Title :
Experimental results pertinent to the modelling of defibrillation
Author :
Ideker, Raymond E. ; Krassowska, Wanda ; Wharton, J. Marcus ; Smith, William M.
Author_Institution :
Duke Univ. Med. Center, Durham, NC, USA
Abstract :
Recent experimental results pertinent to the modeling of defibrillation are presented. The extracellular potential gradient created by a large electric stimulus predicts whether or not several different types of electrophysiologic response will occur for a given stimulus waveform. Stimulation of fully recovered myocardium occurs for a truncated exponential monophase waveform when the potential gradient is greater than 0.64 V/cm along myofibers or 1.84 V/cm across fibers. A potential gradient of approximately 6 V/cm is needed throughout for all or almost all of the ventricular myocardium to defibrillate. More than approximately 60 V/cm causes a temporary conduction block. Thus, defibrillation electrode configurations should create cardiac fields with the highest gradient no more than ten times the lowest gradient. Values for stimulation, defibrillation, and conduction block are probably different for other waveforms
Keywords :
bioelectric phenomena; cardiology; patient treatment; physiological models; conduction block; defibrillation electrode configuration; defibrillation modelling; extracellular potential gradient; large electric stimulus; truncated exponential monophase waveform; Biomedical engineering; Current density; Defibrillation; Electric shock; Electrodes; Extracellular; Heart; Myocardium; Optical fiber theory; Pathology;
Conference_Titel :
Engineering in Medicine and Biology Society, 1989. Images of the Twenty-First Century., Proceedings of the Annual International Conference of the IEEE Engineering in
Conference_Location :
Seattle, WA
DOI :
10.1109/IEMBS.1989.95579
