Cardiac arrhythmias during outpatient dental anaesthesia: comparison of halothane with enflurane

In 75 young female patients undergoing extraction of 3rd molar teeth during halothane or enflurane anaesthesia, the electrocardiogram was recorded on magnetic tape and analysed subsequently for arrhythmias, using a high-speed analyser. Enflurane induced a much lower frequency of arrhythmia during surgery than halothane, but there was otherwise little difference between the two drugs in the quality of anaesthesia or recovery. Many arrhythmias occurred before exposure of the patient to enflurane or halothane; the significance of this is discussed.