Reflex disturbances of cardiac rhythm during ophthalmic surgery.

Cardiac rhythm was monitored in 219 patients who had ocular operations under general anaesthesia and in 15 patients who had cataract surgery under local analgesia. Of these, 140 were children having squint surgery. The high incidence of the oculo-cardiac reflex and the adequate protective effect of atropine 0-01 mg/kg given intravenously was confirmed. Isolated extrasystoles were common, particularly in older patients, and sustained ectopic cardiac arrhythmias were observed in 4-6 per cent of patients of all ages. The significance of these arrhythmias in relation to surgical stimulation and the anaesthetic drugs used is discussed.