Arrhythmias in patients with congenital heart disease.

Improved surgical outcome for patients with congenital heart disease (CHD) has created a rapidly expanding population of adolescents and young adult survivors. Cardiac arrhythmias are a common late sequelae of this form of heart disease. Effective treatment requires clear understanding of the underlying anatomic defect as well as the specific surgical interventions. Intraatrial reentrant tachycardia (IART) is the most common and difficult arrhythmia encountered in these patients. Traditional IART treatment with medication has been largely unsuccessful, but radiofrequency ablation has emerged in recent years as a promising option for many patients. The availability of three-dimensional mapping systems and irrigated-tip ablation catheters has improved acute success rates for IART to better than 90%. Postablation recurrence of IART still remains problematic for patients who have undergone the Fontan operation, in which case atrial maze surgery may be considered. Ventricular tachycardia (VT) is seen in a smaller number of CHD patients, most notably those with tetralogy of Fallot or aortic stenosis. The adoption of implantable defibrillator (ICD) therapy for these patients has improved outcome. Owing to their complex anatomy, the CHD population presents unique challenges during both catheterization and device implant. Multicenter study of this unique patient group is needed in order to develop more objective treatment guidelines.