Babbs C F, Whistler S J, Yim G K, Tacker W A, Geddes L A
J Electrocardiol. 1980;13(1):73-8. doi: 10.1016/s0022-0736(80)80013-6.
The effect of increasing extracellular potassium concentration (Ko) upon electrical ventricular defibrillation threshold was investigated in pentobarbital anesthetized dogs treated with intravenous potassium chloride. Defibrillation threshold fell duirng potassium intoxication. The percent decrease in defibrillation threshold was linearly related to the logarithm of Ko and to the potassium equilibrium potential (Ek), calculated from measured extracellular and intracellular potassium concentrations of ventricular muscle. In dogs supported by left ventricular bypass in order to maintain the circulation during potassium intoxication, the values of Ko and Ek required for spontaneous, K+ induced defibrillation (electrical defibrillation threshold = zero) were 16.6 mEq/L and -46 mV compared to the normal values of 3.9 mEq/L and -84 mV. Changes in defibrillation threshold related to changes in Ek may be significant events in digitalis intoxication and in myocardial anoxia during prolonged fibrillation.
在静脉注射氯化钾治疗的戊巴比妥麻醉犬中，研究了增加细胞外钾浓度（Ko）对心室电除颤阈值的影响。在钾中毒期间除颤阈值下降。除颤阈值的降低百分比与Ko的对数以及根据测量的心室肌细胞外和细胞内钾浓度计算出的钾平衡电位（Ek）呈线性相关。为了在钾中毒期间维持循环而采用左心室旁路支持的犬中，自发的、钾离子诱导的除颤（电除颤阈值=0）所需的Ko和Ek值分别为16.6 mEq/L和-46 mV，而正常值分别为3.9 mEq/L和-84 mV。与Ek变化相关的除颤阈值变化可能是洋地黄中毒和长时间颤动期间心肌缺氧中的重要事件。
