Flecainide Is Associated With a Lower Incidence of Arrhythmic Events in a Large Cohort of Patients With Catecholaminergic Polymorphic Ventricular Tachycardia.

BACKGROUND: In severely affected patients with catecholaminergic polymorphic ventricular tachycardia, beta-blockers are often insufficiently protective. The purpose of this study was to evaluate whether flecainide is associated with a lower incidence of arrhythmic events (AEs) when added to beta-blockers in a large cohort of patients with catecholaminergic polymorphic ventricular tachycardia. METHODS: From 2 international registries, this multicenter case cross-over study included patients with a clinical or genetic diagnosis of catecholaminergic polymorphic ventricular tachycardia in whom flecainide was added to beta-blocker therapy. The study period was defined as the period in which background therapy (ie, beta-blocker type [beta1-selective or nonselective]), left cardiac sympathetic denervation, and implantable cardioverter defibrillator treatment status, remained unchanged within individual patients and was divided into pre-flecainide and on-flecainide periods. The primary end point was AEs, defined as sudden cardiac death, sudden cardiac arrest, appropriate implantable cardioverter defibrillator shock, and arrhythmic syncope. The association of flecainide with AE rates was assessed using a generalized linear mixed model assuming negative binomial distribution and random effects for patients. RESULTS: A total of 247 patients (123 [50%] females; median age at start of flecainide, 18 years [interquartile range, 14-29]; median flecainide dose, 2.2 mg/kg per day [interquartile range, 1.7-3.1]) were included. At baseline, all patients used a beta-blocker, 70 (28%) had an implantable cardioverter defibrillator, and 21 (9%) had a left cardiac sympathetic denervation. During a median pre-flecainide follow-up of 2.1 years (interquartile range, 0.4-7.2), 41 patients (17%) experienced 58 AEs (annual event rate, 5.6%). During a median on-flecainide follow-up of 2.9 years (interquartile range, 1.0-6.0), 23 patients (9%) experienced 38 AEs (annual event rate, 4.0%). There were significantly fewer AEs after initiation of flecainide (incidence rate ratio, 0.55 [95% CI, 0.38-0.83]; P=0.007). Among patients who were symptomatic before diagnosis or during the pre-flecainide period (n=167), flecainide was associated with significantly fewer AEs (incidence rate ratio, 0.49 [95% CI, 0.31-0.77]; P=0.002). Among patients with ≥1 AE on beta-blocker therapy (n=41), adding flecainide was also associated with significantly fewer AEs (incidence rate ratio, 0.25 [95% CI, 0.14-0.45]; P<0.001). CONCLUSIONS: For patients with catecholaminergic polymorphic ventricular tachycardia, adding flecainide to beta-blocker therapy was associated with a lower incidence of AEs in the overall cohort, in symptomatic patients, and particularly in patients with breakthrough AEs while on beta-blocker therapy.

A unique phenomenon: triple-chambered left ventricle with transposition of great arteries.

A rare case of unique and previously unreported variant of transposition of great arteries with bilateral coni, ventricular septal defect, and triple-chambered left ventricle which led to an unexpected and accelerated post-natal cardiac anatomical and physiologic deviation from prenatal and immediate postnatal diagnosis altering the surgical management and patient outcome.

Current status of cardiopulmonary resuscitation training and automatic external defibrillator availability in high schools in Halifax, Nova Scotia, Canada.

Background: School-based cardiopulmonary resuscitation (CPR) training and early use of an automated external defibrillator (AED) have proven to increase the survival of victims of sudden cardiac arrest (SCA). This study aimed to determine the status of CPR training, availability of AEDs, and medical emergency response programs (MERPs) in high schools in Halifax Regional Municipality. Method: High school principals were asked to participate in a voluntary online survey comprising questions about demographics, AEDs availability, CPR training for staff and students, the existence of MERPs, and perceived barriers. Three autogenerated reminders followed the initial invitation. Results: Out of 51 schools, 21 (41%) responded, only 10% (2/21) and 33% (7/21) reported providing CPR training to students and staff, respectively. About 35% (7/20) of the schools reported having AEDs, but only 10% (2/20) have MERPs for SCA. All respondents reported in favor of AED availability in schools. The reported barriers to CPR training included limited financial resources (54%), perception of low priority (23%), and time constraints (23%). Respondents reported limited financial resources (85%) and the lack of trained staff to use (30%) as the main reasons for the unavailability of AEDs. Conclusion: This survey showed that all respondents overwhelmingly favour having access to AEDs. However, the availability of CPR and AED training for staff and students in schools remains inadequate. Emergency action plans have not been devised, and few schools have AED devices. More education and awareness are needed to ensure lifesaving equipment and practices in all Halifax Regional Municipality schools.

