Transesophageal echocardiography provides excellent images of intracardiac masses; however, its use among a series of patients with central venous lines has not been fully described. Nineteen patients (aged 52 +/- 16 years; 10 women) had masses detected by transesophageal echocardiography in the presence of a permanent (0.2 to 16 years) pacing wire (n = 8), and a current (n = 9) or recent (n = 2) (1 to 281 days) indwelling catheter. Transthoracic echocardiography suggested the presence of a mass in 5 patients (26%), although in only 2 cases were its findings consistent with transesophageal findings. Transesophageal echocardiography indicated the presence of a mass in or near the superior vena cava in 13 patients, in the right atrium in 6, and adjacent to the tricuspid valve in 3. Discrete masses measured 1.6 +/- 2.1 cm2 in area during transesophageal echocardiography. Eleven patients had positive blood cultures, 7 with staphylococcal species. Mass size was not significantly altered by the type of line or sepsis, but showed a weak correlation with line age (r = 0.56). Transesophageal echocardiography altered the management of 9 patients, prompting surgery (n = 3) and line removal (n = 3), and antibiotic (n = 2) or anticoagulation (n = 3) therapy.