Limited prospective data are available regarding the influence of pacemaker leads on tricuspid valve function. To examine the true incidence of these complications, 35 patients were prospectively examined by two-dimensional and Doppler echocardiography before and after implantation of either a permanent pacemaker or an automatic implantable cardioverter-defibrillator. Of the 35 patients imaged preoperatively, the amount of tricuspid regurgitation (TR) was judged as normal or trivial in 15 (43%), mild in 10 (29%), moderate in 8 (23%), and severe in 2 (6%). Following electrode implantation, TR was noted to be normal or trivial in 13 (38%), mild in 15 (48%), moderate in 6 (17%) and severe in 1 (3%). We conclude that implantation of permanent right ventricular electrodes is not usually associated with an acute worsening of tricuspid regurgitation in most patients.