Background: The aim of the study was to document cardiovascular clinical findings, cardiac imaging and laboratory markers in children presenting with the novel multisystem inflammatory syndrome (MIS-C) associated with COVID-19 infection. Methods: A real-time internet-based survey endorsed by the Association for European Paediatric and Congenital Cardiologists (AEPC) Working Groups for Cardiac Imaging and Cardiovascular Intensive Care. Inclusion criteria was children 0-18 years admitted to hospital between February 1 and June 6, 2020 with diagnosis of an inflammatory syndrome and acute cardiovascular complications. Results: A total of 286 children from 55 centers in 17 European countries were included. The median age was 8.4 years (IQR 3.8-12.4 years) and 67% were males. The most common cardiovascular complications were shock, cardiac arrhythmias, pericardial effusion and coronary artery dilatation. Reduced left ventricular ejection fraction was present in over half of the patients and a vast majority of children had raised cardiac troponin (cTnT) when checked. The biochemical markers of inflammation were raised in majority of patients on admission: elevated CRP, serum ferritin, procalcitonin, NT-proBNP, IL-6 level and D-dimers. There was a statistically significant correlation between degree of elevation in cardiac and biochemical parameters and need for intensive care support (p <0.05). Polymerase chain reaction (PCR) for SARS-CoV-2 was positive in 33.6% while IgM and IgG antibodies were positive in 15.7% and IgG 43.6 % cases, respectively when checked. One child died in the study cohort. Conclusions: Cardiac involvement is common in children with multisystem inflammatory syndrome associated with Covid-19 pandemic. A majority of children have significantly raised levels of NT pro-BNP, ferritin, D-dimers and cardiac troponin in addition to high CRP and procalcitonin levels. Compared to adults with Covid-19, mortality in children with MIS-C is uncommon despite multi-system involvement, very elevated inflammatory markers and need for intensive care support.

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Drug-induced BS is associated with atrial arrhythmias and SND. Children are at higher risk of ajmaline-induced VAs. The rate of device-related complications, leading to lead replacement or inappropriate shocks, is considerable and even higher than with appropriate interventions. Based on these findings, the optimal management of BS in childhood should remain individualized, taking into consideration the patient's clinical history and family's wishes.

Background Brugada Syndrome is an inherited arrhythmogenic disease, characterized by the typical coved type ST-segment elevation in the right precordial leads from V1 through V3. The BrugadaDrugs.org Advisory Board recommends avoiding administration of propofol in patients with Brugada Syndrome. Since prospective studies are lacking, it was the purpose of this study to assess the electrocardiographic effects of propofol and etomidate on the ST- and QRS-segments. In this trial, it was hypothesized that administration of propofol or etomidate in bolus for induction of anesthesia, in patients with Brugada Syndrome, do not clinically affect the ST- and QRS-segments and do not induce arrhythmias. Methods In this prospective, double-blinded trial, 98 patients with established Brugada syndrome were randomized to receive propofol (2 to 3 mg/kg-1) or etomidate (0.2 to 0.3 mg/kg-1) for induction of anesthesia. The primary endpoints were the changes of the ST- and QRS-segment, and the occurrence of new arrhythmias upon induction of anesthesia. Results The analysis included 80 patients: 43 were administered propofol and 37 etomidate. None of the patients had a ST elevation greater than or equal to 0.2 mV, one in each group had a ST elevation of 0.15 mV. An ST depression up to −0.15mV was observed eleven times with propofol and five with etomidate. A QRS-prolongation of 25% upon induction was seen in one patient with propofol and three with etomidate. This trial failed to establish any evidence to suggest that changes in either group differed, with most percentiles being zero (median [25th, 75th], 0 [0, 0] vs. 0 [0, 0]). Finally, no new arrhythmias occurred perioperatively in both groups. Conclusions In this trial, there does not appear to be a significant difference in electrocardiographic changes in patients with Brugada syndrome when propofol versus etomidate were administered for induction of anesthesia. This study did not investigate electrocardiographic changes related to propofol used as an infusion for maintenance of anesthesia, so future studies would be warranted before conclusions about safety of propofol infusions in patients with Brugada syndrome can be determined. Editor’s Perspective What We Already Know about This Topic What This Article Tells Us That Is New

Objective: This study was undertaken to determine the plasma concentration and pharmacokinetic variability of fenfluramine (FFA) and its main active metabolite norfenfluramine (norFFA) in relation to the prevalence of adverse effects in patients with refractory epilepsy treated with FFA. In addition, the interaction with concomitant antiseizure medications including stiripentol (STP) is studied. Methods: Patients were recruited at our center from two open-label sources, an investigator-initiated observational study and an international multicenter extension study. Venous blood samples were collected between June 2015 and December 2020. Plasma FFA and norFFA concentrations were determined by liquid chromatography tandem spectrometric analysis. Clinical data were collected retrospectively. Intrapatient coefficient of variation was calculated for all patients with at least three samples. Interpatient variability was calculated based on the concentration to weight-adjusted dose ratio (C/D) of all patients.Results: We collected 321 samples from 61 patients (49 with Dravet syndrome, seven with Lennox-Gastaut syndrome, and five with a developmental and epileptic encephalopathy). With a mean daily dose of .33 mg/kg/day (SD = ±.16), the median FFA plasma concentration was 41.4 µg/L (range = 5.1-712.5) and median norFFA concentration 28.1 µg/L (range = 2.6-149.6). The FFA plasma concentration was linearly related to the daily dose (p < .001) and norFFA levels (p < .001). The C/D of FFA increased with age (p < .001). Median FFA C/D was 428% higher (p < .001), norFFA C/D 83% lower (p < .001), and norFFA/ FFA 23% lower (p < .001) in patients treated with STP comedication. Higher FFA concentration was associated with fatigue (p = .001) and somnolence (p < .001), but not anorexia (p = .0619) or reduction in seizure frequency (p = .772). Gender and other ASMs were not associated with significant variations in (nor)FFA C/D ratio.

