EFFECTS OF ANESTHETICS ON THE INCIDENCE AND DURATION OF REPERFUSION ARRHYTHMIAS IN ISOLATED RAT-HEART

The present study was carried out to evaluate the effect of anesthetic s on reperfusion arrhythmias. Male Wistar rats (200-300 g) were inject ed ip with heparin (200 IU), followed by anesthesia with thiopental (4 0 mg/kg), pentobarbital (30 mg/kg), urethane (1.2 g/kg), ether, or hal othane and sacrificed by decapitation. The isolated heart (5 to 8 per group) was perfused with Locke solution by the Langendorff method and the left coronary artery was ligated for 10 min. The incidence of repe rfusion arrhythmias (100%) was similar in hearts of control and previo usly anesthetized rats, but the duration of the arrhythmias was signif icantly increased by anesthesia (5-fold with thiopental, 15-fold with pentobarbital, ether and halothane, and 30-fold with urethane). In hea rts taken from unanesthetized rats and perfused with Locke solution co ntaining anesthetics (5-7 per group), the duration of reperfusion arrh ythmias decreased with thiopental (0.23 +/- 0.15 min), did not change with pentobarbital (1.14 +/- 0.26 min) and increased with urethane (16 .10 +/- 5.60 min). Our results show that anesthetics alter the duratio n of reperfusion arrhythmias in the isolated rat heart.