Extracellular measurement of anisotropic bidomain myocardial conductivities. I. Theoretical analysis

Citation
P. Le Guyader et al., Extracellular measurement of anisotropic bidomain myocardial conductivities. I. Theoretical analysis, ANN BIOMED, 29(10), 2001, pp. 862-877
Citations number
24
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Multidisciplinary
Journal title
ANNALS OF BIOMEDICAL ENGINEERING
ISSN journal
0090-6964 → ACNP
Volume
29
Issue
10
Year of publication
2001
Pages
862 - 877
Database
ISI
SICI code
0090-6964(200110)29:10<862:EMOABM>2.0.ZU;2-2
Abstract
The passive electrical properties of cardiac tissue, such as the intracellu lar and interstitial conductivities along the longitudinal and transverse a xes have not been often measured because intracellular electrodes are usual ly needed for these measurements. In this paper, we present a theoretical a nalysis of two myocardial models developed to estimate these properties by analyzing potentials recorded with a pair of extracellular electrodes while infecting alternating current between another pair of electrodes. First, t he cardiac tissue is represented by a standard bidomain model which include s a membrane capacitance; second, this model is modified by adding an intra cellular capacitance representing tile intercalated disks. Numerical soluti ons are computed with a fast Fourier transform algorithm without constraini ng the anisotropy ratios of the interstitial and intracellular domains. We systematically investigate the effects of changes in the bidomain parameter s on tile voltage-to-current ratio curves. We also demonstrate how the bido main parameters can be theoretically estimated by fitting, with a modified Shor's algorithm, the simulated potentials along the longitudinal and trans verse axes for different frequencies between 10 and 10 000 Hz. An important finding is that the interelectrode distance must be similar to the myocard ial space constant so as to obtain frequency dependent measurements. (C) 20 01 Biomedical Engineering Society.