© Author(s) (or their employer(s)) 2020. The development of heart surgery is briefly reviewed, and the impact it has made on our concepts of life and death are considered. For centuries, death was defined by the cessation of heart beat. In the early days of heart surgery in the 1940s and 1950s, the heart sometimes temporarily stopped beating, but could be resuscitated, and some concluded that the patient had been 'dead' for a period of time. Subsequently, when the patient's brain and other vital organs were protected either by the induction of a state of total body hypothermia or by the support of a heart-lung machine, the heart was purposely stopped from beating for periods of a few minutes to even several hours, but the patient remained alive. When heart transplantation was introduced in 1967, for a period of time the patient not only had no heartbeat, but had no heart, yet was not dead. When total artificial hearts were introduced, the patient permanently had no heart, but remained alive. In the near future, it is likely that the native heart will be permanently replaced by a genetically-engineered pig heart. Organ transplantation, particularly of the heart, contributed further to our changing concepts of life and death. In 1963, surgeons began to remove organs from donors whose brain had been irreversibly damaged, and had been diagnosed as being 'brain-dead', but in whom the heart was still beating. By 1968, the beating heart was routinely removed from brain-dead donors and transplanted into recipients, but this was no longer considered to be illegal as brain death had become the definitive definition of death, not lack of a heart beat or even lack of a heart.