The impact of catheter ablation on the dynamic function of the left atrium in patients with atrial fibrillation: Insights from four-dimensional computed tomographic images

Functional Evaluation of the LA by Dynamic CT. Introduction: Elucidating the functional properties and remodeling process of the entire left atrium (LA) is important not only for offering the mechanistic insight into atrial fibrillation (AF) but also for assessing the effectiveness of catheter ablation. Methods: We included 65 patients with paroxysmal AF and 29 controls. Baseline multidetector computed tomography (MDCT) was acquired in all subjects and a follow-up MDCT was available in 48 patients after pulmonary vein and LA ablation. The 3-dimensional images at atrial end-diastole (ED) and end-systole (ES) were analyzed. Results: The LA volume (ED: 61.11 ± 15.94 vs 54.12 ± 8.94 mL/m², P = 0.03; ES: 45.29 ± 17.64 vs 33.38 ± 7.78 mL/m², P < 0.001) was increased, and ejection fraction (EF) (26.93 ± 13.40 vs 38.09 ± 11.62%, P < 0.001) decreased in AF patients as compared to controls. After ablation, the ES LA volume (44.73 ± 14.93 vs 38.04 ± 11.51 mL/m², P = 0.04) decreased and the LA EF (25.04 ± 13.13 vs 30.82 ± 7.85%, P = 0.03) increased in patients without any AF recurrence. The wall motion (WM) analysis of the 18 segments of LA revealed increased motional magnitudes of entire LA except for the anterior roof. In contrast, the volume, EF, and WM of LA remained similar in patients with recurrence. Conclusion: Dilated LA with global hypokinesia was noted in AF patients. Improved LA transport function was demonstrated in patients without any recurrence after ablation. However, the anatomic and functional reverse remodeling was not significant in patients with AF recurrence.