ECG-gated dual-source CT for detection of left atrial appendage thrombus in patients undergoing catheter ablation for atrial fibrillation

  • Suraj Kapa
  • Matthew W. Martinez
  • Eric E. Williamson
  • Steve R. Ommen
  • Imran S. Syed
  • DaLi Feng
  • Douglas L. Packer
  • Peter A. BradyEmail author



Left atrial ablation is increasingly used to treat patients with symptomatic atrial fibrillation (AF). Prior to ablation, exclusion of left atrial appendage (LAA) thrombus is important. Whether ECG-gated dual-source computed tomography (DSCT) provides a sensitive means of detecting LAA thrombus in patients undergoing percutaneous AF ablation is unknown. Thus, we sought to determine the utility of ECG-gated DSCT in detecting LAA thrombus in patients with AF.


A total of 255 patients (age 58 ± 11 years, 78% male, ejection fraction 58 ± 9%) who underwent ECG-gated DSCT and transesophageal echocardiography (TEE) prior to AF ablation between February 2006 and October 2007 were included. CHADS2 score and demographic data were obtained prospectively. Gated DSCT images were independently reviewed by two cardiac imagers blinded to TEE findings. The LAA was either defined as normal (fully opacified) or abnormal (under-filled) by DSCT.


An under-filled LAA was identified in 33 patients (12.9%), of whom four had thrombus confirmed by TEE. All patients diagnosed with LAA thrombus using TEE also had an abnormal LAA by gated DSCT. Thus, sensitivity and specificity for gated DSCT were 100% and 88%, respectively. No cases of LAA filling defects were observed in patients <51 years old with a CHADS2 of 0.


In patients referred for AF ablation, thrombus is uncommon in the absence of additional risk factors. Gated DSCT provides excellent sensitivity for the detection of thrombus. Thus, in AF patients with a CHADS2 of 0, gated DSCT may provide a useful stand-alone imaging modality.