Background Maternal tachycardia is the most frequently occurring cardiac complication during pregnancy. Often administration of drugs is required as a treatment. The drug of choice is intravenously administered adenosine because it is considered safe, though there are limited studies regarding safety for the foetus with the use of adenosine. Case summary We report a conversion of maternal atrio-ventricular (AV) nodal reentry tachycardia during pregnancy with the use of intravenous adenosine whilst continuous electrophysiological foetal monitoring. Four seconds after the maternal conversion, the foetal tracing suggests the presence of a ventricular extrasystole or a transient AV block. Discussion This case report illustrates that the administration of adenosine intravenously during pregnancy could have an effect on the foetal conduction system. Therefore, further investigation to assess the electrophysiological effect of adenosine on the foetal electrocardiogram seems required.

Aims: Brugada syndrome (BrS) is an inherited cardiac arrhythmia with an increased risk for sudden cardiac death (SCD). About 20% of BrS cases are explained by mutations in the SCN5A gene, encoding the main cardiac sodium Na v 1.5 channel. Here we present a severe case of cardiac sodium channelopathy with BrS caused by SCN5A compound heterozygous mutations. We performed a genetic analysis of SCN5A in a male proband who collapsed during cycling at the age of 2 years. Because of atrial standstill, he received a pacemaker, and at the age of 3 years, he experienced a collapse anew with left-sided brain stroke. A later ECG taken during a fever unmasked a characteristic BrS type-1 pattern. The functional effect of the detected genetic variants was investigated. Methods and Results: Next-generation sequencing allowed the detection of two SCN5A variants in trans: c.4813+3_4813+6dupGGGT-a Belgian founder mutation-and c.4711 T>C, p.Phe1571Leu. A familial segregation analysis showed the presence of the founder mutation in the proband's affected father and paternal aunt and the de novo occurrence of the p.Phe1571Leu. The functional effect of the founder mutation was previously described as a loss-of-function. We performed a functional analysis of the p.Phe571Leu variant in HEK293 cells alone or co-expressed with the β 1-subunit. Compared to the SCN5A wild type, p.Phe1571Leu displayed a hyperpolarizing shift in the voltage dependence of inactivation (loss-of-function), while the activation parameters were unaffected. Using the peptide toxin nemertide α-1, the variant's loss-of-function effect could be restored due to a toxin-dependent reduction of channel inactivation. Nijak et al. Functional Characterization of p.Phe1571Leu in SCN5A Conclusion: This is the first report providing support for the pathogenicity of the p.Phe1571Leu SCN5A variant which, together with the c.4813+3_4813+6dupGGGT founder mutation, explains the severity of the phenotype of cardiac sodium channelopathy with BrS in the presented case.

Background Transcriptome profiling of blood cells is an efficient tool to study the gene expression signatures of rheumatic diseases. This study aims to improve the early diagnosis of pediatric rheumatic diseases by investigating patients’ blood gene expression and applying machine learning on the transcriptome data to develop predictive models. Methods RNA sequencing was performed on whole blood collected from children with rheumatic diseases. Random Forest classification models were developed based on the transcriptome data of 48 rheumatic patients, 46 children with viral infection, and 35 controls to classify different disease groups. The performance of these classifiers was evaluated by leave-one-out cross-validation. Analyses of differentially expressed genes (DEG), gene ontology (GO), and interferon-stimulated gene (ISG) score were also conducted. Results Our first classifier could differentiate pediatric rheumatic patients from controls and infection cases with high area-under-the-curve (AUC) values (AUC = 0.8 ± 0.1 and 0.7 ± 0.1, respectively). Three other classifiers could distinguish chronic recurrent multifocal osteomyelitis (CRMO), juvenile idiopathic arthritis (JIA), and interferonopathies (IFN) from control and infection cases with AUC ≥ 0.8. DEG and GO analyses reveal that the pathophysiology of CRMO, IFN, and JIA involves innate immune responses including myeloid leukocyte and granulocyte activation, neutrophil activation and degranulation. IFN is specifically mediated by antibacterial and antifungal defense responses, CRMO by cellular response to cytokine, and JIA by cellular response to chemical stimulus. IFN patients particularly had the highest mean ISG score among all disease groups. Conclusion Our data show that blood transcriptomics combined with machine learning is a promising diagnostic tool for pediatric rheumatic diseases and may assist physicians in making data-driven and patient-specific decisions in clinical practice.