“…The methods studied provide a history of the development of non‐invasive tools to assess cardiac function over the past 25 years. These methods range from intramyocardial leads placed at the time of transplantation (12) to the use of myocardial scintillography to detect changes in cardiac perfusion during rejection (13). As each new tool was incorporated into the care of the patient with heart disease, studies of its potential applicability in the diagnosis of cardiac allograft rejection inevitably followed.…”