Brater D C, Morrelli H F
Acta Med Scand Suppl. 1981;647:79-85. doi: 10.1111/j.0954-6820.1981.tb02642.x.
Reviews of large series of patients with digitalis-induced arrhythmias create a seeming paradox: Hypokalemia is infrequently associated with digitalis-induced arrhythmias but the clinical benefit of supplementation of potassium for most digitalis-induced arrhythmias is obvious. Examination of the electrophysiologic abnormalities induced by digitalis coupled with the electrophysiologic effects dependent on the ratio of intracellular to extracellular concentrations of potassium clarifies the issue. We present evidence that supports additive effects of the toxicity of digitalis and abnormal ratios of concentrations of potassium inside and outside the cardiac cell using metabolic alkalosis as a marker of intracellular potassium depletion. Patients with metabolic alkalosis and normokalemia with "therapeutic" concentrations of digoxin had significantly greater prevalence of arrhythmias than did patients without alkalosis. We presume this effect of alkalosis to be mediated by effects on extra- to intracellular ratios of potassium.
低钾血症很少与洋地黄所致心律失常相关，但补充钾对大多数洋地黄所致心律失常的临床益处是明显的。对洋地黄引起的电生理异常以及依赖于细胞内与细胞外钾浓度比值的电生理效应进行研究，阐明了这个问题。我们提供的证据表明，以代谢性碱中毒作为细胞内钾耗竭的标志物，洋地黄毒性与心肌细胞内外钾浓度异常比值具有相加作用。患有代谢性碱中毒且血钾正常但地高辛处于“治疗”浓度的患者，心律失常的发生率显著高于无碱中毒的患者。我们推测碱中毒的这种作用是通过对细胞内外钾比值的影响来介导的。
