Repolarization alternans and ventricular arrhythmia in a repaired tetralogy of Fallot animal model

Shuenn Nan Chiu, Chia Ti Tsai, Lian Yu Lin, Shu Chien Huang, Yih Sharng Chen, Jou Kou Wang, Mei Hwan Wu, Ling Ping Lai, Jiunn Lee Lin

研究成果: 雜誌貢獻文章

7 引文 斯高帕斯(Scopus)

摘要

Background-Ventricular arrhythmia is an important cause of late death in patients with repaired tetralogy of Fallot (rTOF). By using an rTOF canine model, we investigated the role of repolarization alternans and its electrophysiological mechanisms. Methods and Results-Six dogs received right ventricular outflow tract (RVOT) transannular patch, pulmonary valve destruction, and right bundle branch ablation to simulate rTOF. After 1 year, we performed high-resolution dual-voltage and calcium optical mapping to record action potentials and calcium transients on the excised right ventricular outflow tract wedges. Another 6 dogs without operation served as control. The rTOF group was more susceptible to action potential duration alternans (APD-ALT) and spatially discordant APD-ALT than control (threshold for APD-ALT: 516±36 vs 343±36 ms; P=0.017; threshold for discordant APD-ALT: 387±30 vs 310±14 ms; P=0.046). We detected 2 episodes of ventricular tachycardia in the rTOF group, but none in the control. Expressions of Kv4.3 and KChIP2 decreased in the rTOF group. Expression of connexin 43 also decreased in the rTOF group with a corresponding decrease of conduction velocity and might contribute to spatially discordant APD-ALT. We also found distinct electrophysiological features of the RVOT, including biphasic relationship between magnitude of APD-ALT and pacing cycle length, uncoupling of APD-ALT, and calcium transients alternans, and shortened APD, but unchanged, APD restitution in rTOF. Conclusions-We demonstrated novel electrophysiological properties of the RVOT. In an rTOF model, the RVOT exhibits increased susceptibility to temporal and spatially discordant APD-ALT, which was not totally dependent on calcium transient alternans.
原文英語
文章編號e002173
期刊Journal of the American Heart Association
4
發行號12
DOIs
出版狀態已發佈 - 十二月 1 2015
對外發佈Yes

Keywords

  • Action potentials
  • Connexin 43
  • Ion channels
  • Tachyarrhythmias
  • Tetralogy of Fallot

ASJC Scopus subject areas

  • Cardiology and Cardiovascular Medicine

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  • 引用此

    Chiu, S. N., Tsai, C. T., Lin, L. Y., Huang, S. C., Chen, Y. S., Wang, J. K., Wu, M. H., Lai, L. P., & Lin, J. L. (2015). Repolarization alternans and ventricular arrhythmia in a repaired tetralogy of Fallot animal model. Journal of the American Heart Association, 4(12), [e002173]. https://doi.org/10.1161/JAHA.115.002173