[Hypomagnesemic coma in heart failure: description of a case].

The case of a patient developing hypomagnesemic encephalopathy and coma secondary to intensive treatment for severe cardiac failure, is reported. Following an early improvement of symptoms and signs of cardiac failure, a rapidly developing neurologic disorder appeared. This was characterized by insomnia, agitation, mental derangement and, finally, sopor and I-II degree coma. Serum magnesium concentration was 1.0 mEq/l. Magnesium sulfate iv infusion was followed by a immediate and complete recovery from the neurological disorder. Patients with cardiac failure undergoing prolonged intensive therapy are prone to develop hypomagnesemia. This electrolyte alteration may be responsible for symptoms and signs of central nervous system involvement (metabolic encephalopathy) that need to be differentiated from those of organic origin.