title: T-wave axis deviation as an independent predictor of mortality in chronic Chagas' disease.
abstract: The T-wave axis shift has been reported to represent a general marker of ventricular repolarization abnormalities and a potential indicator of increased risk for cardiovascular mortality. We assessed the prognostic importance of the T-wave axis deviation for mortality rate in patients with chronic Chagas' disease. In a long-term follow-up prospective study, 738 adult outpatients in the chronic phase of Chagas' disease were enrolled. The frontal plane T-wave axis was estimated from 12-lead electrocardiograms obtained on admission and categorized as normal (15 degrees to 75 degrees ), borderline (75 degrees to 105 degrees or 15 degrees to -15 degrees ), and abnormal (>105 degrees or < -15 degrees ). Clinical and radiologic data, 2-dimensional echocardiographic data, and other electrocardiographic data were also recorded. Primary end points were all-cause, those related to Chagas' disease, and sudden cardiac deaths. Statistical analyses included Kaplan-Meier estimation of survival curves and multivariate Cox's proportional hazards models. During a follow-up of 58 +/- 39 months, 62 patients died, 54 from causes related to Chagas' disease and 40 due to sudden cardiac death. Kaplan-Meier survival curves showed that the 3 categories of T axis had significantly different prognoses. Multivariate Cox's survival analysis demonstrated that an abnormal T axis increases the risk of death threefold and sudden death nearly sixfold after adjustment for other covariates, including left ventricular systolic function and other electrocardiographic abnormalities. Borderline T-wave axis also indicated a worse prognosis, particularly in the subgroup of patients with abnormal baseline electrocardiograms. These results indicate that T-wave axis deviation is an easily quantified, strong, and independent mortality risk predictor in patients with chronic Chagas' disease.
authors.affiliation: Department of Internal Medicine, Clementino Fraga Filho University Hospital, Medical Faculty, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil. gilsalles@hucff.ufrj.br
authors.forename: Gil F
authors.initials: GF
authors.lastname: Salles
authors.forename: Sergio S
authors.initials: SS
authors.lastname: Xavier
authors.forename: Andrea S
authors.initials: AS
authors.lastname: Sousa
authors.forename: Alejandro
authors.initials: A
authors.lastname: Hasslocher-Moreno
authors.forename: Claudia R L
authors.initials: CR
authors.lastname: Cardoso
mesh_terms: D000328:Adult; D014355:Chagas Disease / Q000175:diagnosis / Q000401:mortality* / Q000503:physiopathology; D002908:Chronic Disease; D004562:Electrocardiography; D005260:Female; D005500:Follow-Up Studies; D006329:Heart Conduction System / Q000473:pathology / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011379:Prognosis; D011446:Prospective Studies; D016019:Survival Analysis; D016277:Ventricular Function, Left / Q000502:physiology