Catheter ablation of cardiac arrhythmias

In humans, the typical range of the resting sinus heart rate is 50-90 beats per minute (bpm); most average healthy individuals have resting rates in the 60-70 bpm range. Bradycardia (slow heart beat) is a term used to refer to any heart rate <60 bpm, and tachycardia (fast heart beat) indicates rates >100 bpm. Disturbances of cardiac impulse formation and/or transmission comprise the principal mechanisms causing abnormalities of heart rhythm. In basic terms, these are classified as being either brady- or tachy-arrhythmias. The primary goals for treatment of arrhythmias are: (1) to alleviate symptoms and thus improve an individual's quality of life; and (2) to prolong patient survival. Pharmacologic treatment has been the mainstay for management of most cardiac arrhythmias, although in recent years, implantable devices and ablations have become increasingly important. Therefore, nonpharmacologic therapies have begun to play an increasingly important role in curing many arrhythmias (catheter ablation), and preventing their life-threatening consequences [implantable cardioverter defibrillator (ICD) therapy for both primary and secondary prevention of sudden cardiac death (SCD)].