Author/Editor		Kotnik, Tadej; Sobie, Eric A; Tung, Leslie
Title		Possible mechanisms of the delayed shift of transmembrane voltage in cardiac cells during electric field stimulation
Translated title		Možni mehanizmi zakasnjenega premika transmembranske napetosti pri srčnih celicah med stimulacijo z električnim poljem
Type		članek
Source		In: Zajc B, editor. Zbornik 6. elektrotehniške in računalniške konference ERK'97. Zvezek B. Računalništvo in informatika, umetna inteligenca, robotika, razpoznavanje vzorcev - 3. letna konferenca SDRV, biomedicinska tehnika, močnostna elektrotehnika, didaktika, študentski članki; 1997 sep 25-27; Portorož. Ljubljana: Slovenska sekcija IEEE,
Publication year		1997
Volume		str. 371-4
Language		eng
Abstract		Based on the model of ionic channel activity in cardiac cells (Luo-Rudy model), we attempted to determine which ionic channels could cause the nonlinear relation between external electric field strenght and magnitude of induced transmembrane voltage during the action potential. The introduction gives a brief summary of experimental results that led to this theoretical study. Next, we set forth a hypothesis proposing that the induced voltage that is superimposed onto the action potential consists of two components - an immediate shift and a delayed shift. The immediate shift is induced by the electric field, while the delayed shift is due to the ionic currents through the voltage-dependent channels. Using the method of steady-state analysis, we obtained the voltage-current relations of separate Luo-Rudy channels. Based on this analysis, we conclude that either the relations of the model are incorrectly described outside the physiological range, or that there is another as yet undescribed mechanism that adds to the currents of the model outside this range. For the first case, slow time dependent K+ channels seem to be the most probable sources. In the conclusion, directions for the further studies are given.
Descriptors		MYOCARDIUM ACTION POTENTIALS ION CHANNELS ELECTRIC STIMULATION MEMBRANE POTENTIALS