Journal of Arrhythmia (Oct 2013)

Unidirectional block on the mitral isthmus during radiofrequency application for perimitral atrial tachycardia

  • Seigo Yamashita, MD,
  • Teiichi Yamane, MD,
  • Seiichiro Matsuo, MD,
  • Keiichi Ito, MD,
  • Ryohsuke Narui, MD,
  • Mika Hioki, MD,
  • Shin-ichi Tanigawa, MD,
  • Michifumi Tokuda, MD,
  • Keiichi Inada, MD,
  • Taro Date, MD,
  • Ken-ichi Sugimoto, MD,
  • Michihiro Yoshimura, MD

DOI
https://doi.org/10.1016/j.joa.2012.12.006
Journal volume & issue
Vol. 29, no. 5
pp. 270 – 274

Abstract

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We present the case of a patient who developed regular, narrow QRS tachycardia after ablation for long-standing persistent atrial fibrillation. During the electrophysiological study, this tachycardia was diagnosed as macroreentrant atrial tachycardia circulating around the mitral annulus. Catheter ablation was performed to treat the tachycardia by targeting the linear region between the annulus and the left inferior pulmonary vein. Although linear radiofrequency application along the mitral isthmus (MI) line resulted in the termination of this tachycardia, a unidirectional conduction block was observed through the MI. Bidirectional conduction block was subsequently achieved by delivering supplemental radiofrequency energies at the gap on the MI.

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