The antagonism of curare: the cardiac effects of atropine and neostigmine

Abstract

In a series of 82 selected surgical cases, continuous E.K.G. tracings were recorded during the administration of atropine and neostigmine for the reversal of curare-induced neuromuscular blockade. The drugs were administered intravenously and at separate times at the close of tfie surgical operations, during which various anaesthetic agents had been used. Analysis of the E.K.G. tracings showed that arrhythmias occurred in 19 cases, and that in most instances the type of arrhythmia was not clinically significant. No arrhythmia was observed following the administrai ion of neostigmine, and none following atropine when the injection time for this drug was greater than 5 seconds. It is suggested that cardiac response to atropine may be related almost entirely to the size of the dose that first reaches the heart; large or rapidly injected doses may affect cardiac conduction at other levels in addition to vagal endings. It is concluded that neostigmine and atropine are safe to use for the reversal of the effects of curare. © 1963 Canadian Anesthesiologists.