Atrial fibrillation substrate: The “unknown species”— From lone atrial fibrillation to fibrotic atrial cardiomyopathy

Abstract

m s F c p u t r d v “ i a t Catheter ablation of atrial fibrillation (AF) is now a routine procedure with pulmonary vein (PV) isolation as the cornerstone. However, the consequences of ablation on the structural atrial remodeling process of the underlying chronic and progressive disease are widely unknown. In this issue of HeartRhythm, Teh et al describe a progresive atrial electroanatomic substrate remodeling despite sucessful ablation. In their study, 11 patients without apparent tructural heart disease undergoing catheter ablation of AF ere investigated at baseline and 6 months after successful blation. Detailed right atrial electroanatomic maps were contructed for extensive measurements of voltages, conduction imes, refractory periods, and complex signals. Most imporantly, at 10 13 months of follow-up, the AF group demontrated—compared with baseline and despite successful elimnation of AF—no reversal of remodeling but a further reduced ower voltage, either no improvement or further slowing of onduction, and further prolongation of regional refractoriness ut only a reversal of left atrial dilatation. The authors have clearly stated and discussed the limitations of their clinical study, including the small sample size, the inclusion of patients with both paroxysmal and persistent AF within this small sample size, and the missing left atrial measurements due to ethical considerations. Nevertheless, the data from their study provide important new clinical data that after successful ablation of AF, the remodeling process not only may reverse but may even progress.