Abstract
Alternans, a condition in which there is a beat-to-beat alternation in the electromechanical response of a periodically stimulated cardiac cell, has been linked to the genesis of life-threatening ventricular arrhythmias. Optical mapping of membrane voltage (Vm) and intracellular calcium (Ca i) on the surface of animal hearts reveals complex spatial patterns of alternans. In particular, spatially discordant alternans has been observed in which regions with a large-small-large action potential duration (APD) alternate out-of-phase adjacent to regions of small-large-small APD. However, the underlying mechanisms that lead to the initiation of discordant alternans and govern its spatiotemporal properties are not well understood. Using mathematical modeling, we show that dynamic changes in the spatial distribution of discordant alternans can be used to pinpoint the underlying mechanisms. Optical mapping of Vm and Cai in paced rabbit hearts revealed that spatially discordant alternans induced by rapid pacing exhibits properties consistent with a purely dynamical mechanism as shown in theoretical studies. Our results support the viewpoint that spatially discordant alternans in the heart can be formed via a dynamical pattern formation process which does not require tissue heterogeneity.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 448-460 |
| Number of pages | 13 |
| Journal | Biophysical Journal |
| Volume | 92 |
| Issue number | 2 |
| DOIs | |
| State | Published - Jan 2007 |
| Externally published | Yes |
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ASJC Scopus subject areas
- Biophysics
Cite this
Dynamic origin of spatially discordant alternans in cardiac tissue. / Hayashi, Hideki; Shiferaw, Yohannes; Sato, Daisuke; Nihei, Motoki; Lin, Shien Fong; Chen, Peng Sheng; Garfinkel, Alan; Weiss, James N.; Qu, Zhilin.
In: Biophysical Journal, Vol. 92, No. 2, 01.2007, p. 448-460.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Dynamic origin of spatially discordant alternans in cardiac tissue
AU - Hayashi, Hideki
AU - Shiferaw, Yohannes
AU - Sato, Daisuke
AU - Nihei, Motoki
AU - Lin, Shien Fong
AU - Chen, Peng Sheng
AU - Garfinkel, Alan
AU - Weiss, James N.
AU - Qu, Zhilin
PY - 2007/1
Y1 - 2007/1
N2 - Alternans, a condition in which there is a beat-to-beat alternation in the electromechanical response of a periodically stimulated cardiac cell, has been linked to the genesis of life-threatening ventricular arrhythmias. Optical mapping of membrane voltage (Vm) and intracellular calcium (Ca i) on the surface of animal hearts reveals complex spatial patterns of alternans. In particular, spatially discordant alternans has been observed in which regions with a large-small-large action potential duration (APD) alternate out-of-phase adjacent to regions of small-large-small APD. However, the underlying mechanisms that lead to the initiation of discordant alternans and govern its spatiotemporal properties are not well understood. Using mathematical modeling, we show that dynamic changes in the spatial distribution of discordant alternans can be used to pinpoint the underlying mechanisms. Optical mapping of Vm and Cai in paced rabbit hearts revealed that spatially discordant alternans induced by rapid pacing exhibits properties consistent with a purely dynamical mechanism as shown in theoretical studies. Our results support the viewpoint that spatially discordant alternans in the heart can be formed via a dynamical pattern formation process which does not require tissue heterogeneity.
AB - Alternans, a condition in which there is a beat-to-beat alternation in the electromechanical response of a periodically stimulated cardiac cell, has been linked to the genesis of life-threatening ventricular arrhythmias. Optical mapping of membrane voltage (Vm) and intracellular calcium (Ca i) on the surface of animal hearts reveals complex spatial patterns of alternans. In particular, spatially discordant alternans has been observed in which regions with a large-small-large action potential duration (APD) alternate out-of-phase adjacent to regions of small-large-small APD. However, the underlying mechanisms that lead to the initiation of discordant alternans and govern its spatiotemporal properties are not well understood. Using mathematical modeling, we show that dynamic changes in the spatial distribution of discordant alternans can be used to pinpoint the underlying mechanisms. Optical mapping of Vm and Cai in paced rabbit hearts revealed that spatially discordant alternans induced by rapid pacing exhibits properties consistent with a purely dynamical mechanism as shown in theoretical studies. Our results support the viewpoint that spatially discordant alternans in the heart can be formed via a dynamical pattern formation process which does not require tissue heterogeneity.
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UR - http://www.scopus.com/inward/citedby.url?scp=33846446729&partnerID=8YFLogxK
U2 - 10.1529/biophysj.106.091009
DO - 10.1529/biophysj.106.091009
M3 - Article
C2 - 17071663
AN - SCOPUS:33846446729
VL - 92
SP - 448
EP - 460
JO - Biophysical Journal
JF - Biophysical Journal
SN - 0006-3495
IS - 2
ER -