that requires multiple cardiac surgeries and procedures with an uncertain long-term outcome. Given the rarity of the types of CHD that require this procedure, many children with a Fontan do not know any others like them. METHODS: With the cancelation of medically supervised heart camps due to the COVID-19 pandemic, we have organized several physician-led virtual day camps for children with a Fontan operation to connect with others in their province and across Canada. The aim of this study was to describe the implementation and evaluation of these camps via the use of an anonymous online survey immediately after the event and reminders on days 2 and 4 postevent. RESULTS: Fifty-one children have participated in at least 1 of our camps. Registration data showed that 70% of participants did not know anyone else with a Fontan. Postcamp evaluations showed that 86% to 94% learned something new about their heart and 95% to 100% felt more connected to other children like them. CONCLUSION: We have demonstrated the implementation of a virtual heart camp to expand the support network for children with a Fontan. These experiences may help to promote healthy psychosocial adjustments through inclusion and relatedness.

Effect of a Hedonic Stimulus on the Sleep Architecture of Male Wistar Rats.

Objective Nocturnal animals forage and eat during the night and sleep during the day. When food is available only for a short period during the day, animals develop a catabolic state and exhibit locomotor behavior before accessing food, termed food anticipatory activity . Consequently, there is a disruption in the sleep pattern. The present study aimed to explore how anticipatory arousal emerges under circadian exposure to a palatable meal (PM) and disrupts sleep architecture. Materials and Methods Adult male Wistar rats were implanted with electrodes for continuous sleep recording and housed under a light/dark 12/12-hour cycle with free access to food and water. After basal recordings, the rats had access to a PM during the light period for eight days. Results The anticipatory arousal started on the third day. On the eighth day, we found an increase in wake time and a decrease in the non-rapid eye movement sleep (NREMS) and rapid eye movement sleep (REMS) times 45 minutes before the PM compared with the basal recordings. The REMS transitions (events from NREMS to REMS) showed a significant reduction during the light period of the eighth day of PM. In contrast, the number of NREMS transitions (events from wakefulness to NREMS) remained unchanged. Conclusion The results suggest that palatable food induces a motivational timing that leads the rat to wake by altering the sleep quota.

The medical management of pediatric arrhythmias.

OPINION STATEMENT: Arrhythmias are an important cause of morbidity and mortality in children. Despite recent technological advances in treatment, pharmacologic therapy remains the most common treatment modality for pediatric arrhythmias. The choice of antiarrhythmic agent, the duration of therapy, and the dosing schedule depend on multiple factors including the recurrence risk and the arrhythmia burden (the latter being determined by the hemodynamic effect of the arrhythmia), and the frequency and duration of episodes. As with all pediatric medications, consideration must be given to the drug formulation, palatability, adverse effects and adherence issues. There are very few randomized trials available to guide the choice of therapy for pediatric arrhythmias, and thus treatment options often reflect physician or institutional preferences. Although various classification schemes exist, we classify antiarrhythmic agents based on their primary site of action: atrial muscle/accessory pathway (class IA, IC, and III agents); the atrioventricular node (beta-blockers, calcium channel blockers, digoxin, and class III agents); or ventricular muscle (class I and III agents). This type of categorization assists in the approach to treatment required for each type of arrhythmia encountered.

Approach to Wide Complex Tachycardia in Paediatric Patients.

Wide complex tachycardia (WCT) is an infrequently encountered condition in paediatric patients and may be due to a variety of causes including supraventricular tachycardia with aberrant conduction, ventricular activation via an accessory pathway, ventricular pacing, or ventricular tachycardia. Immediate tachycardia termination is required in haemodynamically unstable patients. After stabilization or in those with haemodynamically tolerated WCT, a careful review of electrocardiographic tracings and diagnostic manoeuvres are essential to help elucidate the cause. Subacute and chronic management for WCT will depend on the underlying cause as well as features of the patient and the tachycardia presentation. This article will review the epidemiology, potential causes, and management of WCT in children. A detailed review of the pathophysiology, differential diagnosis, and diagnostic and treatment options is provided to enable the reader to develop a practical approach to managing this condition in young patients.

