The Fontan palliation is a life-saving surgical strategy used for management of children born with single ventricle physiology. Despite early successes in childhood, long- term complications are common in the adult, and occur irrespective of underlying cardiac anatomy or type of Fontan connection created. Ubiquitous abnormalities in hemodynamics can be attributed to chronically elevated systemic venous pressures, decreased cardiac output, or a combination of the two. As Fontan survivorship continues to expand, our understanding of the development of late complications continues to evolve, although much still remains unknown.

The burden of illness is substantial in adulthood and is likely to escalate with increasing numbers of late survivors, with more adults currently living with congenital heart disease as compared with children.1 Nevertheless, survival to the fifth decade of life and beyond, is associated with cautious optimism as the prognosis remains guarded for the older Fontan patient. Specifically, there are data which suggest that life expectancy of a 40 year Fontan survivor, expressed as a standardized mortality ratio, is equivalent to a 75 year old in the general population.2 Pressures within the Fontan circulation are expected to be higher than typical right atrial pressures, will typically rise over time, and are often linked with increased premature morbidity and early mortality.