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 anesthetics on reperfusion arrhythmias. Male Wistar rats (200-300 g) were injected ip with heparin (200 IU), followed by anesthesia with thiopental (40 mg/kg), pentobarbital (30 mg/kg), urethane (1.2 g/kg), either, or halothane 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 reperfusion arrhythmias (100%) was similar in hearts of control and previously anesthetized rats, but the duration of the arrhythmias was significantly increased by anesthesia (5-fold with thiopental, 15-fold with pentobarbital, ether and halothane, and 30-fold with urethane). In hearts taken from unanesthetized rats and perfused with Locke solution containing anesthetics (5-7 per group), the duration of reperfusion arrhythmias 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 duration of reperfusion arrhythmias in the isolated rat heart.