| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH |
|
|
|
|||||||
|
|||||||||
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
1 Cardiovascular Research Laboratory, University of California, Los Angeles, Los Angeles, CA, USA; Departments of Medicine (Cardiology), University of California, Los Angeles, CA, USA
2 Division of Cardiology, Cedars-Sinai Research Institute, Los Angeles, CA, USA
3 Cardiovascular Research Laboratory, University of California, Los Angeles, Los Angeles, CA, USA; Departments of Medicine (Cardiology), University of California, Los Angeles, CA, USA; Department of Physiological Science, University of California, Los Angeles, CA, USA
4 Cardiovascular Research Laboratory, University of California, Los Angeles, Los Angeles, CA, USA; Departments of Medicine (Cardiology), University of California, Los Angeles, CA, USA; Department of Physiology, University of California, Los Angeles, CA, USA
* To whom correspondence should be addressed. E-mail: zqu{at}mednet.ucla.edu.
The role of dynamical instabilities in the initiation of reentry in diseased (remodeled) hearts remains poorly explored. Using computer simulations, we studied the effects of altered Na+ channel and cell coupling properties on the vulnerable window (VW) for reentry in simulated 2D cardiac tissue with and without dynamical instabilities. We related the VW for reentry to effects on conduction velocity, action potential duration (APD) and effective refractory period dispersion and restitution, and concordant and discordant APD alternans. We found that: 1) reduced INa density and slowed recovery promoted postrepolarization refractoriness and enhanced concordant and discordant APD alternans, which increased the VW for reentry; 2) uniformly reduced cell coupling had little effect on cellular electrophysiological properties and the VW for reentry. However, randomly reduced cell coupling combined with decoupling promoted APD dispersion and alternans, which also increased the VW for reentry; 3) The combination of decreased Na+ channel conductance, slowed Na+ channel recovery and cellular uncoupling synergistically increased the VW for reentry; 4) the VW for reentry was greater when APD restitution slope was steep than when it was flat. In summary, altered Na+ channel and cellular coupling properties increase vulnerability to reentrant arrhythmias. In remodeled hearts with altered Na+ channel properties and cellular uncoupling, dynamical instabilities arising from electrical restitution exert important influences on the VW for reentry.
This article has been cited by other articles:
|
|
 |
|
  K. S. Dujardin, B. Dumotier, M. David, M. Guizy, C. Valenzuela, and L. M. Hondeghem Ultrafast sodium channel block by dietary fish oil prevents dofetilide-induced ventricular arrhythmias in rabbit hearts Am J Physiol Heart Circ Physiol, October 1, 2008; 295(4): H1414 - H1421. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
C. de Diego, R. K. Pai, A. S. Dave, A. Lynch, M. Thu, F. Chen, L.-H. Xie, J. N. Weiss, and M. Valderrabano Spatially discordant alternans in cardiomyocyte monolayers Am J Physiol Heart Circ Physiol, March 1, 2008; 294(3): H1417 - H1425. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. L. Kjolbye, M. Dikshteyn, B. C. Eloff, I. Deschenes, and D. S. Rosenbaum Maintenance of intercellular coupling by the antiarrhythmic peptide rotigaptide suppresses arrhythmogenic discordant alternans Am J Physiol Heart Circ Physiol, January 1, 2008; 294(1): H41 - H49. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 K. Tanaka, S. Zlochiver, Karen. L. Vikstrom, M. Yamazaki, J. Moreno, M. Klos, Alexey. V. Zaitsev, R. Vaidyanathan, D. S. Auerbach, S. Landas, et al. Spatial Distribution of Fibrosis Governs Fibrillation Wave Dynamics in the Posterior Left Atrium During Heart Failure Circ. Res., October 12, 2007; 101(8): 839 - 847. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
V. Gudzenko, Y. Shiferaw, N. Savalli, R. Vyas, J. N. Weiss, and R. Olcese Influence of channel subunit composition on L-type Ca2+ current kinetics and cardiac wave stability Am J Physiol Heart Circ Physiol, September 1, 2007; 293(3): H1805 - H1815. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. A. Kondratyev, J. G. C. Ponard, A. Munteanu, S. Rohr, and J. P. Kucera Dynamic changes of cardiac conduction during rapid pacing Am J Physiol Heart Circ Physiol, April 1, 2007; 292(4): H1796 - H1811. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
N. Ono, H. Hayashi, A. Kawase, S.-F. Lin, H. Li, J. N. Weiss, P.-S. Chen, and H. S. Karagueuzian Spontaneous atrial fibrillation initiated by triggered activity near the pulmonary veins in aged rats subjected to glycolytic inhibition Am J Physiol Heart Circ Physiol, January 1, 2007; 292(1): H639 - H648. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 Z. Qu, A. Garfinkel, and J. N. Weiss Vulnerable Window for Conduction Block in a One-Dimensional Cable of Cardiac Cells, 1: Single Extrasystoles Biophys. J., August 1, 2006; 91(3): 793 - 804. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
Z. Qu and J. N. Weiss Effects of Na+ and K+ channel blockade on vulnerability to and termination of fibrillation in simulated normal cardiac tissue Am J Physiol Heart Circ Physiol, October 1, 2005; 289(4): H1692 - H1701. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. Miyauchi, Z. Qu, Y. Miyauchi, S.-M. Zhou, H. Pak, W. J. Mandel, M. C. Fishbein, P.-S. Chen, and H. S. Karagueuzian Chronic nicotine in hearts with healed ventricular myocardial infarction promotes atrial flutter that resembles typical human atrial flutter Am J Physiol Heart Circ Physiol, June 1, 2005; 288(6): H2878 - H2886. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
Z. Qu Dynamical effects of diffusive cell coupling on cardiac excitation and propagation: a simulation study Am J Physiol Heart Circ Physiol, December 1, 2004; 287(6): H2803 - H2812. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH |
| Visit Other APS Journals Online |
