RESUMEN
BACKGROUND: A recent study reported the close relationship between high dominant frequent (DF) sites [atrial fibrillation (AF) nest] and the intrinsic cardiac autonomic nervous system. The aim of this study was to investigate the correlation between the regional distribution of epicardial fat and the properties of the biatrial substrates in AF patients. METHODS: We studied 32 patients with paroxysmal (n = 23) and persistent (n = 9) AF. The epicardial fat volume around the left atrium (LA) was evaluated using 64-slice multidetector computed tomography and the topographic distribution of the fat volume was assessed. The biatrial DFs, voltages, and total activation times (TATs) were obtained during sinus rhythm. RESULTS: Out of the 8 divided LA regions, a significant linear correlation existed between the LA fat and mean DF values in the right upper anterior LA, left upper anterior LA, right lower anterior LA, right upper posterior LA, left upper posterior LA, and left lower posterior LA. There was no significant correlation between the regional LA fat distribution and regional LA peak-to-peak bipolar voltage and TAT. During a mean follow-up of 17 ± 8 months, 22 of the 32 (69%) patients were free of AF. In the multivariate analysis, only the mean LA DF was found to be a significant predictor of recurrence. CONCLUSIONS: There was a close association between the regional distribution of the LA epicardial fat and the atrial substrate manifesting high frequency during sinus rhythm (AF nest). Those nests were related to ablation outcome. Hence, epicardial fat may play a significant role in atrial substrate remodeling and thereby in the pathogenesis and maintenance of AF. KEY WORDS: Atrial fibrillation ⢠Dominant frequency ⢠Epicardial fat ⢠Nest ⢠Recurrence.
RESUMEN
BACKGROUND: The recurrence of atrial fibrillation (AF) is not uncommon in the era of catheter ablation. This study aimed to evaluate the characteristics of AF patients who underwent multiple (>2) ablation procedures. METHODS AND RESULTS: Of 666 consecutive patients (53 ± 11 y/o, 484 men) who underwent catheter ablation of AF (paroxysmal AF, n = 530), 144 (22%) underwent 2 procedures and 52 (8%) underwent more than 2 procedures due to symptomatic recurrences refractory to medication during 48 ± 23 months of follow-up. Baseline and procedural characteristics at the index procedure were investigated to determine their impact on the necessity of multiple procedures. After 2 procedures, 48 (92%) of 52 patients had pulmonary vein (PV) ectopic beats initiating AF. Coexisting PV and non-PV triggers were found in 23 of 48 patients. In a multivariate analysis, the presence of non-PV triggers (P = 0.004; odds ratio 2.69, 95% CI 1.37-5.28) at the index procedure was the only independent predictor of necessary multiple procedures. Among patients with non-PV ectopic beats initiating AF at the index procedure, the presence of ligament of Marshall triggers (P = 0.001, odds ratio 6.74, 95% CI 2.13-21.32) could predict the necessity of multiple procedures. CONCLUSIONS: The need for multiple catheter ablation procedures can be predicted by the presence of non-PV ectopic beats initiating AF at the index procedure. However, PV-initiated AF remains the major cause of AF recurrence despite multiple catheter ablation procedures.