Catheter ablation has become an integral part of the management of atrial fibrillation (AF). Based on the phenomenological observation of ectopic beats arising from the pulmonary veins (PV) as the initiation mechanism of AF and subsequent evidence of efficacy from randomized clinical trials, 1,2 PV isolation (PVI) has been the undisputed procedural technique for more than 2 decades for paroxysmal AF ablation. Although not uniformly effective, its shortcomings have been attributed to the technical limitations of catheter techniques and technologies in achieving complete and durable PVI-technical failures, rather than mechanistic paradigm failures.The validity of PVI as a mechanistic paradigm is debatable for persistent AF because the more logical therapeutic target would be the substrate that sustains AF beyond its initiation, rather than AF's initiating triggers. The inferior results of PVI in persistent AF compared with paroxysmal AF are consistent with this contention. Thus, multiple strategies have been attempted to improve ablation results in persistent AF using approaches that add additional interventions to standard PVI (beyond-PVI). Under the (unsubstantiated) assumption that fractionation and complexity of local electrical signals conveys mechanistic relevance, ablation of complex potentials has been proposed. Additionally, with the goal of eliminating macroreentrant circuits around the left atrial roof and mitral annulus, lin-