A 44-year-old female had Chagas' disease with right bundle branch block, right axis deviation, and ventricular ectopic beats. An invasive evaluation showed a prolonged HV interval of 100 ms. A Medtronic Versatrax 7000 was implanted, after which a pacemaker-mediated tachycardia was observed. The esophageal lead ruled out the possibility of an atrial triggered tachycardia. The diagnosis was pacemaker-mediated tachycardia due to abnormal sensing of the terminal forces of the ventricular activation because of malposition of the atrial lead in the right ventricular out-flow tract.