Trigger Versus Substrate Ablation for Atrial Fibrillation.

Elimination of triggers has become the hallmark of catheter ablation of atrial fibrillation (AF). In particular, much attention has been paid to the elimination of triggering impulses from the pulmonary veins via pulmonary vein ablation procedures. While this approach has a proven track record for paroxysmal AF, the efficacy in non-paroxysmal AF has been less convincing. Thus, attention has been paid to elimination of the substrate responsible for AF perpetuation, including complex fractionated electrograms, dominant frequency sites, and autonomic ganglionated plexi. None of these targets has yet become mainstream, but they are all under active investigation. As our knowledge of these targets increases and clinical studies are performed, a more refined approach to AF ablation will surely emerge.