Idiopathic ventricular tachycardia: diagnosis and management. Curr Probl Cardiol. 2007;32:7 43. S5.1.5.2-39. Gill JS, Ward DE, Camm AJ. Comparison of verapamil and dil- tiazem in the suppression of idiopathic ventricular tachycardia. Pacing Clin Electrophysiol. 1992;15:2122 6. S5.1.5.2-40. Investigators in the Magnesium in Coronaries (MAGIC) Trial. Early administration of intravenous magnesium to high-risk patients with acute myocardial infarction in the Magnesium in Coronaries (MAGIC) Trial: a randomised controlled trial. Lancet. 2002;360:1189 96. S5.1.5.2-41. Cooper HA, Dries DL, Davis CE, et al. Diuretics and risk of arrhyth- mic death in patients with left ventricular dysfunction. Circulation. 1999;100:1311 5. S5.1.5.2-42. Kafka H, Langevin L, Armstrong PW. Serum magnesium and potassium in acute myocardial infarction. Influence on ventricular arrhythmias. Arch Intern Med. 1987;147:465 9. S5.1.5.2-43. Yan GX, Antzelevitch C. Cellular basis for the normal T wave and the electrocardiographic manifestations of the long-QT syn- drome. Circulation. 1998;98:1928 36. S5.1.5.2-44. Tzivoni D, Banai S, Schuger C, et al. Treatment of torsade de pointes with magnesium sulfate. Circulation. 1988;77:392 7. S5.1.5.2-45. Leier CV, Dei CL, Metra M. Clinical relevance and management of the major electrolyte abnormalities in congestive heart failure: hyponatremia, hypokalemia, and hypomagnesemia. Am Heart J. 1994;128:564 74. S5.1.5.2-46. Cohn JN, Kowey PR, Whelton PK, et al. New guidelines for potas- sium replacement in clinical practice: a contemporary review by the National Council on Potassium in Clinical Practice. Arch Intern Med. 2000;160:2429 36. S5.1.5.2-47. Macdonald JE, Struthers AD. What is the optimal serum potas- sium level in cardiovascular patients? J Am Coll Cardiol. 2004;43:155 61. S5.1.5.2-48. Goyal A, Spertus JA, Gosch K, et al. Serum potassium levels and mortality in acute myocardial infarction. JAMA. 2012;307:157 64. S5.1.5.2-49. Leaf A, Kang JX, Xiao YF, et al. 