EFFECTS OF INHALATION ANESTHETICS ON EXCI TATION, CONDUCTION, AND REFRACTORY PARAMETERS OF THE HEART - AN INVESTIGATION IN DOGS

Cardiac excitation, conduction, and refractory parameters of the heart were investigated in 40 beagle dogs to obtain basic values under the influence of the following 9 inhalation anaesthetic regimes using HIS- bundle electrography and programmed stimulation: 1. halothane; 2. enfl urane; 3. isoflurane; 4. halothane + nitrous oxide; 4. enflurane + nit rous oxide; 6, isoflurane + nitrous oxide; 7. alfentanil/midazolam/suc cinylcholine + nitrous oxide; 8. fentanyl/midazolam/pancuronium bromid e + nitrous oxide; 9. propofol + nitrous oxide. It could be shown that inhalation anaesthetics under laboratory conditions exert some influe nces on the observed cardiac parameters, although they are not as stro ng as those of intravenous anaesthetics. Therefore their effects shoul d be considered in experiments with other substances or in cardiovascu lar results.