GP or no GP, is that the question?

t has long been recognized, on the basis of numerous experimental and clinical studies, that the autonomic nervous system has a significant role in the pathogenesis of atrial fibril-lation (AF). More recent studies have focused on the ganglion-ated plexi (GP), which are part of an interconnected structural and functional atrial neural network constituting the intrinsic cardiac autonomic nervous system. The procedure known presently as pulmonary vein isolation (PVI) has undergone substantial changes from ablation of ectopic firing within the pulmonary veins 4,5 to segmental ostial ablation 6 to circum-ferential PVI (CPVI). 7,8 Similarly, targeting the GP has also shown a progression of changes in this procedure. Initially, the GP were identified by high-frequency electric stimulation, which caused a marked slowing of the ventricular response during AF. Further studies found that efficacy of GP abla-tion could be enhanced by a combination of CPVI and GP ablation. Still others chose to ablate GP using an anatomic approach, which they found to be more effective than using high-frequency electric stimulation to identify and ablate GP and thereby terminate AF. More than a decade of catheter ablation for AF using the myo-cardial approach (CPVI) with additional linear lesions has resulted in outcomes ranging from 29% to 61%. 13–17 Follow-up periods have been as long as 6 years. Success rates have been consistently better in paroxysmal AF, particularly in those patients without structural heart disease and lowest in those with long-standing persistent AF, particularly in patients with comorbidities. In any event, the long-term success rates for catheter ablation for all forms of AF fall far short of those achieved with catheter ablation in patients with the Wolff– Parkinson–White syndrome, AV junctional re-entrant tachy-cardia, and atrial flutter. The general impression has formed that isolation of the pulmonary veins alone may not be sufficient to achieve optimal success. 18 Others have surmised that differences in outcomes are likely related to a more complex atrial substrate in patients with persistent AF and the fact that the mechanisms responsible for maintenance of persistent AF more often reside outside the pulmonary veins. 19 The same could be said for GP ablation with or without CPVI. A very recent randomized study for catheter ablation in patients with persistent/long-standing persistent AF 20 compared CPVI and additional linear lesions with GP ablation plus CPVI. Although the 3-year follow-up showed a superior result for a single procedure , in the latter group, the best …