Society for Cardiovascular Magnetic Resonance 2019 Case of the Week series.

The Society for Cardiovascular Magnetic Resonance (SCMR) is an international society focused on the research, education, and clinical application of cardiovascular magnetic resonance (CMR). The SCMR web site ( https://www.scmr.org ) hosts a case series designed to present case reports demonstrating the unique attributes of CMR in the diagnosis or management of cardiovascular disease. Each clinical presentation is followed by a brief discussion of the disease and unique role of CMR in disease diagnosis or management guidance. By nature, some of these are somewhat esoteric, but all are instructive. In this publication, we provide a digital archive of the 2019 Case of the Week series as a means of further enhancing the education of those interested in CMR and as a means of more readily identifying these cases using a PubMed or similar search engine.

Arrhythmias in Children with Peripherally Inserted Central Catheters (PICCs).

To analyze the prevalence, types, and risk factors for cardiac arrhythmias associated with peripherally inserted central catheters (PICCs) in children. This is a case-control single center retrospective study. From 3180 PICCs inserted in children (< 18 years old) between 2009 and 2013, cases with new onset arrhythmias were identified. Demographics, type and timing of arrhythmias, and possible risk factors were analyzed. ECGs, rhythm strips, physicians' records, and anti-arrhythmic management were confirmatory. The level of the PICC's tip in the superior vena cava (SVC) or right atrium (RA) was ascertained from chest X-rays and counted in rib units (RU) and vertebra units (VU). Cases were matched (1:1 ratio) to controls by weight and date of insertion. Descriptive statistics were performed. A two-sided p value < 0.05 was considered significant. Thirty-one children (1%) developed arrhythmias, 16/31 (56%) were males, and 24/31 (77%) were < 1-year age. Arrhythmias were atrial 22 (71%), ventricular 4 (13%), and undetermined 5 (16%). Median PICC dwell time was 16 days. 14/31 (45%) cases and 9/31 (29%) controls had underlying structural heart disease. PICCs central tip position was lower among cases than controls (RU 6 vs 5). Odds Ratio for developing arrhythmia was 4.5 (95% CI 0.98-20.83) if the tip lays below 6.25RU. Arrhythmias were resolved with anti-arrhythmic agents in 52% (16/31) and with PICC exchange/manipulation in 32% (10/31) cases. Two children died unrelated to arrhythmia. Prevalence of arrhythmias associated with PICCs in children is low (1%). Arrhythmias are 4.5 times more likely when PICC's central tip position is deeper than 6.25RU.

Taut and click: an unusual left ventricular false tendon.

A case of an asymptomatic child presenting with persistent systolic ejection click and found to have an unusual left ventricular false tendon attached to aortic valve that has not been described previously and may be responsible for the click.

Exploring Health-Related Quality of Life in Children With Hypertrophic Cardiomyopathy and Relationship to Physical Activity.

