In a patient of congenital prolonged QT syndrome and intermittent torsedes points, which of the following drug should be prescribed

Magnesium is a agent of choice for the immediate treatment of torsedes points associated with both congenital and acquired long QT syndrome . Use of intravenous isoproterenol is limited only to acquired long qt syndrome Long term treatment with oral beta blockers is required only for congenital disease Refer Goodman and Gilman 11e 929,930