Targeting nonpulmonary vein triggers during atrial fibrillation ablation: is the game worth the candle?

Triggers for atrial fibrillation are found outside the pulmonary veins in 12-20% of cases. The role of addressing these triggers during catheter ablations has not been well defined. Therefore, the aim of this review is to summarize the effect of ablation of nonpulmonary vein triggers in addition to pulmonary vein isolation across the spectrum of atrial fibrillation in patients receiving catheter ablation.

In paroxysmal atrial fibrillation, an inducible nonpulmonary vein trigger is an independent predictor of recurrence. These triggers are inducible by adenosine and isoproterenol infusion. Nonpulmonary vein triggers cause a significant proportion of atrial fibrillation recurrence seen during repeat procedure and addressing them decreases such recurrence. Targeting inducible nonpulmonary vein triggers also decreases recurrence in persistent atrial fibrillation and was associated with a 25-30% relative reduction in arrhythmia recurrence compared with pulmonary vein isolation alone. In persistent atrial fibrillation, the addition of left atrial appendage isolation was associated with 55% reduction in arrhythmia recurrence. There was no benefit to the empirical ablation of the superior vena cava and the addition of extensive linear lines. There was insufficient evidence to assess the effects of empirical ablation of the coronary sinus, crista terminalis, left atrial posterior wall and the vein of Marshall on arrhythmia recurrence.

Evidence suggests that the presence of an inducible nonpulmonary vein trigger is a strong predictor of arrhythmia recurrence. Efforts to detect and ablate nonpulmonary vein triggers are warranted. Further studies are required to fully identify the role nonpulmonary vein trigger ablation.