title: Electrocardiographic abnormalities in Trypanosoma cruzi seropositive and seronegative former blood donors.
abstract: BACKGROUND
  Blood donor screening leads to large numbers of new diagnoses of Trypanosoma cruzi infection, with most donors in the asymptomatic chronic indeterminate form. Information on electrocardiogram (ECG) findings in infected blood donors is lacking and may help in counseling and recognizing those with more severe disease.
  
  
  OBJECTIVE
  To assess the frequency of ECG abnormalities in T.cruzi seropositive relative to seronegative blood donors, and to recognize ECG abnormalities associated with left ventricular dysfunction.
  
  
  METHODS
  The study retrospectively enrolled 499 seropositive blood donors in São Paulo and Montes Claros, Brazil, and 483 seronegative control donors matched by site, gender, age, and year of blood donation. All subjects underwent a health clinical evaluation, ECG, and echocardiogram (Echo). ECG and Echo were reviewed blindly by centralized reading centers. Left ventricular (LV) dysfunction was defined as LV ejection fraction (EF)<0.50%.
  
  
  RESULTS
  Right bundle branch block and left anterior fascicular block, isolated or in association, were more frequently found in seropositive cases (p<0.0001). Both QRS and QTc duration were associated with LVEF values (correlation coefficients -0.159,p<0.0003, and -0.142,p = 0.002) and showed a moderate accuracy in the detection of reduced LVEF (area under the ROC curve: 0.778 and 0.790, both p<0.0001). Several ECG abnormalities were more commonly found in seropositive donors with depressed LVEF, including rhythm disorders (frequent supraventricular ectopic beats, atrial fibrillation or flutter and pacemaker), intraventricular blocks (right bundle branch block and left anterior fascicular block) and ischemic abnormalities (possible old myocardial infarction and major and minor ST abnormalities). ECG was sensitive (92%) for recognition of seropositive donors with depressed LVEF and had a high negative predictive value (99%) for ruling out LV dysfunction.
  
  
  CONCLUSIONS
  ECG abnormalities are more frequent in seropositive than in seronegative blood donors. Several ECG abnormalities may help the recognition of seropositive cases with reduced LVEF who warrant careful follow-up and treatment.
authors.affiliation: Hospital das Clínicas and Faculdade de Medicina, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil.
authors.forename: Antonio L
authors.initials: AL
authors.lastname: Ribeiro
authors.forename: Ester C
authors.initials: EC
authors.lastname: Sabino
authors.forename: Milena S
authors.initials: MS
authors.lastname: Marcolino
authors.forename: Vera M C
authors.initials: VM
authors.lastname: Salemi
authors.forename: Barbara M
authors.initials: BM
authors.lastname: Ianni
authors.forename: Fábio
authors.initials: F
authors.lastname: Fernandes
authors.forename: Luciano
authors.initials: L
authors.lastname: Nastari
authors.forename: André
authors.initials: A
authors.lastname: Antunes
authors.forename: Márcia
authors.initials: M
authors.lastname: Menezes
authors.forename: Cláudia Di Lorenzo
authors.initials: CD
authors.lastname: Oliveira
authors.forename: Vandana
authors.initials: V
authors.lastname: Sachdev
authors.forename: Danielle M
authors.initials: DM
authors.lastname: Carrick
authors.forename: Michael P
authors.initials: MP
authors.lastname: Busch
authors.forename: Eduard L
authors.initials: EL
authors.lastname: Murphy
mesh_terms: D000328:Adult; D000913:Antibodies, Protozoan / Q000097:blood*; D001782:Blood Donors; D001938:Brazil / Q000453:epidemiology; D002598:Chagas Cardiomyopathy / Q000453:epidemiology*; D004562:Electrocardiography; D005260:Female; D006321:Heart / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D014349:Trypanosoma cruzi / Q000276:immunology*
chemical_list: D000913:Antibodies, Protozoan