Sheehan's syndrome with hypomagnesemia and polymorphous ventricular tachycardia

A 40 year old woman with Sheehan's syndrome demonstrated polymorphous ventricular tachycardia and hypomagnesemia. The diagnosis of Sheehan's syndrome was based on her history, physical examination and endocrinological data. Serum magnesium level was 1.5 mg/dl. After the treatment of polymorphous ventricular tachycardia by lidocaine, an electrocardiogram showed low voltage, T-wave inversion or flattening and QT-prolongation, and these electrocardiographic abnormalities gradually improved after the initiation of cortisone therapy. A chest roentgenogram, an echocardiogram, thallium-201 scan of the myocardium and hemodynamic parameters indicated no abnormal findings. It is suspected that hypomagnesemia caused polymorphous ventricular tachycardia. However, the cause of hypomagnesemia and its relation to Sheehan's syndrome in the present case were not determined, although, hypomagnesemia was improved after the administration of cortisone.