Box Isolation for Atrial Fibrillation

Abstract

Since the first report of catheter ablation curing atrial fibrillation (AF), numerous techniques have evolved, from linear ablation to segmental pulmonary vein (PV) isolation, extensive encircling PV isolation, LA linear ablation, ablation of complex fragmented atrial electrograms (CFAE) and stepwise ablation. We developed a new approach for complete isolation of the posterior LA including all PVs, namely box isolation. In the posterior LA, there are many arrhythmogenic substrates for AF, including the triggers, reentries and ganglionated plexi. Box isolation can contain these abnormal substrates in the posterior LA. Box isolation is associated with a high clinical success rate in paroxysmal AF. However, in persistent AF or longstanding persistent AF, only box isolation may not be sufficient, therefore, additional ablation at sites with CFAE outside the box area is needed to improve the clinical outcome. A hybrid approach of combining box isolation with CFAE ablation is highly effective in the majority of patients with persistent AF or longstanding persistent AF. Thus, AF ablation is an effective and safe treatment for AF that offers an excellent chance for a lasting cure. (J Arrhythmia 2011; 27: 255-267)

Pulmonary vein isolation plus left atrial posterior wall isolation and additional nonpulmonary vein trigger ablation using high‐dose isoproterenol for long‐standing persistent atrial fibrillation

“…12 As an explanation for these results, several studies have suggested that the LAPW plays an important role in initiating and maintaining AF. [13][14][15][16] However, there is little evidence regarding which LSPAF patients achieve sufficiently good outcomes from PVI plus PWI alone. Therefore, the endpoint of catheter ablation of LSPAF patients has never been determined.…”

Effects of additional ablation of low‐voltage areas after Box isolation for persistent atrial fibrillation

“…Therefore, we developed an approach for a complete isolation of the posterior LA including all PVs, namely the Box isolation (BOXI). 10,11 Furthermore, an individualized approach for AF ablation based on low-voltage areas (LVAs), which are correlated with atrial fibrosis, has been provided. [12][13][14][15][16] Previous studies reported that LVA ablation after PVI improved the success rate in persistent AF patients with LVAs.…”

Catheter Ablation of Lone Atrial Fibrillation

“…There are three basic strategies for modification of AF substrate: LA defragmentation by ablation of the complex fragmented atrial electrograms (CFAE), linear ablation of LA and ganglionated plexi ablation [3,[21][22][23][24][25][26][27][28][29]. CFAE are the electrograms during AF which have short cycle length (<120ms) or which are fractionated into two or more components, or show continuous atrial electrical activation [50].…”