ACCURACY OF TRANSESOPHAGEAL ECHOCARDIOGRAPHY FOR IDENTIFYING LEFT ATRIAL THROMBI - A PROSPECTIVE, INTRAOPERATIVE STUDY

Objective: To determine the ability of transesophageal echocardiograph y to accurately identify or exclude left atrial thrombi. Design: Prosp ective cohort study. Setting: University hospital. Patients: 231 conse cutive patients having transesophageal echocardiography before electiv e repair or replacement of the mitral valve or excision of a left atri al tumor. Fifty-six percent of patients had a history of atrial fibril lation, and 17% had a history of thromboembolism. Measurement: Identif ication of left atrial thrombi during transesophageal echocardiographi c examination and comparison with direct near-simultaneous visualizati on during cardiac surgery. Results: Transesophageal echocardiography i dentified 14 left atrial thrombi in 14 patients (6%). Thrombus size ra nged from 3 to 80 mm. Surgery confirmed 12 of 14 thrombi (86%), includ ing 9 thrombi confined to the left appendage. No additional thrombi we re found on direct inspection of the atria (sensitivity, 100% [95% CI, 74% to 100%]; specificity, 99% [CI, 97% to 99.9%]; positive predictiv e value, 86% [12/14]; negative predictive value, 100% [217/217]; for a population that had a 5.2% prevalence of thrombi). All 12 surgically confirmed thrombi were identified by two independent observers. Neithe r thrombus seen by only a single observer on transesophageal echocardi ography was confirmed during direct inspection of the atria at surgery . Conclusion: Transesophageal echocardiography is highly accurate for identifying left atrial thrombi and can be used clinically to exclude left atrial thrombi.