title: Prolongation of the corrected QT interval in adult patients with anti-Ro/SSA-positive connective tissue diseases.
abstract: OBJECTIVE
  Newborns of mothers positive for anti-Ro/SSA autoantibodies may develop a series of electrocardiographic (EKG) disturbances. Prolongation of the corrected QT (QTc) interval was recently reported in a significant proportion of children with maternally acquired anti-Ro/SSA antibodies, with a concomitant disappearance of EKG abnormalities and acquired maternal autoantibodies during the first year, suggesting a direct, reversible electrophysiologic effect of anti-Ro/SSA antibodies on the ventricular repolarization. On this basis, we investigated whether these antibodies may also affect cardiac repolarization in anti-Ro/SSA-positive adult patients with connective tissue diseases.
  
  
  METHODS
  Fifty-seven patients with connective tissue diseases were selected: 31 had anti-Ro/SSA antibodies and 26 did not (controls). In all subjects, we analyzed the QTc interval, heart rate variability, and signal-averaged high-resolution EKG recording.
  
  
  RESULTS
  Anti-Ro/SSA-positive patients showed a significant prolongation of the mean QTc interval compared with the controls (mean +/- SD 445 +/- 21 versus 419 +/- 17 msec; P = 0.000005). Eighteen of the 31 anti-Ro/SSA-positive patients (58%) and none of the 26 anti-Ro/SSA-negative patients had QTc values above the upper limit of normal (440 msec). Both groups had a reduction in heart rate variability, with a prevalence for the sympathetic nervous system and a high incidence of ventricular late potentials; these values were not significantly different between the 2 groups.
  
  
  CONCLUSIONS
  Adult patients with anti-Ro/SSA-positive connective tissue diseases showed a high prevalence of QTc interval prolongation. This feature, with the concomitant abnormalities in the autonomic tone and ventricular late excitability observed in all patients studied, suggests that anti-Ro/SSA-positive patients may have a particularly high risk of developing life-threatening arrhythmias.
authors.affiliation: University of Siena, Siena, Italy.
authors.forename: Pietro Enea
authors.initials: PE
authors.lastname: Lazzerini
authors.forename: Maurizio
authors.initials: M
authors.lastname: Acampa
authors.forename: Francesca
authors.initials: F
authors.lastname: Guideri
authors.forename: Pier Leopoldo
authors.initials: PL
authors.lastname: Capecchi
authors.forename: Valeria
authors.initials: V
authors.lastname: Campanella
authors.forename: Gabriella
authors.initials: G
authors.lastname: Morozzi
authors.forename: Mauro
authors.initials: M
authors.lastname: Galeazzi
authors.forename: Roberto
authors.initials: R
authors.lastname: Marcolongo
authors.forename: Franco
authors.initials: F
authors.lastname: Laghi-Pasini
mesh_terms: D000328:Adult; D000974:Antibodies, Antinuclear / Q000097:blood*; D003240:Connective Tissue Diseases / Q000453:epidemiology* / Q000276:immunology*; D016757:Death, Sudden, Cardiac / Q000453:epidemiology; D004562:Electrocardiography; D005260:Female; D006339:Heart Rate; D006801:Humans; D008133:Long QT Syndrome / Q000175:diagnosis / Q000453:epidemiology* / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D012307:Risk Factors; D016036:Seroepidemiologic Studies
chemical_list: D000974:Antibodies, Antinuclear; C035356:SS-A antibodies