antiarrhythmic agent, Group IC

Indications

• atrial fibrillation
• atrial flutter
• suproventricular tachycardia
• ventricular arrhythmias
• chemical cardioversion

Contraindications

• class Ic agents should not be used in patients with structural heart disease because of their proarrhythmic potential, including widening of the QRS complex

Mechanism of action

• markedly slows conduction, slightly prolongs repolarization
• class Ic antiarrhythmic agents have little effect on repolarization
• they possess local anesthetic & membrane stabilizing properties characteristic of all class I agents
• class Ic agents have potent effects on inhibition of Na+ influx during phase 0 of the fast sodium channel action potential

More general terms

• antiarrhythmic agent, Group I

More specific terms

• dofetilide (Tikosyn)
• encainide (Enkaid)
• flecainide (Tambocor)
• ibutilide (Corvert)
• propafenone (Rythmol, Baxarytmon)