[Effect of several inhalation anesthetics on ectopic cardiac automaticity. Intervention of the calcium ion]

The effect of halothane, enflurane and isoflurane (at concentrations ranging from 0.1 v/v% to 5 v/v%) on ventricular automaticity induced by a local injury, has been studied in the isolated right ventricle of the rat. Both, halothane and isoflurane, effectively reduces ventricular frequency at all concentrations tested. On the contrary, enflurane (0.3, 0.5 and 1 v/v%) increases ventricular automaticity. The effect of enflurane was either potentiated or reduced respectively in the presence of lower or higher calcium concentrations.