• arrhythmias
• adult congenital heart disease
• atrial tachycardia
• intra-atrial re-entrant tachycardia
• ventricular arrhythmia
• bradycardia

• AICD: automatic implantable cardioverter-defibrillator
• AV: atrioventricular
• IART: intra-atrial re-entrant tachycardia
• CHD: congenital heart disease
• TOF: tetralogy of Fallot
• VT: ventricular tachycardia

Refinement of surgical techniques for the treatment of congenital heart disease (CHD) has created a new population of young adults with heart disease. In the USA, it is estimated that there are nearly one million CHD patients, 15–20% with disease of severity to warrant surgical intervention. As surgical mortality has fallen, the number of adults living with major congenital heart defects has increased.¹

Arrhythmias complicate the care of many adults with CHD. Their prevalence and the difficulty of treatment have made arrhythmia a major focus of interest for physicians working in this area. The presence of longstanding CHD in an arrhythmia patient significantly alters the nature and potential severity of the arrhythmia complaint and the safety and feasibility of various treatments. In addition to analysis of the targeted arrhythmia complaint, the physician must have complete and specific knowledge of the patient's cardiovascular anatomy and the consequences of that anatomy and subsequent surgical modifications on cardiovascular function.

The arrhythmogenic substrate in adults with CHD is complex. All arrhythmias prevalent in the normal population may also occur in CHD, and some specific associations are observed—for example, Wolff-Parkinson-White syndrome and Ebstein's anomaly. However, more common are acquired arrhythmias that are rarely seen in normal young adult hearts, and that are associated with longstanding hypertrophy and fibrosis caused by cyanosis, chronic haemodynamic overload, and superimposed surgical scarring. These arrhythmias include re-entrant atrial and ventricular tachycardias, heart block, and sinus node dysfunction. This article will review the evaluation and management of these more common arrhythmia problems in adults with CHD.