Diagnosis of a Bilobed Left Atrial Appendage and Pectinate Muscles Mimicking Thrombi on Real-time 3-Dimensional Transesophageal Echocardiography

Abstract

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.

Real time 3-dimensional transesophageal echocardiography is more specific than 2-dimensional TEE in the assessment of left atrial appendage thrombosis

“…Not only the above mentioned en-face view; even the transverse Xplane (2 perpendicular planes screened simultaneously) can help. This has also been documented in other published case reports and small studies [3][4][5] . A typical picture of musculi pectinati seen in 2DE and 3DE is seen in (Fig.…”

“…Only a few minor studies have been published on this topic, mainly in the form of case reports [3][4][5] . A typical LAA thrombus on RT3DTEE is seen in (Fig.…”

Left Atrial Appendage Lipoma: An Unusual Location of Cardiac Lipomas

“…Myxomas characteristically have a strong hyperintense signal on T 2 -weighted imaging, whereas fibroelastoma exhibits a hypointense signal. 9 Although TEE is the procedure of choice to evaluate for atrial thrombus and masses, it might be difficult to conclude a diagnosis especially in the LAA. 7 Multidetector CT (MDCT) like MRI can help differentiate benign from malignant masses.…”

“…Of those one patient was found to have a bilobed LAA and two others a prominent pectinate muscles mimicking thrombus. 9 Although TEE is the procedure of choice to evaluate for atrial thrombus and masses, it might be difficult to conclude a diagnosis especially in the LAA. Pitfalls in the diagnosis usually occur when the attachment site is atypical, the mass is small or not well defined, and when the clinical picture does not favor a thrombus.…”

Transesophageal echocardiography for the assessment of left atrial appendage thrombus: Study of the additional value of systematic real time 3D imaging after regular 2D evaluation

“…However, the assessment of LAA thrombus using real time 3DTEE is of uncertain interest, as it has mostly been described in case reports, non comparative studies, and in a single comparative study where no patient had an actual LAA thrombus.…”