Transesophageal Echocardiography in the Diagnosis of Thrombosis Associated with Permanent Transvenous Pacemaker Electrodes PETRI J. KORKEILA, M.D., MARKKU K. SARASTE, M.D., KAI M. NYMAN, M.D., JUHANI KOISTINEN, M.D., JUHA LUND, M.D., and KARL EINO JUHANI AIRAKSINEN, M.D., F.E.S.C. From the Division of Cardiology, Department of Internal Medicine and Clinical Physiology, Turku University Central Hospital, Turku, Finland Objectives: We sought to assess the value of transesophageal echocardiography (TEE) in the diagnosis of PM-lead-associated central venous thrombi. Background: Venous thrombosis is not infrequent after pacemaker (PM) or implantable cardioverter- defibrillator (ICD) implantation. Previous incidence studies of thrombosis have been based on venography or Doppler ultrasound, but the role of TEE has not been systematically evaluated in this setting. Methods: Study group comprised 66 consecutive patients (mean age 64 years, 67 % male) referred for implantation of their first PM or ICD and with a successful TEE, transthoracic echocardiography (TTE) and venography at 6 months after implantation. The total number of implanted leads was 110. During the 6 months of clinical follow-up, nuclear ventilation-perfusion scan or spiral computed tomography was performed when symptoms aroused a clinical suspicion of PE. Results: TEE revealed a right atrium (RA) or lower superior vena cava (SVC) thrombus in 6 (9%) patients. These thrombi were not visualized by TTE or venography. Additionally, 12 (20%) patients were found to have venographic subclavian or innominate vein thrombi, but none of those could be diagnosed with TEE. Symptomatic pulmonary embolism (PE) was diagnosed in two and an asymptomatic PE in one individual and two of these occurred among the six patients with a thrombus in TEE. No clinical predictors for thrombosis were found. Conclusions: TEE is an excellent method to visualize electrodes within the RA and proximal SVC. Electrode-associated RA thrombi appear to be relatively common after PM implantation, and they may re- main undetectable by venography or TTE. Although these thrombi are mostly asymptomatic, they can give rise to pulmonary embolism and should also be kept in mind in the differential diagnosis of endocarditis. TEE is the method of choice for the diagnosis of these lesions. (PACE 2006; 29:1245–1250) transesophageal echocardiography, venography, thrombosis, pacemaker, cardioverter-defibrillator Introduction Central venous catheters and pacemaker (PM) electrodes are known to predispose to throm- bus formation. 1–3 Several methods of detecting thrombosis associated with PM or implantable cardioverter-defibrillator (ICD) leads have been de- scribed, 3–6 and intravenous contrast venography has emerged as the gold standard. 7 Transesophageal echocardiography (TEE) may be useful in the detection of thrombosis in the superior vena cava (SVC). 8–10 However, studies focused on the role of TEE in the diagnosis of This study has received financial support from Southwestern Finland Hospital District Research Fund, the Finnish Cardiac Society, and the Finnish Foundation for Cardiovascular Re- search, Helsinki, Finland. Address for reprints: Petri Korkeila, M.D., Kiinamyllynkatu 4-8, PL 52, 20520 Turku, Finland. Fax: 358-2-2030; e-mail: petri.korkeila@tyks.fi Received March 2, 2006; revised July 7, 2006; accepted August 2, 2006 electrode-associated thrombosis are lacking, and there are only case reports on TEE in this indica- tion. 11–13 The aim of our study was to assess the fea- sibility and findings of TEE in a prospective se- ries of patients receiving their first permanent implantable device, and compare TEE to con- ventional venography and transthoracic echocar- diography (TTE) in the detection of PM or ICD electrode-associated thrombi. Material and Methods Study Population This is a substudy of a larger study protocol designed to assess thrombosis and bleeding com- plications of invasive cardiac procedures in South- western Finland. All patients referred for implan- tation of a first PM or ICD in Turku University Cen- tral Hospital were asked to participate in a study of venous complications associated with the de- vice implantation. Patients with contraindications C 2006, The Authors. Journal compilation C 2006, Blackwell Publishing, Inc. PACE, Vol. 29 November 2006 1245