Demonstration of Arrhythmia Substrate-Associated Dispersion of Repolarization by Epicardial Unipolar Mapping in Brugada Syndrome

Satoshi Nagase*, Naoya Kataoka, Hiroshi Morita, Tsukasa Kamakura, Akira Ueoka, Toshihiro Nakamura, Satoshi Oka, Yuichiro Miyazaki, Akinori Wakamiya, Kenzaburo Nakajima, Nobuhiko Ueda, Mitsuru Wada, Kohei Ishibashi, Yuko Inoue, Koji Miyamoto, Takeshi Aiba, Kengo Kusano

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

8 Scopus citations

Abstract

Background: Epicardial unipolar mapping has not been thoroughly investigated in Brugada syndrome (BrS). Objectives: This study aims to examine the characteristics of epicardial unipolar potentials in BrS and investigate the differences from overt cardiomyopathy. Methods: Epicardial mapping was performed in 8 patients with BrS and 6 patients with cardiomyopathy. We investigated the J-wave amplitudes using unipolar recordings at delayed potential (DP) sites via bipolar recordings. The repolarization time (RT) at and around the DP recording sites was measured, and maximum dispersion of the RT divided by the distance was defined as the RT dispersion index. Results: Epicardial mapping at baseline revealed significantly higher J-wave amplitude with bipolar DP in patients with BrS than in patients with cardiomyopathy. J-wave amplitude ≥0.42 mV had 99.1% sensitivity and 100% specificity for diagnosing BrS. The RT dispersion index was significantly higher in patients with BrS than in patients with cardiomyopathy at baseline. In all patients with BrS, coved-type unipolar electrograms without negative T waves (short RT) appeared close to coved-type electrograms with negative T waves (long RT) at the DP recording sites after pilsicainide administration. Thus, a steep RT dispersion was observed in this region, and ventricular arrhythmias emerged from this shorter RT area in all 3 patients with BrS in whom ventricular arrhythmias were induced. Conclusions: Bipolar DP-related prominent unipolar J waves and steep repolarization gradients may be more specific for characterizing BrS than for overt cardiomyopathy. Ventricular arrhythmias in BrS are associated with a steep repolarization gradient, indicating phase 2 re-entry as a possible cause.

Original languageEnglish
Pages (from-to)1576-1588
Number of pages13
JournalJACC: Clinical Electrophysiology
Volume10
Issue number7
DOIs
StatePublished - 2024/07

Keywords

  • Brugada syndrome
  • J-wave syndrome
  • early repolarization syndrome
  • phase 2 re-entry
  • repolarization
  • ventricular fibrillation

ASJC Scopus subject areas

  • Cardiology and Cardiovascular Medicine
  • Physiology (medical)

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