[Atrioventricular block (Wenckebach type) induced by atropine during 5% pethidine spinal anesthesia]

A 38-year-old male received internal hemorrhoidectomy under spinal anaesthesia. Subarachnoid puncture was performed between the L4-5 lumbar interspace by a 25 gauge disposable spinal needle under sitting position. Forty five mg of 5% pethidine was injected into the subarachnoid space. The level of analgesia was L3. After 15 minutes, sinus brady-dysrhythmia was observed on ECG monitor. Heart rate dropped to 37 beats.min-1 and blood pressure was 85/39 mm Hg. Following administration of atropine 0.5mg intravenously, atrioventricular block (Wenckebach type) was observed. In a short period, ECG changed to normal sinus rhythm but PQ interval remained at 0.2 msec (1st degree AV block), but blood pressure returned to normal. Thereafter no ECG change was observed during intra and postoperative periods.