Effects of coupling heterogeneity on fractionated electrograms in a model of nonuniformly anisotropic ventricular myocardium.
To further understand the relation between heterogeneously infarcted myocardium and fractionated electrograms, a computer model was used to test the hypothesis that the way electrogram metrics change with electrode location relates to statistical properties of the underlying myocardium. A sheet of Beeler-Reuter elements was coupled with cytoplasmic resistance to form cells. Junctional resistance values were assigned using a recursive randomization to produce a fractal pattern, simulating damage from disrupted blood supply. The pattern's correlation dimension, D, was a statistical measure of heterogeneity. Unipolar electrogram's amplitude, duration, number of inflections, peak frequency, bandwidth, and the rate of change of metrics with height were calculated. Analysis of variance indicated (P < .0001) that peak-to-peak amplitude and bandwidth decreased at a slower rate when height was increased above heterogeneous tissue as compared with homogeneous tissue. These findings could be useful during clinical mapping procedures as statistical estimates of tissue structure.
Ellis
W S
WS
Bioengineering Graduate Group, University of California, San Francisco, CA 94143-1354.
Auslander
D M
DM
Lesh
M D
MD
D016880:Anisotropy; D003198:Computer Simulation; D004562:Electrocardiography / Q000379:methods; D017709:Fractals; D016276:Ventricular Function