Sudden cardiac death in adults with congenital heart disease

Sudden cardiac death is one of the leading causes of death in patients with congenital heart disease, especially in patients with repaired cyanotic and left heart obstructive lesions. While the overall annual incidence of sudden cardiac death is relatively low, estimated at 0.09% per year, this nonetheless represents a many-fold increase over that of comparable age-matched control populations. The most frequent cause of sudden cardiac death is believed to be arrhythmic, usually ventricular arrhythmia. Most studies investigating risk factors for ventricular arrhythmia and/or sudden cardiac death have focused on patients with repaired tetralogy of Fallot and patients with Mustard/Senning repair for complete transposition of the great arteries. Despite a multitude of risk factors, their predictive value for the occurrence of sudden cardiac death is relatively low. Current experience with implantable cardioverter defibrillators in this patient population is limited to observational studies and the selection of patients for prophylactic implantable cardioverter defibrillator implantation is impeded both by the absence of randomized trials and weak predictors. Catheter ablation of ventricular tachycardia has emerged as a promising therapy for abolishing or reducing the burden of arrhythmia but experience is still limited and the impact on long-term outcome uncertain. Future studies will have to focus on improving risk stratification of patients with congenital heart disease.