title: Association of congenital, diffuse electrical disease in children with normal heart: sick sinus syndrome, intraventricular conduction block, and monomorphic ventricular tachycardia.
abstract: BACKGROUND
  Rhythm disturbances in children with structurally normal hearts are usually associated with abnormalities in cardiac ion channels. The phenotypic expression of these abnormalities ("channelopathies") includes: long and short QT syndromes, Brugada syndrome, congenital sick sinus syndrome, catecholaminergic polymorphic ventricular tachycardia, Lènegre-Lev disease, and/or different degrees of cardiac conduction disease.
  
  
  METHODS
  The study group consisted of three male patients with sick sinus syndrome, intraventricular conduction disease, and monomorphic sustained ventricular tachycardia. Clinical data and results of electrocardiography, Holter monitoring, electrophysiology, and echocardiography are described.
  
  
  RESULTS
  In all patients, the ECG during sinus rhythm showed right bundle branch block and long QT intervals. First-degree AV block was documented in two subjects, and J point elevation in one. A pacemaker was implanted in all cases due to symptomatic bradycardia (sick sinus syndrome). Atrial tachyarryhthmias were observed in two patients. The common characteristic ventricular arrhythmia was a monomorphic sustained ventricular tachycardia, inducible with ventricular stimulation and sensitive to lidocaine. In one patient, radiofrequency catheter ablation was successfully performed. No structural abnormalities were found in echocardiography in the study group.
  
  
  CONCLUSIONS
  Common clinical and ECG features suggest a common pathophysiology in this group of patients with congenital severe electrical disease.
authors.affiliation: Department of Electrocardiology, National Institute of Cardiology, Ignacio Chávez, Mexico City, Mexico.
authors.forename: Pedro
authors.initials: P
authors.lastname: Iturralde-Torres
authors.forename: Santiago
authors.initials: S
authors.lastname: Nava-Townsend
authors.forename: Jorge
authors.initials: J
authors.lastname: Gómez-Flores
authors.forename: Argelia
authors.initials: A
authors.lastname: Medeiros-Domingo
authors.forename: Luis
authors.initials: L
authors.lastname: Colín-Lizalde
authors.forename: Antonio G
authors.initials: AG
authors.lastname: Hermosillo
authors.forename: Diana
authors.initials: D
authors.lastname: Victoria
authors.forename: Manlio F
authors.initials: MF
authors.lastname: Márquez
mesh_terms: D054537:Atrioventricular Block / Q000151:congenital* / Q000175:diagnosis*; D002648:Child; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D012804:Sick Sinus Syndrome / Q000151:congenital* / Q000175:diagnosis*; D017180:Tachycardia, Ventricular / Q000151:congenital* / Q000175:diagnosis*