ON THE GENESIS OF THE INJURY POTENTIALS

摘要

Our previous studies suggested that a bipolar lead with one of the electrodes in the injured region showed the potential variation corresponding to the membrane potential of the tissue under the other electrode. The present study is undertaken to confirm previous results and to obtain more comprehensive view on the relation of intra- and extracellular potentials with the existence of tissue injury by means of simulation studies on two-dimensional myocardial tissue immersed in a conducting solution. Membrane activities were reproduced by Luo-Rudy model and intra- and extra cellular potentials were calculated with use of bidomain. A limited region of injury was simulated by a loss of membrane potential due to high extracellular K concentration. Unipolar and bipolar ECGs were constructed with electrodes located at injured and intact regions. Effects of changes of the extracellular resistivity in the cable equation on the injury potentials were examined. The distance between electrodes of the bipolar lead was examined to relate the electrogram with local membrane potentials. The results confirmed that the monophasic curves were derived from the membrane potential at the electrode of uninjured side. Display was attempted including potentials of different sites relative to the injured region.