title: Conventional pulmonary vein isolation compared with the "box isolation" method: a randomized clinical trial.
abstract: OBJECTIVE
  Esophageal injury is a potential complication with radiofrequency ablation in the posterior wall of the left atrium (LA). The "box isolation" method isolates the posterior LA wall including the pulmonary veins without ablation on the posterior LA wall. This study compares the acute and long-term efficacy of the box isolation method with conventional circumferential pulmonary vein isolation (PVI) for catheter ablation of AF.
  
  
  METHODS
  Twenty-nine patients (age 60 ± 9 years, 62% male, 79% paroxysmal) with drug refractory AF underwent catheter ablation. Sixteen of the 29 patients (55%) underwent box isolation. Recurrence of AF was detected by checking the daily recorded rhythm strip on a portable home ECG monitor, irrespective of the symptoms. Mean follow-up duration was 10 ± 2 months.
  
  
  RESULTS
  Complete isolation of the posterior LA using box isolation lesions was achieved in three of 16 (19%) patients. The other 13 patients underwent creation of additional lesions until all PVs were isolated. Of the 16 patients who underwent box isolation, four patients (25%) had complete success, six patients (38%) had improvement, and the remaining six patients (37%) had failure. Of the 13 patients who underwent the standard PV isolation, two patients (15%) had complete success, eight patients (62%) had improvement, and the remaining three patients (23%) had failure (p = 0.44).
  
  
  CONCLUSIONS
  In this pilot study, the efficacy of box isolation is similar to the circumferential PVI for catheter ablation of AF. Few patients achieved PVI with box method alone. Based on these results, we do not recommend the box isolation strategy.
authors: Division of Cardiology, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
authors: Karuna
authors: K
authors: Chilukuri
authors: Daniel
authors: D
authors: Scherr
authors: Darshan
authors: D
authors: Dalal
authors: Alan
authors: A
authors: Cheng
authors: David
authors: D
authors: Spragg
authors: Saman
authors: S
authors: Nazarian
authors: Bernadette D
authors: BD
authors: Barcelon
authors: Joseph E
authors: JE
authors: Marine
authors: Hugh
authors: H
authors: Calkins
authors: Charles A
authors: CA
authors: Henrikson
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