[Suspected diltiazem intoxication resulting in repeated asystole after the induction of anesthesia]

We present a case of diltiazem intoxication resulting in repeated asystole after the induction of anesthesia. A 39-year-old man was diagnosed as subarachnoid hemorrhage, and cerebral aneurysm clipping was scheduled on the next day. Electrocardiogram revealed normal sinus rhythm with complete right bundle branch block. Continuous intravenous administration of diltiazem, nicardipine and midazolam were started for intractable hypertension and tachycardia. In the operating room, electrocardiogram showed atrioventricular nodal rhythm. Nicardipine and midazolam were stopped and anesthesia was induced with thiamylal, fentanyl and vecuronium, and was maintained with sevoflurane. After tracheal intubation, the patient developed asystole, and cardiopulmonary resuscitation was provided immediately. Diltiazem was stopped. Cardiac rhythm was restored 8 min afterwards; however, asystole recurred six times. Temporary cardiac pacing was effective, and percutaneous cardiopulmonary support (PCPS), intraaortic balloon pumping (IABP), and continuous hemodiafiltration (CHDF) were initiated. The operation was canceled. On the next day, normal sinus rhythm was restored and the temporary pacing, PCPS, IABP, and CHDF were discontinued. Cerebral aneurysm was treated by endovascular coiling and the patient was discharged from the hospital without sequelae. This case illustrates asystole associated with diltiazem intoxication. It is necessary to consider this potential complication when diltiazem is used.