Q: Which of the following may prevent recurrent episodes in polymorphic Ventricular Tachycardia (VT) with a normal baseline QT interval?
A) Beta-blocker (BB)
B) IV amiodarone
The most common cause for polymorphic VT with a normal baseline QT interval is myocardial ischemia. If a patient is hemodynamically unstable then the first line of action is cardioversion, otherwise, BB and/or IV amiodarone is preferred. The need is to get rid of the underlying cause by emergent coronary angiography and revascularization. These patients frequently require transient mechanical support. IV amiodarone has the advantage of preventing recurrent episodes. Reflexly clinicians may order magnesium but it has no role in polymorphic VT with normal baseline QT.
Sorajja D, Munger TM, Shen WK. Optimal antiarrhythmic drug therapy for electrical storm. J Biomed Res. 2015;29(1):20-34. doi:10.7555/JBR.29.20140147