Abstract 16615: Left Atrial (LA) Wall Motion Velocity Distribution Evaluated by 5-Dimensional Computed Tomography (5D-CT) and Its Relationship With LA Wall Remodeling in Atrial Fibrillation
Background: Atrial remodeling provides a substrate for atrial fibrillation (AF) and has been shown to stratify prognosis. Wall stretch analysis of left atrium (LA) is considered a valuable method to evaluate LA function and remodeling. However, standard method of stretch analysis is not yet established. Velocity evaluation should be essential to analyze stretch function, and the recent development of 5D-CT imaging (a new voxel tracking technique) has allowed evaluation of wall motion velocity in addition to conventional parameters.
Objective: The aim of this study was to evaluate the regional wall motion velocity of LA by 5D-CT and to examine the association with LA remodeling in patients with AF.
Method: We studied 53 consecutive patients with AF who underwent cardiac CT for 3D electroanatomical mapping system. The CT images were analyzed to evaluate regional wall motion velocity quantitatively using the PhyZiodynamics software package (Ziosoft Inc., Japan). This software evaluates the voxel-to-voxel motion to estimate velocity using multi-phase data sets, and displays the results on a velocity map. Several voxels of interest (VOIs) were set in high- and low-velocity regions on the velocity map, and the regional wall motion velocities of LA were calculated automatically. LA volume was used as an index of LA remodeling.
Results: Velocity map revealed heterogeneous distribution and several peaks. High-velocity regions localized particularly in the right anterior wall (87.5%) and LA roof (60.0%). Average velocities in high-velocity regions and low-velocity were 20.8 ± 4.8 and 7.8 ± 1.8mm/sec, respectively (p < 0.01). A significant correlation between velocity in high-velocity region and LA volume (r = -0.43, p = 0.008) was observed.
Conclusion: Regional LA wall motion velocity was evaluated by 5D-CT with voxel tracking technique. Evaluation of wall velocity potentially provides important clinical information on LA function and remodeling of LA wall.
Author Disclosures: Y. Utanohara: None. N. Iguchi: None. K. Tanizaki: None. J. Umemura: None. T. Sumiyoshi: None. H. Tomoike: None.
- © 2014 by American Heart Association, Inc.