Sudden cardiac death is a leading cause of mortality in industrialized nations, accountingfor 50% of all cardiovascular deaths. Carefully performed randomized trials, technological advances and better understanding of arrhythmia mechanisms have resulted in improved approaches to rhythm disturbances. Risk assessment has to be individualized and can be approached through an analysis based upon all other clinical characteristics of the patient. The need for long-term therapy must be carefully individualized to each patient, since the severity and importance of symptoms are highly variable. This review will summarize the classification of antiarrhythmic drugs and main pharmacokinetic properties. Newer antiarrhythmic drugs either block a specific ionic current (eg, dofetilide-induced blockade of the rapidly activating component of the delayed rectifier potassium current) or block multiple ionic channels (eg, ibutilide and azimilide) in order to prolong atrial and ventricular action potentials without other specific pharmacological effects. Additionally, this manuscript reviews the newer class III agents' effectiveness in treating atrial and ventricular arrhythmias, and the development of novel antiarrhythmic drugs that act specifically to alter cell communication.