College Park, MD (July 20, 2010) — Chaos models may someday help model cardiac arrhythmias — abnormal electrical rhythms of the heart, say researchers in the journal CHAOS, which is published by the American Institute of Physics. In recent years, medical research has drawn more attention to chaos in cardiac dynamics. Although chaos marks the disorder of a dynamical system, locating the origin of chaos and watching it develop might allow researchers to predict, and maybe even counteract, certain outcomes.
An important example is the chaotic behavior of ventricular fibrillation, a severely abnormal heart rhythm that is often life-threatening. One study found chaos in two and three dimensions in the breakup of spiral and scroll waves, thought to be precursors of cardiac fibrillation. Another study found that one type of heartbeat irregularity, a sudden response of the heart to rapid beating called “spatially discordant alternans,” leads to chaotic behavior and thus is a possible predictor of a fatal heart attack.
Mathematicians Shu Dai at Ohio State University and David Schaeffer at Duke University have built on this work to find another chaotic solution to an equation for alternans along a one-dimensional fiber of cardiac tissue with stimuli applied at one end. Assigning extreme parameter values to the model, the team was able to find chaotic behavior in space over time. The resulting chaos may have a unique origin, which has not yet been identified. — VC, En
The article, “Chaos for cardiac arrhythmias through a one-dimensional modulation equation for alternans” by Shu Dai and David G. Schaeffer was published online in the journal CHAOS on June 30, 2010. See: http://link.aip.org/link/CHAOEH/v20/i2/p023131/s1
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Image Caption: A space-time plot of the alternans along a cardiac fiber is a solution to the Echebarria-Karma equation.
Chaos is an interdisciplinary journal of non-linear science. The journal is published quarterly by the American Institute of Physics and is devoted to increasing the understanding of nonlinear phenomena and describing the manifestations in a manner comprehensible to researchers from a broad spectrum of disciplines. Special focus issues are published periodically each year and cover topics as diverse as the complex behavior of the human heart to chaotic fluid flow problems. See: http://chaos.aip.org/
The American Institute of Physics is a federation of 10 physical science societies representing more than 135,000 scientists, engineers, and educators and is one of the world’s largest publishers of scientific information in the physical sciences. Offering partnership solutions for scientific societies and for similar organizations in science and engineering, AIP is a leader in the field of electronic publishing of scholarly journals. AIP publishes 12 journals (some of which are the most highly cited in their respective fields), two magazines, including its flagship publication Physics Today; and the AIP Conference Proceedings series. Its online publishing platform Scitation hosts nearly two million articles from more than 185 scholarly journals and other publications of 28 learned society publishers.