Impact of clinical and genetic findings on the management of young patients with Brugada syndrome.

BACKGROUND: Brugada syndrome (BrS) is an arrhythmogenic disease associated with sudden cardiac death (SCD) that seldom manifests or is recognized in childhood. OBJECTIVES: The objectives of this study were to describe the clinical presentation of pediatric BrS to identify prognostic factors for risk stratification and to propose a data-based approach management. METHODS: We studied 106 patients younger than 19 years at diagnosis of BrS enrolled from 16 European hospitals. RESULTS: At diagnosis, BrS was spontaneous (n = 36, 34%) or drug-induced (n = 70, 66%). The mean age was 11.1 ± 5.7 years, and most patients were asymptomatic (family screening, (n = 67, 63%; incidental, n = 13, 12%), while 15 (14%) experienced syncope, 6(6%) aborted SCD or symptomatic ventricular tachycardia, and 5 (5%) other symptoms. During follow-up (median 54 months), 10 (9%) patients had life-threatening arrhythmias (LTA), including 3 (3%) deaths. Six (6%) experienced syncope and 4 (4%) supraventricular tachycardia. Fever triggered 27% of LTA events. An implantable cardioverter-defibrillator was implanted in 22 (21%), with major adverse events in 41%. Of the 11 (10%) patients treated with hydroquinidine, 8 remained asymptomatic. Genetic testing was performed in 75 (71%) patients, and SCN5A rare variants were identified in 58 (55%); 15 of 32 tested probands (47%) were genotype positive. Nine of 10 patients with LTA underwent genetic testing, and all were genotype positive, whereas the 17 SCN5A-negative patients remained asymptomatic. Spontaneous Brugada type 1 electrocardiographic (ECG) pattern (P = .005) and symptoms at diagnosis (P = .001) were predictors of LTA. Time to the first LTA event was shorter in patients with both symptoms at diagnosis and spontaneous Brugada type 1 ECG pattern (P = .006). CONCLUSION: Spontaneous Brugada type 1 ECG pattern and symptoms at diagnosis are predictors of LTA events in the young affected by BrS. The management of BrS should become age-specific, and prevention of SCD may involve genetic testing and aggressive use of antipyretics and quinidine, with risk-specific consideration for the implantable cardioverter-defibrillator

Le syndrome du QT long congénital

Le syndrome du QT long congénital est une maladiele plus souvent familiale, rare dont la gravité est liée aux troubles du rythme ventriculaire qu'elle peut entraîner. L'étude rétrospective réalisée comporte trois familles atteintes de SQTL, dont deux génotypées. Tous les enfants et les adultes symptomatiques (sauf la mère de ClaireL) sont traités par béta-bloquants, parfois associés à un stimulateur cardiaque dans le cas de bloc auriculo-ventriculaire persistants. Depuis l'introduction du traitement, ils sont tous asymptomatiques avec une parfaite tolérance médicamenteuse. Les béta-bloquants restent le traitement de référence et l'existence de troubles de conduction fonctionnels n'est pas un obstacle à leur utilisation. Enfin, ces enfants dont le pronostic est le plus souvent favorable, sont autorisés à mener une vie normale et à faire un peu de sport, sans compétition.TOULOUSE3-BU Santé-Centrale (315552105) / SudocTOULOUSE3-BU Santé-Allées (315552109) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF

Particularité pédiatrique de l'hypertension artérielle pulmonaire à propos de quatre cas toulousains récents

TOULOUSE3-BU Santé-Centrale (315552105) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF

Evaluation de la fonction endothéliale et des propriétés mécaniques artérielles à distance d'une maladie de Kawasaki

TOULOUSE3-BU Santé-Centrale (315552105) / SudocSudocFranceF

Role of aerosol size distribution and source location in a three- dimensional simulation of a Saharan dust episode tested against satellite-derived optical thickness

International audienceAn off-line global three-dimensional tracer model based on analyzed wind fields was augmented to simulate the atmospheric transport of mineral dust. The model describes the evolution of the aerosol size distribution and hence allows to compute aerosol number and mass concentrations. In this study we describe the parameterization of the sedimentation process and include a preliminary source formulation but exclude wet deposition. Validation of the model is done during a 16-day period in June-July 1988 with very scarce precipitation. It is based on a comparison of every model grid box with daily satellite-derived optical thickness observations of Saharan dust plumes over the North Atlantic and the Mediterranean. The model reproduces accurately the daily position of the dust plumes over the ocean, with the exception of Atlantic regions remote from the African coast. By systematic analysis of transport and aerosol components we show that the largest uncertainty in reproducing the position of the dust clouds is the correct localization of the source regions. The model simulation is also very sensitive to the inclusion of convection and to an accurate treatment of the sedimentation process. Only the combination of source activation, rapid transport of dust to higher altitudes by convective updraft and long-range transport allows the simulation of thc dust plumes position. This study shows that a mineral dust transport model is only constrained if both the sourcc strength and the aerosol size distribution are known. The satellite observation of optical thickness over the Mediterranean and assumptions about the size distribution indicate that the dust emission flux was of the order of 17x 106 t for the 16-day period under invcstigation. The simulations suggest that a major aerosol mode initially around 2.5 [tm with a standard deviation of 2.0 plays the dominant role in long-range transport of mineral dust