BACKGROUND: Hypertrophic cardiomyopathy is a burdensome condition that inflicts both physical and psychological impairment on those with the disease, negatively impacting health-related quality of life (HRQoL). Given the abundance of evidence suggesting a role of physical activity (PA) in modulating HRQoL in healthy populations of children, we sought to determine the relationship between HRQoL and PA in children diagnosed with hypertrophic cardiomyopathy. METHODS AND RESULTS: A multicenter prospective observational cohort study was conducted, with patients with hypertrophic cardiomyopathy aged 10 to 19 years being provided a wrist-worn activity tracker (Fitbit Charge HR) to wear for 14 days. Patients self-reported on Pediatric Quality of Life 4.0 quality of life inventory items, which were associated with PA metrics following covariate adjustment using linear regression. A total of 56 participants were recruited to the study. The median age at enrollment was 15.5 years (interquartile range, 13.8-16.8), and 16 out of 56 (29%) of the cohort were girls. The cohort reported decreased metrics of physical, psychosocial, and total summary scores compared with health reference populations, with scores comparable with that of published populations with chronic disease. Increased physical HRQoL scores were significantly associated with increased daily steps taken, distance traveled, and flights of stairs climbed. CONCLUSIONS: These results show that impaired PA correlates with reduced HRQoL in children with hypertrophic cardiomyopathy, suggesting PA may partially mediate HRQoL in this population.

Using Smartphone Wireless ECG Monitoring to Provide Symptom-Rhythm Correlation in the Paediatric Population.

Children frequently present with symptoms of palpitations. These symptoms can occur in isolation or in association with other presentations such as chest pain, presyncope, or syncope. Usually, their symptoms are episodic in occurrence; therefore, establishment of symptom-rhythm correlation is challenging but critical for accurate diagnosis and management. We reviewed the use of smartphone-based wireless electrocardiogram monitoring with AliveCor Kardia, to establish symptom-rhythm correlation in a paediatric case series at a single Canadian tertiary care centre.

Les enfants présentent fréquemment des symptômes de palpitations. Ces symptômes peuvent se produire isolément ou en association avec d'autres manifestations comme la douleur thoracique, la présyncope ou la syncope. Habituellement, les symptômes sont épisodiques, d'où la difficulté d'établir une corrélation entre les symptômes et le rythme cardiaque, un exercice pourtant essentiel pour poser un diagnostic précis et assurer la prise en charge du patient. Nous avons passé en revue les données relatives à la surveillance électrocardiographique sans fil effectuée au moyen d'un téléphone intelligent via la technologie Kardia d'AliveCor afin d'établir une telle corrélation dans une série de cas pédiatriques issue d'un même centre de soins tertiaires canadien.

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.

Interprofessional Patient-Specific Simulation Preparation to Improve Management of Neonatal High-Acuity Low-Occurrence (HALO) Scenarios.

Fetal compressive intrapericardial teratoma is a rare and life-threatening condition, qualifying as a high-acuity low-occurrence (HALO) event. To prepare for delivery and immediate neonatal management, specialists from pediatric cardiology, cardiac surgery, maternal-fetal-medicine, neonatology, cardiac anesthesia, critical care, clinical perfusion, obstetrical nursing, and operating room nursing convened. An in situ operating room simulation was used to identify and introduce key team members, derive and practice the anticipated clinical management algorithm, position human and equipment resources strategically, and ensure that each specialist team was familiar with the environment and available equipment. As rehearsed in the simulation, the cesarean delivery of the patient and neonatal cardiac surgery was uncomplicated and yielded a favourable clinical outcome. A patient-specific HALO simulation preparation (PSHSP) can facilitate positive clinical outcomes and improve health care team confidence in HALO scenarios such as the birth of newborns anticipated to have cardiorespiratory instabilty.

Practice Variation in Establishing the Adequacy of Beta-Blockers as an Antiarrhythmic Agent in School-Aged Children and Adolescents.

