The right ventricular (RV) apex has long been the most common site of endocardial pacing, due to its anterior location and technical ease of lead placement. However previous data show that RV apical pacing can cause or worsen mitral regurgitation, increase BNP levels and may increase mortality. Additionally, a dose-dependent relationship, attributed to cardiac dyssynchrony, has been shown between RV apical pacing and both hospitalization for heart failure and mortality. Thus, alternative RV sites have been evaluated. Accordingly, we aimed to assess the effects of RV pacing site (apical vs. non-apical) on functional class, left ventricular (LV) function, and serum B-type natriuretic peptide (BNP) 6 months and 1 year after lead placement. Uniquely, our population contains a large percentage of patients with Chagas disease, in whom the effect of RV pacing site is not well investigated.