Usefulness of multiplane transesophageal echocardiography in the recognition of artifacts and normal anatomical variants that may mimic left atrial thrombi in patients with atrial fibrillation.

BACKGROUND

Transesophageal echocardiography (TEE) is the method of choice for the evaluation of the left atrium and of left atrial appendage (LAA) thrombosis. However, the anatomy of the left appendage is complex and reverberations from anatomical structures may create images and ghosting which mimic left atrial thrombosis. The purpose of this study was to investigate whether a systematic approach through TEE may facilitate the recognition of LAA anatomical variants and artifacts.

METHODS

One hundred and sixty-four consecutive patients scheduled for cardioversion of atrial fibrillation (study population) and 30 patients (control group) undergoing mitral valve surgery were submitted to TEE using a multiplane probe in order to obtain a systematic evaluation of the LAA. The number of LAA lobes and the presence of thrombi and artifacts were evaluated.

RESULTS

The majority of the study patients had a bilobed (53.1%) or single-lobed (34.1%) LAA. Thrombi were identified in 6%. Artifacts were found in 38 cases (23.2%) and their position was localized precisely at a distance from the transducer which was twice that from the partition-bend between the left upper pulmonary vein and left appendage, suggesting a reverberation. No differences in echocardiographic parameters were found in patients with (group 1) or without (group 2) artifacts. Cardioversion was successful in a similar percentage of cases in the two groups (group 1 68%, group 2 76%) without complications. In controls, the percentages of a single-(33%) and bilobed (40%) left appendage were similar to those found in the study population. Artifacts were identified in 11 controls (37%); no thrombi were detected during surgical left appendage inspection in these cases.

CONCLUSIONS

A systematic approach with multiplane TEE facilitates the evaluation of the LAA anatomy and the recognition of artifacts, thus reducing the likelihood of false positive or negative diagnoses of left appendage thrombi.