BACKGROUND: Beta-blockers (BBs) are commonly prescribed to manage arrhythmias in children and adolescents without any standardised approach to establish BB adequacy. We invited all Canadian pediatric cardiologists to participate in an anonymous survey to understand practice variation in the assessment of BB adequacy in school-aged children and adolescents with arrhythmia or the potential for arrhythmia. METHODS: An electronic survey approved by the Institutional Ethics Board was distributed by e-mail to 96 Canadian pediatric cardiologists who had been active in practice for at least 1 year. Incomplete surveys were excluded. RESULTS: Forty-one cardiologists (43%) responded to all questions in the survey. Thirteen cardiologists (32%) reported always assessing BB adequacy, 17 (41%) did so only for specific arrhythmias, and 11 (27%) reported never performing such an assessment. A total of 19 cardiologists (46%) and 18 cardiologists (44%) reported using Holter monitoring and exercise testing, respectively, to assess beta receptor blockade adequacy. Thirteen cardiologists (32%) considered BB therapy adequate if Holter demonstrated a 20% decrease in heart rate (HR) from baseline, and 10 respondents (24%) defined adequate BB therapy using exercise testing as a 20% decrease in maximal HR or blood pressure from baseline. CONCLUSION: Despite wide variation in practice, Holter monitoring and exercise testing are commonly used methods to measure the adequacy of BB therapy. There are no standard criteria, but the majority (56%) reported using a 20% decrease in HR or blood pressure from the pretreatment state as a criterion for adequate BB therapy in children and adolescents with arrhythmia or the potential for arrhythmia.

CONTEXTE: Les bêtabloquants (BB) sont couramment prescrits pour traiter les arythmies chez l'enfant et l'adolescent, en l'absence de méthode standardisée permettant d'établir le caractère adéquat du traitement par ces agents. Nous avons invité tous les cardiologues pédiatriques canadiens à participer anonymement à une enquête visant à rendre compte de la variabilité observée en pratique dans l'évaluation du caractère adéquat du traitement par BB chez l'enfant d'âge scolaire ou l'adolescent atteints d'arythmie ou susceptibles de l'être. MÉTHODOLOGIE: Un questionnaire électronique approuvé par le comité d'éthique en établissement a été distribué par courriel à 96 cardiologues pédiatriques canadiens en exercice depuis au moins un an. Les questionnaires partiellement remplis ont été exclus. RÉSULTATS: Parmi les participants, 41 cardiologues (43 %) ont répondu à toutes les questions de l'enquête. D'après les réponses obtenues, 13 cardiologues (32 %) évaluent toujours le caractère adéquat du traitement par BB, 17 (41 %) l'évaluent uniquement en présence de certains types d'arythmies et 11 (27 %) ne l'évaluent jamais. Au total, parmi les cardiologues interrogés, 19 (46 %) et 18 (44 %) affirment avoir recours respectivement à l'électrocardiographie (ECG) ambulatoire et à l'épreuve d'effort pour évaluer le caractère adéquat du blocage des récepteurs bêta. Ainsi, 13 cardiologues (32 %) jugent que le traitement par BB est adéquat si l'enregistrement ECG ambulatoire démontre une diminution de 20 % de la fréquence cardiaque (FC) maximale par rapport à la valeur de référence, et 10 cardiologues (24 %) estiment qu'il en est de même si le résultat obtenu à l'épreuve d'effort démontre une diminution de 20 % de la FC maximale ou de la pression artérielle par rapport aux valeurs de référence. CONCLUSION: Malgré de grandes variations observées en pratique, l'ECG ambulatoire et l'épreuve d'effort sont des méthodes couramment utilisées pour mesurer le caractère adéquat du traitement par BB. Il n'existe pas de critères standard, mais la majorité (56 %) des répondants ont indiqué qu'une diminution de 20 % de la FC ou de la pression artérielle par rapport aux valeurs de référence obtenues avant le traitement constitue un critère du caractère adéquat du traitement par BB chez l'enfant ou l'adolescent atteints d'arythmie ou susceptibles de l'être.

Initially unexplained cardiac arrest in children and adolescents: A national experience from the Canadian Pediatric Heart Rhythm Network.

