Successful resuscitation and neurologic recovery from refractory ventricular fibrillation after magnesium sulfate administration.

A 46-year-old man suffered a witnessed cardiac arrest. Ventricular fibrillation persisted despite 62 minutes of basic and advanced cardiac life support measures in the field. On arrival in the emergency department, he received 4 g magnesium sulfate IV and was defibrillated successfully to normal sinus rhythm with the next countershock. The patient was discharged neurologically intact. We discuss the possible mechanisms of action and clinical use of IV magnesium sulfate in cardiac arrest.