Abstract 11476: Left Atrial Mechanical and Substrate Abnormalities Assessed by Three-Dimensional Speckle-Tracking Echocardiography and Electroanatomical Mapping System in Patients With Paroxysmal Atrial Fibrillation
Purpose: Slowing of local conduction in the low-voltage zone (LVZ) of the left atrium (LA) has been reported in patients with atrial fibrillation. The purpose of this study was to clarify the relationship between LA mechanical dysfunction and LVZ using three-dimensional (3D) speckle-tracking strain echocardiography and the electroanatomical mapping (CARTO®) system in patients with paroxysmal atrial fibrillation (PAF).
METHODS: A total of 33 patients (28 males; age 61 ± 12 years) with PAF undergoing pulmonary vein antrum isolation (PVAI) were examined. LA global peak area strain (LA-GPS) and standard deviation of the time to peak strain in each LA segment (SD-TPS) were measured using 3D speckle-tracking strain echocardiography before PVAI.
Contact bipolar voltage maps of the LA were constructed during sinus rhythm before PVAI using CARTO®. LVZ was determined with a local bipolar electrogram amplitude of <0.5 mV. The patients were divided into one group with LVZ (LVZ group) and the other without LVZ (NLVZ group).
RESULTS: LVZ was detected in 11 (33.3%) patients. Using 3D speckle-tracking analysis, LA-GPS was significantly lower (42.0 ± 17.5 vs. 57.1 ± 20.1, p < 0.047) and SD-TPS was significantly higher (120.1 ± 50.2 vs. 76.4 ± 56.0, p < 0.034) in the LVZ group than in the NLVZ group. LA volume index was similar in both groups and no relationship was noted with any 3D parameters.
CONCLUSION: LA LVZ is not related to LA size but to LA mechanical function. We propose the hypothesis for AF pathogenesis that LA regional remodeling and heterogeneity may lead to LA mechanical deformation and vulnerability to AF.
- © 2013 by American Heart Association, Inc.