title: High prevalence of early repolarization in the paediatric relatives of sudden arrhythmic death syndrome victims and in normal controls.
abstract: OBJECTIVE
  Elevation of the ECG J-point in the inferior and lateral leads (early repolarization) has been described in survivors of ventricular fibrillation (VF) arrest and occurs in adult first-degree relatives of sudden cardiac death (SCD) probands at a frequency significantly greater than in controls, raising the possibility that this could represent an independent risk factor in the aetiology of SCD. However, data on early repolarization in the paediatric population are lacking. This study aimed to assess the prevalence of early repolarization in paediatric first-degree relatives of sudden arrhythmic death syndrome (SADS) victims.
  
  
  RESULTS
  Paediatric relatives (aged <18 years) of SADS probands referred to the Inherited Arrhythmia Clinic at Great Ormond Street Hospital had their initial screening ECG reviewed for evidence of J-point elevation. J-point elevation was defined as QRS-ST slurring or a discrete notch in two or more inferior (II, III, aVF) or lateral (I, aVL, V4, V5, V6) leads with the change beginning >1 mV from baseline. The ECGs of 77 consecutive paediatric first-degree relatives of SADS victims from 46 families were reviewed by two assessors. J-point elevation was present in 24 patients (31%) of this patient group compared with the reported prevalence of 5-13% in the published general paediatric population (P = 0.02) and that of 19% in the internal control group (P = 0.07). Subgroup analysis according to J-point elevation and ST segment morphologies showed a significantly higher prevalence of inferior early repolarization 0.1-0.2 mV in the study group compared with controls (75 vs. 38%; P = 0.02).
  
  
  CONCLUSIONS
  Inferolateral J-point elevation occurs in a substantial proportion of paediatric first-degree relatives of SADS probands with a similar prevalence to that described in adults. This suggests that early repolarization could be an important inherited trait when evaluating relatives of SADS victims. However, prospective follow-up of this group of children is important to establish the implication of this finding in future risk stratification, given the apparently high prevalence in normal individuals.
authors.affiliation: Inherited Cardiovascular Diseases Unit, Department of Cardiology, Great Ormond Street Hospital, London WC1N 3JH, UK.
authors.forename: Anna
authors.initials: A
authors.lastname: McCorquodale
authors.affiliation: Inherited Cardiovascular Diseases Unit, Department of Cardiology, Great Ormond Street Hospital, London WC1N 3JH, UK.
authors.forename: Rachel
authors.initials: R
authors.lastname: Poulton
authors.affiliation: Inherited Cardiovascular Diseases Unit, Department of Cardiology, Great Ormond Street Hospital, London WC1N 3JH, UK.
authors.forename: Jennifer
authors.initials: J
authors.lastname: Hendry
authors.affiliation: Inherited Cardiovascular Diseases Unit, Department of Cardiology, Great Ormond Street Hospital, London WC1N 3JH, UK.
authors.forename: Gabrielle
authors.initials: G
authors.lastname: Norrish
authors.affiliation: Inherited Cardiovascular Diseases Unit, Department of Cardiology, Great Ormond Street Hospital, London WC1N 3JH, UK.
authors.forename: Ella
authors.initials: E
authors.lastname: Field
authors.affiliation: Inherited Cardiovascular Diseases Unit, Department of Cardiology, Great Ormond Street Hospital, London WC1N 3JH, UK.
authors.forename: Sarah
authors.initials: S
authors.lastname: Mead-Regan
authors.affiliation: Inherited Cardiovascular Diseases Unit, Department of Cardiology, Great Ormond Street Hospital, London WC1N 3JH, UK.
authors.forename: Martin
authors.initials: M
authors.lastname: Lowe
authors.affiliation: Inherited Cardiovascular Diseases Unit, Department of Cardiology, Great Ormond Street Hospital, London WC1N 3JH, UK.|Institute of Cardiovascular Science, University College London, London, UK.
authors.forename: Juan Pablo
authors.initials: JP
authors.lastname: Kaski
mesh_terms: D000200:Action Potentials; D000293:Adolescent; D000328:Adult; D000367:Age Factors; D001145:Arrhythmias, Cardiac / Q000175:diagnosis / Q000235:genetics / Q000401:mortality* / Q000503:physiopathology; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D016757:Death, Sudden, Cardiac / Q000453:epidemiology*; D004562:Electrocardiography; D005190:Family; D005260:Female; D020022:Genetic Predisposition to Disease; D006329:Heart Conduction System / Q000503:physiopathology*; D006339:Heart Rate; D040941:Heredity; D006801:Humans; D008131:London / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D010375:Pedigree; D015995:Prevalence; D012307:Risk Factors; D013997:Time Factors; D055815:Young Adult
keywords: Children; Ion channel disease; Paediatric arrhythmias; Sudden cardiac death; Ventricular arrhythmia