Prevention of sudden cardiac death: The role of the implantable cardioverter-defibrillator

Sudden cardiac death, usually due to fatal ventricular tachyarrhythmias, results in the loss of 300,000-400,000 lives each year in the United States. Implantable cardioverter-defibrillator therapy has revolutionized both the secondary and, increasingly, the primary prevention of sudden cardiac death. In the last decade, subcutaneous pectoral implantation with transvenous lead placement has lessened perioperative risk considerably, raising the benefit/risk ratio for many candidates. As a consequence, the list of approved indications for implantable cardioverter-defibrillator therapy has expanded rapidly in recent years. Current devices offer tiered therapy utilizing bradycardia pacing, anti-tachycardia pacing, low-energy cardioversion, and high-energy defibrillation. Hybrid therapy, combining device, drugs and radiofrequency catheter ablation as required, has become the standard of care for reducing booth appropriate and inappropriate shocks. As implantation rates continue to rise, so will the number of patients presenting with electrical storm. The dilemma of how our society will cope with the enomous projected costs of implantable cardioverter-defibrillator therapy has yet to be resolved.