The effect of myocardial infarction on the cardiac sensitization potential of certain halocarbons.

We have previously shown that many halocarbons and hydrocarbons are capable of producing cardiac sensitization. Briefly, the test method involved exposure of healthy, unanesthetized, beagle dogs to various inspired levels of sensitizing agent, followed by an intravenous dose (8 mug/kg) of epinephrine. Along, this epinephrine dose produces only mild ECG alterations, but, at threshold levels of a sensitizing agent, may induce a serious cardiac arrhythmia and sometimes death. Using the same test protocol, dogs with experimentally-induced myocardial infarctions were used to determine whether this type of heart condition might significantly lower the threshold for cardiac sensitization. Test results on three halocarbons showed no greater potential for cardiac sensitization among dogs having recovered from myocardial infarction as compared to normal, healthy animals.