EFFECTS OF DESFLURANE, SEVOFLURANE AND HALOTHANE ON POSTINFARCTION SPONTANEOUS DYSRHYTHMIAS IN DOGS

Background: Although desflurane (DES) and sevoflurane (SEV) have desir able features for use in patients with coronary artery disease, their effects on ventricular dysrhythmias following infarction are less know n. We therefore examined the effects of DES and SEV upon spontaneous p ostinfarction ventricular dysrhythmias in dogs, and compared those eff ects to the well-established antidysrhythmic effects of halothane (HAL ) in this model. Methods: After institutional approval, the left anter ior descending coronary artery was ligated in 16 adult mongrel dogs du ring isoflurane anesthesia. All dogs developed acute myocardial infarc tion and severe ventricular tachydysrhythmias. Twenty-two hours after infarction, dogs were anesthetized at 1.5 MAC with desflurane (10.8%) followed by sevoflurane (3.5%) in the treatment group (n=10), or halot hane (1.3%) in the other group (n=6). Anesthetic gases were allowed to equilibrate for at least 20 min at each end-tidal concentration. At t his time, the ECG was recorded for 9 min and evaluated for the number of ventricular ectopic and sinoatrial beats and summed duration of ven tricular tachycardia. Results: DES and SEV reduced the average rate of total ventricular ectopic beats by 40+/-4% and 42+/-4%, respectively. HAL decreased total ventricular ectopic rate by 59+/-6% and 62+/-5% a fter durations of anesthesia comparable to DES and SEV, respectively. Decreases in dysrhythmia in the presence of DES and SEV were significa ntly smaller than those produced by HAL after a comparable total durat ion of anesthesia. Conclusion: DES and SEV inhibit spontaneous postinf arction ventricular dysrhythmias, although attenuation of dysrhythmias was smaller than the inhibition during comparable doses of HAL.