[2] Fontan's father was a cyclist who was leading the 1929 Tour de France before his bicycle was damaged in an accident, forcing him to withdraw from the race.

He was affected by the death of a young teenager with tricuspid atresia, and Dubourg told him that he should use the experience as motivation to research possible treatments for the condition.

In tricuspid atresia, the patient does not have a functioning right ventricle, so at the time heart transplant was thought to be the only viable surgical option.

[2] Fontan completed a thesis on extracorporeal circulation, discussing new technology (such as the heart-lung bypass machine) that allows a patient's blood to be oxygenated through a pump on the outside of the body in situations such as open heart surgery.

In the hope of treating patients in whom the flow of blood through the right side of the heart was impaired, Fontan endeavoured to create a shunt between the vena cava and the pulmonary artery.