Flecainide acetate is a class Ic antiarrhythmic agent used to prevent and treat tachyarrhythmias (abnormal fast rhythms of the heart). It is used to treat a variety of cardiac arrhythmias including paroxysmal atrial fibrillation (episodic irregular heartbeat originating in the upper chamber of the heart), paroxysmal supraventricular tachycardia (episodic rapid but regular heartbeat originating in the atrium), and ventricular tachycardia (rapid rhythms of the lower chambers of the heart). Flecainide works by regulating the flow of sodium in the heart, thus slowing nerve impulses.
Flecainide was originally sold under the trade name Tambocor® (manufactured by 3M pharmaceuticals). Flecainide went off-patent on February 10th, 2004, and is now available under the trade names Almarytm®, Apocard®, Ecrinal®, and Flécaine®. It is also available generically.

Flecainide - Familydoctor.org - Information for patients in English and Spanish.