Prevalence of Left Atrial Thrombus and Dense Spontaneous Echo Contrast in Patients With Short-Term Atrial Fibrillation < 48 Hours Undergoing Cardioversion: Value of Transesophageal Echocardiography to Guide Cardioversion

Background The aim of this study was to investigate the value of transesophageal echocardiography (TEE)–guided cardioversion (CV) to prevent thromboembolic complications in patients with short-term atrial fibrillation (AF) < 48 hours in duration. Methods This single-center, observational study comprised 366 consecutive, unselected patients with short-term AF < 48 hours in duration. During the first 2 years, CV was performed using the conventional approach without TEE. Thereafter, CV guided by TEE was performed in consecutive patients. Results TEE revealed left atrial thrombi in 1.4% and left atrial dense spontaneous echo contrast in 10% of patients with short-term AF (n = 207), of whom 63% were receiving anticoagulation therapy. Patients without prior anticoagulation had a 4% prevalence of left atrial thrombi. A low ejection fraction and an enlarged left atrium tended to be associated with an increased prevalence of thrombus or dense spontaneous echo contrast. During the first month after CV, there were no significant differences in the rate of embolic events between the two treatment groups. Conclusions These results underline the need for further studies on the usefulness of TEE-guided CV in patients with short-term AF who are not therapeutically anticoagulated at presentation.