Antidysrhythmic medications are widely used to treat or prevent abnormalities in cardiac rhythms. They accomplish this through a number of mechanisms involving automaticity or ion channel dynamics, which in turn affect the propagation of the myocardial electrical impulse via change in conduction velocity or refractory period.
Antidysrhythmics alter the propagation and mechanisms of cardiac rhythms, making toxicity from these agents highly lethal. In fact, antidysrythmics can be prodysrhythmic at both therapeutic and toxic serum concentrations