Torsade de pointes is caused by: (A) Hypermagnesemia, (B) Metabolic acidosis, (C) Hypomagnesmia, (D) Metabolic alkalosis
Answer is C. Electrolyte disturbances including hypomagnesmia predispose patients for marked QT prolongation and Torsade de pointes as a result of reduced repolarization reserve Ref Harrison 20th edition pg 1423