The management of cardiac arrhythmias has been revolutionized by the use of new diagnostic and therapeutic modalities. The development and advancement of both pharmacologic and nonpharmacologic therapies, particularly radiofrequency catheter ablation and new implantable devices, have resulted in better treatment, suppression, and frequently cure of otherwise recalcitrant and life-threatening cardiac arrhythmias. Furthermore, catheter ablation has also helped to better elucidate the pathophysiology of these arrhythmias. For the purpose of this chapter, the management of cardiac arrhythmias is divided into that of tachyarrhythmias and bradyarrhythmias. Tachyarrhythmias are managed by antiarrhythmic drugs, radiofrequency catheter ablation, and implantable devices. Bradyarrhythmias are treated mainly by pacemakers.