Morphologic Assessment of the Left Atrial Appendage in Patients with Atrial Fibrillation by Gray Values-Inverted Volume-Rendered Imaging of Three-Dimensional Transesophageal Echocardiography: A Comparative Study with Computed Tomography.

BACKGROUND: Accurate assessment of left atrial appendage (LAA) morphology is crucial in determining an LAA occlusion strategy. The aim of this study was to develop a novel echocardiographic volume-rendered imaging technique to visualize LAA morphology.

METHODS: This was a retrospective study. Forty patients with atrial fibrillation who underwent three-dimensional (3D) transesophageal echocardiography (TEE) and cardiac computed tomographic angiography (CCTA) before catheter ablation were enrolled. Full-volume 3D data were acquired and displayed in gray values-inverted (GVI) mode. Threshold segmentation and interactive segmentation were used to create 3D digital replicas of the LAA chambers. The morphologic classification, number of lobes, and dimensions of the LAA were analyzed and compared with the data obtained with CCTA.

RESULTS: LAA morphology and measurements were successfully acquired via CCTA and 3D GVI TEE in all 40 cases. In terms of LAA morphologic classifications, 19 cases of chicken wing, eight of windsock, nine of cauliflower, and four of cactus morphology were determined using 3D GVI TEE, and 20 cases of chicken wing, eight of windsock, eight of cauliflower, and four of cactus morphology were determined using CCTA. The κ value between these two methods was 0.963. Measurements of maximal diameter, minimal diameter, and area of the ostia and the depth of the LAAs were larger when based on the 3D GVI transesophageal echocardiographic data than when using cardiac computed tomographic angiographic data (P < .01); however, there was agreement between the results. Formed thrombi were well displayed by both computed tomography and 3DGVI TEE.

CONCLUSIONS: Three-dimensional GVI TEE can be used to acquire LAA morphologic volume-rendered images that are similar to computed tomographic volume-rendered images, and it shows promise as a feasible and valuable modality for planning individual LAA occlusion procedures.