Effects of desflurane, sevoflurane and halothane on postinfarction spontaneous dysrhythmias in dogs.
BACKGROUND: Although desflurane (DES) and sevoflurane (SEV) have desirable features for use in patients with coronary artery disease, their effects on ventricular dysrhythmias following infarction are less known. We therefore examined the effects of DES and SEV upon spontaneous postinfarction ventricular dysrhythmias in dogs, and compared those effects to the well-established antidysrhythmic effects of halothane (HAL) in this model. METHODS: After institutional approval, the left anterior descending coronary artery was ligated in 16 adult mongrel dogs during isoflurane anesthesia. All dogs developed acute myocardial infarction 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 halothane (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 this time, the ECG was recorded for 9 min and evaluated for the number of ventricular ectopic and sinoatrial beats and summed duration of ventricular 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% after durations of anesthesia comparable to DES and SEV, respectively. Decreases in dysrhythmia in the presence of DES and SEV were significantly smaller than those produced by HAL after a comparable total duration of anesthesia. CONCLUSION: DES and SEV inhibit spontaneous postinfarction ventricular dysrhythmias, although attenuation of dysrhythmias was smaller than the inhibition during comparable doses of HAL.