BACKGROUND: Unexplained cardiac arrest (UCA) is rare in children. Despite investigations, the etiology in up to one-half of patients remains unknown. OBJECTIVE: The purpose of this study was to assess the management and outcomes of pediatric UCA survivors through the Canadian Pediatric Heart Rhythm Network. METHODS: A retrospective case series of children (age 1-19 years) who presented with UCA between January 1, 2004, and November 1, 2017, was conducted. Patients with known heart disease pre-UCA were excluded. UCA details, investigations, genetic test results, treatment, implantable cardioverter-defibrillator (ICD) data, subsequent diagnoses, and family screening data were collected. RESULTS: Forty-six patients (61% male) were survivors of sudden unexpected death and met inclusion criteria at 8 participating sites. Median age at UCA was 13.8 years (interquartile range [IQR] 9-16 years). Baseline retrievable investigations included electrocardiogram (96%), echocardiogram (85%), exercise stress test (73%), and cardiac magnetic resonance imaging (57%). The presumed etiology for the UCA was identified in 24 (52%), mainly long QT syndrome or catecholaminergic polymorphic ventricular tachycardia. Genetic testing was performed in 33 of 46 (72%), with pathogenic/likely pathogenic variants identified in 13 of 33 (39%) and variants of uncertain significance in 8 of 33 (24%). ICDs were implanted in 35 of 46 (76%). Over median follow-up of 36 months (IQR 17-57 months), 8 of 35 had arrhythmia events captured on device interrogation. Families of 26 of 46 patients(57%) underwent screening, leading to a cardiac diagnosis in 6 of 26 families. CONCLUSION: A cause for UCA was not identified in nearly 50% of patients despite extensive investigations, including cascade screening. A large proportion (75%) of ICD shocks occurred in patients without a diagnosis.

Tricuspid Intervention Following Pulmonary Valve Replacement in Adults With Congenital Heart Disease.

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.

Practice Variation Among Canadian Pediatric Cardiologists in Medical Management of Dilated Ascending Aorta in Patients With Bicuspid Aortic Valve.

BACKGROUND: Medical therapy is often prescribed to reduce the rate of aortic dilatation and prevent aortic dissection in patients with bicuspid aortic valve (BAV) despite a lack of evidence. We conducted an anonymous survey to gain insight into Canadian clinical practice regarding medical therapy used to slow the progression of aortic dilatation in patients with BAV. METHODS: A questionnaire was sent to 115 paediatric cardiologists and 18 adult congenital heart disease specialists in Canada. RESULTS: Ninety of 113 paediatric cardiologists (80%) completing the questionnaire reported prescribing medication to reduce the rate of aortic dilatation. Some 75% (61/81) of them reported prescribing medications on the basis of aortic size z scores, and 78% (48/61) considered medication at a z score between ≥ 2 and < 5. The remaining 25% of responders (20/81) reported prescribing medications on the basis of absolute aortic diameter, and 80% (16/20) of them considered initiating medical therapy at an aortic diameter > 40 mm to < 50 mm. For practical purposes, however, 40% of respondents (45/113) would not or rarely consider medical therapy for this indication because of variation in the threshold for initiating treatment. Ten of 14 adult congenital heart disease specialists' responses (71%), reported prescribing medications who were excluded because of missing data. CONCLUSION: The majority of Canadian paediatric cardiologists reported prescribing medications to slow the rate of aortic dilatation in patients with BAV. However, there is heterogeneity in the criteria to prescribe medical therapy. A multicenter randomized controlled trial is needed to establish the role of medical therapy in this patient population.

INTRODUCTION: En dépit du manque de données probantes, un traitement médical est souvent prescrit pour réduire le taux de dilatation aortique et prévenir la dissection aortique chez les patients ayant une bicuspidie aortique (BA). Nous avons mené une enquête anonyme pour avoir un aperçu de la pratique clinique au Canada en ce qui concerne le traitement médical utilisé pour ralentir la progression de la dilatation aortique chez les patients ayant une BA. MÉTHODES: Nous avons envoyé un questionnaire à 115 cardiologues en pédiatrie et à 18 spécialistes en cardiopathie congénitale de l'adulte du Canada. RÉSULTATS: Quatre-vingt-dix des 113 cardiologues en pédiatrie (80 %) ayant rempli le questionnaire ont signalé prescrire des médicaments pour réduire le taux de dilatation aortique. Certains d'entre eux, soit 75 % (61/81) ont signalé prescrire des médicaments en fonction du Z-score de la taille aortique, et 78 % (48/61) ont envisagé de prescrire les médicaments lorsque le Z-score était entre ≥ 2 et < 5. Les 25 % de répondants restants (20/81) ont signalé prescrire des médicaments en fonction du diamètre aortique absolu, et 80 % (16/20) d'entre eux ont envisagé de faire commencer le traitement médical lorsque le diamètre aortique était entre > 40 mm et < 50 mm. Concrètement, toutefois, 40 % des répondants (45/113) n'ont pas envisagé ou ont rarement envisagé de prescrire un traitement médical pour cette indication en raison de la variation dans le seuil de mise en place du traitement. Dix des 14 réponses (71 %) des spécialistes de la cardiopathie congénitale de l'adulte ont signalé prescrire des médicaments qui étaient exclus en raison de données manquantes. CONCLUSION: La majorité des cardiologues en pédiatrie du Canada ont signalé prescrire des médicaments pour ralentir le taux de dilatation aortique chez les patients ayant une BA. Toutefois, les critères utilisés pour prescrire un traitement médical sont hétérogènes. Un essai clinique multicentrique et à répartition aléatoire est nécessaire pour déterminer le rôle du traitement médical dans cette population de patients.

