Stepwise catheter ablation (step-CA) can terminate long-standing persistent atrial fibrillation (LS-pAF) within the left atrium (LA) or may require additional right atrial (RA) ablation. Intracardiac organization indices such as AF cycle length (AFCL) have been used to track the efficiency of step-CA, but predictive parameters of procedural success are lacking. In this study, we hypothesized that the oscillations of time intervals between consecutive AF wavefronts reflect the underlying AF dynamic. We report a new method for quantifying the temporal variability of atrial activation wavefronts (VAW). Our results suggest that the mean and variance of the oscillations around the mean AFCL computed before any ablation can identify patients whose LS-pAF will terminate within the left atrium. These findings are indicative of a higher baseline organization in AF terminated within the left atrium.