Sudden Cardiac Death in Adult Congenital Heart Disease.

Sudden death of presumed arrhythmic etiology is a leading cause of mortality in adults with congenital heart disease. Anticipated benefits of the implantable cardioverter-defibrillator (ICD) must be weighed against high complication rates. Without robust evidence from randomized trials, caregivers face difficult decisions in selecting appropriate candidates. Although secondary prevention indications are often clear-cut, risk stratification for primary prevention ICDs is more challenging. Factors associated with sudden death in patients with tetralogy of Fallot are reasonably consistent across studies. In contrast, identification of high-risk patients with systemic right ventricles or univentricular hearts remains controversial.