Metoprolol in anaesthesia for oral surgery. The effect of pretreatment on the incidence of cardiac dysrhythmias.

Metoprolol, a cardioselective beta-adrenergic blocking drug, was given, with a placebo as an alternative, in a double-blind trial to 60 patients who were undergoing removal of third molar teeth under general anaesthesia. Dyshythmias occurred in significantly fewer patients in the metoprolol group than in the control group, and when ventricular dyshythmias occurred they were abolished in every case by the administration of metoprolol. It is concluded that metoprolol is effective in preventing cardiac dysrhythmias occurring during oral surgery carried out under general anaesthesia.