A transient, dose-dependent cardiac depression was produced by defibrillator shocks in an isolated, working canine heart preparation perfused with oxygenated arterial blood from a support dog. Accompanying this depression was an efflux of potassium (K+ ), forced out of the myocardial cells by the passage of defibrillating current. The transient increase in extracellular K + concentration was recorded graphically in the venous outflow. It was found that 5-msec rectangular wave shocks, from three to ten times defibrillatory current threshold, released doserelated pulses of K+ . We conclude that because extracellular K + is a myocardial depressant, at least part of the myocardial depression after defibrillation is caused by the release of K+ from the myocardial cells.
defibrillation, myocardial damage, toxicity, ventricular fibrillation, waveform
Date of this Version
Niebauer, M J.; Geddes, L A.; and Babbs, Charles F., "Potassium Efflux from Myocardial Cells Induced by Defibrillator Shock" (1986). Weldon School of Biomedical Engineering Faculty Publications. Paper 97.
This is the author accepted manuscript of Niebauer M.J., Geddes L.A., Babbs C.F., Potassium efflux from myocardial cells induced by defibrillator shock, Medical Instrumentation 20, 135-137, 1986. Copyright Elsevier, it is made available here CC-BY-NC-ND, and the version of record is available through the publisher http://www.sciencedirect.com/.