T-wave alternans associated with heart failure and hypomagnesemia in alcoholic cardiomyopathy.

Marked T wave abnormality developed in a patient with alcoholic cardiomyopathy. The T negativity was of giant size and occurred in an alternating sequence in the presence of sinus rhythm. This change was rapidly transient, disappearing in 3 days. The complete electrocardiographic recovery was temporally related to successful treatment of severe heart failure, normalization of initially low serum magnesium level, and abolition of recurrent ventricular fibrillation.