La tachycardie à complexes QRS larges est rare en pédiatrie et peut avoir diverses causes, notamment une tachycardie supraventriculaire avec trouble de la conduction, l'activation ventriculaire par une voie accessoire, une stimulation ventriculaire ou une tachycardie ventriculaire. La suppression immédiate de la tachycardie est primordiale lorsque l'état hémodynamique du patient est instable. Une fois l'état du patient stabilisé, ou en cas de tachycardie à complexes QRS larges tolérée sur le plan hémodynamique, l'examen minutieux des tracés électrocardiographiques et des manœuvres diagnostiques est crucial pour en élucider la cause. La prise en charge des cas subaigus et chroniques de tachycardie à complexes QRS larges dépend de sa cause sous-jacente ainsi que des caractéristiques du patient et du tableau clinique de la tachycardie. Cet article porte sur l'épidémiologie, les causes possibles et la prise en charge de la tachycardie à complexes QRS larges chez les enfants. Un examen approfondi de la physiopathologie, du diagnostic différentiel et des options diagnostiques et thérapeutiques est présenté pour permettre au lecteur d'élaborer une approche pratique pour la prise en charge de cette affection chez leurs jeunes patients.

Medical Management of Infants With Supraventricular Tachycardia: Results From a Registry and Review of the Literature.

Background: Several medication choices are available for acute and prophylactic treatment of refractory supraventricular tachycardia (SVT) in infants. There are almost no controlled trials, and medication choices are not necessarily evidence based. Our objective was to report the effectiveness of management strategies for infant SVT. Methods: A registry of infants admitted to hospital with re-entrant SVT and no haemodynamically significant heart disease were prospectively followed at 11 international tertiary care centres. In addition, a systematic review of studies on infant re-entrant SVT in MEDLINE and EMBASE was conducted. Data on demographics, symptoms, acute and maintenance treatments, and outcomes were collected. Results: A total of 2534 infants were included: n = 108 from the registry (median age, 9 days [0-324 days], 70.8% male) and n = 2426 from the literature review (median age, 14 days; 62.3% male). Propranolol was the most prevalent acute (61.4%) and maintenance treatment (53.8%) in the Registry, whereas digoxin was used sparingly (4.0% and 3.8%, respectively). Propranolol and digoxin were used frequently in the literature acutely (31% and 33.2%) and for maintenance (17.8% and 10.1%) (P < 0.001). No differences in acute or prophylactic effectiveness between medications were observed. Recurrence was higher in the Registry (25.0%) vs literature (13.4%) (P < 0.001), and 22 (0.9%) deaths were reported in the literature vs none in the Registry. Conclusion: This was the largest cohort of infants with SVT analysed to date. Digoxin monotherapy use was rare amongst contemporary paediatric cardiologists. There was limited evidence to support one medication over another. Overall, recurrence and mortality rates on antiarrhythmic treatment were low.

