Tips …Antiarrhythmic drugs
Class I antiarrhythmic drugs work best with rapid heart rates , so more suited for acute ttt if arrhythmia.
Class III antiarrhythmic are more suited for prevention of arrhythmia as they work best with slower heart rate .
Dofetilide and Ibutilide are pure K channel blockers , however amiodarone and sotalol are mixed blockers ( all are class III).
Dofitilide and Ibutilide are used as IV for conversion of atrial flutter or fibrillation .Ther are associated with high risk of TdP .
Amiodarone and sotalol can prolong QT intervals , however sotalol is more associated with TdP , which is rare with amiodarone.
Class Ic drugs only used with no structural heart disease .
Diltiazem or verapamil ( class 4 )can prolong QT , however beta blockers are used in ttt of long QT syndrome .
Procainamide is used for resistant VT and preexcited AF .Disopyramide is used for AF prevention in HOCM patients .Quinidine is used in ttt of Brugada syndrome .