Recurrent Strokes After Gore Septal Occluder Device Closure of Atrial Septal Defect.

We report a case of recurrent strokes in a healthy teenager after complete closure of atrial septal defect with Gore Septal Occluder (W.L. Gore and Associates, Newark, DE) device. The disk of the device produced a friction injury to the left atrial endocardium promoting thrombus formation with subsequent embolization to the brain requiring surgical intervention.

Comparison of Profiles of Perioperative Serum C-Reactive Protein Levels in Neonates Undergoing the Norwood Procedure or Arterial Switch Operation.

OBJECTIVES: Serum C-reactive protein (CRP) is a marker of systemic inflammatory response induced by cardiopulmonary bypass (CPB). Neonates undergoing the Norwood procedure (NP) have a poorer systemic oxygen transport status than those after other CPB surgeries. We compared the perioperative CRP in neonates undergoing NP or arterial switch operation (ASO). METHODS: Data obtained prior to and within postoperative day (POD) 15 from 64 neonates in NP group and 47 in ASO group. Plasma CRP, white blood cells, doses of inotropes and steroid, cultures of blood and body fluids were recorded simultaneously. Demographic data included the durations of CPB, aortic cross clamp (ACC) and circulatory arrest, intensive care unit and hospital stay, and death. RESULTS: NP group had a shorter CPB and ACC but a longer circulatory arrest than ASO group. CRP was higher preoperatively in NP group than ASO group (21 ± 24 vs.13 ± 26 mg/L, P = 0.01). CRP increased to 80 ± 48 mg/L after NP and 73 ± 36 mg/L after ASO on POD1-2, and then gradually decreased to 51 ± 35 mg/L in NP group and to 43 ± 46 mg/L in ASO group by POD-15. Throughout the postoperative period, CRP, as well as lactate, was significantly higher in NP group than ASO group (P = 0.04 and 0.003, respectively). CRP correlated positively with neutrophil count and negatively with lymphocyte count, CPB duration, and doses of hydrocortisone. CONCLUSIONS: Neonates undergoing NP have a higher level of serum CRP, reflecting a greater systemic inflammatory response before and after CPB than those undergoing ASO, despite of shorter CPB and ACC. The higher level of serum CRP was associated with a significantly higher level of arterial lactate in the NP group than in the ASO group. This may suggest an important role of systemic oxygen transport in systemic inflammatory response in addition to CPB in neonates with congenital heart defects.

Clinical Hemodynamic Parameters Do Not Accurately Reflect Systemic Oxygen Transport in Neonates after the Norwood Procedure.