Computed tomography Atrial fibrillation Thrombus Echocardiography 


Funding sources/Financial support


Disclosures/Conflict of interest



  1. 1.
    Martinez, M. W., Kirsch, J., Williamson, E. E., Syed, I. S., Feng, D., Ommen, S., et al. (2009). Utility of nongated multidetector computed tomography for detection of left atrial thrombus in patients undergoing catheter ablation of atrial fibrillation. JACC Cardiovascular Imaging, 2, 69–76.CrossRefPubMedGoogle Scholar
  2. 2.
    Shapiro, M. D., Neilan, T. G., Jassal, D. S., Samy, B., Nasir, K., Hoffman, U., et al. (2007). Multidetector computed tomography for the detection of left atrial appendage thrombus: a comparative study with transesophageal echocardiography. Journal of Computer Assisted Tomography, 31, 905–909.CrossRefPubMedGoogle Scholar
  3. 3.
    Burke, S. J., Aggarwala, G., Stanford, W., Mullan, B., Thompson, B., & van Beek, E. J. (2008). Preablation assessment of the left atrium: comparison of ECG-gated cardiac CT with echocardiography. Academic Radiology, 15, 835–843.CrossRefPubMedGoogle Scholar
  4. 4.
    Hausleiter, J., Meyer, T., Hadamitzky, M., Huber, E., Zankl, M., Martinoff, S., et al. (2006). Radiation dose estimates from cardiac multislice computed tomography in daily practice: impact of different scanning protocols on effective dose estimates. Circulation, 113, 1305–1310.CrossRefPubMedGoogle Scholar
  5. 5.
    Jakobs, T. F., Becker, C. R., Ohnesorge, B., Flohr, T., Suess, C., Schoepf, U. J., et al. (2002). Multislice helical CT of the heart with retrospective ECG gating: reduction of radiation exposure by ECG-controlled tube current modulation. European Radiology, 12, 1081–1086.CrossRefPubMedGoogle Scholar
  6. 6.
    Hausleiter, J., Meyer, T., Hermann, F., Hadamitzky, M., Krebs, M., Gerber, T. C., et al. (2009). Estimated radiation dose associated with cardiac CT angiography. JACC Cardiovascular Imaging, 301, 500–507.Google Scholar
  7. 7.
    Fatkin, D., Kelly, R. P., & Feneley, M. P. (1994). Relations between left atrial appendage blood flow velocity, spontaneous echocardiographic contrast and thromboembolic risk in vivo. Journal of the American College of Cardiology, 23, 961–969.CrossRefPubMedGoogle Scholar
  8. 8.
    Gage, B. F., van Walraven, C., Pearce, L., Hart, R. G., Koudstaal, P. J., Boode, B. S. P., et al. (2004). Selecting patients with atrial fibrillation for anticoagulation: stroke risk stratification in patients taking aspirin. Circulation, 110, 2287–2292.CrossRefPubMedGoogle Scholar
  9. 9.
    Gage, B. F., Waterman, A. D., Shannon, W., Boechler, M., Rich, M. W., & Radford, M. J. (2001). Validation of clinical classification schemes for predicting stroke: results from the National Registry of Atrial Fibrillation. JACC Cardiovascular Imaging, 285, 2864–2870.Google Scholar
  10. 10.
    Agmon, Y., Khandheria, B. K., Gentile, F., & Seward, J. B. (2002). Clinical and echocardiographic characteristics of patients with left atrial thrombus and sinus rhythm: experience in 20, 643 consecutive transesophageal echocardiographic examinations. Circulation, 105, 27–31.CrossRefPubMedGoogle Scholar
  11. 11.
    Patel, A., Au, E., Donegan, K., Kim, R. J., Lin, F. Y., Stein, K. M., et al. (2008). Multidetector row computed tomography for identification of left atrial appendage filling defects in patients undergoing pulmonary vein isolation for treatment of atrial fibrillation: comparison with transesophageal echocardiography. Heart Rhythm, 5, 253–260.CrossRefPubMedGoogle Scholar
  12. 12.
    Kim, Y. Y., Klein, A. L., Halliburton, S. S., Popovic, Z. B., Kuzmiak, S. A., Sola, S., et al. (2007). Left atrial appendage filling defects identified by multidetector computed tomography in patients undergoing radiofrequency pulmonary vein antral isolation: a comparison with transesophageal echocardiography. American Heart Journal, 154, 1199–1205.CrossRefPubMedGoogle Scholar
  13. 13.
    Gottlieb, I., Pinheiro, A., Brinker, J. A., Corretti, M. C., Mayer, S. A., Bluemke, D. A., et al. (2008). Diagnostic accuracy of arterial phase 64-slice multidetector CT angiography for left atrial appendage thrombus in patients undergoing atrial fibrillation ablation. Journal of Cardiovascular Electrophysiology, 19, 247–251.CrossRefPubMedGoogle Scholar
