The Role of Left Atrial Muscular Bundles in Catheter Ablation of Atrial Fibrillation

Shih Lin Chang, Ching Tai Tai, Yenn Jiang Lin, Wanwarang Wongcharoen, Li Wei Lo, Kun Tai Lee, Sheng Hsiung Chang, Ta Chuan Tuan, Yi Jen Chen, Ming Hsiung Hsieh, Hsuan Ming Tsao, Mei Han Wu, Ming Huei Sheu, Cheng Yen Chang, Shih Ann Chen

Research output: Contribution to journalArticlepeer-review

44 Citations (Scopus)


Objectives: We sought to investigate the imaging of the left atrial (LA) muscular bundle and the relationship between the bundle and inducibility of tachyarrhythmia after pulmonary vein isolation (PVI). Background: Noninducibility is used as a clinical end point of atrial substrate ablation after PVI. However, little is known about the role of the LA muscular bundles in tachyarrhythmia after PVI. Methods: Forty-three consecutive patients with paroxysmal atrial fibrillation who underwent catheter ablation were included. Bi-atrial isochronal mapping was performed with the NavX system (St. Jude Medical Inc., St. Paul, Minnesota) during sinus rhythm. After 4 PVI, inducible organized LA flutter with or without transforming to atrial fibrillation (AF) (LA flutter/AF) was ablated with additional lines at the roof and/or mitral isthmus. Results: The existence of bilateral muscular bundles was an independent predictor of LA flutter/AF after PVI (p = 0.02). Patients with LA flutter/AF after PVI had a greater index of the double potentials (5.4 ± 3.4% vs. 2.8 ± 1.8%, p = 0.006) and interpotential interval (33 ± 5 ms vs. 29 ± 4 ms, p = 0.02) than without LA flutter/AF. The muscular bundles were identified in 28% patients using 16-slice multidetector computed tomography, which were identical to the isochrone map. Patients with noninducible LA flutter/AF after PVI plus the additional linear ablation had a lower recurrence rate as compared with the patients without it (19% vs. 75%, p = 0.02). Conclusions: Left atrial muscular bundles may provide a conduction block line and barrier, which is important for the formation of LA flutter/AF after PVI. The noninducibility of LA flutter/AF achieved after additional linear ablation may contribute to a better outcome in RF ablation of paroxysmal atrial fibrillation.

Original languageEnglish
Pages (from-to)964-973
Number of pages10
JournalJournal of the American College of Cardiology
Issue number10
Publication statusPublished - Sept 4 2007

ASJC Scopus subject areas

  • Nursing(all)


Dive into the research topics of 'The Role of Left Atrial Muscular Bundles in Catheter Ablation of Atrial Fibrillation'. Together they form a unique fingerprint.

Cite this