title: Sinus node disease in subjects with type 1 ECG pattern of Brugada syndrome.
abstract: BACKGROUND
  The spectrum of phenotypes related to mutations of the SCN5A gene include Brugada syndrome (BS), long QT syndrome, progressive cardiac conduction defect, and sinus node disease (SND). The present study investigated the incidence of SND in subjects with type 1 electrocardiogram (ECG) pattern of BS.
  
  
  RESULTS
  The study population consisted of 68 individuals (55 males, mean age 44.8±12.8 years) with spontaneous (n=27) or drug-induced (n=41) type 1 ECG pattern of BS. Twenty-eight subjects were symptomatic with a history of syncope (41.2%). SND was observed in 6 symptomatic subjects (8.8%), and was mainly attributed to sino-atrial block with sinus pauses. Two patients were initially diagnosed with SND, and received a pacemaker. Patients with SND displayed an increased P-wave duration in leads II and V2, PR interval in leads II and V2, QRS duration in leads II and V2, and increased QTc interval in lead V2 (p<0.05). AH and HV intervals as well as corrected sinus node recovery time (cSNRT) were significantly prolonged in subjects with SND (p<0.05). During a mean follow-up period of 5.0±3.6 years, five subjects with a history of syncope suffered appropriate implantable cardioverter defibrillator (ICD) discharges due to ventricular arrhythmias (7.4%). None of those diagnosed with SND suffered syncope or ICD therapies.
  
  
  CONCLUSIONS
  SND is not an uncommon finding in subjects with type 1 ECG pattern of BS. The occurrence of SND in relatively young patients may deserve meticulous investigation including sodium channel blocking test.
authors: Second Department of Cardiology, Evangelismos General Hospital of Athens, Greece. k.letsas@mail.gr
authors: Konstantinos P
authors: KP
authors: Letsas
authors: Panagiotis
authors: P
authors: Korantzopoulos
authors: Michael
authors: M
authors: Efremidis
authors: Reinhold
authors: R
authors: Weber
authors: Louiza
authors: L
authors: Lioni
authors: George
authors: G
authors: Bakosis
authors: Vassilios P
authors: VP
authors: Vassilikos
authors: Spyridon
authors: S
authors: Deftereos
authors: Antonios
authors: A
authors: Sideris
authors: Thomas
authors: T
authors: Arentz
mesh_terms: D000328:Adult; D000367:Age Factors; D053840:Brugada Syndrome / Q000150:complications* / Q000235:genetics; D017147:Defibrillators, Implantable; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D009154:Mutation; D062554:NAV1.5 Voltage-Gated Sodium Channel / Q000235:genetics; D010138:Pacemaker, Artificial; D011379:Prognosis; D012804:Sick Sinus Syndrome / Q000175:diagnosis / Q000453:epidemiology* / Q000235:genetics / Q000628:therapy
chemical_list: D062554:NAV1.5 Voltage-Gated Sodium Channel; C568320:SCN5A protein, human