Second-degree atrioventricular block induced by electrical stimulation of transcranial motor-evoked potential: a case report.

BACKGROUND

Although several complications of transcranial motor-evoked potentials (Tc-MEPs) have been reported, reports of arrhythmias during Tc-MEP are very rare.

CASE PRESENTATION

A 71-year-old woman underwent transforaminal lumbar interbody fusion under general anesthesia, with intraoperative Tc-MEP monitoring. Preoperative electrocardiography showed an incomplete right bundle branch block but no cardiovascular events in her life. After induction of anesthesia, Tc-MEP was recorded prior to the surgery. During the Tc-MEP monitoring, electrocardiography and arterial blood pressure showed a second-degree atrioventricular block, but it improved rapidly at the end of the stimulation, and the patient was hemodynamically stable. Tc-MEP was recorded seven times during surgery; the incidence of P waves without QRS complexes was significantly higher than before stimulation. The surgery was uneventful, and she was discharged eight days postoperatively without complications.

CONCLUSIONS

Our case suggests that electrical stimulation for Tc-MEP can cause arrhythmia. Electrocardiography and blood pressure must be closely monitored during Tc-MEP monitoring.