Cardiac beat-to-beat alternations driven by unusual spiral waves

Yun Kim Tae, Sung Jae Woo, Seong Min Hwang, Hee Hong Jin, Kyoung J. Lee

Research output: Contribution to journalArticlepeer-review

21 Citations (Scopus)


Alternans, a beat-to-beat temporal alternation in the sequence of heartbeats, is a known precursor of the development of cardiac fibrillation, leading to sudden cardiac death. The equally important precursor of cardiac arrhythmias is the rotating spiral wave of electro-mechanical activity, or reentry, on the heart tissue. Here, we show that these two seemingly different phenomena can have a remarkable relationship. In well controlled in vitro tissue cultures, isotropic populations of rat ventricular myocytes sustaining a temporal rhythm of alternans can support period-2 oscillatory reentries and vice versa. These reentries bear "line defects" across which the phase of local excitation slips rather abruptly by 2π, when a full period-2 cycle of alternans completes in 4π. In other words, the cells belonging to the line defects are period-1 oscillatory, whereas all of the others in the bulk medium are period-2 oscillatory. We also find that a slowly rotating line defect results in a quasi-periodic like oscillation in the bulk medium. Some key features of these phenomena can be well reproduced in computer simulations of a nonlinear reaction-diffusion model.

Original languageEnglish
Pages (from-to)11639-11642
Number of pages4
JournalProceedings of the National Academy of Sciences of the United States of America
Issue number28
Publication statusPublished - 2007 Jul 10


  • Cardiac reentry
  • Discordant alternans
  • Line defect
  • Nodal lines
  • Period-2 oscillation

ASJC Scopus subject areas

  • General


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