Amiodarone, an iodinated benzofuran derivative, introduced in 1960's as an anti-anginal agent, emerged as a potent anti-arrhythmic agent by 1970's and is currently one of the most commonly prescribed drugs in US for ventricular and atrial arrhythmias. Although amiodarone is considered a class III anti-arrhythmic agent, it also has class I, II, IV actions, making it a unique and effective anti-arrhythmic agent.