Arrhythmias, conduction disorders and electrophysiological anomalies in the adult with congenital cardiac disease

Adult congenital heart disease has become an increasingly common issue in the cardiology community, with rhythm abnormalities being one of the most frequent comorbidities. Arrhythmia affects adult congenital heart disease patients in excess of the general population regardless of the congenital abnormality, but the degree of risk generally depends on the specific lesion. Postsurgical bradyarrhythmias include sinus node dysfunction and AV block and are seen with increased frequency among patients with complex repairs. Permanent pacing may require special consideration for various surgical subtypes, especially after atrial baffle repair. Atrial tachyarrhythmias also pose a particularly troublesome problem, with management strategies involving various combinations of antiarrhythmic medication administration, catheter ablation, and antitachycardia pacing. The general approach to catheter ablation in the setting of adult congenital heart disease is presented, with a focus on the most common substrates of cavotricuspid isthmus-dependent atrial flutter and scar-based or intra-atrial reentry tachycardia. Finally, ventricular tachyarrhythmia and sudden cardiac death are discussed. Management strategies in this last category continue to evolve, but improved catheter ablation strategies and the now time-tested efficacy of implantable cardioverter-defibrillator placement have emerged as highly effective therapies for these patients. Although data remain incomplete, risk factors for sudden cardiac death have emerged in this population and evidence-based indications for device therapy of sudden cardiac death are presented.