title: QT dispersion in patients with Churg-Strauss syndrome.
abstract: BACKGROUND
  Churg-Strauss syndrome (CSS) is a rare, systemic necrotising small and middle-sized vessel vasculitis, accompanied by blood eosinophilia, eosinophil infiltration of various tissues and bronchial asthma. Cardiac injury caused by myocardial eosinophilic infiltration and/or vasculitis in CSS seems to be very common. Active inflammatory process accompanied by myocardial fibrosis has been described in this population even despite disease remission. Nevertheless, little is known about the possible myocardial repolarisation abnormalities in CSS which may lead to life-threatening ventricular arrhythmias.
  
  
  OBJECTIVE
  To evaluate myocardial repolarisation in CSS patients at the time of initial diagnosis and during the last disease remission.
  
  
  METHODS
  In 20 CSS patients (8 male, 12 female) QT dispersion (QTd) and QTc dispersion (QTcd) calculated from heart rate corrected QT (QTc) from the surface 12-lead electrocardiograms were measured at the time of initial diagnosis and during the last disease remission. As a control group, 20 sex- and age-matched healthy volunteers were studied. Transthoracic echocardiography was performed in all CSS patients at remission and in the control group.
  
  
  RESULTS
  QTcd was higher in CSS (n = 20) than in healthy controls (n = 20) in each period of time: at the time of initial diagnosis (45.4 ± 14.2 vs 26.1 ± 6.5, p < 0.0001) and at the remission (38.6 ± 13.4 vs 26.1 ± 6.5, p = 0.002). At the time of initial diagnosis in CSS patients with heart involvement (n = 13), when compared to patients without heart involvement, (n = 7), both QTcd (52.2 ± 12.1 vs 34.7 ± 10.7, p = 0.007) and QTd (37.7 ± 12.7 vs 24 ± 11.4, p = 0.008) were higher, and this difference remained significant at remission only for QTcd (46.7 ± 13.2 vs 33.1 ± 10.8, p = 0.03). No significant correlation was observed between QTcd/QTd and disease activity (measured using the Birmingham Vasculitis Activity Score - BVAS), eosinophil blood count, presence of ANCA, nor the duration of the disease.
  
  
  CONCLUSIONS
  The most pronounced increased QTcd was detected in the CSS patients with cardiac involvement at the time of initial diagnosis and remained higher at remission in all CSS patients when compared to healthy controls. Nevertheless, in the CSS patients, QTcd remains within the normal ranges, which may explain the relatively small number of ventricular arrhythmias in these patients.
authors.affiliation: 2nd Department of Internal Medicine, Jagiellonian University Medical College, Krakow, Poland. wszczeklik@gmail.com
authors.forename: Wojciech
authors.initials: W
authors.lastname: Szczeklik
authors.forename: Barbara Magdalena
authors.initials: BM
authors.lastname: Sokołowska
authors.forename: Lucyna
authors.initials: L
authors.lastname: Mastalerz
authors.forename: Tomasz
authors.initials: T
authors.lastname: Miszalski-Jamka
authors.forename: Karolina
authors.initials: K
authors.lastname: Pacult
authors.forename: Jacek
authors.initials: J
authors.lastname: Górka
authors.forename: Jacek
authors.initials: J
authors.lastname: Musiał
mesh_terms: D000328:Adult; D001145:Arrhythmias, Cardiac / Q000209:etiology* / Q000503:physiopathology; D016022:Case-Control Studies; D015267:Churg-Strauss Syndrome / Q000150:complications* / Q000503:physiopathology; D004452:Echocardiography / Q000379:methods; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D018709:Statistics, Nonparametric