In the United States, 50-60 individuals suffer a cardiac arrest each hour, amounting to approximately 250,000 deaths every year. In the first five minutes of a cardiac arrest, ventricular tachycardia (VT) and ventricular fibrillation are the most frequent cardiac arrhythmias encountered. Despite emergency medical response systems, the long-term survival from out-of-hospital cardiac arrest remains poor in most US cities. Paramount to achieving successful resuscitation of a cardiac arrest victim is providing early defibrillation. This issue of Cardiac Electrophysiology Clinics covers a full spectrum of issues related to sudden cardiac death, including the epidemiology of sudden cardiac death, advances in CPR, the implantable cardiac defibrillator (ICD), and VT ablation.