Amiodarone belongs to the class III antiarrhythmic drugs. Similar to other drugs in this class, the primary mechanism of amiodarone involves the inhibition of potassium rectifier currents responsible for repolarizing the heart during phase 3 of the cardiac action potential. This potassium channel-blocking effect results in increased action potential duration and a prolonged effective refractory period in cardiac myocytes. Myocyte excitability is reduced, thus hindering the continuation of tachyarrhythmias by preventing reentry mechanisms and ectopic foci. Electrocardiographic (ECG) evidence of these effects is observed by prolonging the QRS duration and QTc interval.Unlike other class III agents, amiodarone has a broader range of action, encompassing the blocking of beta-adrenergic receptors, such as beta-1 and calcium and sodium channels. Furthermore, the drug's electrophysiological effects encompass a decrease in the automaticity of the sinoatrial (SA) node, a reduction in AV node conduction velocity, and the inhibition of ectopic pacemaker automaticity. In some instances, these additional mechanisms of action can result in undesired adverse effects, including bradycardia, hypotension, and the development of Torsades de pointes (TdP)..