Prevalence and clinical significance of left atrial spontaneous echo contrast detected by transesophageal echocardiography.

The prevalence and clinical significance of left atrial spontaneous echo contrast (SEC) were studied in patients undergoing transesophageal echocardiography (TEE). The study group included 290 consecutive patients (186 male and 104 female, aged 17-86 years, mean age 56.1 +/- 12.8 years). Left atrial SEC was found in 50 (17.2%) patients, and was significantly associated with atrial fibrillation, mitral stenosis, absence of mitral regurgitation, and left atrial dimension. Atrial fibrillation was recorded in 44 (88%) patients, mitral stenosis or mitral valve replacement in 21 (42%) patients, and left atrial thrombus or previous embolism in 23 (46%) patients with SEC. Univariate analysis showed a significant association between the presence of SEC and atrial fibrillation, mitral stenosis or mitral valve replacement, and left atrial size. Multivariate analysis showed the presence of left atrial SEC and atrial fibrillation to be independent factors for thrombus formation and/or thromboembolism. Since left atrial SEC associated with atrial fibrillation, left atrial enlargement, mitral stenosis, or mitral valve prosthesis was found in 17.2% of patients undergoing TEE, it might be considered a marker of left atrial thrombus or previous thromboembolism.