Adult congenital heart disease: a review of the moderately complex lesions.

The population of adults living with congenital heart disease (CHD) has expanded substantially over the last 40 years due to advances in diagnostic, transcatheter, and surgical techniques. Consequently, clinicians, regardless of their specialty, will encounter patients presenting with sequelae of both simple and complex CHD more frequently. Familiarisation with the pathophysiology and basic management of these conditions, including the role of adult congenital heart disease (ACHD) centres, is, therefore, vital. The moderately complex congenital heart defects that may present in adulthood include atrioventricular septal defects (AVSD), Ebstein's anomaly (EA), tetralogy of Fallot (TOF) and transposition of the great arteries (TGA). Some of these defects are typically diagnosed and repaired in infancy, so clinicians must be aware of the possibility of adults presenting with post-repair complications, but some patients with unrepaired or undiagnosed defects remain asymptomatic until middle age, where they may present with heart failure, arrhythmia, endocarditis or even sudden cardiac death.