<prompt> Class 3 antiarrhythmic drugs isAmiodaronePhenytoinPropafenonePindolol  <response>: Refer kDT 6e p 511 Class III agents have the potential to prolong the QT interval of the EKG, and may be proarrhythmic more associated with development of polymorphic VT. Class III agents include: bretylium, amiodarone, ibutilide, sotalol, dofetilide, vernakalant and dronedarone 