Analysis of in vivo left atrial appendage morphology in patients with atrial fibrillation: a direct comparison of transesophageal echocardiography, planar cardiac CT, and segmented three-dimensional cardiac CT.

Purpose: Recent development of percutaneous left atrial appendage (LAA) occlusion devices has underscored the need for an accurate understanding of LAA morphology and the interchangeability of results from differing imaging modalities. The purpose of this study is to assess LAA morphology and location in AF patients, directly comparing transesophageal echocardiography (TEE), planar cardiac computed tomography (CT), and three-dimensional segmented CT reconstructions.

Methods: Fifty-three patients underwent adequate TEE and cardiac CT. Quantitative measurements of maximal LAA orifice diameters, widths, and depths were obtained from each imaging modality. Left atrial and LAA volumes were measured using segmented CT.

Results: The mean LAA orifice diameter for segmented CT, planar CT, and TEE was 28.5 +/- 4.5, 26.3 +/- 4.1, and 26.1 +/- 6.4 mm, respectively.

Conclusions: LAA orifice measurements among these imaging modalities are not interchangeable. This difference may be clinically significant because of the need for accurate sizing of LAA occlusion devices. Use of preprocedural segmented CT may improve initial device sizing.