OBJECTIVES: Clinical hemodynamic parameters (heart rate, systolic arterial pressure [SAP], and arterial and venous oxygen saturation saturations [SaO2 and SvO2 ]) are commonly used to guide management to optimize oxygen transport after the Norwood procedure. The adequacy of this practice has not been demonstrated. We examined the correlations between these clinical parameters and direct measurements of oxygen transport in these patients. METHODS: Oxygen consumption (VO2 ) was measured using respiratory mass spectrometry for 72 hours in 17 neonates after the Norwood procedure. Arterial, superior vena caval, and pulmonary venous blood gases and pressures were measured at intervals of 2-4 hours to calculate cardiac output (CO), systemic and pulmonary blood flows (Qs , Qp), systemic vascular resistance (SVR), total pulmonary vascular resistance including the Blalock-Taussig shunt (tPVR), oxygen delivery (DO2), and extraction ratio (ERO2 ). Heart rate and SAP were also recorded. RESULTS: Heart rate was positively correlated with VO2 (P = .004) and ERO2 (P = .005). SAP was positively correlated with CO (P = .006), VO2 (P = .02), ERO2 (P = .01), and SVR (P = .08). SaO2 was negatively correlated with tPVR, Qs, and DO2 but positively with Qp and SVR (P < .05 for all). SvO2 was positively correlated with CO, Qs , and DO2 (P < .0001 for all) and negatively correlated with SVR, VO2, and ERO2 (P < .05 for all). CONCLUSIONS: Routine clinical hemodynamic parameters do not accurately reflect oxygen transport after the Norwood procedure, except for SvO2, which does not differentiate between VO2 and DO2. Higher heart rate and SAP are correlated with a worse balance of oxygen transport. The results of clinical hemodynamic monitoring should be interpreted with caution. Direct measurements of oxygen transport parameters are important in the care of neonates after the Norwood procedure.

Spontaneous endogenous microbubbles in a child with Berlin heart ventricular assist device.

We report the case of an 11-year-old boy with familial dilated cardiomyopathy on biventricular assist devices (Berlin Heart EXCOR) who was found to have spontaneous endogenous microbubbles in the left ventricular (LV) cavity on routine echocardiogram. Although no major sequelae resulted from the presence of these microbubbles, it did however lead to several noninvasive investigations. To our knowledge, this is a novel observation of spontaneous endogenous microbubbles in a patient with a Berlin Heart. The unknown clinical significance of this phenomenon highlights the need for further studies.

The relationship between plasma concentrations of ionized calcium and magnesium with cardiac energetics and systemic oxygen transport in neonates after the Norwood procedure.

OBJECTIVE: We sought to determine the relationship between plasma calcium and magnesium concentrations with postoperative systemic hemodynamics and oxygen transport in neonates after the Norwood procedure. METHODS: Postoperative systemic oxygen consumption was continuously measured using respiratory mass spectrometry for 72 hours in 17 neonates. Arterial, superior vena caval and pulmonary venous blood gases and pressures, plasma calcium, and lactate levels were measured at 2- to 4-hour intervals to calculate cardiac output, rate pressure product, cardiac power output, systemic oxygen delivery, and oxygen extraction ratio. Plasma magnesium levels were measured at 2- to 8-hour intervals. RESULTS: Plasma calcium levels decreased in the first 8 hours from 1.08±0.13 mmol/L to 0.98±0.08 mmol/L, followed by an increase to 1.10±0.26 mmol/L at 72 hours (P<.0001). Mg2þ change was significantly related to time after logarithmic transformation, rapidly decreasing from 1.62±0.25 mg/L to 0.90±0.15 mg/L in the first 40 hours and further decreasing slowly thereafter to 0.64±0.13 mg/L at 72 hours (P<.0001). Plasma magnesium levels had a significant positive correlation with cardiac output (P=.008) and cardiac power output (P=.01), and a negative correlation with heart rate (P=.05). Plasma magnesium levels correlated positively with systemic oxygen delivery and negatively with systemic oxygen consumption (P=.08 for both), resulting in significant negative correlations with oxygen extraction ratio (P=.04) and lactate levels (P=.05). For a given cardiac power output, plasma magnesium showed a significantly negative correlation with rate pressure product (P=.01). Plasma calcium levels showed the opposite trend, which was statistically insignificant except for lactate (P=.007). CONCLUSIONS: Plasma magnesium may exert favorable effects on myocardial energetics and systemic oxygen transport in neonates after the Norwood procedure, whereas plasma calcium may be harmful. Maintaining a relatively high level of plasma magnesium and a low level of plasma calcium may improve myocardial work efficiency and the balance of systemic and myocardial oxygen transport.