Abstract
Atrial fibrillation (AF) is associated with progressive left atrial (LA) remodeling - electrical, structural, and mechanical - that perpetuates the arrhythmia in a self-reinforcing cycle classically described as “AF begets AF”. Successful catheter ablation may reverse this process, a phenomenon known as LA reverse remodeling. This prospective longitudinal study evaluated changes in left atrial (LA) morphology in 25 patients with atrial fibrillation undergoing pulmonary vein isolation with a second-generation 28-mm cryoballoon system. Multislice computed tomography (MSCT) was performed pre-procedure and at 6 months post-ablation to measure LA diameters along three orthogonal axes (antero-posterior, transverse, and supero-inferior). Mean age was 60.0 ± 12.7 years. At 6 months, the antero-posterior diameter decreased from 38.4 ± 6.3mm to 34.8 ± 7.5mm (p = 0.026) and the supero-inferior diameter decreased from 65.6 ± 8.8mm to 61.5 ± 8.5mm (p = 0.010), while the transverse diameter did not change significantly (57.8 ± 9.3mm to 56.1 ± 8.9mm; p = 0.476). Baseline LA size negatively correlated with the magnitude of shrinkage on both the antero-posterior (r = -0.44, p = 0.027) and supero-inferior axes (r = -0.45, p = 0.024). In conclusion, cryoballoon ablation was associated with statistically significant reverse remodeling of the left atrium along the antero-posterior and supero-inferior axes at 6 months, correlating with baseline LA size. MSCT serves as an objective, operator-independent tool for monitoring post-ablation LA morphological change.
