Novel Approach to Ablation for Persistent AF

Pulmonary vein isolation (PVI) is effective for most patients with paroxysmal atrial fibrillation (AF). However, PVI is not enough for treatment of persistent and longstanding persistent AF. Further modification of atrial substrate maintaining AF seems necessary in those patients. To improve the clinical outcome in patients with persistent AF, extensive ablations have been adopted, including, ablation of complex fractionated atrial electrograms (CFAE), multiple linear lesions, posterior left atrial box isolation, ganglionated plexi ablation, rotor/driver ablation, and ablation of low-voltage areas (LVA). Recent randomized clinical trials, including STAR AF II etc., demonstrated that ablation of CFAE showed no benefit over PVI in patients with persistent AF. However, ablation of CFAE terminates AF in rare cases. There may be culprit and bystander CFAE. Although it is difficult to distinguish them, antiarrhythmic drugs use or modification of CFAE module may focus on culprit CFAE. Moreover, there is no correlation between CFAE areas during AF and LVA during sinus rhythm, and LVA during sinus rhythm do not always coincide with those during AF. Although CFAE and LVA may be associated with rotors or abnormal substrate, they are indirect indicators of drivers. Recent studies using the phase mapping systems revealed that rotors and multiple wavelets did not always correlate with CFAE and LVA. However, the data of rotor/driver ablation using novel phase mapping systems are limited. Thus, efficacy of ablation of CFAE, LVA and rotors is controversial. Therefore, we will discuss which approach is more effective, anatomical or electrophysiological target, for persistent AF beyond PVI.