### Abstract

Effects of cell-to-cell coupling conductance on dynamics of sinus node cells are examined. Cell models are biophysically detailed, and are based on the kinetic equations developed by Noble ct al. [Neuronal and Cellular Oscillators, edited by J. W. Jacklet. Marcel Deckker, New York (1989).] Resistively coupled cell pairs show five regimes of behavior as a function of coupling conductance: (1) independent oscillation for G(c) < 1 pS; (2) primarily quasiperiodic oscillation for 1 less than or equal to G(c) < 116 pS; (3) windows of periodic behavior which undergo period doubling bifurcation to chaos for 116 less than or equal to G(c) < 212 pS; (4) frequency entrainment for G(c) greater than or equal to 212 pS; (5) waveform entrainment for G(c) greater than or equal to 50 nS. Thus, only 4-5 gap junction channels are required for frequency entrainment. This is shown to also be the case for large networks of sinus cells modeled on the Connection Machine CM-5. A biophysically detailed two-dimensional network model of the cardiac atrium has also been implemented on the CM-5 supercomputer. The model is used to study effects of spatially localized inhibition of the Na-K pump. Na overloading produced by pump inhibition can induce spontaneous, propagating ectopic beats within the network. At a cell-to-cell coupling value yielding a realistic plane wave conduction velocity of 60 cms(-1) pump inhibition in small regions of the network containing as few as 1000 cells can induce propagating ectopic beats.

Original language | English |
---|---|

Pages (from-to) | 491-512 |

Number of pages | 22 |

Journal | Chaos, Solitons & Fractals |

Volume | 5 |

Issue number | 3-4 |

Publication status | Published - 1995 |

### Keywords

- MASSIVELY PARALLEL COMPUTER
- GAP JUNCTIONAL CHANNELS
- RAT-HEART
- CALCIUM-CONCENTRATION
- INTRACELLULAR SODIUM
- CONNECTION MACHINE
- STRANGE ATTRACTORS
- PURKINJE-FIBERS
- CELL NETWORKS
- FERRET HEARTS

### Cite this

*Chaos, Solitons & Fractals*,

*5*(3-4), 491-512.

**GENERATION AND PROPAGATION OF NORMAL AND ABNORMAL PACEMAKER ACTIVITY IN NETWORK MODELS OF CARDIAC SINUS NODE AND ATRIUM.** / WINSLOW, R L ; CAI, D M ; VARGHESE, A ; LAI, Y C ; Lai, Ying-Cheng.

Research output: Contribution to journal › Article

*Chaos, Solitons & Fractals*, vol. 5, no. 3-4, pp. 491-512.

}

TY - JOUR

T1 - GENERATION AND PROPAGATION OF NORMAL AND ABNORMAL PACEMAKER ACTIVITY IN NETWORK MODELS OF CARDIAC SINUS NODE AND ATRIUM

AU - WINSLOW, R L

AU - CAI, D M

AU - VARGHESE, A

AU - LAI, Y C

AU - Lai, Ying-Cheng

PY - 1995

Y1 - 1995

N2 - Effects of cell-to-cell coupling conductance on dynamics of sinus node cells are examined. Cell models are biophysically detailed, and are based on the kinetic equations developed by Noble ct al. [Neuronal and Cellular Oscillators, edited by J. W. Jacklet. Marcel Deckker, New York (1989).] Resistively coupled cell pairs show five regimes of behavior as a function of coupling conductance: (1) independent oscillation for G(c) < 1 pS; (2) primarily quasiperiodic oscillation for 1 less than or equal to G(c) < 116 pS; (3) windows of periodic behavior which undergo period doubling bifurcation to chaos for 116 less than or equal to G(c) < 212 pS; (4) frequency entrainment for G(c) greater than or equal to 212 pS; (5) waveform entrainment for G(c) greater than or equal to 50 nS. Thus, only 4-5 gap junction channels are required for frequency entrainment. This is shown to also be the case for large networks of sinus cells modeled on the Connection Machine CM-5. A biophysically detailed two-dimensional network model of the cardiac atrium has also been implemented on the CM-5 supercomputer. The model is used to study effects of spatially localized inhibition of the Na-K pump. Na overloading produced by pump inhibition can induce spontaneous, propagating ectopic beats within the network. At a cell-to-cell coupling value yielding a realistic plane wave conduction velocity of 60 cms(-1) pump inhibition in small regions of the network containing as few as 1000 cells can induce propagating ectopic beats.

AB - Effects of cell-to-cell coupling conductance on dynamics of sinus node cells are examined. Cell models are biophysically detailed, and are based on the kinetic equations developed by Noble ct al. [Neuronal and Cellular Oscillators, edited by J. W. Jacklet. Marcel Deckker, New York (1989).] Resistively coupled cell pairs show five regimes of behavior as a function of coupling conductance: (1) independent oscillation for G(c) < 1 pS; (2) primarily quasiperiodic oscillation for 1 less than or equal to G(c) < 116 pS; (3) windows of periodic behavior which undergo period doubling bifurcation to chaos for 116 less than or equal to G(c) < 212 pS; (4) frequency entrainment for G(c) greater than or equal to 212 pS; (5) waveform entrainment for G(c) greater than or equal to 50 nS. Thus, only 4-5 gap junction channels are required for frequency entrainment. This is shown to also be the case for large networks of sinus cells modeled on the Connection Machine CM-5. A biophysically detailed two-dimensional network model of the cardiac atrium has also been implemented on the CM-5 supercomputer. The model is used to study effects of spatially localized inhibition of the Na-K pump. Na overloading produced by pump inhibition can induce spontaneous, propagating ectopic beats within the network. At a cell-to-cell coupling value yielding a realistic plane wave conduction velocity of 60 cms(-1) pump inhibition in small regions of the network containing as few as 1000 cells can induce propagating ectopic beats.

KW - MASSIVELY PARALLEL COMPUTER

KW - GAP JUNCTIONAL CHANNELS

KW - RAT-HEART

KW - CALCIUM-CONCENTRATION

KW - INTRACELLULAR SODIUM

KW - CONNECTION MACHINE

KW - STRANGE ATTRACTORS

KW - PURKINJE-FIBERS

KW - CELL NETWORKS

KW - FERRET HEARTS

M3 - Article

VL - 5

SP - 491

EP - 512

JO - Chaos, Solitons & Fractals

JF - Chaos, Solitons & Fractals

SN - 0960-0779

IS - 3-4

ER -