Re-evaluating the multiple wavelet hypothesis for atrial fibrillation

Prasanth Ganesan, Sanjiv M Narayan

Abstract: There continues to be great interest in better defining mechanisms of atrial fibrillation (AF) to improve therapy and guide ablation beyond pulmonary vein isolation. The multiple wavelet hypothesis (MWH), proposed by Moe et al1 from canine and computer experiments and further elaborated by Allessie et al,2 proposes that disordered AF can self-perpetuate by 3–6 wavelets, which spatially meander within available atrial tissue.2,3 The MWH is an elegant hypothesis that is widely known, provides a solid foundation to describe disorganized activity in AF, and may explain observations such as why AF is more difficult to treat in patients with larger atria (ie, because there is more atrial space for wavelets to meander, AF is less amenable to treatment). Conversely, it is not clear that disorganization in AF is always self-sustaining rather than downstream from other mechanisms. Moreover, the MWH may not explain consistent gradients in frequency4 or electrogram patterns5 in AF that have been reported in patients, and it does not explain the success of pulmonary vein isolation or other ablation procedures. The Moe hypothesis arose from studies that, although classic, may have been limited by the mapping techniques available at that time.