trade names: Cardioquin, CinQuin, Duraquin, Quinidex Extentabs, Quinora; drug class: antidysrhythmic (class IA); action: prolongs effective refractory period; decreases myocardial excitability, conduction velocity, and contractility; uses: premature ventricular contractions, atrial flutter and fibrillation, paroxysmal atrial tachycardia, ventricular tachycardia.