Atrial Appendage Thrombosis Risk Is Lower for Atrial Flutter Compared with Atrial Fibrillation

Structured Abstract Background The risk of stroke and thromboembolism in atrial fibrillation is established. There are clear guidelines in anticoagulation management of patient's with atrial fibrillation, however, the evidence surrounding the risk of thromboembolism in patients with atrial flutter is not as clear. We hypothesized that atrial flutter would have indicators of less risk for thromboembolism compared with atrial fibrillation on transesophageal echocardiography (TEE); thereby possibly leading to a lower stroke risk. Methods A retrospective review of 2,225 patients undergoing TEE was performed. Those with atrial fibrillation or atrial flutter were screened. Exclusion criteria were: patients being treated with chronic anticoagulation, the presence of a prosthetic valve, moderate to severe mitral regurgitation or stenosis, congenital heart disease, or a history of heart transplantation. One hundred and fourteen patients with atrial fibrillation and fifty-five patients with atrial flutter met the above criteria and were included in the analysis. Results Twelve patients (11%) in the atrial fibrillation group had left atrial appendage thrombus versus zero in the atrial flutter group (p 60 cm/sec. All twelve patients with left atrial appendage thrombus in the atrial fibrillation group had left atrial spontaneous echo contrast. Conclusions Patients with atrial flutter have a lower incidence of left atrial appendage thrombi, higher LAAEV and less left atrial spontaneous contrast compared with atrial fibrillation patients, suggesting a lower risk for potential arterial thromboembolism.