ABSTRACT
Measurement of intracardiac pressures provides valuable insight into the functional status of the heart. Since the heart is a pump, to obtain a more quantitative picture of cardiac performance, cardiac output should also be measured. Typically, in vivo cardiac experiments are more time consuming and costly than in vitro cardiac experiments. Measuring cardiac output is of particular value in chronic heart disease, as it is a primary indicator of the stage of the disease. That is, as the disease progresses, cardiac output will progressively fall. Indeed, cardiac index, which is cardiac output divided by surface area, is one of the main parameters used to determine whether a patient requires cardiac transplantation. In simple terms, the function of the heart is to ensure that blood flow within the vasculature is maintained. This is achieved by the myocardium imparting energy to the blood, a process which occurs because the heart is able to contract.
