Antiarrhythmics are used to treat irregular heart rhythms, such as atrial fibrillation and ventricular tachycardia. These medications work by altering the electrical signals in your heart to help it beat more regularly. Antiarrhythmics come in different forms, including oral pills and injections. Examples include amiodarone (Pacerone), sotalol (Betapace), dofetilide (Tikosyn), propafenone (Rythmol SR), and disopyramide (Norpace).