title: Right bundle branch block: a predictor of mortality in early systemic sclerosis.
abstract: OBJECTIVE
  To evaluate the prognostic significance of baseline electrocardiogram (ECG) abnormalities in a multiethnic cohort of patients with early systemic sclerosis (SSc) and to determine the serological, clinical, and echocardiogram correlates of ECG findings.
  
  
  METHODS
  SSc patients with disease duration of≤5 years were enrolled in the GENISOS (Genetics versus Environment in Scleroderma Outcome Study) cohort. At the first visit, a standard 12 lead ECG was obtained along with demographic information, clinical data, and autoantibodies. The results of echocardiograms were also recorded. All ECGs were interpreted by a cardiologist unaware of the patients' clinical data.
  
  
  RESULTS
  Of 265 SSc patients with average disease duration at enrollment of 2.5 years, 140 (52.8%) had abnormal ECG findings. These findings were not associated with SSc disease type or autoantibody profile but were associated with more severe heart and lung involvement. A total of 75 patients (28.3%) died over a follow up time of 9.9 years. Complete right bundle branch block (± left anterior hemiblock) on ECG, present in 7 (2.6%) patients, predicted a higher risk of mortality (HR: 5.3; 95% CI: 2.1 to 13.4; p<0.001). The predictive significance of right bundle branch block was independent of age at enrollment, gender, ethnicity and risk factors for coronary artery disease.
  
  
  CONCLUSIONS
  ECG abnormalities are common in patients with early SSc and are associated with the severity of lung and heart involvement. Right bundle branch block is an independent predictor of mortality, and should be considered a marker of disease severity in SSc.
authors.affiliation: Division of Rheumatology, University of Texas Health Science Center at San Antonio, San Antonio, Texas, United States of America.
authors.forename: Hilda T
authors.initials: HT
authors.lastname: Draeger
authors.forename: Shervin
authors.initials: S
authors.lastname: Assassi
authors.forename: Roozbeh
authors.initials: R
authors.lastname: Sharif
authors.forename: Emilio B
authors.initials: EB
authors.lastname: Gonzalez
authors.forename: Brock E
authors.initials: BE
authors.lastname: Harper
authors.forename: Frank C
authors.initials: FC
authors.lastname: Arnett
authors.forename: Ameena
authors.initials: A
authors.lastname: Manzoor
authors.forename: Richard A
authors.initials: RA
authors.lastname: Lange
authors.forename: Maureen D
authors.initials: MD
authors.lastname: Mayes
mesh_terms: D002037:Bundle-Branch Block / Q000150:complications*; D015331:Cohort Studies; D004562:Electrocardiography; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D012595:Scleroderma, Systemic / Q000097:blood / Q000150:complications / Q000175:diagnosis* / Q000401:mortality*