Contexte: De nombreux choix de médicaments existent pour le traitement aigu et prophylactique de la tachycardie supraventriculaire (TSV) réfractaire chez les nourrissons. Or, il n'y a presque pas d'essais contrôlés à ce sujet, et les choix de médicaments ne sont pas nécessairement fondés sur des données probantes. Notre objectif était de faire état de l'efficacité des stratégies de prise en charge de la TSV chez les nourrissons. Méthodologie: Un registre des nourrissons admis à l'hôpital pour une TSV par réentrée, sans cardiopathie d'importance hémodynamique, a été tenu de façon prospective dans 11 centres de soins tertiaires à l'échelle mondiale. De plus, une revue systématique des études sur la TSV par réentrée chez le nourrisson a été effectuée dans MEDLINE et EMBASE. Des données sur les caractéristiques démographiques, les symptômes, les traitements aigus et d'entretien, et les résultats ont été recueillis. Résultats: Un total de 2 534 nourrissons ont été inclus : n = 108 du registre (âge médian de 9 jours [0-324 jours], 70,8 % de sexe masculin) et n = 2 426 de la revue de la littérature (âge médian de 14 jours; 62,3 % de sexe masculin). Le propranolol était le traitement de soins aigus (61,4 %) et d'entretien (53,8 %) le plus fréquent dans le registre, alors que la digoxine a été utilisée occasionnellement (respectivement dans 4,0 % et 3,8 % des cas). Dans la littérature, le propranolol et la digoxine étaient fréquemment utilisés en soins aigus (31 % et 33,2 %) et en traitement d'entretien (17,8 % et 10,1 %) (p < 0,001). Aucune différence n'a été observée entre les médicaments au chapitre de l'efficacité du traitement de soins aigus ou du traitement prophylactique. Le taux de récurrence était plus élevé dans le registre (25,0 %) que dans la littérature (13,4 %) (p < 0,001), et 22 (0,9 %) décès ont été signalés dans la littérature, mais aucun dans le registre. Conclusion: Il s'agit de la plus grande cohorte de nourrissons atteints de TSV analysée à ce jour. De nos jours, les cardiologues pédiatriques prescrivent rarement la digoxine en monothérapie. Peu de données probantes favorisent l'utilisation d'un médicament par rapport à l'autre. Dans l'ensemble, les taux de récurrence et de mortalité sous traitement antiarythmique étaient faibles.

Leptin and adiponectin regulate the activity of nuclei involved in sleep-wake cycle in male rats.

Epidemiological and experimental evidence recognize a relationship between sleep-wake cycles and adiposity levels, but the mechanisms that link both are not entirely understood. Adipose tissue secretes adiponectin and leptin hormones, mainly involved as indicators of adiposity levels and recently associated to sleep. To understand how two of the main adipose tissue hormones could influence sleep-wake regulation, we evaluated in male rats, the effect of direct administration of adiponectin or leptin in the ventrolateral preoptic nuclei (VLPO), a major area for sleep promotion. The presence of adiponectin (AdipoR1 and AdipoR2) and leptin receptors in VLPO were confirmed by immunohistochemistry. Adiponectin administration increased wakefulness during the rest phase, reduced delta power, and activated wake-promoting neurons, such as the locus coeruleus (LC), tuberomammillary nucleus (TMN) and hypocretin/orexin neurons (OX) within the lateral hypothalamus (LH) and perifornical area (PeF). Conversely, leptin promoted REM and NREM sleep, including increase of delta power during NREM sleep, and induced c-Fos expression in VLPO and melanin concentrating hormone expressing neurons (MCH). In addition, a reduction in wake-promoting neurons activity was found in the TMN, lateral hypothalamus (LH) and perifornical area (PeF), including in the OX neurons. Moreover, leptin administration reduced tyrosine hydroxylase (TH) immunoreactivity in the LC. Our data suggest that adiponectin and leptin act as hormonal mediators between the status of body energy and the regulation of the sleep-wake cycle.

Impact and Modifiers of Ventricular Pacing in Patients With Single Ventricle Circulation.

BACKGROUND: Palliation of the single ventricle (SV) circulation is associated with a burden of lifelong complications. Previous studies have identified that the need for a permanent ventricular pacing system (PPMv) may be associated with additional adverse long-term outcomes. OBJECTIVES: The goal of this study was to quantify the attributable risk of PPMv in patients with SV, and to identify modifiable risk factors. METHODS: This international study was sponsored by the Pediatric and Congenital Electrophysiology Society. Centers contributed baseline and longitudinal data for functionally SV patients with PPMv. Enrollment was at implantation. Controls were matched 1:1 to PPMv subjects by ventricular morphology and sex, identified within center, and enrolled at matched age. Primary outcome was transplantation or death. RESULTS: In total, 236 PPMv subjects and 213 matched controls were identified (22 centers, 9 countries). Median age at enrollment was 5.3 years (quartiles: 1.5-13.2 years), follow-up 6.9 years (3.4-11.6 years). Median percent ventricular pacing (Vp) was 90.8% (25th-75th percentile: 4.3%-100%) in the PPMv cohort. Across 213 matched pairs, multivariable HR for death/transplant associated with PPMv was 3.8 (95% CI 1.9-7.6; P < 0.001). Within the PPMv population, higher Vp (HR: 1.009 per %; P = 0.009), higher QRS z-score (HR: 1.19; P = 0.009) and nonapical lead position (HR: 2.17; P = 0.042) were all associated with death/transplantation. CONCLUSIONS: PPMv in patients with SV is associated with increased risk of heart transplantation and death, despite controlling for increased associated morbidity of the PPMv cohort. Increased Vp, higher QRS z-score, and nonapical ventricular lead position are all associated with higher risk of adverse outcome and may be modifiable risk factors.

