The cardiac function curve refers to the cardiac output as a function of right atrial pressure, whereas the vascular function curve refers to venous return as a function of right atrial pressure. The two curves intersect at the value where the cardiac output and venous return are equal.
Altering cardiac and vascular functions can be done through several different methods. One common method is through the use of medications known as vasodilators. These drugs work to relax the muscles in the walls of blood vessels, which allows them to widen and results in improved blood flow. Another approach is by surgically altering the structure of the heart or arteries. This can be done for a variety of purposes, such as to treat coronary heart disease or to improve blood flow to organs that have been damaged by injury or disease. There are many other ways in which cardiac and vascular function can be altered, and the best approach depends on the specific situation.