Heart failure devices: implantable cardioverter-defibrillators and biventricular pacing therapy.

Although the age-adjusted mortality from heart disease has declined in the United States, cardiovascular disease remains the No. 1 cause of death.1,2 Patients with cardiac disease generally die of one of 2 causes: sudden, unexpected cardiac death or progressive heart failure. Chronic heart failure (CHF) has become an epidemic in the United States. Implantable cardioverter-defibrillator (ICD) therapy has had a major impact on the treatment of heart failure in the United States. The ICD has been shown to decrease mortality relative to the best medical therapy in patients who have survived an episode of sustained ventricular tachycardia (VT) or ventricular fibrillation (VF).3 Unfortunately, only a small minority of patients who experience an out-of-hospital cardiac arrest in the United States are successfully resuscitated.4 Thus, ICD therapy has been applied for the primary prevention of sudden death in patients at high risk of cardiac arrest. Once thought to be a “bystander” curiosity in the progression of heart failure, electrical-conduction disturbances are now recognized to be important causes of left ventricular (LV) dysfunction. Cardiac resynchronization therapy (CRT) can restore more-normal electrical contraction and, when combined with defibrillation (CRTD), can have a major impact on the mortality and morbidity of heart failure. Although there remain many limitations and challenges to the appropriate application of ICDs or CRTD, there is no question that device therapy has had a major impact on the management of patients with LV dysfunction.