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
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.
In: Chaos, Solitons & Fractals, Vol. 5, No. 3-4, 1995, p. 491-512.Research output: Contribution to journal › Article
}
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 -