  14. 14.
    Jaber, W. A., White, R. D., Kuzmiak, S. A., Boyle, J. M., Natale, A., Apperson-Hansen, C., et al. (2004). Comparison of ability to identify left atrial thrombus by three-dimensional tomography versus transesophageal echocardiography in patients with atrial fibrillation. The American Journal of Cardiology, 93, 486–489.CrossRefPubMedGoogle Scholar
  15. 15.
    Tang, R. B., Dong, J. Z., Zhang, Z. Q., Li, Z. A., Liu, X. P., Kang, J. P., et al. (2008). Comparison of contrast enhanced 64 slice computed tomography and transesophageal echocardiography in detection of left atrial thrombus in patients with atrial fibrillation. Journal of Interventional Cardiac Electrophysiology, 22, 199–203.CrossRefPubMedGoogle Scholar
  16. 16.
    Flohr, T. G., McCollough, C. H., Bruder, H., Petersilka, M., Gruber, K., Sub, C., et al. (2006). First performance evaluation of a dual-source CT (DSCT) system. European Radiology, 16, 1405.CrossRefGoogle Scholar
  17. 17.
    Singh, N. J., Nallmothu, N., Zuck, V. P., & Issa, Z. F. (2009). Left atrial appendage filling defects on 64-slice multidetector computed tomography in patients undergoing pulmonary vein isolation: predictors and comparison to transesophageal echocardiography. Journal of Computer Assisted Tomography, 33, 946–951.CrossRefPubMedGoogle Scholar
  18. 18.
    Achenbach, S., Sacher, D., Ropers, D., Pohle, K., Nixdorff, U., Hoffmann, U., et al. (2004). Electron beam computed tomography for the detection of left atrial thrombi in patients with atrial fibrillation. Heart, 90, 1477–1478.CrossRefPubMedGoogle Scholar
  19. 19.
    Schertler, T., Wildermuth, S., Willmann, J. K., Crook, D. W., Marincek, B., & Boehm, T. (2004). Retrospectively ECG-gated multi-detector row CT of the chest: does ECG-gating improve three-dimensional visualization of the bronchial tree? Fortschritte auf dem Gebiete der Röntgenstrahlen und der Nuklearmedizin, 176, 513–521.CrossRefPubMedGoogle Scholar
  20. 20.
    Marten, K., Funke, M., Rummeny, E. J., & Engelke, C. (2005). Electrocardiographic assistance in multidetector CT of thoracic disorders. Clinical Radiology, 60, 8–21.CrossRefPubMedGoogle Scholar
  21. 21.
    Desjardins, B., & Kazerooni, E. A. (2004). ECG-gated cardiac CT. AJR. American Journal of Roentgenology, 182, 993–1010.PubMedGoogle Scholar
  22. 22.
    Khan, M. N., Usmani, A., Noor, S., Elayi, S., Ching, S., Biase, C. K., et al. (2008). Low incidence of left atrial or left atrial appendage thrombus in patients with paroxysmal atrial fibrillation and normal EF who present for pulmonary vein antrum isolation procedure. Journal of Cardiovascular Electrophysiology, 19, 356–358.CrossRefPubMedGoogle Scholar
  23. 23.
    Saremi, F., Channual, S., Gurudevan, S. V., Narula, J., & Abolhoda, A. (2008). Prevalence of left atrial appendage pseudothrombus filling defects in patients with atrial fibrillation undergoing coronary computed tomography angiography. Journal of Cardiovascular Computed Tomography, 2, 164–171.CrossRefPubMedGoogle Scholar
  24. 24.
    Daniel, W. G., Erbel, R., Kasper, W., Visser, C. A., Engberding, R., Sutherland, G. R., et al. (1991). Safety of transesophageal echocardiography: a multicenter study of 10,419 examinations. Circulation, 83, 817–821.PubMedGoogle Scholar
  25. 25.
    Chyou, J. Y., Biviano, A., Magno, P., Garan, H., & Einstein, A. J. (2009). Applications of computed tomography and magnetic resonance imaging in percutaneous ablation therapy for atrial fibrillation. Journal of Interventional Cardiac Electrophysiology, 26, 47–57.CrossRefPubMedGoogle Scholar

Copyright information

© Springer Science+Business Media, LLC 2010

Authors and Affiliations

  • Suraj Kapa
    • 1
  • Matthew W. Martinez
    • 2
  • Eric E. Williamson
    • 3
  • Steve R. Ommen
    • 2
  • Imran S. Syed
    • 2
  • DaLi Feng
    • 2
  • Douglas L. Packer
    • 2
  • Peter A. Brady
    • 2
    Email author
  1. 1.Division of Cardiology, Department of MedicineUniversity of PennsylvaniaPhiladelphiaUSA
  2. 2.Division of Cardiovascular Diseases, Department of Internal MedicineMayo ClinicRochesterUSA
  3. 3.Department of RadiologyMayo ClinicRochesterUSA

Personalised recommendations