Diagnosis of a bilobed left atrial appendage and pectinate muscles mimicking thrombi on real-time 3-dimensional transesophageal echocardiography.

Objective: Transesophageal echocardiography (TEE)-guided cardioversion is an established strategy for managing atrial arrhythmias and is commonly used as an alternative to the conventional approach of administering several weeks of anticoagulation before cardioversion. However, the safety of this approach depends on the exclusion of left atrial appendage (LAA) thrombi with a high level of diagnostic confidence. The objective of this case series is to explore the use of real-time 3-dimensional (RT3D) TEE in the precardioversion evaluation of patients with complex anatomy in their LAAs.

Methods: We used RT3D TEE to further assess the LAAs of 3 patients being evaluated for cardioversion who had inconclusive 2-dimensional (2D) TEE studies because of complex anatomic variants of the LAA. We imaged the LAA using the 3D zoom mode and rotated this image to view the LAA en face from the perspective of its ostium. Further cropping was performed as needed.

Results: In all 3 patients, the additional views of the appendage obtained by RT3D TEE were decisive in excluding contraindications to cardioversion. The unique en face view of the LAA acquired with 3D TEE, which was previously unobtainable using 2D TEE, was particularly useful. In 1 patient, a bilobed LAA mimicked a thrombus. In 2 other patients, prominent pectinate muscles masqueraded as thrombi.

Conclusions: Three-dimensional TEE is valuable for the precardioversion evaluation of patients with complex anatomic variants of the LAA.