Idiopathic dilated cardiomyopathy is characterized by early ventricular enlargement and systolic contractile dysfunction with congestive heart failure not secondary to recognizable causes. Symptoms of congestive heart failure develop at a later stage, usually between 18 and 50 years of age, although they may occasionally occur earlier as a first manifestation of the underlying disease. Mechanisms of life-threatening arrhythmias are facilitated by subendocardial scarring, electrolyte unbalance, stretch-induced electrophysiological changes, autonomic impairment, conduction delay, or proarrhythmic effects of drug therapy. Sudden death may occur as a consequence of ventricular fibrillation, but electromechanical dissociation or bradycardia may also be a possible underlying cause. Most of the clinical characterization of idiopathic dilated cardiomyopathy is drawn from studies also enrolling patients with cardiomyopathies secondary to variable underlying conditions. Secular trends have improved the ability of early diagnosis, and the therapeutic strategies used to prevent sudden death. Among them are angiotensin-converting enzyme inhibitors, beta blockers, and mineralocorticoids/aldosterone receptor antagonists. The role of implantable cardioverter defibrillator (ICD) therapy for the primary prevention of all-cause mortality is controversial with some studies showing and others questioning the benefit of ICD in this population. Survivors of near-fatal arrhythmias have a high risk of recurrence, which may often be fatal. Idiopathic dilated cardiomyopathy contributes to less than 15% of all such patients. Previous randomized studies conducted in large heterogeneous populations showed that ICD therapy is beneficial and improves survival by about 30%. This therapy is currently recommended for all survivors of a near-fatal arrhythmia regardless of the underlying substrate.
Corrigendum to ?The role of implantable cardioverter defibrillator for primary vs secondary prevention of sudden death in patients with idiopathic dilated cardiomyopathy? [Europace 2004;6:400?406]
