“…Furthermore this effect is independent of rate. As partial depolarization is a well-known feature of myocardial ischaemia (see Janse & Kleber, 1981, for review), such a selective effect, already demonstrated for lignocaine (Kupersmith, Antman & Hoffman, 1975;El-Sherif, Scherlag & Lazzara, 1977), could well be of considerable clinical relevance. Finally, it should be noted that any effect on refractoriness due to this shift in the V,,-membrane potential relationship would only be minor, since membrane voltage is changing very rapidly with time during the terminal phase of the action potential.…”