Chah Q T, Braly G, Bouzouita K, Faucon G
Naunyn Schmiedebergs Arch Pharmacol. 1982 May;319(2):178-83. doi: 10.1007/BF00503934.
The effects of hypokalemia were studied on the various parts of the conduction system by means of His bundle potential recording in the heart of vagotomized dogs. Plasma potassium concentration was lowered by extracorporeal dialysis, precautions being taken against the simultaneous impairment of other parameters, especially humoral. In order to make sure that the changes in atrioventricular conduction observed were due to hypokalemia, a control series of experiments was carried out, under strictly identical conditions except that the dialysis fluid was not devoid of potassium. The following alterations were observed during the lowering of potassium concentration from 3.2 to 1.6 mmol/l: atrioventricular node conduction time (AH interval) increased steadily up to 250% of control values; conduction time in atrial contractile tissue (SA interval) and His Purkinje system (HV interval) exhibited variations much later and much smaller; conduction time in ventricular contractile tissue was not significantly affected; effective refractory period (ERP) of atrial muscle, initially the longest in ERPs of conduction system in vagotomized animals, was shortened by about 20%. The mechanism of all these alterations is discussed.
通过在迷走神经切断的犬心脏中记录希氏束电位，研究了低钾血症对传导系统各部分的影响。通过体外透析降低血浆钾浓度，同时采取预防措施防止其他参数尤其是体液参数的同时受损。为了确保观察到的房室传导变化是由低钾血症引起的，进行了一系列对照实验，实验条件严格相同，只是透析液中不缺钾。在钾浓度从3.2mmol/L降至1.6mmol/L的过程中，观察到以下变化：房室结传导时间（AH间期）稳步增加，直至对照值的250%；心房收缩组织的传导时间（SA间期）和希氏-浦肯野系统的传导时间（HV间期）变化出现得晚得多且小得多；心室收缩组织的传导时间未受到显著影响；心房肌的有效不应期（ERP），最初是迷走神经切断动物传导系统ERP中最长的，缩短了约20%。讨论了所有这些变化的机制。
