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Effects of Electroporation on the Transmembrane Potential Distribution in a Two‐Dimensional Bidomain Model of Cardiac Tissue
Author(s) -
AGUEL FELIPE,
DEBRUTN KATHERINE A.,
KRASSOWSKA WANDA,
TRAYANOVA NATALIA A.
Publication year - 1999
Publication title -
journal of cardiovascular electrophysiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.193
H-Index - 138
eISSN - 1540-8167
pISSN - 1045-3873
DOI - 10.1111/j.1540-8167.1999.tb00247.x
Subject(s) - electroporation , bidomain model , transmembrane protein , biophysics , conductance , membrane potential , stimulation , membrane , defibrillation , electrode , medicine , physics , chemistry , condensed matter physics , biology , receptor , biochemistry , quantum mechanics , gene
Electroporation in a Two‐Dimensional Myocardium. Introduction : Defibrillation shocks, when delivered through internal electrodes, establish transmembrane potentials (V m ) large enough to electroporate the membrane of cardiac cells. The effects of such shocks on the transmembrane potential distribution are investigated in a two‐dimensional rectangular sheet of cardiac muscle modeled as a bidomain with unequal anisotropy ratios. Methods and Results : The membrane is represented by a capacitance C nv , a leakage conductance g v and a variable electroporation conductance G, whose rate of growth depends exponentially on the square of V m . The stimulating current I o , 0.05–20 A/m, is delivered through a pair of electrodes placed 2 cm apart for stimulation along fibers and 1 cm apart for stimulation across fibers. Computer simulations reveal three categories of response to I o : (1) Weak I o . below 0.2 A/m, cause essentially no electroporation, and V m : increases proportionally to I o . (2) Strong I o , between 0.2 and 2.5 A/m, electroporate tissue under the physical electrode. V m is no longer proportional to I o ; in the electroporated region, the growth of V m is halted and in the region of reversed polarity (virtual electrode), the growth of V m is accelerated. (3) Very strong I o , above 2.5 A/m, electroporate tissue under the physical and the virtual electrodes. The growth of V m in ail electroporated regions is halted, and a further increase of V o : increases both the extent of the electroporated regions and the electroporation conductance G. Conclusion : These results indicate that electroporation of the cardiac membrane plays an important role in the distribution of V m : induced by defibrillation strength shocks.