Electrophysiologic considerations in congenital heart disease and their relationship to heart failure.

Current survival rates for complex forms of congenital heart disease (CHD) are excellent, allowing for an ever-growing population of adult survivors. Previous interventions and complex physiology, including the systemic right ventricle and single ventricle circulations, predispose these patients to heart failure and arrhythmias. The relationship between arrhythmias and heart failure in CHD is complex: cause and effect are not always readily separated. Therefore, the assessment and management of these patients requires an understanding of the relationship between the 2, with careful review of risk factors and arrhythmia substrates. Several forms of CHD predispose to arrhythmias even in the absence of surgical intervention because of abnormalities of the conduction system and intrinsic structural malformations. Surgical interventions might result in sinus node dysfunction and propensity for supraventricular and ventricular arrhythmias. Arrhythmias are important risk factors for sudden death in the CHD population. Device therapies directed at maintaining chronotropic competence, cardiac resynchronization, and preventing sudden death are increasingly used. These challenges unique to CHD underscore recommendations for such complex patients to be referred to specialized centres with expertise in managing CHD and its complications. In this review, we explore the complex interplay between arrhythmogenesis, CHD, and heart failure.