Niebauer M J, Geddes L A, Babbs C F
Med Instrum. 1986 May-Jun;20(3):135-7.
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 dose-related pulses of K+. It is concluded that because 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.
在用来自供体犬的含氧动脉血灌注的离体、工作的犬心脏标本中，除颤器电击可产生短暂的、剂量依赖性心脏抑制。伴随这种抑制的是钾离子（K+）外流，除颤电流通过时将其从心肌细胞中挤出。细胞外K+浓度的短暂升高在静脉流出液中以图形方式记录下来。研究发现，5毫秒的矩形波电击，强度为除颤电流阈值的三到十倍，会释放出与剂量相关的K+脉冲。得出的结论是，由于K+是一种心肌抑制剂，除颤后至少部分心肌抑制是由K+从心肌细胞中释放所致。
