イヌ心室筋の"スパイク"及び"プラトー"電位に及ぼすPropranolol,Quinidine及びLidocaineの影響

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概要

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• Among the antiarrhythmic agents in current use, quinidine, procainamide and related compounds are capable of causing a shift, to the right, to the S-shaped curve (Weidmann curve) that related maximum rate of rise (MMR), or overshoot, of the cardiac muscle action potential to the resting potential (RP). This effect, so-called "membrane stabilizing effect", is considered to be chiefly responsible for the antiarrhythmic actions intrinsic to these agents. On the other hand, lidocaine, another antiarrhythmic agent, is said to differ considerably in its electrophysiological properties from "quinidine-like" substances; lidocaine was found to increase the duration of the absolute refractory period relative to the total duration of the action potential. Evidences are accumulating recently in favor of a concept that the upstroke of the cardiac muscle action potential is composed of two distinct components, i.e., rapid initial rising phase and slow rising phase. The rapid rising phase is probably due to a rapid inflow of sodium ions into the cell and the end-point of the rapid rising phase has been termed the spike potential. Slow rising phase is probably due partly to slow inflow of calcium ions and partly to the decaying portion of the once very fast inflow of sodium ions. It is also becoming more and more evident that the slow inward flow of calcium ions is an important constituent of the plateau phase of the ventricular muscle action potential. In view of these new knowledges, what has been termed overshoot in the past may mean either the spike potential or the peak of the plateau potential. Therefore. there is an need of re-evaluating the past studies where antiarrhythmic agents and other compounds were examined for their effects on overshoot, among other things. In the present study, the influence of a series of antiarrhythmic agents, propranolol, quinidine and lidocaine, were examined for their effects on action potentials of dog's ventricular muscle fibers, with special emphasis on the spike and plateau potentials and for the formation of plateau phase, studies were made also of the "spike-plateau-relationship", plotting plateau potential in ordinate and spike potential in abscissa with and without these antiarrhythmic agents. Description of these new factual informations is the purpose of this paper.

• 社団法人日本循環器学会の論文
• 1971-12-20

著者

• 稲垣 卓男

  岐阜大学医学部第二内科

関連論文

• Propranololの心筋膜電位に及ぼす影響, 特にレセルピン前処置の場合について
• イヌ心室筋の"スパイク"及び"プラトー"電位に及ぼすPropranolol,Quinidine及びLidocaineの影響
• 心室筋膜電位, 特にプラトー電位に対するカテコラミンの影響

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