This Article Figures Only Full Text Full Text (PDF) All Versions of this Article: j.jacc.2007.05.026v1 50/10/964    most recent Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Chang, S.-L. Articles by Chen, S.-A. Search for Related Content PubMed Articles by Chang, S.-L. Articles by Chen, S.-A.

CLINICAL RESEARCH: HEART RHYTHM DISORDERS

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

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

^_* Division of Cardiology and Cardiovascular Research Center
Radiology, National Yang-Ming University, School of Medicine, Taipei, Taiwan
Taipei Veterans General Hospital, Division of Cardiovascular Medicine, Division of Cardiovascular Medicine, Suao Veterans Hospital, Taipei Medical University, Taipei, Taiwan
Wan-Fang Hospital, Taipei, Taiwan
^¶ Division of Cardiovascular Medicine, I-Lan Hospital, Taipei, Taiwan

Manuscript received February 16, 2007; revised manuscript received May 21, 2007, ^_* Reprint requests and correspondence: Dr. Shih-Ann Chen, Division of Cardiology, Veterans General Hospital-Taipei, 201 Sec. 2, Shih-Pai Road, Taipei, Taiwan. (Email: epsachen{at}ms41.hinet.net).

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.

Abbreviations and Acronyms   CS = coronary sinus   CT = crista terminalis   DP = double potential   LA = left atrial   MDCT = multidetector computed tomography   PV = pulmonary vein   PVI = pulmonary vein isolation   RF = radiofrequency

This article has been cited by other articles:

				M. Klos, D. Calvo, M. Yamazaki, S. Zlochiver, S. Mironov, J.-A. Cabrera, D. Sanchez-Quintana, J. Jalife, O. Berenfeld, and J. Kalifa Atrial Septopulmonary Bundle of the Posterior Left Atrium Provides a Substrate for Atrial Fibrillation Initiation in a Model of Vagally Mediated Pulmonary Vein Tachycardia of the Structurally Normal Heart Circ Arrhythm Electrophysiol, August 1, 2008; 1(3): 175 - 183. [Abstract] [Full Text] [PDF]

				N.-W. Hsu, Y.-J. Lin, C.-T. Tai, T. Kao, S.-L. Chang, W. Wongcharoen, L.-W. Lo, A. R. Udyavar, Y.-F. Hu, H.-W. Tso, et al. Frequency analysis of the fibrillatory activity from surface ECG lead V1 and intracardiac recordings: implications for mapping of AF Europace, April 1, 2008; 10(4): 438 - 443. [Abstract] [Full Text] [PDF]