|
|
||||||||
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
1 Medicine (Cardiology), David Geffen School of Medicine at UCLA, Los Angeles, California, United States; Physiology, UCLA, Los Angeles, California, United States; Physiological Sciences, UCLA, Los Angeles, California, United States
2 Physiological Sciences, UCLA, Los Angeles, California, United States
* To whom correspondence should be addressed. E-mail: abaher{at}ucla.edu.
Short-term cardiac memory refers to the effects of pacing history on action potential duration (APD). Although the ionic mechanisms for short-term memory occurring over many heartbeats (also called APD accommodation) are poorly understood, they may have important effects on reentry and fibrillation. To explore this issue, we incorporated a generic memory current into the Phase I Luo and Rudy (LR1) action potential model, which lacks short-term memory. The properties of this current were matched to simulate quantitatively human ventricular monophasic action potential accommodation. We show that, theoretically, short-term memory can resolve the paradox of how Mother Rotor fibrillation is initiated in heterogeneous tissue by physiological pacing. In simulated heterogeneous 2D tissue and 3D ventricles containing an IK1 gradient, short-term memory could spontaneously convert Multiple Wavelet fibrillation to Mother Rotor fibrillation, or to a mixture of both fibrillation types. This was due to progressive acceleration and stabilization of rotors as accumulation of memory shortened APD and flattened APDR slope non-uniformly throughout the tissue.
This article has been cited by other articles:
![]() |
S. Weinberg, S. Iravanian, and L. Tung Representation of Collective Electrical Behavior of Cardiac Cell Sheets Biophys. J., August 1, 2008; 95(3): 1138 - 1150. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. F. Huizar, M. D. Warren, A. G. Shvedko, J. Kalifa, J. Moreno, S. Mironov, J. Jalife, and A. V. Zaitsev Three distinct phases of VF during global ischemia in the isolated blood-perfused pig heart Am J Physiol Heart Circ Physiol, September 1, 2007; 293(3): H1617 - H1628. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH |
| Visit Other APS Journals Online |