AF Termination: the Holy Grail of Persistent AF Ablation?

The optimal catheter ablation approach for longstanding persistent atrial fibrillation (AF) remains elusive despite significant advances made in our understanding of this arrhythmia. A recent systematic review highlighted the significant variation in procedural success rate both within and between techniques, necessitating repeat ablation procedures and anti-arrhythmic drugs to achieve improved outcomes in those with long-standing persistent AF.1 Indeed, current expert consensus statement recommended ablation beyond ostial pulmonary vein isolation for these patients.2 Despite incorporating various substrate modification techniques which commonly include linear lesions and targeting of complex fractionated electrograms, the reported success rates from various laboratories are still below par to those in paroxysmal AF patients.1 Perhaps the often dilated and chronically remodeled atria in longstanding persistent AF patients harbor complex structural substrates capable of maintaining the arrhythmia beyond amelioration even with extensive catheter ablation in some. Certainly, this reflects our incomplete understanding of the complex mechanisms underlying this arrhythmia.