Résumé : To evaluate (1) whether right ventricular (RV) dysfunction, evaluated using tricuspid annular plane systolic excursion (TAPSE) is associated with a worse outcome in patients with the Eisenmenger syndrome, (2) which variables are related to RV dysfunction, and (3) whether differences exist among simple pretricuspid, simple post-tricuspid, and combined shunt lesions. Patients with Eisenmenger syndrome, aged >18 years, who underwent echocardiography, were selected from the Belgian Eisenmenger registry and prospectively followed up using a Web-based registry. Cox regression analysis was performed to evaluate the relation to outcomes, defined as all-cause mortality, transplantation, and hospitalization for cardiopulmonary causes. Comparative and bivariate analysis was performed, where applicable. A total of 58 patients (mean age 35.1 ± 13.2 years, 32.8% men) were included. During a mean follow-up of 3.2 years, 22 patients (37.9%) reached the predefined end point. Only TAPSE (hazard ratio 0.820, 95% confidence interval 0.708 to 0.950; p = 0.008) was related to the adverse outcomes on multivariate analysis. Patients with pretricuspid shunt lesions were older (p <0.0001) had greater left (p <0.0001) and right atrial (p <0.0001) dimensions, greater RV dimensions (p = 0.002), and more tricuspid regurgitation (p = 0.012) compared to patients with post-tricuspid lesions. Lower TAPSE was related to the presence of pulmonary artery thrombosis (R = -0.378; p = 0.006). In conclusion, in patients with Eisenmenger syndrome, RV dysfunction, evaluated using TAPSE, is related to worse outcomes. Patients with Eisenmenger syndrome with pretricuspid shunt lesions were older and had greater left atrial, right atrial, and RV dimensions compared to patients with post-tricuspid lesions, indicating a difference in the RV response. Lower TAPSE was associated with the presence of pulmonary artery thrombosis.