Antidysrhythmic pharmacology organizes agents by the cardiac ion channel or receptor system they modify, so that a drug's electrophysiologic mechanism predicts which rhythm disturbances it corrects and which it can provoke. Cardiac glycosides act outside this channel-based taxonomy, producing a positive inotropic effect that increases contractile force alongside a negative chronotropic effect that slows conduction and rate; Class I agents block sodium channels to depress impulse conduction, and Class II agents blunt sympathetic beta-adrenergic drive to reduce rate and automaticity. The topic belongs to cardiovascular pharmacology within nursing pharmacotherapeutics and rests on the parent discipline's central tension: every drug that alters cardiac conduction is inherently proarrhythmic, giving each class a narrow therapeutic margin that defines its monitoring requirements.
Antidysrhythmic pharmacology organizes agents by the cardiac ion channel or receptor system they modify, so that a drug's electrophysiologic mechanism predicts which rhythm disturbances it corrects a…