Defibrillation Safety Margin Testing in Patients With Congenital Heart Disease: Results From the NCDR.

OBJECTIVES: This study analyzed the predictors of defibrillation safety margin (DSM) testing at the time of implantable cardioverter-defibrillator (ICD) insertion and factors associated with inadequate DSM in patients with congenital heart disease (CHD). BACKGROUND: There are few data about the prevalence and safety of DSM testing in those with CHD. METHODS: A retrospective analysis was performed of all patients with atrial or ventricular septal defect, tetralogy of Fallot, transposition of the great vessels, Ebstein anomaly, or common ventricle undergoing a transvenous ICD procedure in the National Cardiovascular Data Registry (NCDR) ICD Registry from April 2010 to March 2016, and DSM testing was assessed. Inadequate DSM was defined as a lowest successful energy tested <10 J than the maximum output of the ICD generator. RESULTS: Of all ICD recipients (N = 7,024), DSM testing was performed in 52.0% (n = 3,654). The mean lowest successful energy tested was 20.7 ± 7.3 J. Of those with DSM adequacy data available (n = 3,623), an inadequate DSM occurred in 13.8% (n = 501). After multivariable adjustment, DSM testing was not associated with in-hospital complications or death (odds ratio [OR]: 1.00; 95% confidence interval [CI]: 0.79 to 1.28) but was associated with lower odds of prolonged hospital stay (>3 days) (OR: 0.71; 95% CI: 0.60 to 0.84; p < 0.0001). An inadequate DSM was not associated with in-hospital death or complications (OR: 1.27; 95% CI: 0.79 to 2.04) or prolonged hospital stay (OR: 1.34; 95% CI: 0.995 to 1.81). CONCLUSIONS: DSM testing is being performed less frequently over time and seems safe in those with CHD. An inadequate DSM was not associated with worse in-hospital outcomes.

Increased alcohol consumption in sleep-restricted rats is mediated by delta FosB induction.

The reduction of sleep hours is a public health problem in contemporary society. It is estimated that humans sleep between 1.5 and 2 h less, per night, than 100 years ago. The reduction of sleep hours is a risk factor for developing cardiovascular, metabolic, and psychiatric problems. Previous studies have shown that low sleep quality is a factor that favors relapse in addicted patients. In rodents, sleep deprivation increases the preference for methylphenidate and the self-administration of cocaine. However, it is unknown whether chronic sleep restriction induces voluntary alcohol consumption in rats and whether alcohol intake is associated with delta FosB expression in the brain reward circuit. Potentially, chronic sleep restriction could make the brain vulnerable and consequently promote addictive behavior. Therefore, the present study's objective was to evaluate alcohol consumption in a chronic sleep restriction model and determine the expression of delta FosB in brains of adult rats. For this purpose, male Wistar rats (300-350 g body weight) were divided into four experimental groups (n = 6 each group): control (without manipulation), sleep restriction (SR) for 7 days, SR and ethanol exposure (Ethanol + SR), and a group with just ethanol exposure (Ethanol). At the end of the management, rats were sacrificed, and the brains were dissected and processed for immunohistochemical detection of delta FosB. The results showed that SR stimulates alcohol consumption compared to unrestricted-sleep rats and induces a significant increase in the number of delta FosB-positive cells in brain nuclei within the motivation/brain reward circuit. These results suggest that chronic reduction of sleep hours is a risk factor for developing a preference for alcohol consumption.