Electrocardiographic re-polarization parameters are potential markers of arrhythmogenic risk and have not been evaluated inChagas’ disease. The aim of this report was to investigate their associations with LV systolic function as-sessed by two-dimensional echocardiography. In a cross-sectional study involving 738 adult outpatientsin the chronic phase of Chagas’ disease, maximal QTc and T wave peak-to-end (TpTe) intervals, and QT,QTapex (QTa), JT and TpTe interval dispersions, and variation coefficients were measured and calculatedfrom 12-lead standard ECGs. Clinical, radiological, ECG, and echocardiographic data were recorded. Inbivariate statistical analysis, all repolarization parameters were significantly increased in patients withmoderate or severe LV systolic dysfunction, and these patients showed more clinical, radiologic, and ECGabnormalities. Receiver operating characteristic curve analysis demonstrated that isolatedly QTd had thebest predictive performance for LV dysfunction, with an 80% specificity and 67% sensitivity for values>60 ms in the subgroup of chagasic patients with abnormal ECGs and no heart failure. Multivariate lo-gistic regression selected, as the best predictive model for LV dysfunction in this subgroup of patients, thepresence of cardiomegaly on chest X ray (OR 14.06, 95% CI, 5.54–35.71), QTd>60 ms (OR 9.35, 95% CI,4.01–21.81), male gender (OR 7.70, 95% CI, 2.98–19.91) and the presence of frequent premature ventric-ular contractions (PVCs) on ECG (OR 4.06, 95% CI, 1.65–9.97). This model showed 90% specificity and71% sensitivity. In conclusion, QTd was associated to LV systolic function and could be used to predictasymptomatic dysfunction in chronic Chagas’ disease. The presence of cardiomegaly, frequent PVCs, andmale sex refined LV function stratification in these patients.2020-06-24