Procainamide and its metabolite n-acetylprocainamide have potassium channel blocking properties that may prolong the QT interval. In patients who already have QT prolongation, administration of procainamide may further prolong the QT inter- val and lead to torsades de pointes.S6-11 A single RCT of 33 patients comparing sotalol with lido- caine for treating patients with hemodynami- cally stable VT showed that VT was terminated in 69% of patients using sotalol and 18% Intravenous sotalol has been approved for use in the United States. Sotalol has potassium channel blocking properties that may prolong the QT interval. In patients who already have QT interval prolongation, administration of sotalol may further prolong the QT interval and lead to torsades de pointes.S6-25 Figure 2. Management of sustained monomorphic VT. Colors correspond to Class of Recommendation in Table 1. See Sections 7, 8.1.3, 8.2.3, and 10 for discussion. *Known history of verapamil sensitive or classical electrocardiographic presentation. ACLS indicates advanced cardiovascular life support; ECG, electrocardiogram; VA, ventricular arrhythmia; and VT, ventricular tachycardia. CLINICAL STATEMENTS AND GUIDELINES 12. Epinephrine may increase coronary and cerebral perfusion pressure during CPR because of its vasoconstrictive effects. High doses of epineph- rine (0.1 to 0.2 mg/kg IV, as opposed to a stan- dard dose of 1 mg) have been studied in RCTs. In out-of-hospital cardiac arrest unresponsive to defibrillation, administration of high-dose epi- nephrine improved survival to hospital admis- sion, but there was no difference compared to standard dose epinephrine in survival to hospital There was also no improvement in Of note, the administra- tion of vasopressin is no longer recommended in the most recent advanced cardiovascular life sup- 13. Magnesium may suppress automaticity, suppress early and late after-depolarizations, and inhibit calcium flux into cardiomyocytes. It is effective in suppressing VA related to acquired long QT syndrome. 